Cold Extension - Insulation Issues?

[marshian]

1 hour ago, SteamyTea said:

No one told you that it is on a BMW and not an Audi.

And the driver is not sitting in the middle.

 

OT

 

I lived for years first on a Volvo 3.0 CD and then a Senator 3.0 CD plate was relevant to both 😉 rather than to me

 

When I couldn't find another Senator that wasn't full of tin worm it carried on first on my BMW 740i and now on my current BMW "130i"

 

I did get a daft offer once from someone who wanted it for their Audi A3 but I kinda like it and 30 years is a long time to have a plate

 

 

[dwhhhhhhhhhh]

This is so similar to the issue which we have been struggling with on our extension. We had some work done in 2020 and have had issues with cold in the new space since completion. I originally put it down to lots of glazing, large space to heat etc but after realising 2020 space was always significantly colder than 1920s original building I started more detailed investigation. We’ve found holes behind kitchen cabinets, missing insulation, poor installation of insulation and many other things. In March, we actually took out the entire kitchen, lifted the floors and refit the under floor insulation. Thermal imaging confirmed that that was an issue prior to doing this - which was a massive job. Here are some pics of what we found - gaping holes open to the outside letting cold air directly into the space. The only insulation over those parts of the floor was effectively the cork laminate tiles. When we did the reinstatement work, we installed a best-in-class air tight system with use of FM330, airtight membrane, and airtight tapes at joints (including skirting.) I have only done under the kitchen.  There is a small (12m2) are in the space which I now need to do before winter kicks in proper. 
 

I’m now thinking I might need to inspect the joints between the walls and roof to check whether there are gaps where the insulation should otherwise overlap. I might come back to ask for advice. 

Edited September 5 by dwhhhhhhhhhh

[marshian]

Jesus that is shoddy!!!

[Big Jimbo]

The builders strike again. It is sad how much shoddy, bad building work you see. Especially with the cost of builders.

Not saying that there are not any good ones. But as rare as rocking horse poo.

[Super_Paulie]

this is why i have trust issues with trades and do the majority of stuff myself if i can. And the associated 3 years build time...

 

I just wasnt going to trust a company to make my place tight enough for the underfloor to work to any degree.

[dwhhhhhhhhhh]

So I’ve since taken up the other part of the floor in the extension and rectified the insulation install (using FM330 to get as much air tightness as possible.) In totality this work has made a significant difference to thermal comfort in the space. Drafts definitely feel down. I can no longer feel significant cold air on e.g. my hands or neck when I sit in the space. Heat retention is also much improved- the temp drops overnight of course but today the heating fired in the morning and never fired again all day once up to temp. Previously it would fire multiple times a day. 
 

it’s still not 100% though. I can definitely still feel a slight cooling air in the space. It’s subtle but I feel it. I can definitely feel air coming out of some of the sockets too (e.g. on one of the exterior facing walls.) I’m at a loss to figuring out where air is now getting into the space. I’ve got a clear view of where insulation is still incomplete (through my TopDon thermal camera) but the air leaks are quite subtle now.
 

Would an air blower / air tightness test allow me to locate the source of air ingress? Or do they just give you an overall rating of the system?

 

I think I’m going to isolate electrics, take off all sockets, foam behind them and install putty pads. I might also get a box of FM330 and blow foam into the spaces in the walls that the TopDon shows are cold. Ideally I’d like to close off the source of the drafts though…

Edited October 1 by dwhhhhhhhhhh

[dwhhhhhhhhhh]

Here’s some pics of the insulation install I uncovered in the second part of the floor.