New extension - air coming through electrical sockets

[S_P]

Hi,

 

I'm looking for some advice, recently had an extension built & as the topic says i have draughts coming through the sockets, for the most part i kept my eye on the company i chose to do the build but with now having this issue it has made me want to try & understand where the issue has arisen from.

 

I have 2 suspicions ;

 

1) The 25mm Kingspan Kooltherm insulation between the strapping behind the plasterboard has been left out? The builder states they have pictures to prove it had been installed but i'm still waiting on these.

 

2) The inner leaf was to be as stated in the planning application 100mm Celcon high strength blockwork, when i look at these online the brick appears much smoother on the surface compared to what i have, i have attached a picture of the build showing the blocks used, i found a delivery note stating "heavy weight blocks 7N", could it be the wrong blocks have been used therefor allowing air to flow more easily through the inner leaf?

 

Everything else from what i can see was carried out correctly.

 

Any advice is much appreciated.

[Bramco]

We had this on an extension in a previous house - and in the winter the cold draft was a gale when it was blowing outside.

 

Ours wasn't specced anywhere near as detailed as yours but was a similar build. In the end, I worked out that the air was getting in through the top of the wall which wasn't sealed adequately from the roof space. So the cold air simply ran down the inside of the plasterboard and out wherever there was a socket or light switch. Which meant that we were losing a lot of heat.

 

Our new build was specced a lot better...

[S_P]

41 minutes ago, Bramco said:

We had this on an extension in a previous house - and in the winter the cold draft was a gale when it was blowing outside.

 

 

Thanks Bramco,

 

There is s definite difference in the flow of air depending on the strength of the wind outside, your experience sounds similar to what we are now experiencing.

 

So by the plans there "should" have been cavity closers fitted at the top of the inner & outer leaf, having not been present when the roof went on i cannot confirm that these were fitted, certainly in the pics i have up to that point they had not been.

 

If something like this has been fundamentally missed out apart from the obvious of taking it apart does anyone know if there is an easy fix around the air coming through? If there is such a thing.

 

Thanks

[ProDave]

If you read this forum you will find the devil is in the detail.

 

What has probably happened, is you have a "plasterboard tent".  That is, lack of detailing means the space behind the plasterboard is open somewhere to a cold space probably the loft, allowing cold air to get behind your plasterboard, bypassing all the insulation.  I see this regularly with cold air from switches and sockets.  The clue is they need cables and the cables have to go somewhere often into a cold loft, and the hole drilled for them is oversized and never sealed.

 

Do you have any pictures of how the plasterboard was fixed to the walls after the final layer of insulation?

[Bramco]

35 minutes ago, S_P said:

So by the plans there "should" have been cavity closers fitted at the top of the inner & outer leaf

 

And they may have been - but as @ProDave says there are many ways they can prove useless even if fitted.

 

Sounds like you might need to send a small child into the loft space to crawl round the edges of the roof space to see if there are any obvious issues.

[S_P]

1 hour ago, ProDave said:

Do you have any pictures of how the plasterboard was fixed to the walls after the final layer of insulation?

Having not really been on site while sheeting out was actually taking place I question whether the 25mm insulation was installed between the strapping, however as the air is still getting there it’s possible to say even if it is/was this may still be happening.

[S_P]

So as you can see this is a brand new build, I certainly didn’t expect the finished result to have this issue, in my opinion something has been missed out somewhere or done incorrectly even if there is a small hole from a hole drilled for wires that hadn’t been plugged afterwards, is that fair to assume? 
 

I have been advised by the company that built the extension that gaskets could be put around the electrical outlets, is this the correct way going forward to resolve the issue? Should I be satisfied with that or would it be considered a quick fix & not dealing with the issue at its root cause?

 

Should I worry about long term issues from something like this if it’s left as it is & gaskets installed as in damp/mould?

 

Thanks again for your input 🙏

Edited January 28 by S_P
Additional detail

[ProDave]

I assume that is a window or door reveal before being boarded up?

 

On the face of it, it looks good with gaps sealed up with expanding foam.

 

One can only speculate but somewhere that didn't happen or not happen properly.

 

A thermal imaging camera is about the only thing that may help you track down where.

[Nickfromwales]

13 hours ago, S_P said:

1) The 25mm Kingspan Kooltherm insulation between the strapping behind the plasterboard has been left out? The builder states they have pictures to prove it had been installed but i'm still waiting on these.

Take the socket out and have a look? Do you know if they’re metal boxes or fast fix (plastic into plasterboard) boxes? Beware stripping the threads when removing / reinserting the plate screws that hold the socket on. 

[Nickfromwales]

Having that 25mm insulation in there won’t stop draughts getting in when there’s a hoolie blowing outside. Air finds its way through tiny gaps, benefitting from when there are lots and lots of them, but it certainly loves any bigger ones!
 

