aj mccormack and son

Other Pavings - Page 05
The Brew Cabin
other pavings


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Forum Question Terracotta Tiles for a Patio - Pete M - Mar 20th 2003

I have some lovely rustic looking hand made terracotta tiles. A good 1" think and heavy. I want to use them to make a patio. I'm told I can't wet lay these but need to make a concrete base and dry lay them.

Q1. What sort of mix would I need to dry lay them?

Q2. I had planned a patio on a slightly raised level - dry laying would presumably make this impractical without securing the edges somehow. Any ideas? I don't want to spoil the effect with a contrasting border.

Thanks - Pete

forum answer Tony McCormack - Mar 20th 2003
Hi Pete,

if you can't lay them on a wet bed, how are they supposed to be laid? Assuming they are floor tiles, then they would normally be laid with a cement-based tile adhesive, which is wet. I can't think of any tiles that are laid 'dry'!

I'd lay them on a semi-dry concrete bed, using a C7.5 equivalent concrete, as described on the Concrete Mixes page. They'll still need to be jointed, somehow, and, if a mortar isn't acceptable, then perhaps a polymeric sand would be the thing to use.

The issue of loose tiles at the edges, though, is more of a problem. I can't think of any alternative to laying them on a mortar bed on top of the concrete base to ensure proper adhesion. If the underside of the tiles was reasonably flat, then you might be able to use an epoxy or polymer adhesive, but, as they are hand-made, it's unlikely that such a methodology would be possible.

Forum Question Sub-base showing through shingle - Miss P - Apr 12th 2003
I seem to find that large bits of type 1sub-base material keep coming up through the shingle. I used a wackerplate to compact the type 1, so would using a roller prevent this or is it inevitable that it will come through?
forum answer Tony McCormack - Apr 13th 2003
Mmmm. Is this 'shingle' a thin surface dressing of gravel? If so, it's likely that the gravel/shingle is being scuffed off the hard surface of the underlying chunky bits of DTp1. Whether you use a vib plate or a roller won't make any difference - it's that fact that chunky bits are on the surface of the sub-base layer that's causing the 'bald' spots.

One solution for the worst spots, is to pummel down the chunky bits with a hammer, driving them deeper into the sub-base layer, and then topping-up with finer material or extra gravel/shingle. This makes it less likely for that spot to be scuffed and exposed.

Forum Question Jointing Granite Setts - Ian King - Apr 15th 2003
I am in the process of laying 500 Granite Setts as a pathway for light pedestrian use only. The setts are been laid on a layer of hardcore over very hard soil, and set in a 4-1 mortar.

As an amateur, I am finding it to be a as time consuming a job as I thought it would be, but I think it will look great when it is finished.

My dilemma though is how do I joint them? After 3 days of back and knee breaking laying, the thought of having to joint them all with mortar.....

I have read the forums view on the dry mortar method with watering afterwards. If I were to do this, what sort of mortar mixture should I mix?

If the view is though that a proper mortar joint is best, and will give the best appearance, I may look at getting a builder to joint them for me.

I was intrigued to read about the pitch method of jointing, but I am not convinced yet that it would look right in front a modern townhouse. Is it as tricky as it sounds?

By the way Tony, a superb website and just goes to show you that the Internet never lets you down when you are looking for information of any kind.

forum answer Tony McCormack - Apr 15th 2003
I've spent most of the day doing a granite sett design for a project in Kuwait, and I think they'll be haunting my dreams tonight!

If you opt for a dry, brush-in jointing, then a 4:1 mix will be fine. Wet jointing is slow work, and, to be honest, you'll be bloody lucky to find a builder willing to take it on. It's a labour of love, and if someone else has done all the laying, then there's no real incentive for a builder or contractor to come in just to do the pointing.

Pitch sealing is great fun, honestly, and easier than mortar pointing, but you have to be prepared to hire in a tar boiler and spend a full day watching bitumen slowly melt! But the finished effect is the Badger's Nadgers, no mistake!

There are also pourable polymer-modified jointing materials that you might consider. Basically, you make them into a soup, and pour them into the joints from an owld watering can. They set in 30-60 mins and are a real doddle, if a little pricey. Instarmac at Tamworth in the W.Midlands do their Ultracrete Flowpoint in 25Kg packs. I'm not sure how much they'd charge for a few bags to do your job, but if you call them on 01827 872244 and tell them I referred you, then they'll give you more info and a price.   smile

Ian King
Apr 15th 2003

Many thanks for your reply.

You have almost persuaded me, and I might go for the pitch sealing although I will look at these ploymer-modified jointing materials. I assume it is laid similiar to the pitch with the gravel fill first. I will ask Instarmac about colours, but if black were a choice it sounds as though it would have the same effect as the pitch and emphasise the silvery granite. I will certainly take you up on your offer and use you as a reference.

Can't say I envy you laying setts in Kuwait. Sounds like hot sweaty work and you probably have a few more than 500 to lay!

It was pretty warm here though on Sunday which made all the difference.

You could find yourself out there for a while, as there are certain to be some paving work 'next door' soon!

Just one last thing which has come to mind, if I am pouring in a 'soup', I will presumably need to mortar the open ends to stop it flowing away.

Many thanks again.

Tony McCormack
Apr 15th 2003
My days of laying setts are over, Ian. My back is buggered (3 ruptured discs!) and my heart is having problems with its plumbing, so I'm not allowed to work, even though I'm 20-odd years away from official retirement age. The job in Kuwait is a project where I do the advising and some other poor sods do the physical work. They email me with photos and questions, and I email back with 'comments' and 'suggestions'. It's not quite the same as venting your frustrations and swearing at some eejit on site, but its as near as I'm likely to get for now, and it lets me pretend I've still got a purpose in life!   smile

If you do opt for the 'soup' method, you can stopper-up any open ends of joints with sand or soil or clay or whatever you have. The 'soup' finds its own level and it never flows very far, anyway.

