Rising damp since driveway was installed
Hi,
Last year we had a blockpave driveway installed and since then I've started to noticed external damp patches around our bay window. It's got particularly bad over the past few wet months. We've not had any obvious damp problems prior to the driveway
I've gone back to the driveway installer who is coming over this week. In your opinions would you think this damp is caused directly by the driveway? I'm assuming it's either too high and close to the damp course or they didn't remove the old solid concrete below which is now causing issues with drainage.
Any answers are great-fully received so I have something to go back to him with if he denies causing the problem.
Replies from 11 tradespeople
Hi the driveway should be 150 mm below the damp course, if this is done then if your drive way is on slope then it could be water running down the driveway and hitting the building or or could just be that the water is sitting on top off the concrete slab and running down and getting trapped between the hoise and ground
I would agree with either its either to high or they have not prepared base properly causing issues with drainage
Hello, in terms of the old concrete under your driveway this has nothing to do with the damp. A block pave driveway should not allow hardly any water to penetrate it.
It sounds to me like the drive way is to close within 6 inches 150 mm of your damp course. It is easy to make assumptions but do check to make shore sealant around the window is in good order pointing, rendering etc is good.
Experience will tell you that most houses have a soakaway and whoever installed the driveway should have put a waterproof membrane to the age of the property and also soakaway system as this would take water from reaching the property.
Drainage may need installed at the base of the external wall. Driveway should be around 2 inches bellow damp course
Normally paving should be one brick below damp course so if paving is to high then damp will appear so check the damp course you will see a black strip normally ask him to show you
I think he has gone over the damp course
I believe your paving level is to close to your air brick / dpc it should be a minimum of 150mm below dpc.
I would say the drive way is higher then the damp proof course (dpc)
what is the distance in mm from the surfaced driveway and your damp proof course? it should be 150mm minimum, (2 bricks width roughly) if this can't be achieved a soakaway or drainage system should be installed, I.e aqua channels, open grade tarmac, pea gravel for a soakaway.
If I’m correct, without seeing the property I’m guessing, when the driveway was laid it wasn’t laid correctly I.e (possibly) 150mm below damp course and drainage wasn’t put in place correctly, I could be wrong however with out seeing the property I couldn’t give a correct and accurate answer hope this helps in some way
