Plasterboarding single skin detached garage
Discussion
Equus said:
No, that's a fair question: photo shows insulation between the joists and a chipboard deck, which since there'e no air gap above the insulation hopefully means that there's a room above, and the insulation is there to prevent loss of heat downwards?
It's a flat roof, unfortunately, nothing above! 
Edited by dsme94 on Monday 22 January 11:17
dsme94 said:
It's a flat roof, unfortunately, nothing above!
Then you have potential problems with the insulation*: insulating between the joists like that is normally what we call a 'cold roof', and to prevent condensation problems requires cross-ventilation (a miniumum gap of 50mm, ventilated at opposite eaves) over the top of the insulation, to disperse any moisture that finds its way up between the joists.Even then, 'cold' flat roofs are regarded as bad practice, these days and 'warm' roofs (where rigid insulation is placed above the chipboard deck, immediately below the waterproofing layer) are preferred.
The other possibility is that it's a 'hybrid' roof (ie. a bit of both): do you know if there is a second layer of rigid insulation above the chipboard?
* Albeit that, as per my previous post, you don't get much moisture being generated in garages, so it's a much lower risk than a flat roof over, say, a kitchen.
A garage or shed is fundamentally different from a house, in that it is generally unheated.
This means it spends some hours of most days colder than the out door air, the remperature inside lags behind the outdoor temperature as that varies through the day.
This means that sometimes the general direction of travel of water vapour is inwards.
You can't just build it like a house and expect it to stay dry with no heat.
Depends on your local climate of course.
Around here I'd have a dehumidifier in the garage when needed.
If the battens and plasterboard end up suffering, I think I'd be concerned about the car.
It's probably good practice and not expensive to isolate the battens from the walls.
You probably want the battens and cavity to be able to lose moisture inwards via the plaster board, which means your dehumidifier will be, to some extent 'drying the county', but if you can afford a nice car, you can probably afford to run a dehumdifier inefficiently.
This means it spends some hours of most days colder than the out door air, the remperature inside lags behind the outdoor temperature as that varies through the day.
This means that sometimes the general direction of travel of water vapour is inwards.
You can't just build it like a house and expect it to stay dry with no heat.
Depends on your local climate of course.
Around here I'd have a dehumidifier in the garage when needed.
If the battens and plasterboard end up suffering, I think I'd be concerned about the car.
It's probably good practice and not expensive to isolate the battens from the walls.
You probably want the battens and cavity to be able to lose moisture inwards via the plaster board, which means your dehumidifier will be, to some extent 'drying the county', but if you can afford a nice car, you can probably afford to run a dehumdifier inefficiently.
OutInTheShed said:
You can't just build it like a house and expect it to stay dry with no heat.
Which is why I'd recommend thermostatically controlled background heating, as per my post above.A dehumidifier might achieve the same end result, but in layman's terms, a dehumidifier is pulling water vapour in (water vapour exerts a pressure. when held in air, so if you remove the vapour with the dehumidifier, the vapour in the external air is continuously trying to force its way in to replace it), so...
as OutInTheShed said:
your dehumidifier will be, to some extent 'drying the county',
Whereas maintaining a slight positive temperature differential means that you're pushing the water outI suppose you could argue that heating means that you are, to some extent, 'heating the county', but thermostatic control can ensure that you are only doing so when necessary; and of the two options, background heating also maintains a nicer environment in the garage for humans, of course.
If you can afford a McLaren, you can probably afford to do both.
Done very similar to mine.
Single Skin, with block piers.
Roofing battens used as they are treated, and usefully quite thin. Roll of visqueen used for vapour barrier to stop cavity becoming damp. Taper edge boards, taped and mudded over the joints in the american fashion. End wall in chipboard for hanging cupboards, tool wall, and very sturdy wooden bench.
Simple timber skirting and a door frame added.
2 pack epoxy resin floor with tiles over (I dont use the tiles everywhere now, just near the bench).
