Iv been meaning to attack the garage roof for years now and this latest lockdown would be a good time to do it. Its old corrugated metal and with the current cold weather the condensation is just rediculous…plus it leaks

I think id like to use EPDM and will need to put a wood base down first. The roof slopes slightly right to left and I’m hoping I can reuse the existing timbers in the roof as they look pretty good.

I’m normally quite handy but never done a job like this before so I’m after any tips I can get. Specifically where best to source the materials and what to use for the edges. Also any recommendations for useful how-to videos or blogs or just any other advice highly appreciated.

Cheers

I re-roofed an old sectional concrete single garage – corrugated roof that ran with water in winter. Ripped off the old roof and carted it off the to tip leaving the 2 concrete tie-beams.

Replaced with a pitched roof, so fixed a wooden ring beam around the top.

Built a series of roof trusses from 4×2″ construction timber from builders merchant – was ‘pitched’ such that each diagonal was 2.4m

Boarded over the trusses with OSB, taped joints and painted with bitumen paint.

Covered the roof with red cedar shingles.

Looked 10x better and never had any more condensation problems. Still watertight 16 years later when I sold the house.

EPDM is covered well in Ali Dymock’s series: https://youtube.com/playlist?list=PLyBa0yFBQO7Mc6sAZOMd-xujGuorZAs–

Search on YouTube and most of the EPDM suppliers have their own tutorial videos too.

I did my own flat garage roof in GRP – worked well but I’d probably go EPDM for a simpler roof. The osb sheets usually specified for GRP use (t&g, 8×2 sheets) is much easier to handle by yourself!

I did my garage with a Rubber4roofs kit. I laid it on fresh OSB and it fitted really easily.

Kit had all the edges, trims and adhesive & the videos on their site covered enough for me to DIY it.

I used insulated metal panels (metal, insulation, metal), or the guy I paid did. Looked like a piece of cake, minimal joists, aluminium profiles to cover the edges, self drilling screws straight through into the timber.

No condensation, bright white on the underside, perfectly happy.

I’ve just done a double garage with Onduline on top of 25mm Celotex on top of the old t&g wooden roof that was previously felted. Was pretty straightforward and no special techniques needed – but I know nothing about EPDM.

As well as the insulated steel. Roof panels you can get fleece lined plastic coated steel panels that would be easy to fit.
We replaced the corrugated concrete roof on our 60’x40′ barn and have had no issues with condensation.

We’ve also got EPDM on the beach hut roof and it’s also excellent – but, as you know, you’d need to put a timber roof on first and I’m not sure how dry the weather needs to be for fitting.

If going down the osb route you need osb3 as that’s the weather resistant version. I did a flat roof with osb3 and firestone rubber top. It was easy to fit and smooth out with just a paint roller.

An easy alternative… Stick some batons on top of the existing roof. Stick steel sheets on top with bargeboard to tidy it up. You can get it done in a day.

You can get an idea of cost here: https://www.steelroofsheets.co.uk/quote-calculator/

Just built a new garage and roofed with osb/membrane /battens and steel sheet.

Seemed like the most future maintianance free way to do it.

Not all steel roof is equal. Having seen some right shite on line I ended up paying a tiny bit more and going with a local company who manufacture on site. When comparing with my existing garage metal roof the new stuff is solid and can be walked on. The old stuff dents when you walk on it so you don’t walk on it…..

Looking at 5thelefants calculator…… Going local was actually cheaper.

Most of the cheap stuff I found online was the 0.5mm with some of the eBay stuff being even thinner. I went with 0.7mm as I’m using it as a wall and a roof

I’ve used 0.5 and 0.7mm. 0.5mm will dent if you put all your weight on a ridge. 0.7 is less prone to that. You can walk on both without issue other than that.

But… if you’re dealing with big sheets the extra 40% weight takes it from easy to a major task getting sheets onto the roof. I won’t be using 0.7 again. That was a ballache!

well yes i had an issue pre fabricating a wall that had to go up against a fence.

Turns out that two 2.4m 0.7mm sheets is my limit for lifting … and when 3 were combined with an 8×8 timber frame it was pretty heavy ….. when 6 were combined with a 16×8 timber frame it was unliftable by 2 people … and when 10 were combined with a 25×8 timber frames it was 2 trolly jacks breeze blocks and levers kind of lift.

The 2.4m roof sheets going up singally solo were a breeze by comparison.

Garage aint blowing away any time soon though.

But if your DIYing EPDM probably cheaper to do .

The roof slopes slightly right to left and I’m hoping I can reuse the existing timbers in the roof as they look pretty good

If the joists are good then, lay thick OSB then straight to EPDM probably gets you what you need.

Our garage sized shed would have had EPDM if budget allowed… just felt for now, maybe in five years it will get a fresh covering.

25×8 timber frames

big garage!?

I did my awkward access wall with clapboard over membrane. As it went up 100mm each time there was enough access to reach over the top to put on the next layer. Pain in the proverbials though. Would have been easier to shift a pre-fabbed panel.

EPDM here, can even walk on it, it’s been on for 8 years and looks like it did when it was installed.

Can I ask abour flooring in a garage?

Mine is concrete, and is breaking up to quite an old dusty mess. I’d like to cover in an expoy self levelling substance, but is that a good idea? Perhaps a new layer of concrete screen? It’s too small to think of ever putting a car in there again!

Maybe those interlocking mats?

I’d like to cover in an expoy self levelling substance, but is that a good idea?

When I’ve looked at that the price has put me off. For a small space it might be tolerable.
Rubber stall mats might be an option (depending on what you want to do with the space). Rubber sports hall mats come up on ebay sometimes too. That’s quite a cheap option.

big garage!?

That’s length in feet not timber section.

It’s not so much a garage as an extension of the original filing out the useless tapered corridor down the side and round the back

Going for epoxy once I get the whole lot done. Having seen my dad’s basement and it standing up to his tractor and minidigger going in and out…..where paint seems to struggle with car I’m sold in longevity in a domestic setting.

I have interlocking rubber Matt’s down in my garden Room (zwift/home office area) and they don’t take much punishment but do insulate the slab nicely. Looking pretty tatty now.

On my concrete floor (which is new) I’m going for epoxy paint on the midlife crisis car side and interlocking rubber tiles on the workshop side. They each seem to work out a similar price when I was looking but I like the idea of the insulation benefits from the tiles.