Let us know how you get on.

Ian King
May 7th 2003

Many thanks for all our invaluable advice.

Having now completed the laying of the setts (and with a few weekends away) it is now time to joint them.

I did ring Instarmac, but they couldn't agree on how many bags I would need for the job, at it was going to cost too much.

Have decided therefore to joint with pitch (bitumen).

Have found a roofing company who supply 25kg lumps (I am assuming this would be enough to joint around 460 setts) and plan to do the work this weekend, weather permitting.

One question though, once I have melted the pitch, what would be the best method to pour it between the joints? Would a metal watering can do the job, or would it clog the spout?

I'll send you a picture when it is finished, but pretty proud of my work so far!

Regards - Ian

Tony McCormack
May 8th 2003
460 setts? that's got to be around 8 square metres, is that right? If so, a 25kg block should be plenty, especially if you top up the joints with gravel as mentioned on the Sett Jointing page.

I should say that roofing bitumen is not the ideal choice for pitch jointing setts, but, as this is a residential project with little or no vehicular traffic, and it's such a relatively small area, it will be ok. For larger, commercial projects, special road-grade jointing bitumens are available, albeit at a price that would bring tears to your eyes!

How are you planning to melt the pitch? You can get a roofer's bucket and burner on hire for a few quid. the bucket is a heavy galvanised metal jobby that you fill with smashed up pitch and put on the burner for an hour while it melts. Then being very, very careful, you can pour the molten pitch directly into the joints via the spout on the bucket, but you need to be careful as it is, literally, boiling hot and will take the skin off you if you don't keep your wits about you.

A steel watering can will do, too, but be aware that the narrow spout can soon block up with re-solidified pitch as it cools. You may need to put the spout over the burner for a couple of minutes to clear it.

For smaller jobs, I prefer to use a tar boiler, which holds around 50kg of pitch at a time, and get the pitch all melted in one go, then transfer it to the watering can when it's really hot. The spout on the can allows you to keep it very close to the open joints, which means less is spilled or caught by the breeze, so there's less cleaning up to do afterwards.

Looking forward to the piccies!   smile

Ian King
May 8th 2003
Maybe its my laying or calculations but I reckon about 6 sq metres, enough anyway!

The HSS hire shop say the best they have is calor gas stove on 'steroids', as they put it, with a 17 litre bucket, so I will probably have to heat the pitch in batches as it won't be big enough to do in one go. The guy in the roofing suppliers wasn't clear on the size of the pitch by volume, but it sounded pretty big to me!

I'll try the metal watering can route then (always supposing that you can still buy them) and will top up the joints with gravel as your Sett Joint page suggests.

Tony McCormack
May 9th 2003
The 'Stove on Steroids' and the 17 litre bucket will be the Roofer's Burner and Bucket I described last night. The bucket will get very, very, very hot, so be careful!

Very roughly a 25kg block of pitch will joint 6-10m², depending on joint width and depth. It's only around a tenner a block, so, even if you have to buy two blocks, it's not likely to bust the bank.   smile

The metal cans are available at Greenhams for around 17 quid, IIRC, and, when you've done, it can be cleaned out and used in the garden!

Let us know how it goes.

Forum Question Is this right for a shingle driveway? - Freddie L - Apr 15th 2003
I have just had a shingle driveway completed. On completion I checked the drive to find that no 'membrane' was used, the hardcore is only about 1" (on top of common soil) and that they had not put down a line of block paving towards the pavement as agreed. The agreement for the job was verbal (silly me) but definitely included membrane and block paving.

The workman threatens to come back and dig up the drive unless I pay the remaining £250. What can I do?

I have already given a £500 deposit and it looks like I will end up with not even a driveway!

Any response quickly would be appreciated as he is threatening to come this week.

forum answer Tony McCormack - Apr 15th 2003
You've been done by the Drive Bandits, Freddie.   frown

You need the magic words...."Trading Standards". Mention of their name usually 'persuades' the bandits that it's better to cut their losses (to match all the corners they've cut) and bugger off sharpish before the taxman, the vatman and god knows who else decides to take a closer look at their activities.

They'll be listed in your local 'phone book, so give them a call first thing tomorrow and see what they can do to help. I reckon you might well have seen the last of your 500 quid, though.

Don't tell me you've paid cash, too, have you?   frown

Freddie L
Apr 16th 2003
Thanks for the reply. I'll try to be a BIG boy and stand up to the 'bandit'

I have at least learnt a lesson..

Tony McCormack
Apr 16th 2003
Remember the Golden Rules, Freddie - get three quotes and get them in writing. No decent contractor would ever take umbrage at being asked to put their price on paper - it's what we expect! That way, you know what you're getting for how much, and we know what we've to do for how much, and there's less chance of 'misunderstanding'.

500 quid is a bloody expensive lesson!   frown

Forum Question Concrete or bitmac for a base course? - S DeLaSal - Apr 15th 2003
Hello - well I got my old tarmac drive scraped back to concrete. The top 6m is fine but the lower 6m was non existant. The old tarmac lifted straight off - about 2" of course material topped with 1" of finer. It must have been down >20 years so I'm amazed it survived with minimal base - It did look tatty though. I had the 'missing' section dug out and 150mm of crushed concrete laid.

So, to my question - I was proposing to use 50mm of base course followed by 40mm of wearing course. The few places I've rang tend to say, "Oh - you don't need that: we think you can use, say, 30/25mm instead." Now one guy proposed using 50mm of concrete followed by 40m of wearing course - does this sound okay?

I'm not sure how thick the remnants of the original drive are - I think it's pretty variable - probaly 50-75mm. So the new material would be going on top of that on the old sections and on top of the 150mm of crushed concrete in the renovated sections.


forum answer Tony McCormack - Apr 15th 2003
How big an area is this, Steve? I ask because skimping and using a measly 30mm of base (which would not be acceptable on any highways job I've ever known) isn't going to save all that much dosh, and, if we're only looking at saving, say, 25 quid, then it seems a bit of a false economy. The 'cost per square metre' diff between 50mm of base and 30mm of base is summat like....errrmmm...dur-de-dur-de-dur...around a quid per square metre in small loads. Is it worth it?