Loft space later boarded over aswell.
The point was not to 'seal' it, or make it habitable like the inside of a house.
However it turned a dusty, dark, draughty garage into a space thats very usable, its bright, its not heated but stays dry and cool (and quiet!). Crucially, being a single, I only lost about 25mm depth and only between the piers.
The inside faces of the bricks used are particularly rough and mortar spattered too, hence simply lashing on masonry paint (like i have at the breeze block pillars) would be no good.
I could potentially have done dot+dab direct but I didnt have it skimmed, and this American style method was easy to DIY. It also means I have regular timber battens to fix to, rather than attempting to fix into the awful rough brick through a cavity, and potentially bursting through to outside.
20210328_134749 by simonholehan, on Flickr
20210411_170104 by simonholehan, on Flickr
20210512_211847 by simonholehan, on Flickr
20211111_214242 by simonholehan, on Flickr
Single Skin, with block piers.
Roofing battens used as they are treated, and usefully quite thin. Roll of visqueen used for vapour barrier to stop cavity becoming damp. Taper edge boards, taped and mudded over the joints in the american fashion. End wall in chipboard for hanging cupboards, tool wall, and very sturdy wooden bench.
Simple timber skirting and a door frame added.
2 pack epoxy resin floor with tiles over (I dont use the tiles everywhere now, just near the bench).
Loft space later boarded over aswell.
The point was not to 'seal' it, or make it habitable like the inside of a house.
However it turned a dusty, dark, draughty garage into a space thats very usable, its bright, its not heated but stays dry and cool (and quiet!). Crucially, being a single, I only lost about 25mm depth and only between the piers.
The inside faces of the bricks used are particularly rough and mortar spattered too, hence simply lashing on masonry paint (like i have at the breeze block pillars) would be no good.
I could potentially have done dot+dab direct but I didnt have it skimmed, and this American style method was easy to DIY. It also means I have regular timber battens to fix to, rather than attempting to fix into the awful rough brick through a cavity, and potentially bursting through to outside.
20210328_134749 by simonholehan, on Flickr20210411_170104 by simonholehan, on Flickr20210512_211847 by simonholehan, on Flickr20211111_214242 by simonholehan, on FlickrThis is basically what I did with my garage, DPM on the battens and one on the floor, then insulate (I do have heating and dehumidify), plasterboard and plaster.
What I also did was write on the plasterboard all the dimensions to the stud work and take pictures before it was plastered so I could mount things into solid wood.
What I also did was write on the plasterboard all the dimensions to the stud work and take pictures before it was plastered so I could mount things into solid wood.
wilksy61 said:
This is basically what I did with my garage, DPM on the battens and one on the floor, then insulate (I do have heating and dehumidify), plasterboard and plaster.
What I also did was write on the plasterboard all the dimensions to the stud work and take pictures before it was plastered so I could mount things into solid wood.
What heating system and dehumidifier did you opt for? What I also did was write on the plasterboard all the dimensions to the stud work and take pictures before it was plastered so I could mount things into solid wood.
I'd do that exactly the same as I did mine - between the pillars, but possibly leave that nice sandy stone unpainted (unless it's dusty).
Oh and as per poster above - I have records of where all the timbers are behind the plasterboard so it's great for putting up shelves, hooks etc.
ETA it's your floor that would be giving me sleepless nights!
Oh and as per poster above - I have records of where all the timbers are behind the plasterboard so it's great for putting up shelves, hooks etc.
ETA it's your floor that would be giving me sleepless nights!
If its of any help, I had my detached garage built specifically to have the look and feel of a room inside the house, ie, plastered walls, spotlights, skirting boards etc
I asked the builder to spec it that way and to put a radiator in it (was a new build house as well, not just a garage project) but he never put a radiator in, I can't remember the reason why he didn't, but I've got electric heating in there instead.
