Floor above cellar needing support

29 Jul 2007
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United Kingdom

I have recently bought a Georgian house (character & loveliness = lots, but amount of work to do = LOADS!). The cellar is surprisingly only slightly damp, considering the ridiculous amount of rain we've been having. However, the timber floor joists (for the ground floor of the house) rest on another piece of timber which is rotting due to the damp. This is inset into the cellar wall.

I was wondering if I could repair it by doing:
1. Prop the floor joists using Acrow props
2. hack out the rotting, horizontal timber (the one that's set into the brick cellar wall)
3. fill the void left by the removed timber with some waterproof concrete, which should support the joists
4. If necessary, build a couple of brick columns resting on the cellar floor with a steel lintel across them to form a bridge which the floor joists rest on
5. Remove Acrow props

There are no air bricks, but there is a ~2ft. x 2ft. coal hole/door with a mesh screen on it which I have opened. Hopefully this will help until I can install some air bricks.

The problem is not urgent, but I want to sort it before it gets any worse.

Any thoughts would be greatly appreciated!

- Paul
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This photo might explain things a bit better. Here you can see the floor joists sitting on a timber beam which sits on the cellar's brickwork. I'm proposing shoving waterproof concrete between the top of the wall and the floor joists to support them (as shown in the second photo/"artist's impression"!). Does anyone have any thoughts about this? My only concern is that the dampness that is currently in the floor joists won't be able to dissipate below, but I'm hoping it can just soak into the floorboards above and dissipate into the room (the floorboards are currently bare and the room is empty). The joists aren't cripplingly damp, but I want to get this sorted before they start to rot away.

I've decided that the brick columns/steel 'bridge' is overkill - the timbers are all fairly sound.

- Paul


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