External insulation & bad bathroom smell

[chippengael]

Hi all,

Sorry if this is a bit long, but tearing my hair out trying to solve this and need your help!

We had a company install thick, rendered, polystyrene external insulation on our semi-D a year ago. They completely covered the external toilet downpipe and all the bath/shower/hand basin drains with the insulation. Pretty soon afterwards we noticed a bad smell in our upstairs bathrooms. It eminated from the area where the pipes exit through the house wall.

Assuming it was trapped foul air in the cavity surrounding the pipework outside the house creeping back into the house and spreading through the floor, I got the company to install vents though the external insulation right at the point where the pipework emerges through the wall. This didn't really help.

Recently we got the bathrooms done and pointed out the problem but the bathroom guys just did their work and didn't address this issue - in fact the problem went away for a while, but then came back. It has always been intermittant.

We have also isolated the cause of the problem to the use of one handbasin only! Using any other handbasin or toilet and we have no problem, but just turning on a tap on the offending handbasin produces an ungodly whiff - but not through the plughole, from the floor, starting as I said from the point where the pipes exit the wall.

I checked the outflow of this handbasin and it just goes out to the downpipe where the rest of the shower etc water goes, and NOT into the toilet waste pipe.

There is no apparent leakage in the house from the toilet waste pipe, no wet patch on any ceiling.

So how can it be that one sink alone is causing this issue? Can anyone suggest a means of a) identifying the root cause and b) fixing it?

Where other people have had external insulation applied, how were the external down pipes handled?

All comments appreciated. Thanks

 

[pftg5]

First of all on any ewi job all pipework must be extended to remain on the out side of the external insulation. This is standard practice. Did you use an SEAI registered contractor and NSAI approved contractor. If so you should take photos this and send them in and make a complaint. In order to asses the problem you would obviously need access to the pipes which would involve removing some of the external insulation which presents it's own problems. Sorry I have no answers as to what could be causing this smell but what I do know is that if it was done properly you wouldn't have this problem.

 

[chippengael]

Yes, contractor was SEAI registered. Pipework was not extended. Company who carried out this work has stopped answerig our mail/texts/calls etc. What next?

 

[chippengael]

Update

So in frustration I tore off the vent cover on the external insulation over the weekend and there was a nasty smell trapped behind it - it seems the vent wasn't effective. I'll leave it off for a while. If it solves the problem it means that the original company really shouldn't have covered the external pipework with insulation. Instead they should have extended the pipework outside the new insulation as has been suggested. I am now looking to get this redone.