Hmm. I wonder why the floor joists are rotting...

It's normal for the DPC (Damp Proof Course) to be above floor level with a solid (Concrete) floor but with a suspended wooden floor it should be below the joists, not above!

This is the damp problem in my new house I have to fix. It's very unusual, in the UK at least, to have suspended wooden floor and solid on the ground floor level of a house. This is why the DPC is wrong for the timber floor side. The reason my house is like this is because it's built on a hill and they clearly couldn't be bothered with getting lots of infill to do all solid floors.

I will have to replace the floor joists and fit them on hangers instead of fitting them in to the brickwork. I will also be adding tanking (a cement based slurry) that will waterproof the brickwork from the DPC down to just below the joists which will protect them from moisture in the brickwork. I'll insulate between the joists too. Hopefully the existing floorboards can be reused.

On the concrete & tile side I'll take up the tile and paint a damp proof membrane (DPM) on to the surface and up the wall to the DPC. I'll then add a thin insulating board and thin tiles on top.

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Still waiting for the old house to sell, but there is one couple very interested they just need a buyer for their house. The housing market is always quiet in winter but it'll pick up soon.

The new house is on hold until the old one sells, but I'm still visiting and doing a few jobs in the house and garden. The floor repairs will probably wait until I live there, but I'll probably do more investigating but taking up some floorboards once the weather is warmer.


So how's it going with the joint(s)? Set a date yet or they already busy? Have you sold the old house yet or at least potential buyers have visited?


Looks like a good plan. Water proofing is critical and always harder to do after the fact. Good luck friend.

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This is the proposed repair currently, but it may change as I find out more. Eventually I'll need to get the plan approved and get consent from the local building control before I proceed with the repairs.

I may well wait until I've sold my current house before I get in to the work anyway as I have limited time that I can be there. It'll be a pain in the arse to do while I'm living there too, but I can do one room so it won't be a major problem.