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Doubts on Thermal Insulation on Concrete Floor

Postby learning_rocks » Fri Jun 08, 2018 2:52 pm

Hi All,

As part of the house renovation that we recently bought, we are trying to add an engineered floating floor with insulation in a room (5.5m by 3.4m, around 30 years old construction) with a screed-ed concrete floor. From the looks / feel of it, there is no insulation on the floor.

My plan is to add a damp proof membrane (Not needed since the concrete is pretty solid and old, but does not hurt I guess) followed by a rigid insulation (Celotex TB4000 12mm or similar), and then lay the floating floor straight above it. It would be great if you could give your inputs on the following.

1. Do I have to pin down the insulation board (Washer with screwed down to the concrete or glued down)
2. Do I need to add a thin layer of ply (If so what width should it be) between the insulation and the floating floor.
2a. If not how would the floating floor behave around edges where the insulation boards meet? Won't it sag?
3. Planning to do the same in a adjacent shower room, only change would be to use luxury vinyl with silicon to seal around the edges and shower tray. Is that fine?

Thanks in advance :)
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Simply Build It

Postby ColinB73 » Thu Jan 19, 2023 9:38 pm

Did you ever get anywhere with this? About to embark on similar - engineered wooden floor over existing concrete floor, wanting to insulate...
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