Cavity Wall insulation has moved out of walls

[processpaul]

Hi.

Firstly I have little knowledge of how houses are built so don't really know if this inner wall is right or not.

I've been under the floor today (into a small access hatch in the understair cupboard0, hunting down how a rat is getting in and found this.

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• processpaul
• 30 Oct 2011
• 1

Apart from not really too keen to sit on rat faeces, quite frankly not what I was expecting under my hallway. There is approximately 2m of void space from where the camera was to the front wall. House is 1937 mid terrace.

Cavity wall insulation was done in 1987, 20 years before we purchased.

Gap to the right goes under to the lounge area.

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• processpaul
• 30 Oct 2011
• 1

Any suggestions as to what can I do about this?
Is it likely that it was like that when it was first put in?
Why are there so many gaps between the bricks?

thanks for reading

Processpaul

 

[BigRobCanUFixIt]

would those gaps be purposely built that way to increase airflow, to reduce the chance of condensation and mould.

Im no expert but going by other post I have read this is my assumption.

Im sure an expert will be along soon to confirm or call me a nobber....

 

[stuart45]

would those gaps be purposely built that way to increase airflow, to reduce the chance of condensation and mould.

Im no expert but going by other post I have read this is my assumption.

Im sure an expert will be along soon to confirm or call me a nobber....

Spot on, they are honeycomb sleeper walls.

 

[^woody^]

I can't imagine that cavity wall insulation would leak to such an even level under the floor like that.

Looks like it was done like that for some odd reason

That wall with gaps is a honeycomb wall built to allow airflow throughout the underfloor area

 

[processpaul]

All thanks for replies

Ok so honeycomb sleeper wall for a reason. That figures thinking about it now as we have such a void under the floor it needs quite a bit of ventilation.

Woody, the insulation is not even at all it just looks like it a little in the photo, could it be it just blew that way when they put it in?

Other than pulling the floor up and covering all the holes with chicken wire i'm stumped on how to prevent ratty getting into the void below the floor, now that the gaps are there for a reason.

 

[JohnD]

if you are talking about the sleeper walls that the joists stand on, they are purposely build gappy to allow airflow which runs between the airbricks on both sides of the house, to prevent damp in the underfloor void. While you are down there, clean away the cobwebs and dust from the airbricks.

It looks like your house was insulated with expanded polystyrene beads, which flow like water, and appear to have run out through holes in the brickwork. There might not be any insulation left in your wall cavities now.

I suggest taking some bin-bags down and shovelling up the beads. This will also enable you to see any rat traces.

The rats must be getting into the house from the outside world, so look for holes in the ground under those beads, or gaps in the brickwork round the perimeter of the house.

Rats often get in through holes round drains or pipes. They also need water so will be attracted to any leaks.