The boxes should (could) have foam around them, and the boards foam sealed at the head / foot / sides / returns etc. The issue here is that if it wasn’t specified as an airtight build then the builder hasn’t charged you for one, hence you haven’t got one. What did you ACTUALLY have in the specification and agreement, in terms of these considerations? 

[S_P]

2 hours ago, ProDave said:

I assume that is a window or door reveal before being boarded up? - Yes, a window. 

 

One can only speculate but somewhere that didn't happen or not happen properly. - it’s looking like it.

So it appears that it’s not such a bad job workmanship wise nor in specification, sealing off around the sockets in the cavity should see an end to the draughts & there won’t be any long term affects.

2 hours ago, ProDave said:

 

[S_P]

1 hour ago, Nickfromwales said:

Take the socket out and have a look? Do you know if they’re metal boxes or fast fix (plastic into plasterboard) boxes? Beware stripping the threads when removing / reinserting the plate screws that hold the socket on. 

The plan tomorrow is to do exactly that by the electrician & to put expanding foam in the cavity around the boxes. This has only just come about today, thanks for the heads up on the stripping of threads!

[S_P]

1 hour ago, Nickfromwales said:

The boxes should (could) have foam around them, and the boards foam sealed at the head / foot / sides / returns etc. The issue here is that if it wasn’t specified as an airtight build then the builder hasn’t charged you for one, hence you haven’t got one. What did you ACTUALLY have in the specification and agreement, in terms of these considerations? 

I didn’t specify an airtight build but I certainly didn’t also sign up to draughts blowing through the outlets on new extension, would anybody be happy with that? 

I was reassured a number of times through the building process that this extension due to newer regulations compared to the 13 year old house it has been attached to would become the warmest room in the house, it simply isn’t, due to this leaking airflow.
 

This is a video of what I’m talking about, all be it this is when it’s windy outside.

[ProDave]

Whilst I regularly encounter wind coming out of a socket box, it is usually when i have unscrewed the socket for some reason.  To blow through like that even with the socket in place is unusual.  It might be worth checking if they are all like this or just on one wall?  That might pinpoint where the issue is.

 

Is there any permanently operating extract fan anywhere?

[FuerteStu]

3 hours ago, S_P said:

 

This is a video of what I’m talking about, all be it this is when it’s windy outside.

IMG_5650.mov

 

That's quite a substantial amount of airflow.. 

 

I was thinking it might not be the airflow around the plasterboard, but if you had your sockets fed with conduit that opened out into the loft. I've seen that being an issue before. In that case there's wasn't a whole lot to do because there was almost no access to the eaves, but we used the foam earplugs around the cables in the conduit entry, and a different brand of socket face plates were more airtight than the screwfix budget brand that was fitted. 

[S_P]

2 hours ago, ProDave said:

Whilst I regularly encounter wind coming out of a socket box, it is usually when i have unscrewed the socket for some reason.  To blow through like that even with the socket in place is unusual.  It might be worth checking if they are all like this or just on one wall?  That might pinpoint where the issue is.

 

Is there any permanently operating extract fan anywhere?

There is 2 double gangs on 1 wall & another double gang on another wall, they are all like this even though they are 2 seperate walls. 
 

On trying to piece this together, I’d say the air is flowing up the outer cavity & over to the inner, whilst the expanding foam was used well on the vertical straps holding the insulated plasterboard, it’s questionable whether the upper & lower horizontals where done quite as good 🤔 I’d put my money on this,I did wonder if the right brick was used internally but that doesn’t seem to be the case.

 

The electrical supply has been fed internally from a socket in the kitchen meaning it’s not coming from wires that have been fed from a cold space.

 

We have actually plugged in child guards for now & sadly it’s not to stop little ones fingers.

 

There is no permanently operating extraction fans.

[S_P]

1 hour ago, FuerteStu said:

 

That's quite a substantial amount of airflow.. 

 

I was thinking it might not be the airflow around the plasterboard, but if you had your sockets fed with conduit that opened out into the loft. I've seen that being an issue before. In that case there's wasn't a while lot to do because there was almost no access to the eaves, but we used the foam earplugs around the cables in the conduit entry, and a different brand of socket face plates were more airtight than the screwfix budget brand that was fitted. 

Sadly no conduit as a cause, nor has the supply been fed from a cold space but appreciate the input.

[kandgmitchell]

Well one thing is those aren't celcon high strength blocks. If they were then they'd be smoother and have a black coloured band painted on the ends to identify them. It would be interesting to know what the blocks were as their insulation value could be a lot less than the celcon's, leading to the wall having an overall lower U value. Wouldn't affect the draught problem though, has to be air running down the back of the plasterboard somehow.