DPC FOR GARAGE FLOOR

[serge123]

Hi,

I am due to start a garage conversion and will be raising the floor by using
4x2 battons place on top of the concrete slab with sealed insulation inbetween and then topped with chipboard.
I have had conflicting advise about the polythene DPC whether it should go under the battons on the concrete slab or above the insulation?
Anyone know what is best?

thanks

 

[^woody^]

The idea is to protect the timber from dampness

 

[Deluks]

You can do both if you like. Then the timbers and insul will be sandwiched between 2 moisture barriers. Make sure the timber is dry first though.

 

[Monsoon]

Have you considered using a cement faced insulated tile backer board.

Prime then using a cement based adhesive stick'em down, tape the joints, pour a self leveling compound over the top .... job done

It eliminates the timber, so should improve the insulation as the timber will act as a cold bridge.

The boards are waterproof, so there's your dpm.

Note: If the existing floor *is* damp and doesn't already have a dpm then check the adhesive is ok on a damp floor.

 

[noseall]

we are about to use this product.

you don't even need to us a dpm. click on the thermafloor product then click on the solid floating floor installation.

 

[Monsoon]

we are about to use this product.

you don't even need to us a dpm. click on the thermafloor product then click on the solid floating floor installation.

I'm a big fan of the kingspan/celotex type product, I'm just uncomfortable with the chipboard element.

The good thing about the tilebacker board is it is waterproof. There is always the potential with chipboard (even the moisture resistant stuff) that a mini flood could ruin the floor.

As the chipboard is bonded to the kingspan it could be an expensive job to replace.

Either way an interesting option, I wonder if the boards are acceptable to Building control where a DPM has not been established.

 

[noseall]

Either way an interesting option, I wonder if the boards are acceptable to Building control where a DPM has not been established.

yes they are.