The guy suggesting 50mm of concrete and then a wearing course is making life hard for himself and giving you a job of dubious value. 50mm of concrete isn't really thick enough or strong enough to take the weight of a car, and , even if it was, then getting the wc to bond to the concrete needs a good tack coat, which eliminates any cost saving made by omitting a base course.

You need an absolute minimum of 20mm of wearing course. It is, allegedly, possible to put a standard wearing course down at only 13mm thick (if you're using a 6mm dense product), but it's bloody hard work to get it just right, and so 20mm is a better thickness. 25mm is the norm used for driveways and public footpaths by all but the stingiest of Local Authorities and house builders.

Remind me of the areas involved and I'll have a better idea of the simplest option.

S DeLaSal
Apr 15th 2003
Thanks - the area is 12m x 4m.

So what he suggesting is 50mm concrete and 30mm of w/c ON TOP of my 'foundation'. My foundation consists of 2-3 inches of old concrete drive i.e. what was below the old tarmac and 150mm of crushed concrete where there was nothing below the old concrete.

The price difference is around 150 pounds. The price I'm being quoted for tarmac ranges between 1100 to 2650+vat . This particular guy is the low end. 2" of concrete seems a bit thin to me but if it's a viable option - why not?

I guess I don't really understand the purpose of the base course. Also, what should I be looking for in terms of 'granule size', as I believe that these materials come with different size 'pebbles' for want of a better description.


Tony McCormack
Apr 16th 2003
The base course helps spread the loads imposed upon the surface. One way to think of it is as the load-bearing layer, while the wearing course is the fancy topping that looks nice but has little strength of its own. Typical aggregate size for driveway base course material would be 20mm, and that can be dense or open textured.

So, you have 48m² to re-surface in total. Some of that is over existing concrete, so would need only a wearing course at 20-25mm thick, while some needs re-constructing and will need a base course plus the wearing course.

1 tonne of base course at 50mm thick will cover around 10m². Now, if you had only 10-20m² to bas, then the contractor could either order a 'split load', where the base course material is loaded on the back of the delivery wagon and separated from the wearing course material by means of a board. It can be tipped off first, spread, levelled and compacted, and then the board removed from the wagon and the wearing course tipped. Some contractors would elect to use all wearing course, arguing that it's a private driveway and the extra costs involved in ordering a split load aren't justified, so they would order extra wearing course material and lay some of that as a base, and then lay the remainder of the wc as a standard surface layer. This approach might save 50-75 quid or so on a job of this size.

Even so, the price still seems high. 1100 quid isn't excessive, but 2650+VAT is a rip off, unless, of course, it includes kerbs, drainage or fitting gold-plated taps to your bathroom while they're on the job! To supply and lay bitmac (50mm of bc and 25mm of wc) over the entire job, I'd expect a price of somewhere around 1200-1500 quid, (+VAT) plus extra for any preparation, kerbs, drainage, etc.

S DeLaSal
Apr 19th 2003
I just had another 2 quotes - both suggest using 50mm of dry-mix as a less costly alternative to 50mm of base course tarmac over the pre-existing crushed concrete base. - Tarmac is expensive these days they say!

Nonsense or is it reasonable? If so, why not always use that combination? Unless base course has been cheaper in the past.


Tony McCormack
Apr 241st 2003
Tarmac is relatively expensive, but there's not a great deal of difference between the price per tonne delivered to site for base course or for concrete.

Bitmac is being brought in to do the wearing course, so why not use it for the base course? I cannot see how using 50mm of lean-mix is a viable option, but maybe there are special circumstances in your area, or on you job, that I don't know about.

I've shown your messages to a mate who lays bitmac every day of his working life, and he cannot understand why other contractors are suggesting a lean-mix base course. His first response was "base it out with 50mm of 20mm dense, then top it with a 6mm wearing course" - which is more or less exactly how I would have done it. Maybe we do things differently here in the Peoples' Republic of South Lancashire; maybe the preponderence of batching plants in the area makes tarmac an easier product to price and supply, but I know from the feedback I get from Contractors in other urban areas of Britain, that we all follow a very similar practice. Things are slightly different in rural areas, granted, but, as I said at the top - if bitmac is being brought in as a wearing course, why not get a split load and do it all in bitmac?

Forum Question Tarmac: Commercial vs residential - S DeLaSal - Apr 17th 2003
An observation: The car park at work is a hugh area - 2000 cars, mainly tarmac with block areas too. It's been down >10 years and still looks great.

Yet a lot of residential drives I see in tarmac look a bit tatty - why is this? Is it simply down to different standards of construction?


forum answer Dave L - Apr 18th 2003
Fly-by-night "doing a job down t'road and have a bit of spare 'mac" brigade comes to mind!
Tony McCormack
Apr 19th 2003
The car park at your place of employment was, more than likely, laid by a paver machine, whereas most driveways are hand-laid, and, as a consequence of this, there is a subtle difference in the material used for a wearing course (wc). Hand-lay wc often contains 'cut back', a form of 'thinners' that helps keep the bitmac workable for longer at lower temperatures, whereas machine-laid wc can receive a blast of extra heat from the paver machine just as it's about to be laid. This results in hand-lay material being slightly less 'tough' in the long term, than machine-lay quality wc.

But also, the regular trafficking the car park will receive compared to a driveway, helps keep the surface clean and clear of weeds, mosses, algae, lichens, etc., which is a major contributor to the look of 'tattiness' that can afflict residential bitmac driveways.

