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Laying wooden joists on concrete floor
Anonymous user 28/02/2024 - 3.45 PM
Renovating a bathroom and we have stripped back to the concrete floor underneath. We are putting new wooden joists down and a chipboard floor. Is it enough to just seal the concrete floor? Reading some things where people are saying you must not lay wood directly into concrete. Should we be trying to raise the joists up off the concrete sightly?
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4 Answers
Phoenix Home Improvements
Rating: 4.9 out of 5
There are several things to try to find out in advance . First of all if you could know the thickness of the concrete this would be good as if you drill too deep you could go through the damp proof membrane and this would cause damp issues. Secondly if you have any signs of damp these should be corrected before you put any timbers down . And as a rule you should always pack the new timbers of the sub floor this prevents any issues later on .
Answered6 October 2019
10
A Davies Carpentry & Joinery LTD
Rating: 5 out of 5
I would suggest trying not to use joists, you can buy chipboard with insulation already fixed to the underside of it, I would use this and lay it straight on top of the concrete floor, it will also give you a sound barrier, then if your going to tile the floor use plywood subfloor or ditramat. Hope this helps
Answered6 October 2019
2
EdwardJoseph
Rating: 5 out of 5
Is there a membrane? If not one should be installed - new joists should be packed off the membrane - is their insulation? Is there adequate ventilation
Answered18 October 2019
0
Anonymous user
Generally you need to lay timber joists on to a dpc and are required to have cross-ventilation for building regs. If there is a dpm under the concrete it is possible to lay a floating floor directly on to the concrete.
Answered23 October 2019
0