Filling holes around a soil pipe.

[Lacan07]

Evening all,

The time has come for me to make good the gap(s) in the external wall that were knocked through to accommodate the new soil pipe. Ordinarily I'll cut some original bricks to size and lime them in, but this gap with the soil pipe is trickier and got me thinking...how to detail it over the top and around the pipe? As you can see its quite a deep space.

I know how the trades would do it...expandable foam and cement to finish. I'm not anti-foam but I'd like to avoid it if possible. I want to employ some flexible wood fibre on the internal side of the void to fill some space but for the external side I'm thinking layers of lime mortar with layers of slate and/or bits of broken brick embedded, to help with shrinkage and provide ballast.

Its just laying lime on top of and around a plastic soil pipe seems a bit odd, would you do the same?

 

[WetWales]

Wow! Haha this is great! I’m wondering the exact same thing! We made a new hole for soil pipe - under front doorstep only place to be boxed in inside -
and laid pipe, then the foam glass internally for the limcrete
floor / lime screed : so I made the foam glass and membrane as far over the pipe as i could - then I sort of tucked and pushed loads of the foam glass further into the hole and around the pipe - and did the same from outside , we haven’t finished it yet but thinking I’m going to basically fill the whole thing with the foam glass - the RFG - pack that in the middle , then the outer few inches do as you say,
Lime and slate as it would’ve been - the foam glass should act as a good dpm and hopefully stop much moisture tracking in…
Could be worth a try as I think the RFG can be structural and it’s Meant to be amazing for damp control!

 

[Mikeyboy7]

I'd recommend a hot mix. Any old soft bricks onsite?if you do smash them up into popcorn size and smaller, even keep the dust and add to a 1:3 hotlime mix at 10 to 20% ratio, you'll get a great set and have great pore structure for air and moisture, make the mix stiff by avoiding using too much water, have it as stiff as possible