what should the paving level be?

[pxs871]

I'm lowering the ground level of the patio outside my kitchen due to damp.

What should the level of the new paving be? I've taken a photo.

I can't see the DPC, but further round the house there are airbricks (sealed up because the old wood floor has been filled with concrete), where the top of the airbrick is level with the top of the render, so assuming the airbricks have their base on the DPC this would mean the DPC is halfway down the render. Is this a reasonable assumption or how else would I find out?

Also, the two courses of bricks sit in a concrete foundation slab which seems to be pretty deep. Is there any risk in leaving those courses exposed/ covered in gravel or should they be sealed/re-rendered? I'll run the new paving away from the building.

Many thanks!
Peter

Untitled

• pxs871
• 10 Nov 2012
• 1

 

[r896neo]

the dpc will most likely be on the top of the air bricks and the render is there to protect the bricks below dpc level which are prone to spalling from frost because they are always damp.

 

[r896neo]

finished surface should be 150mm below dpc

 

[pxs871]

thanks a lot!

rightly or wrongly I've knocked away a narrow patch of the render (I'll patch it back up later) to see if I could locate the dpc. Bit hard to see but it looks like a thin strip of slate-like material (certaintly not flexible like modern dpc I've seen) half way down the render, which would be located directly below the air-bricks. not sure why - maybe its something to do with ventilating the floor as it used to be.

anyhow - I'll pave up to 15cm below this and border with gravel nearest the building as well just to be on the safe side. may be being overly conservative but don't want to have to re-do!

thanks for the advice.

Peter