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.

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.

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.  

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.

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!  

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.  

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.

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?  

500 quid is a bloody expensive lesson!  

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.

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.

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?

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!

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.

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?

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?

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.

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).

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.

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.  

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.  

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.

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!  

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.

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.  

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.

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.

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.  

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.

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.

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!  

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.