Rat burrows under screed and UFH

[Brix]

Whilst replacing a kitchen in a ground floor rental flat the fitter has discovered extensive rat burrows under the reinforced screed. Mostly they have stripped out the rigid foam insulation layer between the screed and the slab.

 

The kitchen /living floor construction is floating timber floor finish over mesh reinforced 50mm screed containing UFH pipes over rigid foam insulation over waterproof membrane over slab. I think we have found the point of entry - an uncapped disused drain pipe - but not certain yet. Quite large areas of the screed are left entirely unsupported but there is no sign of instability above.

 

Obviously the most diligent solution would be to lift the entire finished floor, reinforced screed and UFH and re-lay. But it is a huge area (not far off 30sqm) and I think we have the main area.

 

I'm possibly clutching at straws a bit but are there any other options using pumped foam or resin ( a bit like they do for foundation repairs) to back fill the holes without disturbing the otherwise intact screed and UFH and floor? Assuming of course that we can confirm and secure the entry point.

 

There is no sign that it is occupied anymore although that's not to say the would not come back. Goodness know where all the insulation which has been ripped out has been deposited.

 

I'm fairly certain that this is not covered by insurance.

 

Edited September 9, 2020 by Brix

[Big Jimbo]

Wow. Really quite stunning.

[Brix]

Just now, Big Jimbo said:

Wow. Really quite stunning.

Yes - it has blown my mind somewhat.

[Temp]

1 hour ago, Brix said:

Goodness know where all the insulation which has been ripped out has been deposited.

 

They eat the stuff because it makes them feel full. Its deposited wherever they take a s...

[Temp]

Years ago I recall reading about someone that put expanding foam in the metal mast of a yacht. He did it by lowering a plastic pipe into the mast and pouring mixed two part foam down the pipe using a funnel. Someone else gradually pulled out the pipe as the foam went in. I would suggest doing a practice run outdoors somewhere to get the flow rate and pipe removal rate right.

 

I tried putting expanding foam into a stud wall once. It didn't end well. The side I was working looked fine. Later discovered the other side was pregnant.

 

[Ferdinand]

I'd think about blown LECA (can be blown tens of metres), which will be less penetrable by Roland and his friends. It has been used to entirely fill underfloor voids in renos as an alternative to polybeads.

 

Insulation values will be poorer, but it is still an insulator. 

 

It may be an alternative solution to just open a few small (ish) holes in the floor and put in through those. 

 

Also not sure about current prices, but give the circmstances it may be what you need.

Edited September 9, 2020 by Ferdinand

[Onoff]

Down here I think I've said before they would put a layer of crushed glass bottles / old window panes atop the meagre hardcore to stop the tunnel bunnies chewing up through the concrete floors.

 

[markocosic]

There have been cases of much the same in external wall insulation! ?

 

Holes through screed. Water down holes for humidity. Moisture cure foam with modest expansion down the hole so that you're not lifting anything. Call it adequate?

 

Tile finish? Presumably the DPM is trashed and your relying on the for during faster than it gets wet/a floor covering that won't strain if a little humidity dries through it?