Dave's comments on the professionalism or otherwise of the laying contractors is very relevant, too. It's not just the way the wc is spread and levelled, but the way it is compacted. A car park job is more likely to have a decent deadweight roller that gives proven results of compaction, whereas a driveway job , even those laid by the better contractors, may rely on a single drum 'walk-behind' roller. On one job in Liverpool, I saw with my own eyes three eejits precariously balanced on top of a large Calor Gas bottle, 'log-rolling' it back and forth as some sort of home-made roller!

Dave L
Apr 29th 2003
Given the choice - hand lay or machine lay?

Hand Lay - much less shovelling! wink

Tony McCormack
May 1st 2003
There speaks a man who's spent too long keeping warm at the back of a Paver!   wink
Dave L
May 1st 2003
Ahem.....yes.....riding on the back is better than walking believe me!

The old adage "A second class ride is better than a first class walk" is never truer here...... wink

Wednesday was interesting.......the weather was 'changeable' and 'unpredictable' to say the least. We had 120m² of 6mm SMA (Stone Mastic Asphalt) to lay in a driveway turning area - it took a brave man to give the 'go' to start on...

We laid the regulating, just about rolled it and the heavens opened - hail, thunder and lightning.....the lot! In the end, we had to physically scoop the hailstones from the area - they stayed frozen in a heap on the garden all day frown

Needless to say, I was glad to get home yesterday..




Doh! Didn't report the outcome....we left with a 100% job, everyone happy......only just though! That stuff goes off damn quick! frown

Tony McCormack
May 2nd 2003
That's where you're going wrong, Dave - the Tinkers would have rolled-in the hailstones and told the client they were chippings, and that'd be an extra 100 quid, thanks!   wink
Dave L
May 2nd 2003
LOL! - Quite true....must remember that next time!!

I'm glad of the day off today - the weather outside is cats 'n' dogs! frown

Forum Question Bark as a driveway surface - David C - Apr 18th 2003
Well it's not really a driveway surface, more of a turning area, sort of back-in drive-out, approx 6m x 6m and would be cars only.

Idea is rather than going to cost and hassle of a conventional hard surface, put some bark down, say 30mm over say 30mm of roadstone with some weed control fabric in between?

It would certainly get the vote for looks but how sensible? I'm sure I've seen bark used for parking area at some country park/nature reserve.

David C

forum answer Tony McCormack - Apr 19th 2003
There's nowt to stop you using bark, even if it wasn't something I would recommend, personally, but you need a better construction than 30mm of bark over 30mm of sub-base material.

I'd suggest 100-150mm of sub-base material, omit the weed sheet, and then put 30-50mm of woodchips down, and cover the lot with a protection mesh, like the lightweight mesh offered by Tenax. This has the benefit of preventing the bark/woodchips being scuffed to expose the sub-base beneath, it will also help prevent loss of loose surfacing by wind and wildlife and it will dramatically improve trafficability.

David C
Apr 19th 2003
Thanks Tony, I see the benefit of the mesh but how visible would it be? I have this thought it might look a bit naff - like an old lady hair net!

I've had a look on the Tenax website but can't see anything suitable.

Also, I'd like the surface to be permeable because any drain at the edge would have to go uphill and I don't want to dig a soakaway. The area is currently lawn and - although at a low point - it drains well. The bark would be permeable but if I put in 150mm of subbase (and I assume you mean compacted Type 1 roadstone or similar) isn't it going to puddle?

Thanks - David C

Tony McCormack
Apr 19th 2003
The Tenax Grass Protection Mesh is the sort of thing I would use. It would be visible at first, but, as it gets bedded in and the bark near the surface breaks down and gets shifted about, it will become less and less noticeable.

A granular sub-base (using DTp1 as you suggest) is still permeable, but, if you omit it because of your conerns about drainage, then you'll find the car bogged down in your bark-covered patch of mud after the first decent bit of rain. Bark has no load-bearing capacity worth bothering about, so you need a sub-base to carry the loads imposed by the vehicles. You might be able to get away with 75-100mm of DTp1, especially if you have a sandy or gravelly well-drained sub-grade, but you [b]must[/b] have some form of sub-base.

You could always create a dispersal drain at one or two of the edges of your parking area, if drainage is going to be a major issue, or you could select a more open textured sub-base material, one with fewer fines, so that drainage and permeability are maximised, but I really don't think it's going to be much of a problem as the existing ground, from what you've told us so far, is not plagued with drainage problems, so why should a simple granular sub-base and bark surface dressing drastically alter the status quo?

Forum Question Shingle driveway & gullies - staylorz - Apr 28th 2003

I am considering building a shingle/decorative gravel driveway. My questions are this...

  • what is the general makeup of the drive?
  • do i need roadstone on top of the base soil then the gravel, if so what depths of each will I need?
  • what about drainage?

I have a problem in that the drive slopes down from the street then bottoms out then slopes up tp the garage. I was originally going to have tarmac and have allowed for drainage with a gully in the middle of the drive. I assume this will be no good with the gravel drive. If I need a roadstone sub base I assume any rainfall will not drain into the ground naturally. Sorry to make the question so long. Any help would be received most gratefully.

forum answer Tony McCormack - Apr 29th 2003
Most of the answers you require are given on the Gravels page of the site, including a cross-sectional construction diagram and full specification.

Even with gravel on a sub-base, you should allow for drainage and a gully or a linear drain at the foot of the slope would be a sensible idea. Do you have somewhere to connect up the drainage?

Apr 29th 2003
Hi Tony
I found the info, my question now is will the gully finish level with the top of the drive? I can't see how the water will drain if it is. I guess the rain will enter the gaps in the aggregate and not enter the gully. Or do I somehow finish the gulley below the aggregate level?
Tony McCormack
May 2nd 2003
The top of the gully (or linear drain) should be around 6-10mm lower than the 'top' of the surface dressing. Obviously, this is not something that can be accurately set out when using a loose surfacing material, such as gravel, but relies on a bit of guesswork.

