DPM lapped into injected DPC

[joanne sayer]

Hello all,

I'm turning an old pantry into a shower room for my mum. it is roughly 1.8m x 1.2m

I have taken up the old quarry tiles (laid on sand) and excavated two bricks down from previous floor level at a depth of 150mm - the injected dpc on the outside is in the first brick down.

I want to put in a concrete floor in the following order:

1. concrete 80mm
2. DPM
3. 25mm floor insulation
4. 12mm marine plywood
leaving me with 30mm to put the flooring in to bring it up to the previous floor level.

However - does the DPM lap into the mortar beneath the first brick down, or above it?

 

[JohnD]

injected chemical is not much good. Run the dpm up the wall and tack it behind the skirting.

Have you identified and corrected the source of damp yet? For example, is it a leaking pipe or drain in the ground under or close to the floor? Fix it before putting a new floor down. It will be much harder afterwards.

 

[joanne sayer]

Hi JohnD,

Thank you for your response.

There was no damp present, but as I'm putting in a bathroom and the quarry tiles that were down were not suitable I took the tiles up to find earth underneath!

I'll lap into the mortar above the brick containing the chemical DPC.

Best,

Jo

 

[JohnD]

as you're tiling the floor, and it will be a watery room, you might consider omitting the ply, and laying the concrete on top of the insulation, then tile onto concrete. You will need a thin perimeter insulation to hold the slab off the wall. There are diagrams of this method somewhere.

 

[^woody^]

You don't need to put the DPM into the wall