My house is an old one with a poorly done extension, but we've removed and replaced most of the bad stuff over the years.
I'm in the process of extending my bathroom (one of the remaining parts of the old extension) by knocking down a non-load-bearing wall, and was intending to lay a pipe from a new shower under the floor. Surprise - the floor turns out to be concrete, rather than the expected suspended floor, so I'm now hoping to cut a channel in that to accommodate the shower waste pipe.
What I don't understand is what the original builder was trying to achieve with his construction: As you can see in the picture, the concrete subfloor on both sides of the wall I've removed is covered in a blue plastic sheet, which I presumed to be a makeshift DMP. Wooden staves and then chipboard on top of the plastic on either side of the ex-wall.
The wall that I've removed also sat directly on the concrete, but there is no DMP in sight - not on the concrete or in the wall itself. If the blue plastic is a DMP, I would have expected that to have continued into the wall, or any moisture would just travel up the wall.
Can anyone advise whether the plastic is probably a DMP intended to prevent moisture rising up, or is it possible that it's to prevent moisture going down into the concrete and that there is a genuine DPM at the bottom? I need to understand so that I can cut the channel without compromising the damp-proofing. Thanks!
I'm in the process of extending my bathroom (one of the remaining parts of the old extension) by knocking down a non-load-bearing wall, and was intending to lay a pipe from a new shower under the floor. Surprise - the floor turns out to be concrete, rather than the expected suspended floor, so I'm now hoping to cut a channel in that to accommodate the shower waste pipe.
What I don't understand is what the original builder was trying to achieve with his construction: As you can see in the picture, the concrete subfloor on both sides of the wall I've removed is covered in a blue plastic sheet, which I presumed to be a makeshift DMP. Wooden staves and then chipboard on top of the plastic on either side of the ex-wall.
The wall that I've removed also sat directly on the concrete, but there is no DMP in sight - not on the concrete or in the wall itself. If the blue plastic is a DMP, I would have expected that to have continued into the wall, or any moisture would just travel up the wall.
Can anyone advise whether the plastic is probably a DMP intended to prevent moisture rising up, or is it possible that it's to prevent moisture going down into the concrete and that there is a genuine DPM at the bottom? I need to understand so that I can cut the channel without compromising the damp-proofing. Thanks!
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