The Brew Cabin

I am about to lay a large drive/ patio area using a combination of bradstone cobbles, paving and some old sleepers. At present the area to be paved is a mixture of concrete and tarmac surface from when the property used to be used as an industrial premises. Under the surface there is a mixture of soil and waste drainage pipes and I do not want to dig the current base up.

This would normally provide an excellent base to lay a dry sand/cement sub-base on and then the slabs on BUT the damp proof course of the house is already at best 2 brick height and in places only 1 brick height over the existing surface.

I anticipate that the paved area would add an additional 10cm / 4 inches and so rise above the damp proof course which is not ideal.

My question is this - is there any tar like substance or any other method of extending the damp proof course on the outside of the brickwork so that I am able to lay the paving up to the brickwork without causing the bricks to go damp.

If not what gap do I need to leave between the wall and the raised new paved area and is it possible to fill this gap with gravel or some form of drain/gulley?

I look forward to your wise words!!!!

You can't extend a dpc, as far as I know. Tanking is often used to minimise/eliminate damp problems in such situations, but it's not, technically, a dpc.

The usual 'remedy' for this sort of problem is to use a 'dry channel' arrangement, as illustrated on the Dealing with DPCs page. It's a lot cheaper and a lot easier than tanking!