decking causing damp issues

rococomaiden

I've been advised to post here instead

The guy we bought our house from was a bit of a DIY-er...
After we moved in we realised the reason he freshly painted the extension was to hide a damp problem.
Not only that, but a damp tradesman visited today and said the cause of it was the decking he built was higher than the floor of the extension and has suggested we need "tanking" to resolve (if we don't want the decking removed).

The decking meets the level where the two back doors to the garden open, it's maybe half a meter off the ground (with a now empty space under it, we had to throw away all the rubbish the previous owner left).

Should we opt for "tanking" or is there a better solution? I will try to add photos later!

dunroving

rococomaiden wrote: »

I've been advised to post here instead

The guy we bought our house from was a bit of a DIY-er...
After we moved in we realised the reason he freshly painted the extension was to hide a damp problem.
Not only that, but a damp tradesman visited today and said the cause of it was the decking he built was higher than the floor of the extension and has suggested we need "tanking" to resolve (if we don't want the decking removed).

The decking meets the level where the two back doors to the garden open, it's maybe half a meter off the ground (with a now empty space under it, we had to throw away all the rubbish the previous owner left).

Should we opt for "tanking" or is there a better solution? I will try to add photos later!

I had similar issues in my last house - owner was a tradie (painter and decorator) with a local reputation of being the worst kind of numpty (the stubborn kind who just carries on doing what he's doing even when others point out the error of his ways).

Out back of the property, he had poured a 12-inch slab of concrete (for his hot tub! In the west of Scotland!), that not only bridged the damp proof course but also covered the air bricks.

It was going to cost me a small fortune to have it removed and reinstated to paving slabs, so I hired someone with a grinder to grind out and remove a "trench" in the concrete, next to the wall. I then had decking built onto the raised slab, with about a 3-inch gap to the wall.

So, long story short ... could you saw the last 3 inches off your decking planks (being careful not to saw through the joists!)? You could still potentially get splash-back onto your wall, but I know that I never had an issue with damp from my decking after I did that.

phill99

As above. Its much easier and a lot cheaper to deal with the cause of the damp. Tanking is incredibly expensive and really only needed when the source of the damp can't be dealt with eg in basements.


Get a decent chippy in to amend the decking and bring it away from the house.