Although it may seem 'surplus to requirements' on an unbound surface, the provision of drainage remains essential. Once the precipitation hits the surface, it will always seek the easiest route downwards. When it has to permeate through a compacted sub-base, it might find itself in a queue of other raindrops, waiting to proceed directly downwards, so it follows the downward slope of the surface of the compacted sub-base surface, and, eventually, finds its way into a gully or linear drain which, unlike the sub-base, offers no resistance to downwards movement of the water. So, although it might not be immediately apparent, the surface water on an unbound surface will follow the profile of the compacted sub-base and that's why a drain of some form should be provided at a low point within the sub-base. Some of the surface water will, indeed, find its way through the sub-base and then into the sub-grade beneath, and, when the rate of precipitation is light (ie, drizzle) it may be that the majority of the surface water is making its way through the sub-base rather than being diverted into the drainage system, but, in times of heavier rain, then more and more of the water will be directed into the 'fast escape' route offered by a gully or linear drain.

Forum Question Terrazzo-effect drive - Liam Booth - May 3rd 2003
Hi, I have recently watched "Home Front", and seen a patio layed in terrazo (or something like that). It is like marble. I am wondering is it any good for driveways? It is very impressive and looks quite posh.

Thanks - Liam Booth

forum answer Tony McCormack - May 5th 2003
You could use Terrazzo-style paving on your driveway, but I wouldn't. It's best reserved for internal floors as, depending on the actual construction and the aggregates used, it's not ideally suited for external use. The marble can react adversely with the continually damp weather we have and it is easily marked by car tyres. I'd also be concerned about the Polished Paver Value - I haven't seen any data on that, but I'd guess it's not as high as would be ideal for a driveway.

There are two ways of doing it - having a terrazzo finish applied over a purpose-laid concrete slab, or buying in terrazzo 'flags' and laying them on a full mortar bed over a concrete base. The first option is scarily expensive - I asked about this for a client a couple of years ago and was told to expect around 225 quid per square metre!

However, there are some terrazzo-effect patio flags being brought in from Spain that I know of, and they are selling for under 30 quid per square metre. They would have to be laid, as I said, on a full mortar bed over concrete as they are only 32mm thick (from memory).

Forum Question Gravel Drive - edgings, sub-bases and drainage - D J Fryer - May 12th 2003
I have read all of the information on your site in relation to using gravel as a driveway and it has been most helpful in convincing me that this is a job I can do myself (with the help of relatives and friends).

But I still have a few questions that I could do with your advice on: -

1) The new gravel drive will actually be a turnaround section adjacent to our current tarmac driveway (the new section being cut out of established lawn). Will it be okay to bring the gravel right up to the edge of the tarmac drive or should I separate the two with suitable edging?

2) A local builders merchant has said that 'scalpings' would prove an adequate alternative to DTp1 as a hardcore base - he quoted about £20/tonne tipped on site for scalpings. Is this a suitable alternative as I would rather do the job right first time round?

3) The new gravel drive area will need to gently decline away from the house toward the current tarmac drive, then onto the pavement to drainage in the highway outside - does this method of drainage sound adequate, the ground does seem to retain a lot of moisture but it is never 'puddled' even in heavy rain?

As I go I will undoubtedly need more advice but any help will be gratefully received.

PS - Your Site design is superb and very easy to navigate

forum answer Tony McCormack - May 13th 2003
1 - there should be an edging of some form at the interface between the tarmac and the gravel to prevent the tarmac edge being 'crumbled' by the traffic and turned into gravel. A flat-top edging is the usual restraint used in this situation, and there should really be one there now, if the tarmac driveway is already in place. Free edges and tarmac are not a good combination.

2 - "Scaplings" is a bit of a loose term that has no firm definition within the construction industry other than meaning the waste produced in a quarry. It might be decent quality stone, or it could be a right pile of sh...rubbish. However, it seems to be popular in some parts of the country, so all I can suggest is that you have a look at the stuff in their yard and judge for yourself if it's suitable. It needs to be a hard, inert material, with no lumps bigger than about 50mm and a reasonable proportion of fines. The mustn't be any bits of earth, clay, vegeatation, lumps of wood, old cement bags or rusty nails in it. Generally speaking, if a BM says it's ok for driveway sub-bases, then it will be fine.

3 - sounds ok to me, although I'd be concerned that, having gravel at the top of the gradient, it will gradually find its way to the bottom.

D J Fryer
May 13th 2003
Thanks for your replies Tony.

We only bought the house in January and it 'looks' like the tarmac has been laid straight onto a concrete driveway by a person of the travelling persuasion wink

The edges of the tarmac are starting to crumble (as you suggest - because there is no edging between that and the lawn) and there are a few worn patches that will need attention at some point in the future, (including three manhole covers that definitely need renewing/resetting)

I think I will try and lay some brick edging all around the gravel area, (either that or see if I can call on a friend who knows how).

I will check out the scalpings at my local BM and see if they are suitable - he did suggest that it would be okay for a driveway and no doubt it will be cheaper that dtp1

As for drainage - The gravel area will not abutt the house and there is no convenient drainage ducts already in place on the front of the house - the gravel will abutt an area of lawn and soil beds on three out of four sides. If a gradient from the house to the road would cause the gravel to shift toward the road could I divide the drive into two imaginary sections and have one half gradient toward the road and the other toward the house (where the soil flower beds would be), like a camber I suppose ?

Your valued opinion is always welcome smile

Tony McCormack
May 13th 2003
It's the combination of gravel and gradient that's the problem. It doesn't matter which way the gradient is inclined, it is a fundamental law of the universe that gravel will migrate down even the gentlest of slopes over a period of time, and, when vehicles are involved, that period of time might not be very long.

It's not a massive problem, but I thought you chould be aware that you might have to spend an hour or so of valuable pub-time each month barrowing the itinerant gravel back up the hill so it can start its peregrinations all over again.   smile

D J Fryer
May 13th 2003
With list of jobs to do that the wife is giving me I don't have a 'pub' window pencilled in my diary for at least 5 years sulk

To be honest the area isn't that large and if I have to redistribute every now and then then that doesn't sound like too much of a problem so I think I will stick with one directional slope.

