Garage Insulation

Help Support

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Established Member
24 Nov 2003
Reaction score
Dorset, England.
Hi All,
I have just completed insulating one of the two garage doors on my workshop (yes, its a double garage). I only use one of the doors for access (especially since the new table saw arrived :roll: ) and the doors allow quite a draught, as well as a small amount of damp into the garage.
Here's a "before" shot....

As you can see, its not really much use as a door.

This shot shows the door after i have constructed a timber studwork frame, insulated it with double layers of rockwool slab insulation and then clad over with 18mm flooring ply (I do like the T+G on flooring ply).

Here is the finished project-nice and neat. I sealed all the joints with mastic when putting it together and have sealed all ends to keep out any draughts. It looks good and hasn't eaten up any precious floor space. The framework can be taken down if we decide to move or i really need that door for access (although I don't aim to do so!!!!).
I just need to insulate the other door (but allowing that one to still open) and then I'm ready for the Winter. I have a small oil radiator in there (as well as the de-humidifier) to help keep the temperature up. The gas boiler is in the garage which helps keep some warmth in there too.
Since fitting the insulation I've noticed from my digi thermometer that the temperature remains about 3 degrees higher inside than out-a good start I think.
I really need to sort that other door-anyone got any good ideas?
Philly :D
(by the way, I didn't realise I had so many bits of plywood hanging around the workshop!! :shock: I am now building a chest of drawers to get rid of some of it!)
I really need to sort that other door-anyone got any good ideas?

Hi Philly,

If t'were mine, I'd consider chucking the up'n'over door (I, assuming thats what you have now), and replace with hinged, insulated timber doors maybe with either wired glass, or DG lights.

That was my first idea but SWMBO is a little sore at me at the moment due some of my recent purchases....... 8)
I would have to replace both so it "looks right" and that takes it out of the ballpark, moneywise. No, it has to be insulated from the inside and still be usable. Want to stop the draughts too!
Philly :D
Nice one Philly.
I'm not sure how you will insulate an up & over door though, not without it affecting the way the door opens.

What rubbish :oops: how about a 2-3 " flap of rubber to exclude drafts around the door( I have one on my wooden up & over) then polystyrene panels stuck onto the door.............or is this too simple :?

polystyrene panels stuck onto the door.

Nope, should give quite effective insulation - good idea IMO. Only reservation'd be fire/toxic risk but that's probably being too fussy!

Trust you Bean!
Simple-you won't get anywhere doing it simple! :lol:
Yup, sounds like that may be the ticket!
Philly :D
is there any reason why you cannot just use rockwall held in place by hardboard glued to the door or use self taping screws.

Hi Philly

Almost identical to my place. I too have a double garage with up and over fibre glass doors. I have made a false wall inside one of the doors but the other one needs to be able to open should I need to push long timber through the jointer.

Like others have suggested, I taped 1" polystyrene panels all over the inside of the door and the screwed 6mm ply on the back using small self tapping screws into the cross braces.

It doesn't get opened that often but the extra weight doesn't seem to affect it when I've needed to open it.

Looks very nifty, Philly.

Philly":369n9845 said:
18mm flooring ply (I do like the T+G on flooring ply
Okay, I admit I haven't bought any sheet goods for a long time, but isn't that chip? It's not important; I'd just like to know if I'm going slightly more insane than I previously suspected, that's all.

Cheers, Alf
Nice job Philly. I used a similar approach on mine including the T+G :)

I use the side entrance and never open the up-and-over so can't help I'm afriad
Have you thought about painting it white? I found it made a tremendous difference painting walls white - it reflects so much more light - it's well worth the effort.


Nice job, you have now motivated me to do something with my WS. Fisrt i think its the floor and then the walls. I have been following all the threads so have got some good information.

Unfortunately my WS up and over door is in use quite a lot, especially in the summer, so I'll have to think of another way to do this, good points made in this thread regarding other methods, thanks guys.

Philly, how does the 1st Nov sound to you, in the afternnon.

Be good to see you!! Yes!
(By the way-finished my big project at work! Am now in "post-stress chill-out" period and getting stuff done at home again!! :D )
see ya
Philly :D
I don't know............
Every day i check in to the forum, to glean as much knowledge
as i can take in, from all you experienced artisan's :wink:
There are things i'd actually like to make for the house & garden, :roll:
but i can't because i've got a list of projects for my workshop, that'll
take about a year or so to complete.
When i do complete them, i daresay, all you happy posters will have
come up with more creative fixtures and fittings to put me back to square
one :!:
There's dust extractor systems. tool cupboards, workbenches, panelling,
heating,de-humidifying,lighting,decorating and now insulating the up &
over door etc,etc,etc.
Like a sketch from 'Monty Python', when i'm about 90 years old, i'll be
standing in my w/s, with everything organized to a T, i'll pick up a plane
in total readiness and anticipation of my first piece of furniture in 50 yrs,
and........yes, you guessed it.........DOWN LIKE A SACK OF SPUDS :!:

Don't fret Dude-remember, its the journey that is important not the destination. (removes Zen Master hat..... :roll: )
And by the way,the to-do list never, ever, ever gets any shorter. Just longer! :roll: :wink:
best regards
Philly :D
Philly":uyjtrdqq said:
Don't fret Dude... <snippity snip>...(removes Zen Master hat..... :roll: )
Dude? Shouldn't that be "grasshopper". :roll: Of course he's quite right; don't fret. It just adds another load of things to do to your to-do list; scroll saw stand, better lighting, got a scroll saw now - intarsia looks fun... etc etc :roll: :lol:

Cheers, Alf
Alf, Philly,
I enjoy journey velly much, master :roll:
(takes off grasshopper legs*...)

It's just that SWMBO sees a lot going in, and not
much coming out :shock:(of the W/S i mean) :oops:


* not very buddhist i know

Latest posts