Expanding foam around 110mm soil pipe

[TryAgain1]

Got a toilet which has 110mm soil pipe going outside the exterior wall. The hole on the inner wall is oversized and needs filling. Can I stick expanding foam into this hole? Does expanding foam degrade the soil pipe wall?

 

[Wayners]

Uv sunlight degrades foam but it's fine around plastic pipes

 

[just pumps]

You can buy a collar to hide the gap.

 

[thomp1983]

Expanding foam then a collar or expanding foam then finish with some of that cement in a tube

 

[opps]

As above, the expanding foam will not damage the soil pipe. In theory, it will not actually adhere with the plastic but it will adhere to the brickwork. Remove the dust and then mist the area with water- it aids adhesion and speeds up the curing time.

Cut away any excess foam and use your fingernail to enable you to back fill with an interior filler- you said the hole is inside.

 

[^woody^]

Just use foam. It won't be a problem. Job done

 

[TryAgain1]

As above, the expanding foam will not damage the soil pipe. In theory, it will not actually adhere with the plastic but it will adhere to the brickwork. Remove the dust and then mist the area with water- it aids adhesion and speeds up the curing time.

Cut away any excess foam and use your fingernail to enable you to back fill with an interior filler- you said the hole is inside.

Said hole is under a very small crawl space under the floorboards that frankly needs a short anorexic to comfortably get to. Being myself I can just about do it, but it's difficult

 

[thomp1983]

I missed the indoor bit earlier, in that case as above foam is definitely the way to go as it'll prevent any drafts from the cavity too.