Insulating a concrete garage

[jimdonny]

I have a CBS home with an attached garage in South Florida. While the house is very well insulated the garage is not. The mortar lines show through the exterior stucco and the interior gets extremely hot and humid during the day. Can I simply install styrofoam panels on the walls and door? Do I need a vapor barrier between the interior concrete block walls and the insulation and subsequent interior wall board or paneling? Do I have to install studs or strapping on the walls or can I liquid nail the styro directly to the concrete? Any direction would be appreciated.

Jim Donny

 

[Deluks]

You won't receive too many replies on here as this is a UK based website, and building methods and terminology differ slightly. However the principles are all the same so I'll get you started.
Several ways it can be done, the simplest is just to fix some timber to the walls, 2x2 would be adequate, then attach your styrofoam over this (can use glues or screws) then plasterbo..sorry drywall over this, making sure the screws are long enough to go through drywall, foam and most of the way into the timber.
Vapour barrier in our climate would go directly beneath the drywall, in fact we often use stuff that has a foil backing for this purpose.
As you are insulating to keep the cooler air in, this changes the game somewhat, and you should probably be putting a poly sheet all over that concrete wall (beneath the foam), then again under the drywall (over the foam) if you can use the foil backed drywall then this speeds things up somewhat. Just remember to tape up all polythene overlaps, you don't want gaps or holes.

You can also get insulation already stuck to a sheet of drywall, if you can get this then fix that straight to the studs, or use a drywall adhesive, using what we call the 'dot and dab' technique.

You can probably attach the foam to the door, not sure about the drywall though as this may affect the doors weight/hinges/fixings.

 

[theoldun]

Jim,
Nice to hear from some one across the pond.
Read up quite a lot on concrete block stucco homes after one of your hurricanes. Was just interested in general construction round the hurricane areas. Never realised that termites were such a problem in your area and what requires to be done to stop them.
Your problem is the opposite to ours. We spend all our time trying to keep the heat in, you spend yours trying to keep heat out.
Deluke has given you the basic guidelines on what we do, and what he suggests makes good sense, although I would have thought that you would have hooked your air conditioning up into garage.
Tell you what I will do Jim, pay me flight first class both ways, put me up for a little while, say 10 months, give me a bit of beer money each day, say 16 pints and I will sort your problem out for you. Always fancied Florida.
Nice to have spoken to you Jim. Keep in touch. By the way, your team were very lucky.
Regards . old un.

 

[noseall]

Tell you what I will do Jim, pay me flight first class both ways, put me up for a little while, say 10 months, give me a bit of beer money each day, say 16 pints and I will sort your problem out for you.

Count me in but with say 8 instead of 16 pints per day.

 

[Deluks]

I'll do it for 6 none of that LabattsMillerBudCoorsLite nonsense though, you'll have to order in some Wychwood.

 

[theoldun]

Count me in but with say 8 instead of 16 pints per day.

See what you have done now nose. Opened up the floodgates for every layabout and hooligan on the forum to start putting their name down. They will all be digging out their passports, buckets and spades, kiss me quick hats, and booking a cab for Heathrow.
As expected The Duke is the first and he talks gibberish, Labatts Miller and Wychwood. Jim from over the pond must think he is a Viking who has been granted asylum.
Freddy will be next, saying that he designs hurricane proof rabbit hutches.
Oh dear, Oh dear.

 

[chadfieldpropertyservices]

If you have polyurethane type insulation board available in the US this is far better than styrofoam, more expensive, yes but twice the insulation for the same thickness and stronger. Dont batten the walls with timber, this just wastes space. A method I have used in the UK successfuly for some years now is to cut the insulation board to size and wipe clean with a damp cloth, then apply blobs of expanding foam filler ( we now can get foam specifically for attaching boards) about one every square foot, lay the board against the wall and place some straight pieces of timber against the board then prop these bits of timber in place with another piece of timber wedged against some heavy object on the floor. Very little pressure is needed, just enough to hold the board in place till the foam sets in a few minutes, dont move the board around too much as this can "collapse" the foam and you end up with some stuck to the board and some on the wall with no bridge in between - less of a problem if your walls are smooth and flat.
You can then stick a finish board, plasterboard or timber over this using the same method.
On our old 9" victorian walls, 25mm of Kingspan pu board and 12.5mm plasterboard reduces the heat transmission of the wall by about 75%, on a 4" concrete block wall the heat transmission should be reduced by about 85%. the pu foam boards also act as a damp barrier, especially if you tape the joints with aluminium tape.

 

[Deluks]

Dont batten the walls with timber, this just wastes space.

Have you seen the size of Americans garages?
Come to think of it have you seen the size of American cars?
Actually, have you seen the size of Americans??

 

[jimdonny]

I was unaware that this is basically UK site. And as a couple of you will work for beer and board, I would love to host, however it is not to practical. I am aware that some of the construction materials differ from the UK and the US, but I am sure I can find the equivalent here.

Thanks again, Jim Donny