Caulking Stone Tiles to Wall - Large Gap

[^woody^]

[Quoted Woody]

Use expanding foam, then plaster over

Interesting.

"Use foam to gap fill, and plaster to seal."

Is that the same as ...

Expanding foam is not really a draught sealant, but can be used as a packer before sealing with a flexible mastic or caulk. Or foam EPDm/neoprene strips as packing.

 

[noseall]

Interesting.

"Use foam to gap fill, and plaster to seal."

Is that the same as ...

And the other 600 examples of foam draft stopping….

 

[noseall]

"Use foam to gap fill, and plaster to seal."

Is that the same as ...

Desperate.

 

[opps]

You are missing the point.

You can fill a gap around a window with ice cream in February and it will work. But it won't work in May.

Do you still point up around floor joists with mortar?

???

Expanding foam becomes brittle in direct sunlight but, as far as I know, it is not compromised by UK temperature ranges.

Years ago, when I built my garage, I was "gifted" a massive lump of mahogany door threshold. I didn't want to offend the person who gifted it to me even though I know the base was lower than the exterior floor level. It was so tall that the rain water used to run underneath it.

I drilled a series of holes in it and squirted in expanding foam. 20 years later, still no water seeping through.