My garage door is fake, in that, its a proper insulated garage door only I got him to seal it off, rather than have it motorised. Still looks like a normal garage door from the outside. There isn't huge gain insulating a space like that if you've a huge draft coming in at the garage door as any heat will just get sucked out.
My garage is completely sealed but have the option to have the window on a latch to let air circulate as well. It gets stuffy if I don't.
The floor is a typical cement floor, then tiled on top. Much like the garage door, the walls and ceiling are insulated in a similar way. The plasterboard and insulation is all one item, which makes installation a lot simpler and not hugely expensive either. Its that firm foam style insulation, rather than rockwool, same for the ceiling too, and it just attaches to the breeze block, a bit of dry lining finishing and its job complete.
You can have a nosey at my build thread, page 2 is where I discuss the garage and you'll get the idea, although I don't discuss it too much. Its pretty much as is seen in the thread here though, with just the skirtings, spotlights and tiled floor done at a later date. (Ignore the golf simulator garage, that was the previous house I had, where I learned that it didn't matter how good your heating was, if you're garage door is leaky and its windy outside, it just won't warm up)
https://www.pistonheads.com/gassing/topic.asp?h=0&...
This is the type of product here:
https://www.wickes.co.uk/Knauf-XPS-Laminate-Plus-I...
I asked the builder to spec it that way and to put a radiator in it (was a new build house as well, not just a garage project) but he never put a radiator in, I can't remember the reason why he didn't, but I've got electric heating in there instead.
My garage door is fake, in that, its a proper insulated garage door only I got him to seal it off, rather than have it motorised. Still looks like a normal garage door from the outside. There isn't huge gain insulating a space like that if you've a huge draft coming in at the garage door as any heat will just get sucked out.
My garage is completely sealed but have the option to have the window on a latch to let air circulate as well. It gets stuffy if I don't.
The floor is a typical cement floor, then tiled on top. Much like the garage door, the walls and ceiling are insulated in a similar way. The plasterboard and insulation is all one item, which makes installation a lot simpler and not hugely expensive either. Its that firm foam style insulation, rather than rockwool, same for the ceiling too, and it just attaches to the breeze block, a bit of dry lining finishing and its job complete.
You can have a nosey at my build thread, page 2 is where I discuss the garage and you'll get the idea, although I don't discuss it too much. Its pretty much as is seen in the thread here though, with just the skirtings, spotlights and tiled floor done at a later date. (Ignore the golf simulator garage, that was the previous house I had, where I learned that it didn't matter how good your heating was, if you're garage door is leaky and its windy outside, it just won't warm up)
https://www.pistonheads.com/gassing/topic.asp?h=0&...
This is the type of product here:
https://www.wickes.co.uk/Knauf-XPS-Laminate-Plus-I...
This is the radiator I used
https://www.heatershop.co.uk/electric-radiators/ro...
This is the dehumidifier, it is drained to the outside and has trace wire heating so the drain pipe does not freeze.
https://www.eipl.co.uk/static_dryers/CD30.html
https://www.heatershop.co.uk/electric-radiators/ro...
This is the dehumidifier, it is drained to the outside and has trace wire heating so the drain pipe does not freeze.
https://www.eipl.co.uk/static_dryers/CD30.html
dsme94 said:
Well, FINALLY got the keys to this property…..
McLaren is in the garage, garage door is hella snug… tbc
Flat out with the flat renovation so I can get stuck into the garage! Will update this post with more details soon.
How did you get it in? That looks like a hell of a ramp/lip to get it in the door.McLaren is in the garage, garage door is hella snug… tbc
Flat out with the flat renovation so I can get stuck into the garage! Will update this post with more details soon.
If that was my garage I’d build stud walls in between and just slightly proud of the piers, that way the timber is not in contact with the outer leaf and the plaster board will skim past the piers, it also makes the wall completely flush with less chance of damaging the lovely car you have in there.
Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff