Garage roof insulation

[malcolm]

I want to insulate the barn roof before April. It was previously plasterboarded very badly and some of it needed to come off for roof repairs. I'm guessing plasterboard the flat central section with Rockwool on top. The sloping side sections will need eaves ventilation adding, but then what? I'm guessing insulated plasterboard fastened to the bottom of the rafters will be the easiest option. What's everyone else done? - I'm looking for ideas.

 

[Cubist]

The first thought that springs to mind when seeing a roof like that is 'wonderful timber frame work' but the next is 'it must play host to thousands of spiders'. To which I must then add the thought, 'is this space intended to ultimately house that E Type?' If so, you'll need some dust sheets too to protect that paintwork from the spider excreta.

Seriously though I'm surprised the 'warm roof' fans have not been forthcoming with suggestions on how best to proceed but in essence I think your current planning is along the lines I too would be considering.

 

[malcolm]

Asking the question made me realise my original plan was a bit mad I had originally planned to get rid of the horizontal part. The horizontal part isn't all that even - it sits on joist hangers suspended from the existing timber. Maybe I can even it up a little without too much effort. It has been suggested I use Celotex on the sloping parts then put plasterboard on that. It's not my ideal construction but it makes sense to be pragmatic on this occasion, and so long as all the roof space is well ventilated it should work. Not much to be lost covering the roof structure up. Haven't yet figured out how to add eaves ventilation on the side adjoining a flat roof. Probably the trick will be to simply define the eaves as a point above the flat roof.

 

[Kearn]

It really ends on what’s on top membrane wise, and whether you want an old fashioned roof, to manage moisture, or a new style which needs to ideally be protected from underneath from moisture, which isn’t always that easy.

And how much space you have to play with, assuming tiles are staying on.

The former would be proper Irish sheepswool or woodfibre batts between rafters, flush with bottom not top, with a 30-50mm air gap for evaporation.
Underneath woodfibre boards across the undersides of rafters to add extra warmth and minimise cold bridging (could just be wood wool boards), lime plastered.

The latter, PIR between joists as before with a gap above, and lapped across beneath the rafters too or just plasterboard, insulated or other. It’s meant to then have a vapour control barrier below taped at the seams to prevent moisture rising up into the mix. Very hard to achieve in practice. Also, should be the same airtight vapour control layer above directly on top of the PIR, but again tricky to achieve especially from below.

 

[Flyfisher]

The first thought that springs to mind when seeing a roof like that is 'wonderful timber frame work' but the next is 'it must play host to thousands of spiders'. To which I must then add the thought, 'is this space intended to ultimately house that E Type?' If so, you'll need some dust sheets too to protect that paintwork from the spider excreta.

Just a thought, but if the roof work is mainly intended for the benefit of the E-type, has an alternative solution been considered?

I know a classic car restorer who works out of some farm buildings and he also has some interesting cars in storage, for which he uses a sort of zip-up inflatable 'garage' that is maintained at a slight positive pressure from an air-conditioned fan gizmo. The result is a dust-free, temperature and humidity-controlled environment for the car without the cost of maintaining the same for the whole farm building.

I know nothing about them really, so this is not a recommendation, just a suggestion.
Something like this: https://www.demon-tweeks.com/carcoon-evo-indoor-car-storage-system-525094/

 

[Kearn]

Just a thought, but if the roof work is mainly intended for the benefit of the E-type, has an alternative solution been considered?

I know a classic car restorer who works out of some farm buildings and he also has some interesting cars in storage, for which he uses a sort of zip-up inflatable 'garage' that is maintained at a slight positive pressure from an air-conditioned fan gizmo. The result is a dust-free, temperature and humidity-controlled environment for the car without the cost of maintaining the same for the whole farm building.

I know nothing about them really, so this is not a recommendation, just a suggestion.
Something like this: https://www.demon-tweeks.com/carcoon-evo-indoor-car-storage-system-525094/

They are great options, when used properly.

Can’t really tinker with them once in though….

 

[Cubist]

Just a thought, but if the roof work is mainly intended for the benefit of the E-type, has an alternative solution been considered?

I came across a news article this morning about a bloke in Wales that parked his sub £1000 banger/pride and joy on his driveway fifty or so years ago and left it to rust.

Quite recently, after saving up the £400k for its restoration, it's now thought to be worth North of £1,000,000.

It is an Aston Martin DB5 after all but sadly sans the ejector seat, machine guns and other toys.

The story is all the more interesting when you consider the Welsh weather in context with British motor manufacturing products typical failure to cope with our salted roads, exacerbated by the fact that the neighbourhood kids, hoodlums and sundry mice couldn't reduce it to a pile of twisted scrap metal.

At first I thought @Flyfisher was on to a good idea there but now I'm not so sure.

Can’t really tinker with them once in though…

Hmmm, legendary sports cars and a No Tinker Rule? Not perishing likely, where's the fun on that.

Sorry @Kearn I know you meant the tent but I just couldn't resist - my Spanner Fingers were itchy.

 

[Flyfisher]

Yes, I saw that DB5 story as well. Amazing that he left it for so long. The 'car bubble' things are mainly for storage as far as I can tell, though I wouldn't be surprised if there are larger ones available somewhere. But it looks easy enough to roll them out of the 'bubble' when they need fettling.

 

[Cubist]

The piece about the mice brought to mind the time my ride-on brush cutter produced a hellish rattle when I tried to start it. Some local squirrel had found a way to push hazel nuts under the fan guard but clearly hadn't figured out how to get them out later. The local population clearly had a Scrat compliant IQ level.