Dpm cutting

[Morpheus Cane]

Am about to lay my 1200 gauge dpm on my block and beam floor and wondered how I finish off the corners of the room, I saw one post where it said you should cut it in to the corner and tape it up then fit insulation.

Is this correct and if so what tape is best?

Also do you tape up insulation joints on the floor and fill any gaps with expansion foam should there be any?

Many thanks

 

[^woody^]

You fold the corners, not cut them.

You don't need to tape the joints, and there should not be any gaps to fill

 

[Morpheus Cane]

Thanks Woody, I also trying to work out how to finish screed in upto the french doors and back door as the inner skin is pretty much the same level as the outer with a insulated cavity filler covering the void only leaving enough room for a 5 to 10 mm of screeding, will have the same issues when joining the new screed to old as the old external wall is up to to top of floor lvl.

 

[Morpheus Cane]

This picture shows what I mean.

 

[tomfe]

There should be a DPC under the door, there is normally no need to use a DPM over block and beam floors.

 

[^woody^]

Iirc, noseall posted a good image of what to do at thresholds. That inner skin should come down, and the DPM goes across to the external leaf and you screed right across, with a 10mm or 25mm insulation upstand against the external leaf.

Or leave it as it is, drop some celotex in the cavity and then fix a threshold board across.

 

[Morpheus Cane]

Big thank you again woody, I'll have a search for the post, I think I found one similar where the screed was cracking near the door and they took a layer of brick off.