Old tarmac to block paving

[jb2410]

Hi all,

Just wondering on what’s potentially involved with this one.

We have tarmac around the house, front and rear. It’s old, crumbling and a bit crap.

At the back, I’d much prefer block paving. What would be involved here? Feasible to lift the old tarmac, sand or whatever down and relay blocks over the existing sub base or is that too easy?

Cheers

[Peter911]

It will depend on how well the tarmac base was done at the time. Expert or Caravan Club of Ireland?
If its a solid base then run a whacker plate over, add a layer of sand and put the bricks on.

[jb2410]

Thanks, the tarmac is down probably 30-35 years but still flat and level, just crumbly, so I assume the existing base was done well enough at the time.

Maybe straightforward enough then!

[dhutch]

Yeah if its fairly stable, and you can afford the heigh increase, I would be very temping to level it with sand and pave that.

Any professional providing a warranty will want to dig the lot out to over a foot depth, dispose of it all, and replace with virgin hardcore.
However that will clearly cost an awful lot more. Alternatively, gravel is nice, or get a slurry seal (micro asphalt) over the old tarmac is another option.

[M1AGM]

dhutch said:

Yeah if its fairly stable, and you can afford the heigh increase, I would be very temping to level it with sand and pave that.

Any professional providing a warranty will want to dig the lot out to over a foot depth, dispose of it all, and replace with virgin hardcore.
However that will clearly cost an awful lot more. Alternatively, gravel is nice, or get a slurry seal (micro asphalt) over the old tarmac is another option.

Slight thread diversion but I am interested in the slurry seal option for a significant length of old tarmac we have leading to the garages. Whats involved and is it costly?

[dhutch]

M1AGM said:

Slight thread diversion but I am interested in the slurry seal option for a significant length of old tarmac we have leading to the garages. Whats involved and is it costly?

It's a bitumen emulsion (water, bitumen, some detergent) mixed with granite fines and poured and spread over the existing surface.

You will have seen it used on pavements, playgrounds and on side roads by highways contractors. For whole roads they have a waggon and rear spreader but for drives and pavements it's literally mixed in a big cement mixer type contraption and spread with a yard brush. Google it for photos.

I paid £300 cash for two coats having chatted up some local contractors working in the area, but even if you pay full whack it's obviously a lot cheaper than a full tarmac job and very good at consolidating a tired, cracked, worn, surface.

Depending on your expectations, mine was down to the subbase all over the place at the edges once I had removed barrow loads of mud and pressure washed what was left and five years on still looks like a tarmac driveway.

[M1AGM]

Thank you

[Greenmantle]

How long does the slurry seal need to cure?

[Mammasaid]

Greenmantle said:

How long does the slurry seal need to cure?

At least 2 days AND there's can't be any rain on it in those 2 days otherwise it will wash away.

[dhutch]

Mammasaid said:

Greenmantle said:

How long does the slurry seal need to cure?

At least 2 days AND there's can't be any rain on it in those 2 days otherwise it will wash away.

Not really true.

Our first coat went on at half two in the afternoon, middle of May, second coat half 7 the following morning, and that last photo with the standing water on it was at half two that same second day.

Probably not ideal, but we got away with it, all dried fine, and four years on it is still looking good. Don't want to take over the thread, but I can get some photos of the current drive tonight and or over the weekend.

[Mammasaid]

dhutch said:

Mammasaid said:

Greenmantle said:

How long does the slurry seal need to cure?

At least 2 days AND there's can't be any rain on it in those 2 days otherwise it will wash away.

Not really true.

Our first coat went on at half two in the afternoon, middle of May, second coat half 7 the following morning, and that last photo with the standing water on it was at half two that same second day.

Probably not ideal, but we got away with it, all dried fine, and four years on it is still looking good. Don't want to take over the thread, but I can get some photos of the current drive tonight and or over the weekend.

You're lucky, application notes for most slurry seals say 2 days, and we won't apply it if there's any chance of rain within 48 hours.

[dhutch]

Mammasaid said:

You're lucky, application notes for most slurry seals say 2 days, and we won't apply it if there's any chance of rain within 48 hours.

Recommendations are always going to be conservative, its was a reasonably sunny morning, and we where probably both a touch lucky and fairly close to disaster.
However you gotta go with the weather the world gives you, which in Briton includes rain! Plus it was a £300 job and the offered a 3rd coat FOC if it needed it due to rain.