Green Building Forum - Cardboard tent affect

Cardboard tent affect

Davycrocket — Mon, 17 Oct 2022 12:18:16 +0100

Hi

I have a 1 storey extension built in 2005 using dense concrete blocks with a 50mm cavity insulation board installed.

There are zero exit points that are open to the elements.

Can somebody explain why when it's windy does it feel draughty as hell ?

I've sprayed foam where the plasterboard meets the ceiling in the hope it was just a case of the plasterboard not being sealed off, yet I'm still getting noticeable amounts of air coming through electric outlets and below kitchen cupboards etc ?

Do I need to take off roof tiles and check the cavity is closed or ?

Thanks in advance

Dave

Cardboard tent affect

Peter_in_Hungary — Mon, 17 Oct 2022 13:36:35 +0100

The cavity is obviously well ventilated, the cavity insulation board is not too effective and the inner skin mortar has gaps in it. From what you say it sounds like you have dot and dab plasterboard fixed to the wall - yes?

If the above description sounds like your extension then this would be fairly typical.

A fix would be full fill the cavity with say EPS beads and also consider wet plastering the walls having first removed the plasterboard.

Tony may be along soon to advise on the merits of 'plasterboard tents'

Cardboard tent affect

Davycrocket — Mon, 17 Oct 2022 17:26:30 +0100

Hi Peter

Yes it is indeed dot and dab. The worst building material known to man, in the wrong hands !

How effective are these Eps beads i keep hearing about ?

Cardboard tent affect

tony — Mon, 17 Oct 2022 17:51:02 +0100

Yes, eps beads can help, they are both vapour open and air open but offer considerable resistance to air movement. I would open up socket and seal any holes, gaps and cracks and refit, that will stop air whistling in through the face plate. Unfortunately not around behind the boards. Need to foam or seal the bottom as a minimum.

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

Cardboard tent affect

revor — Thu, 20 Oct 2022 13:14:48 +0100

Posted By: DavycrocketYes it is indeed dot and dab. The worst building material known to man, in the wrong hands !

When I was doing my build, I had a very helpful BCO and he told me If I did dot and dab, which I did in places, to ensure a continuous dab around the perimeter of the board.

Cardboard tent affect

WillInAberdeen — Sat, 22 Oct 2022 21:53:07 +0100

Posted By: Davycrocketair coming through electric outlets and below kitchen cupboards

Electricians are the second worst offenders when it comes to creating drafts, close behind kitchen fitters.

I discovered this one today: the sparky has drilled a hole to run cables from the well-ventilated loft, down into the partition stud wall between two bedrooms, pic is from in the loft looking down at the hole. But not just a little hole!

Unsurprisingly, there was a gale blowing around inside the partition wall.

Davy, it might be that you have sparky damage like this, which if you find and plug, would reduce your draftiness?

There were also gales from under the kitchen units, as the fitters didn't feel that holes really count if they couldn't be seen behind the units. Particularly generous holes had been cut to feed the drain pipes through, and cables running up to splashback sockets. I foamed some by peering under with a phone camera. For some others I wound down the screw legs of the unit and slid it out forward from under the worktop to get at the holes.

Cardboard tent affect

tony — Sun, 23 Oct 2022 21:04:32 +0100

ðŸ˜¢

Cardboard tent affect

Davycrocket — Mon, 24 Oct 2022 13:48:45 +0100

Posted By: tonyYes, eps beads can help, they are both vapour open and air open but offer considerable resistance to air movement.

Can this be done diy or would a firm have to do it ?

Unfortunately not around behind the boards. Need to foam or seal the bottom as a minimum.

Ive done the top and bottom and in between as best i could but its non better unfortunately.

Cardboard tent affect

Davycrocket — Mon, 24 Oct 2022 13:50:24 +0100

Posted By: revor
Posted By: DavycrocketYes it is indeed dot and dab. The worst building material known to man, in the wrong hands !

When I was doing my build, I had a very helpful BCO and he told me If I did dot and dab, which I did in places, to ensure a continuous dab around the perimeter of the board.

IThere are some good guys n gals about, not many though at a guess.

Cardboard tent affect

Davycrocket — Mon, 24 Oct 2022 13:53:33 +0100

Posted By: WillInAberdeen
Posted By: Davycrocketair coming through electric outlets and below kitchen cupboards
Electricians are the second worst offenders when it comes to creating drafts, close behind kitchen fitters.

I discovered this one today: the sparky has drilled a hole to run cables from the well-ventilated loft, down into the partition stud wall between two bedrooms, pic is from in the loft looking down at the hole. But not just a little hole!

Unsurprisingly, there was a gale blowing around inside the partition wall.

Davy, it might be that you have sparky damage like this, which if you find and plug, would reduce your draftiness?

There were also gales from under the kitchen units, as the fitters didn't feel that holes really count if they couldn't be seen behind the units. Particularly generous holes had been cut to feed the drain pipes through, and cables running up to splashback sockets. I foamed some by peering under with a phone camera. For some others I wound down the screw legs of the unit and slid it out forward from under the worktop to get at the holes.