I will be taking pictures of the project as I go and will probably be back here every other day for reassurance!

Steve R
May 14th 2003
Not sure what part of the world you are from but I am in Essex and am currently paying £21 a Tonne for granite DTp1 in either 10 or 5 tonne loads.

Regards - Steve

D J Fryer
May 15th 2003
Steve - thanks for that price guide - I am in Bucks. I must concede that I would rather get DTp1 if the additional cost is comparatively small.
Forum Question Rejuvenating an existing driveway - Pete and Shirley - May 13th 2003
We are currently having a major extension completed, and now need to consider our driveway.

This is some 23 years old, and is well-laid tarmac on a deep base (at least 25 cm of hardcore). The drive is in good condition, but has been dug up in part for drainage, soakaways, etc.

We definitely intend to edge the drive with edging stones to separate it from adjacent grass, but are as yet undecided between new tarmac or gravel. The questions we ask are:

  1. Can a new tarmac surface be placed over the existing drive?
  2. Do we need to dig up a basically good solid surface if we decide on gravel - or could gravel be laid on top of tarmac?
  3. Is there any surface which could be used which might avoid digging up the tarmac?

We are talking of about 100 square metres in all.

Many thanks

forum answer Tony McCormack - May 13th 2003
  1. - Yes. it's called an "Overlay" and is dealt with on the Tarmac pages
  2. - Loose gravel should not be laid over tarmac. You could use a binder to 'glue' the gravel to the surface of the tarmac, but this can be quite expensive, more expensive than having a new tarmac surface laid!
  3. - You could use the MicroTop stuff from Bomanite, a Resin-bonded aggregate (either thin layer or surface dressing) or a bitumen-bonded surface dressing.

Bear in mind that you'll need to repair any areas that have been excavated and that a soakaway beneath a driveway is a very silly idea.   frown

Pete and Shirley
May 14th 2003
Many thanks for the helpful information - very useful.

Just to confirm that the digging-up was in fact the channel to a soakaway, and the actual soakaway is in the adjacent grass area.

Forum Question Decorative finish for a sloping drive - Chris Mitchell - May 30th 2003
I have a tarmac driveway approx. 7m long by 4.5m wide, with a 2.5m path (1m wide) leading off to the house doorway. The drive is on a slope of about 1:7 upwards to the garage. I would like to replace this with a decorative drive and was considering a concrete slab with exposed contrasting aggregate in stripes or similar. Is this feasible and are there good contractors in the Bristol area? I would consider other methods but have a budget of about £2000, hope you can help.

Chris M.

forum answer Tony McCormack - Jun 1st 2003
There's no problem using an exposed aggregate concrete on a drive such as that. It's perfectly feasible, and should be just about achievable on your budget.

I can't suggest any contractors, as Bristol is a bit off my patch, but you definitely need an experienced concrete finisher rather than a block-layer or a general builder as the skills involved in creating an exposed aggregate surface are pretty specialised. If you ask at a local BM, such as WT Burdens (who specialise in serving the contractors rather than general builders), then they might be able to put you on to someone local.

Chris Mitchell
Jun 2nd 2003
Thanks for the the advice, it's a good starting point. I wish all websites were as good as this one!

Chris M.

Simeon @ Ronacrete
Jun 9th 2003
Did you achieve what you wanted? You could consider a resin bonded aggregate, as provided by a certain well-known company. smile


Chris Mitchell
Jun 12th 2003
I tried WT Burden, also RMC who make the stuff. None of them seemed to know anything about it and therefore could not recommend anybody to do exposed aggregate work. Funny that the RMC website mentions it but nobody knows anything about it! Resin-bonded sounds good but I suspect would be above my £2K-or-so budget, unless somebody knows otherwise...

Chris M

Simeon @ Ronacrete
Jun 13th 2003

Material cost is around £10 - £12 per m² including resin and aggregate. You could lay it yourself or get one of our trained applicators to quote. I would guess they would quote prep and labour (don't hold me to it because every job is subject to inspection and how much prep work is needed before they start to lay) at around £20 per m² labour for this which is a relatively small job (may be big to you!). Remember to add materials to this. Larger areas will be far less expensive per m².

If it's in your price bracket give Steve Taylor at our HQ a ring on 020 8593 7621 and he can help you further.

Good luck - Simeon

Forum Question Melting tarmac - Fiona - Jun 1st 2003
Our drive was laid three months ago. We experienced early on in unseasonably hot weather when tarmac 'melted' under the pressure of the tyres when the wheels were moved but the car was stationary. The person who laid it said the damage was a result of the hot weather and power steering when the car was stationary. Future damage could be avoided by always ensuring the car was moving, even if very slowly, when the wheels were turned.

The recent very hot weather has meant the problem has recurred, despite no 'stationary' wheel turning.

Is this a standard problem with tarmac drives, or are we being fobbed off with an excuse to cover poor laying. We suspect the latter, especially as our next door neighbours have a drive only slightly older than ours laid by a rival company. They also turn their cars on it and don't seem to have experienced the same phenomenon.

Any advice gratefully received.

forum answer Tony McCormack - Jun 1st 2003
It's not so much a problem with the laying, but with the material that was laid. Some macadams sold as suitable for driveways are quite legitimately doped with a substance known as 'pen oil' which has the benefit of keeping the bitmac fluid and workable at lower temperatures, so that, when an area is being hand-laid, as are most residential driveways, the contractor has more working time before the bitmac cools to the point of solidifying.

However, if we then get a really hot spell, the pen oil can act to re-soften the bitmac, which I'd guess is the case with your driveway.

