Filling in 50 deep hole in utility room floor

boardtc

I posted before about cutting my utility room unit base to enable access to look for a leak. The leak is fixed now and I am left with a 40 cm deep, 560mm tile width hole (below). 2 barrows were filled with what came iout of it plus a black bin bag of insulation. So there was the concrete floor, 5+ cm of insulation, then 20cm more concrete, then rebar, then the plastic vapour barrier.

What would you do regarding refill with insulation/vapour barrier with continuous joins now broken, etc?

con747

I was expecting a 50 metre deep hole there for a second!

https://www.boards.ie/discussion/2058422967/filling-in-50-deep-hole-in-utility-room-floor

standardg60

Quite the job there. What i would do is backfill loose material up to the base of the concrete, then a gravel/cement mix to slightly below the vapour barrier. When that goes off place a DPM lapped up the sides and protruding above floor level, insulation at the bottom and then sand/cement mix. When set trim DPM off flush and replace tile.

Lumen

My hack job would be something like:

• pack out around the sides of the void with crumpled up newspaper
• sink a few concrete screws horizontally into the sides of the hole (maybe use a right angle attachment on the driver)
• fill up to the bottom of the concrete with decent PU foam, carefully in layers
• pour new concrete
• use some combination of air tight paint and tape on the concrete and around where the vapour barrier is
• finish with a final layer of fine concrete/screedy stuff