Driveways Question

Can you tarmac over over old concrete slabs?

mother in law had hexagon slabs laid maybe 30 years ago!the area is approx 30sqaure Metre's sloping slightly down from the back of the house into the garden!mortar in between slabs is loose and some slab faces have perished.A builder has told her slabs can be tarmacked over!is this possible?

7 Answers

Best Answer

Dont use that builder that told you that.
For a start that isnt a proper base for tarmac, you dont know what the underlying ground is like, those slabs are going to move.
First excavate the lot out, you need at least 200mm of good clean hardcore/type 1 mot, this then needs to be vibrate rollered, not a whacker plate.
min 50mm base coat and min 25mm top coat.
For tarmacing get a reputable firm out maybe council approved, as there are a few who posses to be experts.
Try this site and find some one in your area.

Answered 9th Apr 2011


Member since 29 Oct 2008

hi there i will say you must remove all the slabs get in some mot level it out 100mm deep or so then compacted it all will a vibrating plate over it all then go for it. but look at some work that has been finish by the builder you use ok thanks ian

Answered 10th Apr 2011

bedfordshire builders ltd

Member since 30 Sep 2009

you could lay over slabs if you want,however it will only last a couple of days if your lucky,get a few quotes off reccomended local tradesmen do your homework get out and look at what they have done speak to there previous customers.

Answered 21st May 2011

rmb contractors

Member since 22 Jun 2008

No feedback

I wouldn't advise on this as if there is any movement within the paving slabs under neath this would affect the tarmac causing cracks, sinking and pot holes.
If your going to have the job done then please have it done properly the first time with the excisting area removed and a hard standing base applied before tarmac this will guarentee you a driveway fit for many years without the worry of having to spend out on it again.

All the best
Dan G

Answered 10th Apr 2011

Feature Landscapes Ltd

Member since 9 Sep 2010

hi you would needto take the slabs up you need a solid hardcore base to tarmac onto otherwise it will crack

Answered 17th Apr 2011

dpc builders

Member since 18 Nov 2010




Answered 23rd Mar 2013

trojan paving

Member since 29 Aug 2010

From what you say this sounds like a back patio. Who in their right mind recommends tarmac for a patio. Stay well clear.

If you plan to repave then the existing paving need to come up. The base will need to be checked. If this is not sufficient then it will need to be replaced. For a patio I would say 150mm dig out, Geotextile membrane then 100mm type 1 compacted followed by slabs of choice laid on full be of mortar and pointed.

An alternative would be to lay artificial lawn say wonderlawns performance. Came out top in the Mail on Sunday research.

Feel free to get in touch if you need more info.

Answered 11th Apr 2013

Patios & Drives Turfcare

Member since 13 Feb 2012

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