Eventually, the pen oil will evaporate and the bitmac fully hardens and stops going gooey in the hot weather, but this might take 12-24 months. All you can do until then is, as the contractor suggested, take it very, very easy with the power steering when the weather is warm. If you have motorbikes, watch out for the centre stand sinking into the softened bitmac causing the 'bike to fall over - I've seen that happen a few times!   frown

There are bitmacs suitable for residential driveways that don't rely on a pen oil and don't go soft in the hot weather, but not every contractor uses them, as they tend to be a good bit more expensive and to be harder to lay. Your contractor may have a 'get out' in that they supplied a standard wearing course macadam as agreed and that you didn't specify a pen-oil free macadam. A good contractor will have warned you of this at the time, but then, to be fair to the contractor, many householders think they are 'trying it on' when it's suggested that a more expensive, pen-oil free bitmac be used, and many clients are more concerned with the job price that the detailed specification.

I wouldn't be surprised if your contractor refuses to undertake any remedial work without being paid. It's unfortunate, as it's not your fault that you didn't understand the finer points of asphalt technology, but you probably did get what you paid for - a macadam driveway.

If 'turning-on-the-spot' is a feature of your driving when parking up or leaving the driveway, then it's a good idea to get a couple of cheap timber decking sheets (2.4x1.2m sheets of plywood) to protect the surface in the hot weather. The only positive to draw from this is that the raised temperatures will accelerate the evapoation of the pen oil making this problem less likely to happen again next year. Small comfort, I know, but it's better than nowt.

Jun 2nd 2003

Thank you so much for that very helpful reply. I feel much better knowing what's caused the problem and that it won't last forever, and what to do in the meantime.

Thanks again - Fiona

Forum Question Trimming a DPM - Mark Emmett - Jun 12th 2003
Hi there Tony,

I am putting down a 100m concrete slab on top of a 150mm Type 1 sub-base. However in one corner of the area to be concreted there is a 400 mm round manhole. How do I go about fitting the damp proof membrane around this without cutting it?

Thanks Mark

forum answer Tony McCormack - Jun 14th 2003
You have to cut the damp proof membrane - it's the only way!

Lay out the membrane over the area, and then cut a cross in it over the IC cover. Then, trim as required to get the membrane as neat as possible around the IC cover. You're not looking to form a 100% waterproof seal - the DPM is intended to protect the base of the concrete from attack by aggressive groundwater and to prevent the mix water being sucked out of the fresh concrete by the parched sub-base. A gap of 20-50mm around the cover is not a major concern.   smile

Mark Emmett
Jun 14th 2003
Thanks for that reply Tony I new you would have the awnser to this problem. Keep up the good work.


Forum Question Timber edging for a lawn - Michelle Anderson - Jun 19th 2003
Do you think it would be ok to use timber board and pegging to provide definition between lawn and planting? Any tips? The reason for this choice is low cost.
forum answer Tony McCormack - Jun 19th 2003
Yep - no problem using a timber edging for a garden project. Make sure you use treated timber and pegs, otherwise the edging will rot away in a couple of years.

All the best tips I know are already on the Timber Edging page. If you're planning a flush edging, then a simple 50/75x20mm timber will do as the edging, but if you're hoping to provide some upstand, then you might want to choose a more decorative type of timber, such as a deck gravel board.

Forum Question Resurfacing a concrete drive - Rich C - Jun 20th 2003
I have a large expanse of concrete drive that I wish to renew without digging up the old drive. The concrete that is currently there is good quality and upto 6inches deep.

My questions are;

  • Can imprinted concrete be laid on existing concrete?
  • Can tarmac be laid on an existing slab?
  • What are my other options?

I am trying to avoid ripping up about 50 tons of concrete that is both solid and stable. The previous owner had access to large quantities of motorway concrete!

forum answer Tony McCormack - Jun 20th 2003
Any paving can be laid over an existing concrete base, as long as it is sound and in good condition. However, there will be problems with levels at thresholds and possibly with levels at DPCs, which will need some consideration.

Different types of paving will require dirfferent thicknesses to be added to the top of the existing concrete. So, for example, at the lower end of the scale, a Resin Bound overlay might add only 10mm or so, while bitmac would add around 20-30mm. PIC would really need to be at least 50mm thick, and block paving or flags would add at least 80mm to the existing height.

Have a read of the page dealing with laying block paving over an existing base - the principles are the same, whatever paving type you choose.

Rich C
Jun 20th 2003
Thanks for the reply. The site has various levels and slopes so levels at the house can easily be adjusted to stay below the dpc.

Thanks again - Rich C

Forum Question Gravel on Tarmac - Alistair - Jul 9th 2003
I moved house recently and inherited a large tarmac driveway which the bread knife has now decided needs gravelling in one section (approx 60m²).

The area is fairly flat (slight slope towards road) with the odd gentle undulation and the tarmac is sound if a little tired with the odd weed coming through. Assuming I put some kind of kerb stone at either end of the section, can I simply cover the area in 35mm of gravel and jobs done?

Also we're planning to use limestone. Do I use all 20mm or mix of 10 and 20, or even some/all 20mm to dust?

Finally, water currenly runs down the gentle slope, but if I put a kerb stone at the bottom end the area will be bounded on all sides (house & concrete fence bottom at either side). Do I need to put some drainage holes through the kerbs?

Apologies if there are any stupid amateur questions here but that describes my skills pretty well!

Thanks for any help.

forum answer Tony McCormack - Jul 9th 2003
Loose gravel over a tarmac (or concrete) base is not a good idea - think of ball-bearings on a tiled floor!

Don't do it!!

If you want a gravel finish, you need to bind the gravels to the base in some way, and I'm sure Simeon from Ronacrete will be along shortly to tell you how wonderful their FastGrip system is for this sort of project. While you're waiting for him, have a read of the Scatter Coat page to get a feel for what's possible.   smile

Jul 9th 2003
Thanks for the reply

A bit like bambi on the ice then if I leave the tarmac!

Thanks for the resin idea but I'd already looked into that after reading about it on your site and it's out of my current budget.

