Filling gap around water supply pipe??

[cath123]

Hello

Sorry if this the wrong place to put this query. After many many years of a freezing cold kitchen I removed the plinth off the front of the kitchen cabinet housing the water supply pipe to find a hole in my floor.

The water supply pipe comes up through the floor and there is a hole the size of a side plate around it. This hole goes right down into the foundations and was presumably left like that after the house was built in the 1990's. As my house has ventilated foundations (via external airbricks) the cold air just gets sucked up the hole and into my kitchen.

My next step is to plug this hole but I am looking for some advice. I can't use expanding foam as the hole seems bottomless (as deep as the foundations) but don't know what else to try. Not sure what the supply pipe is made of - it looks like blue plastic but may be made out of something else.

Can anyone give me some advice?

 

[Burnerman]

If the supply pipe is blue, its likely to be the recent MDPE stuff.
Consider plugging the hole with some rockwool - the fibre stuff thats used to insulate lofts?
John

 

[cath123]

Thanks John, that sounds very interesting. My last thread on here was about a gap in my loft insulation so I actually have 3/4 of a roll of loft insulation sat unused. It's the eco stuff made out of recycled plastic bottles but I assume it's still worth a go!

Much easier that my latest idea. I went to Wickes this morning and wandered around looking for inspiration. I decided to have a try with the mesh you use to cover holes in plasterboard - cut a few circles to fit, cut a hole in the centre of each for the pipe, glue them down one on top of the other and then use a layer of filler over the top!!! I have no idea how to glue them to the concrete - that was my next question.

 

[Burnerman]

I think you'll find your insulation plug quite sufficient Cath, and further work shouldn't be necessary. Are you concerned about mice gaining access or something?
Sticking stuff to concrete isn't as straightforward as you might imagine, but Wickes do an adhesive in a tube thats used to stick their cement board called Aquapanel (normally used to tile onto) which is good stuff.
John

 

[cath123]

Hi John. I was concerned about the insulation just slipping out and into the foundations. Now I think about it, the part above the concrete floor will expand much further than that in the hole and keep it from slipping down. So, I have my piece of insulation cut and ready - just waiting for it to expand a bit before I cram it in.

Great advice.....thanks again!

 

[HERTS P&D]

Cath, John is one of the main men on this site for all sorts of general information.

Andy

 

[Burnerman]

Cheers Andy - lets hope most of the info isn't useless
John

 

[phatboy]

Why can't you use expanding foam? Its very sticky when first squirted, so it would stick to the pipe a couple of inches down, then expand up and down. This should seal the hole