Garage Insulation

[datadiyer]

Hi All,

Just hoping to get the go ahead from you knowledgeable people on my plan for insulating my garage. The main issue is water penetrating from outside and once I insulated it, I didn’t want the damp transferring to the insulation and beyond. The outside walls are rendered by the way with waterproofing in the render. As you see in my sketch, I have a plan to separate the insulation from the exterior wall with some sort of spacer (I don’t know what material spacer yet), perhaps just a small block of wood. This way I hope to create an air flow to deal with the penetrating damp. Alternatively, I was thinking of painting the walls first with some black bituminous paint and fixing the rockwool slabs direct to the wall. I plan to add a vapour barrier and line the walls with 9mm ply. The structure is a standard 6m x 3m single block build. Does anyone have any thoughts on my idea or advice? I just want it to be a bit snug for the kids to play in during cold/rainy weather.
Many thanks,
Datadiyer

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[theprinceofdarkness]

This is a problem that has occurred here before. As I see it if real water is getting through the wall, sealing it on the inside will allow the water to percolate down the inside of the wall and trickle out over the floor. So some form of drainage should be incorporated at the wall/floor junction, say a 1/2" wide groove with 3/8" holes drilled down at 45 degrees so any water in the groove drips out and downwards to the outside.
Another point is that garages suffer severely from condensation, I was working in one the other day (corrugated iron - an extreme example) and the roof was dripping, pitter, patter, it confused me at first because I thought it was raining. So some thing has to be arranged to collect the drips and channel them outside, else you will have puddle on the floor.
I prefer to use SRBF/cement to waterproof rather then Synthaprufe, which stays sticky for 5 years or so. In either case go over the in side and fill any pin holes, which will leak water (eventually), before you waterproof it. use silicone on you wall plugs, else water will appear around them.
Frank

 

[datadiyer]

Hi Frank,
Thanks for your reply. The roof i'm thinking should be fine as it's got that material lining stuff which absorbs the condensation and airflow dries it out. Good point about the drainage holes, although if I leave the natural ingress of water, perhaps with the airflow created by the spacers, it will just disperse? I maybe wrong. Thanks for the advice on SRBF/cement also, i'll look that up. I guess the question now is whether to waterproof it or allow the airflow to disperse it?
Many thanks,
Datadiyer.

 

[datadiyer]

Hi all,
I've been considering the numerous types of insulation for my Garage project and am interested in Jablite Premium. Has anyone had any experience with it? Also where it can be purchased? It's black in colour with orange specs and can be found at:
http://www.jablite.co.uk/products/show/jabcore-premium

Many thanks,
Datadiyer.

 

[theprinceofdarkness]

It has a max temperature of 80 degs C, so if you use it in the roof layup, there should be an air gap over it, so it does not get overheated in the summer.

FWIW, My builder used some Jabolite to insulate under the floor screed, because the sheets were slightly warped and the weight of the screed was not enough to settle the sheets, It has taken a couple of years for the sheets to settle, the screed to drop and pull the rendering of the walls in places.
Frank

 

[datadiyer]

Hi Frank,
Thanks for the reply. It will be for thermal insulation for the stud walls i'm making in my garage. I've found the following prices which are quite a difference to each other, but are they the same? Suppose a quick visit to Screwfix will answer that. I know Jablight is usually for flooring but the premium stuff would be suitable for Garage walls surely?

http://www.diy.com/departments/jablite-insulation-board-w450mm-l12m-t25mm-pack-of-8/26830_BQ.prd

http://www.screwfix.com/p/b-and-q-premium-insulation-board-450-x-1200m-pack-of-4/66321

Cheers,
Datadiyer.