I have been on this problem for over twenty years now, nothing has changed in site practice, some progress on what should be done

https://readinguk.org/draughtbusters/finding-draughts/dry-lined-homes/

Plenty of info on DraughtBusters website

https://readinguk.org/draughtbusters/going-further/dot-and-dab/

https://readinguk.org/draughtbusters/going-further/first-floor-void/

Bit odd to have wiring running through the cavity (how did it get fitted there?) and to have cold air circulating on the 'warm' side of the cavity insulation.

Are you in contact with the builders, ask them to explain what they were thinking, any kind of guarantee?

Thanks for the comments. I can only see in a small number of the holes. I have no idea if the cavity of the semi cavity double leaf is on the inside or the outside. All I know is there is there some wires running into the holes. The holes are too dark to see any of the 110 Quinn insulation boards that are supposedly inside.

I was thinking of buying a Walabot and finding these in the rest of the house and filling them with cement but I will look into airtightness products. I am bit concerned about running the rather nice skim work though.

Posted By: Nick Parsons'Rather nice skimming' is a mere transient moment in the cold or warm lifetime of your house!!

Perhaps a bit more research is required before I (and others) encourage you to start ripping big holes in the fabric.

You write:''The inner leaf is parged but *surely* (my emphasis, NP) these holes allow huge amounts of cold air to enter and chill the back of drywall''.

Those of us with time-served weariness of massive thermal by-pass jumped to the conclusion (well, I did) that you said: ''these holes allow huge amounts of cold air to enter and chill the back of drywall'', when actually I think you haven't experienced that yet, and are asking ''*will* these holes allow huge amounts of cold air to enter and chill the back of drywall?''

'Research':

1. Wait for a windy day. Open up enough of a hole in the plasterboard to allow you to get the (slightly moistened) back of your hand against one of these hols in the blocks. Can you feel the cold?

2. Augment that 1st stage with an infra-red thermometer, and take readings at and around the hole, and do so for comparison on a still day too.

3. Consider repeating the exercise for other such holes if the results of 1 and 2 suggest that you do have cold air in there.

4. (Maybe this should be (1), but I cannot be bothered to re-number!) Can you find out where those cables are going?


… and Hallelujah that it's parged at all!

Thanks. I will try this. I know that there was cold gusts of wind blowing through some of the power sockets until I sealed them. It is very hard for me to say where the wires go but they come from the power outlets, and one from the kitchen plumbing. Is that normal?

The house was built 3 years ago. Does it have a warranty? (Yes.No: T.B.C.) Is it behaving as designed? No. It leaks cold air. Is it therefore of 'merchantable quality'? (Does the Sale of Goods Act - or equivalent - apply to houses? I suspect not.)

I realise that is very simplistic, and that warranties are only any good if you can make them stick, but have you been in touch with the original builder to explain and discuss the issue? Cold air via the sockets is sadly not rare, but it is undoubtedly not right!

Can the contractor explain why cables run in the cavity? Does (s)he know that they do? Can (s)he comment?

And while you are waiting for that to work.....

Cut out a minimum 150 x 150mm of plasterboard at each cable-hole. If you use a very sharp Stanley knife and bevel the cuts you will have 'plugs' that you can glue back in.

Get yourself an offcut of EPDM rubber roofing, and some air-tightness tape (or buy these ready-made grommets: https://www.greenbuildingstore.co.uk/products/pro-clima-kaflex-cable-grommet/) and primer, and an electrician. Take off the sockets/switches as required, prime the parge-coat, wait till primer is tacky, and slide grommets over the cables. One grommet per cable! But if you make your own, as per my pic, you can make a 2-hole grommet. If you share 2 cables to one hole (as I have seen done) it won't be air-tight.

And repeat....

This does not cure the more fundamentally-worrying issue that there is cold air on what is supposed to be the warm side of the insulation, so do the consultation with the builder first.

I wish you the very best of luck.

I followed the advice here and exposed one of the cables. This must be connecting to the external fuseboard. I thought the best way to seal this would be to stuff the cavity with fibre wool and achieve a a/t seal with cement and sand, possibly with airtightness tape on top, because there is no way to get a rubber grommet on it. Expanding foam is possibly able to dissolve wire insulation too so I want to avoid that, even though I have seen ons of it in fuseboxes around. Would filling the crack with fibre wool be safe? Could it derate the cable?

I would think about gun foam, failing that acrylic sealant.

These holes are causing massive thermal bypass of your insulation, when it is windy it will be doing almost nothing

I would love it if you could post up or share links to the thermal images.

I'll try to get some thermal images up. When it was about 3°C outside, the hole for fuseboard's big grey flat cable (around 17 mm) was producing a cold spot on the drywall about 200 mm in size while a skinny yellow green connecting to the gas connection produced a cold spot about 80 mm in size. I found a third hole for the internet which was producing no cold spot. There are various cold spots under window sills which I am looking into. I could do the same to them and seal them but I feel I should do the best possible solution and lift the sill and fit some top notch insulation like space therm to avoid thermal bridging and then seal. The house plans seem to show a cavity closer structure on the sides of the windows but that is not definitive proof.

We have a 10 year home bond. But I have read online that these Irish bonds only cover structural issues and not insulation, even though it clearly is not as warm a BER A2 should be. The developers stop offering to fix defects after the first year and we had the house two years. I will check with a professional about the bond.

By the way Philedge, I think the insulation is on the inner side of the cavity wall, rather then the outer side in this semi fill design. I havent seen it but that is what i was told and that is how it on the plans.

Posted By: philedgeIf the insulation is on the inner leaf, then your drawings in the original post have caused a bit of confusion!!

But OTOH, next to the inner leaf is where it is supposed to be.