Removing the tarmac won't actually be much work as I've already done it further up where I'm putting a lawn so it should just be a case of getting a spade under it.

Once the tarmac is removed, assuming the hardcore underneath is firm what else do I need to do before gravelling? Do I need to add any sort of membrane to avoid weeds?


Tony McCormack
Jul 10th 2003
I wouldn't bother with a mebrane on a job such as this. It will only be uncovered in next to no time, as you'll only have a couple of centimetres of gravel over the top of it.

Once you've got shut of the bitmac, just spread a thin layer of your chosen gravel over the entire surface, compact it all to bed it into the loosened surface of the sub-base, and then top it up with another 20-30mm or so.

Yes, you will get weeds growing into it (I don't think they are going to suddenly appear from underneath the sub-base) but a twice-yearly dousing with a decent weedkiller will keep the worst of it under control.

Jul 11th 2003
Thanks very much for the help Tony

If I hadn't found your invaluable site I would probably have had 2 broken ankles in the very near future!

Simeon @ Ronacrete
Jul 14th 2003
Hi, it's Simeon, here to shout about why Ronadeck Fast Grip should be considered.

Although budget has been mentioned, 1) it's a product you can lay yourself, and 2) it's one of those exercises which can be seen as an investment rather than an expense. Since your home is (probably) your most valuable asset - short of the properties in the Bahamas and the tax-free sums in Swiss accounts (shhh!) - some money spent on the front driveway may well enhance its value.

And you won't get loose gravel trodden into the house spoiling the carpet.

I'm not that good a salesman and I also won't try and sell you something you know is beyond your limit, so you may decide not to go for our product. But it is good, and if you do buy some you will be joining a growing elite whose lives have changed for the better, whose prospects have grown, who can now dance to impress the ladies and can pull women like a 50% special offer sale at the local handbag and shoe shop.

Sorry, the heat must be getting to me, I'm talking like a politician.

So, to sum up: I commend Ronadeck Fast Grip to the house!

Tony McCormack
Jul 14th 2003
Simeon quoth...I'm not that good a salesman.....!!!!!! wink
Forum Question Resin bonded aggregate on to new asphalt - First Timer - Jul 14th 2003
Hi, this is my first time (hence the name). Next time should I call myself secondtimer? Who knows. Anyway, the question.

I am about to recommend a resin bonded aggregate but have a question. "Does the strength of the asphalt matter? If it's too weak do I have a problem?"

forum answer Tony McCormack - Jul 14th 2003
In a word, yes. There's no great strength in a resin bonded system, whether it's scatter coat or trowel-applied, and so it relies on the substrate to give it the strength to carry loads such as vehicles. If the substrate (asphalt, in your case) is already suspect, then covering it with a resin bonded aggregate will not improve the situation.   frown
First Timer
Jul 15th 2003
What is the worst I could be in for if I lay the RBA on to this weak asphalt? Would it come off? Or crack?

Can I make a weak asphalt stronger?

Thanks for your very fast and convenient service.

Tony McCormack
Jul 18th 2003
The worst that could happen is that it all falls apart (literally!!) and you're left with an embarassing hole in your wallet and a driveway with the structural integrity of a Rhubarb Crumble.

It is possible to reinforce weak asphalts/bitmacs, but I'm not convinced it's feasible or cost-effective on small residential projects where an overlay is often a more realistic solution. To be brutally honest, if the substrate is suspect, as is the cas ewith your asphalt, I wouldn't dream of trying to cover it with RBAs - I'd rip it out, put in a decent base and then do the RBA: it's much cheaper, in the long run, to get it right first time.

Forum Question Re-use a hard sub-grade? - Robbie - Jul 18th 2003
Hi Tony - your website is a godsend, I've recommended it to a few friends who are about to face the horrors of drive resurfacing single-handedly!

I've been planning on laying 100mm of compacted crusher run on my large drive in preparation for gravelling, but having tried to excavate it a bit I find that it is already very solid, although I can still remove it gradually with a mini-digger. It's probably had gravel laid on it for the past 50 years and the majority of the surface is very hard with all the gravel that's been compacted into it over the years. Does this mean that I could leave the really hard areas well alone and get away with laying just 50-75mm of crusher run on them, just applying the recommended 100mm in the odd depression that hasformed on the surface- to level it out?

I would be greatful for your thoughts,

p.s. the driveway in question only needs to stand up to family vehicles.

forum answer Tony McCormack - Jul 18th 2003
Older, long-established driveways that are being 'upgraded' often have an amazingly durable sub-base layer that is best left in place, as any new sub-base you lay will take years to becomes as well compacted as the older stuff.

In a situation such as this, it's best to reduce the surface level to get shut of any looser material or iffy spots, and then rely on a quality granular sub--base material, such as DTp1, to regulate the excavated base and bring it all up to one level, around 30mm or so below intended final level, ie, just enough room to accommodate the gravel surface dressing.

What you want to avoid is undulations in the sub-base layer that would result in a variable thickness of gravel on the surface. Aim to get the sub-base level accurate to within +/- 10mm and so the gravel will always be in the 20-40mm range.

Good luck!   smile

Forum Question Thomson's Drive Seal - Paulo - Jul 20th 2003
I have a tarmac driveway with exposed aggregate, can I use something like Thomson's Drive Seal to re-colour this? Or is the Drive Seal for smooth tarmac only?


forum answer Tony McCormack - Jul 21st 2003
A tarmac with exposed aggregate?? Do you mean there are loose chippings rolled into a tarmac surfacing, or have you got it confused with an exposed aggregate concrete or even a resin-bonded surfacing?

I don't have a data sheet for Drive-Seal, so I'm not sure if it's basically a hard-wearing paint or whether it's a genuine re-sealer that partially dissolves the bitumen binder in the existing surface, and then re-sets as one, homogenous coating. If it's the latter, it will only work with a tarmac surface, not with concrete or resin. Thomson's (part of the RonSeal Massive) would be the best people to ask, I s'pose.


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