The Brew Cabin

Hello, I have recently rewired my new house which was built in the 1920s. In the last heavy rain I noticed that water was collecting under the floor at the back wall of the house. The water sat between the back wall and the first brick beam on which the joists sit. I thought that it may be a high water table as the rear garden slopes down to the house and sometimes about an inch of water can sit on the lawn in places. However, I have single storey extension on half of the rear of the house and on the outside wall of that there was a downpipe.
This downpipe goes into the ground.

When the water had dispersed and the floor dried, I put a hose pipe down the down pipe for about 20 minutes. I checked under the floor and the water was back. I am not sure how this is happening. Do old houses have soakaways under the house which may have degraded or would there be some other drainage under the house.

There is a drain to the side of the house which takes waste water from the kitchen and downstairs bathroom etc.

I would appreciate your thoughts as I am worried it may be causing damage to my house/foundations etc.

Yours

Paul

Do you think the downpipe is the source of the water under the floorboards, Paul? If so, you can check this out by using a drain tracing dye and adding that to the downpipe along with a the hose and see if it turns up under the floor. Yellow might be the best colour to use, although the blue should be easy enough to see with a torch.If it's just a leaking downspout, it could be relatively simple to fix, but you need to establish whether that's the cause, first.

I would strongly suggest you get a builder to look at this. Pre-war houses are pretty much a law unto themselves and it's impossible to say what you might find or what you might not. A soakaway in the sub-floor wouldn't be all that unusual, but there's no way of saying there will/should be one.

Any water hanging under the floorbaords is not only a potential threat to your property, it's a potential health hazard. Get a good local builder, or call the Building Control Officer at your Local Authority. It definitely needs checking out.

Let me know how you get on.