Interlocking of insulation boards

ravendude · 16-09-2019 8:01pm #1

Hi,

Is attention to detail re. interlocking of insulation boards very important?

Getting an extension done. Most of the insulation boards are reasonably well interlocked together on the new part of the house.I do see a few gaps here, but its not too bad, - maybe a few millimetres
One part, where the ground floor wall is being built up, it looks pretty shoddy to my eye at least.
ie. The boards don't even touch in places.It is mostly where it is cut around joists.

Should I be insisting this part is redone?
I will try to upload a few pics if I can

Is there anything else re. insulating of walls I should watching out for
Thanks!!

ravendude · 16-09-2019 8:07pm

Couple of pics:
Looking down from above into the cavity:
https://drive.google.com/file/d/0B1on65pUaYt_SkRDVUpBbHdyMnVaWmlQMjJhcS0tMk9UaGNZ/view?usp=sharing

https://drive.google.com/file/d/0B1on65pUaYt_ZndmcFVFa1Foc3RYN1NDUVd5SEo2MlpHcVp3/view?usp=sharing

Calahonda52 · 16-09-2019 8:29pm

A great example as to why CW construction is .....

ravendude · 16-09-2019 8:37pm

Calahonda52 wrote: »

A great example as to why CW construction is .....

I wanted to go timber frame but cost was prohibitive for the nature of my job. The best I can do in the situation. Is check every day, so particularly interested to know what I should be looking for.
I take it that the attention to detail in the above is crap then and needs to be redone?

Calahonda52 · 16-09-2019 8:39pm

Redoing will be difficult in a CW with both leaves built

ravendude · 16-09-2019 8:44pm

Calahonda52 wrote: »

Redoing will be difficult in a CW with both leaves built

This is only the first block or so, they have just started. It is mostly a first floor extension.The wall is being built up higher from an existing wall, so it's the first stack of board.The existing wall was pumped and had some poly board. So this is going in above existing insulation. And could easily be pulled out and reinserted before they continue

MicktheMan · 16-09-2019 11:49pm

That insulation may as well be attached to your garden wall for all the good it's doing.:eek::eek: In fact it would be better if it was not there - at least the cavity could be pumped at a later stage.

JoeA3 · 17-09-2019 12:12am

First pic is shocking, not sure what’s going on there but the 2nd pic seems much better. That’s looking at it face on though?

ravendude · 17-09-2019 12:20am

JoeA3 wrote: »

First pic is shocking, not sure what’s going on there but the 2nd pic seems much better. That’s looking at it face on though?

The first pic is from a different section, done by a brickie, - that mostly looks OK (except for this one board) and seems to be clipped tight into the wall. This board is the only dodgy one.

The second pic is from another section and I think was done by a different "individual". I think I'll be having words that it needs to be supervised properly.

Calahonda52 · 17-09-2019 9:14am

When in doubt, rip it out

sydthebeat · 17-09-2019 9:57am

the first pic is terrible, i honestly cannot tell which leaf the insulation is supposed to be tight to.
They actually cut the insulation board sooner than install the joist properly and clean up the bed mortar....... completely nuts stuff

ravendude · 18-09-2019 11:38pm

Well it looks like something temporary was going on, went back and it looks like the below.
Not sure it it is what it is supposed to look like (still a work in progress), but looks neater to my eye. Any concerns?
https://drive.google.com/file/d/1-Iv2p_3ZgzNuD_L8JIcDSQLYAcN6KzQk/view?usp=sharing
BTW, The joists were preexisting and not part of the current build. There will be internal lining also FWIW.

Bonzo Delaney · 23-09-2019 6:49am

In a 100mm cavity on an extension I wouldn't bother with insulation been fitted . To much to expect details like corner junctions , window and door junctions and joist penetration areas to be done 100% correctly.
The fail safe and better method is to build away while installing ties and dpc's then pump the full cavity with bead insulation to insure full cover.

BryanF · 23-09-2019 11:51am

Bonzo Delaney wrote: »

In a 100mm cavity on an extension I wouldn't bother with insulation been fitted . To much to expect details like corner junctions , window and door junctions and joist penetration areas to be done 100% correctly.
The fail safe and better method is to build away while installing ties and dpc's then pump the full cavity with bead insulation to insure full cover.

need a wider cavity with EPS beads

Interlocking of insulation boards

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