Insulating a garage with cellotex - what then?

[julianf]

I have a prefab concrete garage stacked up in parts in my garden, and I'm not far off reassembling it.

I'm considering lining the internal walls with cellotex or similar, and the roof, but what then?

In a house you would then have plasterboard and plaster, but, whilst that is pretty cheap, I'm not sure I want a plastered garage!

Not being able to suitably finish the walls is kind of putting me off insulating it, so then I'm back to cold.

The garage will have an oil fired boiler in it, so I will have heat, but, as it will probably need to be warm / dry most of the time, I don't really want to be loosing loads of heat to the environment, hence insulation.

 

[rtcosic]

In a house you would then have plasterboard and plaster, but, whilst that is pretty cheap, I'm not sure I want a plastered garage!

I would leave it as 'bare' plasterboard, just filled joint line and painted white.

I don't see what your objection is.

My garage walls are tiled with cheap white tiles and ceiling plaster board (with a layer of plaster) - reflects the light and makes it seem much brighter.

 

[Barlidge]

You can use plasterboard, you don't have to plaster it, or you could use OSB, MDF, PLY?

 

[Burdekin]

I use OSB on the walls and if you seal the joins it's also a good vapour barrier. I will continue the theme on the wall and ceiling of my new build.

 

[julianf]

My problems with plaster is that it's fragile (so if you knock it with the end of somthing long, it marks / chips / cracks) and that it's absorbant, so you get stains all over it too.

 

[Burdekin]

I have read celotex will increase it's thermal conductivity to that of polystyrene over 7 to 10 years. Don't know if this is true but will try and find out.

 

[gaz1]

heres a guide for those new prefab garages

https://www.lidget.co.uk/concrete-garage-insulation-lining/

 

[MattF]

Mine is a wooden framework faced with 1/2” chipboard for the walls, then lengths of wood laid atop the wall frameworks spanning the workshop, and secured to one of the roof trusses to prevent sag, faced with 3mm ply for the ceiling.

Your main problem with the prefabs is stopping water getting in. Make sure you seal all the joints between panels etc. to the hilt.

 

[julianf]

The garage is early 70s vintage. It was here when we moved, on foundation walls, with a soil floor.

I've taken it down, and am some way into the base. As in many tones of soil have gone, and I've got the shuttering in place.

So, re-errection is immanent.

I would like to render the outer face for cosmetics, but I'm not sure it would work.

It has a smoot-ish outer finish, almost like it's been pressed with fabric. But lime render sticks to pretty much anything, so I reckon it would work.

Planning on sealing every joint with gripfil as it gets put back up.

 

[julianf]

I'm making the foundation walls 4cm larger than the footprint. I know it would be better for moisture to have them exact, but I don't trust my marking out / measuring over the large area better than that. Mainly as I can't be 100 percent sure of the total length of the garage, due to the gapping between the parts

 

[gaz1]

anything like this type

 

[Rig Pig]

My workshop is a prefab built on the back of my garage, as I put it together I expanding foamed the joints, I built it sitting on dpm to try to keep it dry, the walls are studded out and filled with glass wool (have you priced up Cellotex!!) Then a vapor barrier then OSB, roof is the same, currently without the OSB as I haven't got round to it yet! The side facing the garden has been boarded to make it pretty under orders from the wife.
The workshop has been up for a good few years now, my tools don't go rusty any more and with a small heater it's very cosy even in the middle of winter.

 

[bigegg]

I'd clad it in 15mm/18mm ply or even 22mm floorboards.
something that will hold a screw.
then you can fasten shelves/cabinets/tools/sockets/conduit/whatever anywhere you like - and chop and change how you like.

 

[knighty]

I'd line it with OSB, thin stuff (cheap) if you're just covering the insulation, but bit thicker if you're going to hang shelves etc.. from it

or... use whatever else you can get your hands on cheap

a coat of white paint will keep it nice and bright in there... or maybe a light blue/green/whatever if you're worried it'll look dirty

 

[Mikey D]

Dont forget you can get seconds of celotex , I've got 12 sheets ready to go in my shed , I'm lining with osb In your case I would screw treated battons to the. Concrete insulation between then fix your lining to the battons/studs ?

 

[bigegg]

Dont forget you can get seconds of celotex , I've got 12 sheets ready to go in my shed , I'm lining with osb In your case I would screw treated battons to the. Concrete insulation between then fix your lining to the battons/studs ?

I've never had any luck drilling the concrete walls to fasten stuff.
I don't know whether the local manufacturers use hard aggregate, or I've just been unlucky, but I always end up blowing lumps out.

I use construction adhesive, and wire to the bolts that hold the panels together

 

[rtbcomp]

^^ If you follow this link from Post #7

https://www.lidget.co.uk/concrete-garage-insulation-lining/

They advise against drilling the concrete panels and suggest using brackets fastened to the bolts which hold the panels together.

 

[clift_d]

^^ If you follow this link from Post #7

https://www.lidget.co.uk/concrete-garage-insulation-lining/

They advise against drilling the concrete panels and suggest using brackets fastened to the bolts which hold the panels together.

If you use the timber stud detail in the link above, and insulate between the studs, I would also suggest putting a vapour control layer on the inner face of the studs / insulation and then lining out inside with painted OSB / ply.

 

[Rig Pig]

I've never had any luck drilling the concrete walls to fasten stuff.
I don't know whether the local manufacturers use hard aggregate, or I've just been unlucky, but I always end up blowing lumps out.

I use construction adhesive, and wire to the bolts that hold the panels together

When I studded mine out I attached to a wooden floor plate and the roof joists, I didn't fancy trying to drill the panels.

 

[gaz_moose]

there always seems to be people selling insulation panels on the facebook selling pages. if that's any help??