Floor Vapour Barrier damage

mufflets2

Hi Folks

During renovations a friend needed a sewer pipe run under the floor through the Kitchen.

The Builders (who are no longer working for her) cut a 30cm wide 20cm deep channel through the tiles, concrete and what she believes is the moisture/vapour barrier

in order to install the pipe .

Is it essential / Necessary to reseal up the damage to the vapour barrier in some way around or under the pipe before sealing over the new pipe ?

What is the best way to do this ?

Thanks in advance for any advice .

10-10-20

Best practice would be that the floor is reinstated in the same manner as it was constructed so that the DPM is consistent or uniform and overlapped with the existing membrane.

What's the current state of the hole/kitchen? What age is the building and floor and was there insulation previously fitted within the floor which also needs remedying?

mufflets2

The building is at least 100 years old

The slot is cut through the kitchen on the ground floor extension (which i gusee is younger than the house)and has tile over concrete

And she tells me that they cut through plastic as well.

at the moment the slot/trench has plastic pipe running through it sitting in the trench with some gravel at sides of pipe

She plans to retile over the slot/trench and existing tiles , and is woundering is it ok to just fill the trench with concrete and bring it up to the level of the rest of the tiles ?

10-10-20

Do you know roughly how deep the plastic was down in the concrete? Or what colour is the plastic?

I was thinking that she could remove back some of the layers to expose the edges of the plastic, then partially back-fill the trench with compacted sand around the pipe and then top off to the level of the DPM with concrete, replace the DPM and overlap it, then finish off the surface with more concrete up to the existing level of the bottom of the tiles. But that's a fair bit of work!

mufflets2

Ok - So as far as you know it is essential to replace, repair and overlap any damaged Damp proofing layer . Otherwise the risk of rising damp is way too much ?

That is what I suspected but wasnt sure . Cheers

hesker

https://www.boards.ie/discussion/comment/120911924#Comment_120911924

I’ve done this in a boiler house where the floor and subfloor was built the same as the house.

Agree it is worth trying but it’s not easy exposing dpm while not damaging it.

If you get someone to do it I’d insist on inspecting the exposed dpm before new materials are added.