I imagine it has been a bit of this, theyre only interested in what the finished article.

Cardboard tent affect

Davycrocket — Mon, 24 Oct 2022 13:55:00 +0100

Is it worth taking a couple of roof tiles out to see if the cavity is open at the top ?

Cardboard tent affect

Davycrocket — Mon, 24 Oct 2022 13:59:53 +0100

Posted By: WillInAberdeen
Posted By: Davycrocketair coming through electric outlets and below kitchen cupboards
Electricians are the second worst offenders when it comes to creating drafts, close behind kitchen fitters.

I discovered this one today: the sparky has drilled a hole to run cables from the well-ventilated loft, down into the partition stud wall between two bedrooms, pic is from in the loft looking down at the hole. But not just a little hole!

Unsurprisingly, there was a gale blowing around inside the partition wall.

Davy, it might be that you have sparky damage like this, which if you find and plug, would reduce your draftiness?

There were also gales from under the kitchen units, as the fitters didn't feel that holes really count if they couldn't be seen behind the units. Particularly generous holes had been cut to feed the drain pipes through, and cables running up to splashback sockets. I foamed some by peering under with a phone camera. For some others I wound down the screw legs of the unit and slid it out forward from under the worktop to get at the holes.<

I foamed behind all the plaster boards from top to bottom before the kitchen was fitted, So im stumped as to why its no better.

Cardboard tent affect

tony — Mon, 24 Oct 2022 16:40:49 +0100

Re cavity open, I hate closed cavities preferring wall insulation seamlessly joined to ceiling, roof or floor insulation.

Re diy beads, yes it is possible, have done some on my own house and suggesting how it can be done to friend, I can loan you a bead blower.

Re gales under units, is floor edge sealed, holes for services donâ€™t sound sealed, need to inside and outside.

Cardboard tent affect

Davycrocket — Wed, 26 Oct 2022 08:40:20 +0100

Tony.

I'm not even convinced that the cavity insulation is joined to the l insulation to be honest.

How does fibreglass tie into celotex ?

As for the draughts I'll take another look at this perhaps I've missed something.

That's a lovely offer re the blower, whereabouts are you mate ?

Cardboard tent affect

tony — Wed, 26 Oct 2022 18:44:38 +0100

Fibreglass need to fully touch foam sheet insulation, I like to tuck outside layer in behind sheet insulation.

Cardboard tent affect

Davycrocket — Thu, 27 Oct 2022 15:28:08 +0100

Posted By: tonyFibreglass need to fully touch foam sheet insulation, I like to tuck outside layer in behind sheet insulation.

I'll be surprised if that's the case. I'll investigate !

Cardboard tent affect

Davycrocket — Thu, 27 Oct 2022 15:29:00 +0100

Posted By: tony can send in post

How big / small is this

Cardboard tent affect

Davycrocket — Wed, 02 Nov 2022 13:49:31 +0000

That will be great if you can let me know how much postage is I'll transfer you some money across mate.

Thank you.

Cardboard tent affect

Davycrocket — Thu, 01 Dec 2022 21:16:58 +0000

I haven't got the materials yet so maybe wise to let them go first if they are ready to proceed then ?

Cardboard tent affect

tony — Mon, 23 Jan 2023 17:03:46 +0000

Not good at photos on here as a moderator I canâ€™t for some unknown reason post pics

https://www.dropbox.com/s/2u1di3id1du8hss/IMG_4898.HEIC?dl=0

The gun is connected to an old vacuum cleaner tube and to a compressor, you will need a compressor hose too , I use a 50l compressor and while injecting the compressor canâ€™t keep up so runs all the time

Usually the motor and engine is the same on 25l and 50l compressors

Tony

Cardboard tent affect

djh — Mon, 23 Jan 2023 17:54:03 +0000

Here's the photo (after resizing to be small enough to post) ...

Cardboard tent affect

tony — Wed, 25 Jan 2023 21:32:35 +0000

For filling behind plasterboard I drill one 28mm hole near the top 200mm out from the corner, not into a dob of adhesive then roughly at 600cc.

Cardboard tent affect

tony — Thu, 26 Jan 2023 15:06:23 +0000

Filling the cavity between the bricks and the blocks?

My memory is vague as I an involved in lots of jobs, apologies

Cardboard tent affect

tony — Mon, 25 Sep 2023 13:59:40 +0100

Tell me your address, I will let you find an old vacuum cleaner hose and a delivery tube, 28mm copper or plastic or adapt something.

I will tell you postage cost afterwards likely Â£5 ish

Cardboard tent affect

tony — Tue, 03 Oct 2023 23:21:02 +0100

I have sprayed a weak mix in with the beads using a garden sprayer as they were blown in. I think you can buy pre coated beads and the stick together.

Mostly I donâ€™t use pva , biggest job was a floor and didnâ€™t use or need them on that