Insulation...Again!

[wizer]

Too bloody cold in the workshop today, I eventually had to admit defeat and retreated to the warmth. I have the plumber booked to install the radiator next week but I'm concerned all the heat is going to escape. The front of the house and garage has this extended section with a tiled roof:

It wasn't done right when my Dad built it 20yrs ago (he admits), but I can't do anything about it this year. I may replace it next year. But for now the gaps in the tiles and the holes in the felt mean lots of draughts in the workshop.

How might I tackle insulating this? Just rockwool in between the rafters? Should I board it too?

The final culprit is the roller door. I cheaped on it, so it's not insulated and lets in draughts at the sides, I siliconed as much as I could and I have some heavy duty brush strips to install. I think that's the most I can do with this.

 

[ByronBlack]

I would rockwool and line with plasterboard/ply, but perhaps try and tape up some of the obvious gaps with something like gorilla tape - this is the approach I'll be taking to mine, even though the walls are insulated my doors and roof aren't and it makes quite a difference (after visiting a friends completely insulated shop).

 

[OLD]

I would use expanded polystyrene or kingspan board cut for a friction fit between timbers with a vapour barrier say visqueen then osb sheet this will be perminent and not disturbed by any proposed roofing work. The door well you will have to get creative to stop the drafts with say brush type draft proofing seals.

 

[wizer]

Thanks guys, not sure what would be easier to install, rigid or wool. It's hard to get to the bits around the roller.

 

[MikeG.]

Hi Tom,

any and all of those answers are fine......although if you use OSB you don't really need a vapour barrier. Strictly you should have an airgap over the top of the insulation and below the felt, but this is such a tiny roof, and the amount of vapour produced in your workshop so slight, that I wouldn't worry about that too much.

Physically the easiest to do would be the mineral wool ("Rockwool").....just cut it slightly oversize and stuff.......but it will sag out unless you retain it with a net, a lining, or even some battens. You could use a cavity wall batt, which is stiffer and so not likely to sag.

Personally, I would avoid polystyrene.......the little balls get everywhere and will drive you nuts, and the product is a fire-risk so should have a lining. Kingspan is expensive, but a great insulator.....and it is this product I would suggest for insulating your door. Just as important (if not more so) as the insulation is draught-proofing, and that is obviously a test with an up-and-over door. Half inside, half outside.....but it is do-able.

You won't regret spending half a day sorting this!

Cheers

Mike

 

[wizer]

Thanks Mike. With the OSB lining, can I use something else, like Ply? Reason I ask is that I have no use for half a sheet of OSB but I can make use of Ply. If you see what I mean. Or what about Plaster board?

With the rockwool I could staple thin fishing line across the rafters to hold it in. I take it the I can't just stuff loads in there? Just the thickness it comes in against the net?

The door is an automatic roller, single skinned. So the only way to reduce the draughts is to use brush strips, which I have and will install when I do the roof.

 

[wizer]

You won't regret spending half a day sorting this!

6 weeks and 10 more forum posts, with pics and 3 cock-ups (one ending in A&E)

 

[Oryxdesign]

I think you'd be fine with plasterboard, if you're worried use the moisture resistant. It does sag but as long as there is a joist about every 500mm it'll be fine. Platerboard is cheap, easy to cut and gives a bit of fire resistance too. As someone else said it wouldn't hurt to leave a gap above the insulation especially if you use celotex or kingspan which are much nicer to use than rockwool. You shouldn't need too many power tools so I'm hoping not to see any nasty accidents (that last one gave me nightmares) although kingspan/celotex is easy to rip to width on your shiney new saw. I wish I had heating...good luck Simon

 

[MikeG.]

Thanks Mike. With the OSB lining, can I use something else, like Ply? Or what about Plaster board?

With the rockwool I could staple thin fishing line across the rafters to hold it in. I take it the I can't just stuff loads in there? Just the thickness it comes in against the net?

Ply is fine, and just about the same vapour resistance as OSB, obviating the need for a vapour barrier.

You could stuff loads of mineral wool in, but the more you put in the more quickly it will fall out! The trick is to somehow hold it in place until you have got all the insulation in and are ready to do the lining. A bit of string stapled in place would do it, and you can just ply straight over the top of that.

Rember, you will need a dust mask for this job!

Mike

 

[OPJ]

Tom, how often do you use the roller door? I think you have a smaller access door leading from the house, don't you?

If you rarely use it then have you thought about adding a couple of simple 2" thick inward-opening (or outward???) doors on the inside...? I'm thinking of simple 2"x2" frames, insulated with plywood either side - it would keep the noise in and the cold out! :wink: A lot of work, I know but, it could make a real difference.

Just my thoughts...

 

[matt]

How about just stapling some of this across the timbers. You *may* even get away with fixing some to your door too without it messing up the rolling action of the door: http://www.screwfix.com/prods/76477/Building/Roofing-Insulation/Loft-Insulation-400mm-x-5m

 

[MikeG.]

Don't bother going down the "thinsulation" route. Even if it works......and that is highly controversial..........it is a fiddle, with taped seams and battened-out zones. Unnecessary here, when the other solutions are so easy. Save this stuff for a difficult barn conversion......

Mike

 

[wizer]

Good idea Olly, but I use the door often. The missus uses it to bring the shopping into the kitchen...and I don't want to stop food getting into the house now do i?

What about rockwool inbetween the rafters and thinsulate over the top instead of plasterboard/ply?

 

[OLD]

A well insulated workshop is great to have i did mine when i extended it the temperature stays constant it will warm up very quickly and we should all be trying to save energy. I think OPJ idea of a extra wall is great, insulate it even the home made doors (so you can move m/cs about for long stock etc) may be box in the roller and further seal that undercroft think of the cost of the energy you will save and it will be more pleasant to work, in any season.

 

[Grinding One]

Do you have access to a thick sheet of poly (Plastic) if so you could hang that in front of the door and roll it up like a blind when needed...some butcher shops have it hanging here and just cut a overlap in it to walk thru.it seems to keep some of the cold from escapeing while opening the door. So it should work the same way in reverse.Hang a blanket in back of it ,roll them together,up or down....I think it would be a cheap fix for awhile.

 

[wizer]

that's not such a bad idea G1. I will look into it. I guess a 'curtain' would also work.

 

[Grinding One]

Just a buffer is all you need,to knock down the loss of heat

 

[Grinding One]

If all else fails you could go to your local farm and pickup some bales of straw,build a wall. :lol:

 

[wizer]

You assume that a straw bale would fit in my workshop. We don't have the vast workshops you yanks do i'm afraid.

 

[MikeG.]

Apropos of nothing, and simply because there isn't much else going on.......I designed a couple of straw bale buildings a couple of years ago. One of them is a stand-alone music room in a big garden, probably 12 or 15 metres by 6 or 8 (would make a wonderful workshop!!!). It is a brilliant building material, and the place requires virtually no heating.......plus a bomb could go off inside without the neighbours hearing. Only downside for a workshop is that it is difficult to hammer nails into the wall!!! (OK, it is easy hammering them in.........difficult to get them to stay there!)

Mike