Garage ceiling insulation installation

Svenholio

Looking for someone with some knowledge regarding garage ceiling insulation.

We have a bedroom above an internal garage. This room has been cold since we bought the house. After finally getting frustrated with it, I cut an inspection hole into the plasterboard ceiling to check the installation. I found that they were was a gap from the joist to the end of the insulation of about 2". I would think this would make the insulation almost useless. Can anyone enlighten me on a spec/standard for what is acceptable for this? House was built last year.

https://drive.google.com/open?id=1RpExmH1sOU_fW1ZFejQLKMSeI96wbebd

Thanks for any help.

BoxerfanUK

Svenholio wrote: »

Looking for someone with some knowledge regarding garage ceiling insulation.

We have a bedroom above an internal garage. This room has been cold since we bought the house. After finally getting frustrated with it, I cut an inspection hole into the plasterboard ceiling to check the installation. I found that they were was a gap from the joist to the end of the insulation of about 2". I would think this would make the insulation almost useless. Can anyone enlighten me on a spec/standard for what is acceptable for this? House was built last year.

https://drive.google.com/open?id=1RpExmH1sOU_fW1ZFejQLKMSeI96wbebd

Thanks for any help.

I'm with you on this and have similar issues, although my house is around 15 years old. We have a double attached garage with main bedroom above which is also cold. As well as the insulation you mention it would probably help to enable the garage itself to retain as much heat as it can i.e. insulated and draughtproof garage doors.

For the garage I am considering replacing the double doors which are cold and uninsulated with gaps all around for something like these https://www.youtube.com/watch?v=Cwo9xCcArPw not cheap but they need replacing anyway and in theory if the garage stays warmer then less cold to transfer to above bedroom. Also thinking of taking ceiling plasterboard down, re-insulate properly and finish of with a 1 or 2 inch thick layer of Celotex/Kingspan PIR plasterboard finish fixed below and across the joists to help negate thermal bridging. This would obv' need doing before new garage doors.

we have a pitched roof above the bedroom with x2 dormer windows. There is 4" Celotex between the 6" rafters but this has been poorly fitted, so we are probably losing heat from above AND below.

Ideally I would like to take the bedroom ceiling down, fully fill with 6" PIR and finish with 1" PIR/plasterboard face below and under the rafters to give 7" of PIR. Problem is they recommend leaving a 2" air gap between the topside of the PIR and the roofing felt Have considered making some enquiries to remove all roof tiles and re-felt with a breathable membrane and a counter batten system which in theory would allow the rafters to be fully filled but reading conflicting info on this. Plus, again, this wouldn't be cheap.

Any insulation/roofing experts out there?

EDIT: https://www.kingspan.com/gb/en-gb/products/insulation/insulation-boards/kooltherm/kooltherm-k118-insulated-plasterboard

Svenholio

Its extremely hard to find any sort of specification for this. Thanks for the input.

Mutton_Geoff

Svenholio wrote: »

Looking for someone with some knowledge regarding garage ceiling insulation.

I found that they were was a gap from the joist to the end of the insulation of about 2". I would think this would make the insulation almost useless

That isn’t neccesarily true. Air is a good insulator as long as it’s not able to move. It’s how double glazing works. Loft insulation only traps air to stop it moving rather than act as any special blanket.

You’re probably better off tackling this from above and lift the floorboards in the bedroom. If it’s chipboard, hopefully it’s not glued but even if it is, I would lift it all, insulate better and relay new flooring. I’d make sure the void was filled, I’m guessing they are 4x2 joists so 200mm of insulation is right. Don’t be tempted to compress it as it will be less efficient.

Svenholio

When we cut hole in the ceiling and put you hand in the hole, there was a considerable draft coming out of the hole. Still would like to see some sort of spec for this.

Also regarding the insulation gaps. Loft insulation has to be a snug fit to avoid the circulation of air. Should be the same for the ceiling?

Raggie

As you said the house was built last year, why are you not engaging with the builder on this?

Our new build (2009) it wasn't until the winter we found out that the kitchen was cold.. it was cold because the company they subbed the heating installation too had treated the install like every other house on the estate. Not noticing that this one was different and should have had an extra radiator.

They fixed it no problem.

My point is snagging or not.. it's just got cold and you have noticed a cold room. It's not unrealistic to notice that now.

Contact them and see what they say before any remedial work by yourself.