A bit of advice is required, as I might have bitten off more than I can chew or my shed can actually support…

I have a really nice 8×10 apex shed, about 4 years old and the felting needs replacing as the sun/our cat have hammered it a bit. No leaks though. Our roofer wanted to put full on concrete roof tiles on it which I baulked at the +400kg and cost. It has a central brace, I thickened the rafters and added in smaller bits to stiffen it. Paid for extra 34x44mm timber to reinforce the panels/door when it was made.

Decided to go DIY and bought some Pantile 2000 roofing sheets and trims, but pricey but seemed like a simple option but has gotten more complex than I had planned i.e. vertical and horizontal battens, gutter board, new barge boards. Roof sheets ~80kg, wood ~40kg, trims ~20kg.

Can’t face destroying the shed accidentally and now worried about it not being strong enough. What would STW do, currently feels like I should just get it felted instead and chalk this up to experience/sell the bits I can?

Looks like a pretty sturdy roof structure. Concrete tiles sounds a bit ridiculous, but I wouldn’t be thinking twice about the weight a few thin metal roofing sheets.

Not sure why the need for extra battens, can the sheets not just be fixed directly to the existing roof?

i’d do that with a single sheet of EDPM.

I used bituminised corrugated sheets on my 7×8 ft shed, supposedly good for 15 years. Each 2m x950mm sheet weighs 5.6kg, was easy to install and I just reused all the timber edging strips. Screwed or nailed to the tongue and groove roof just like yours. You do need to be careful about the fixings length.
Not to everyone’s taste aesthetically, and EDPM may well be less obtrusive.
https://www.arielplastics.com/en-gb/products/bitumen-roofing-sheet/coroline-sheet-and-accessories.aspx

@northwind – Spoke to the manufacturer, they need a vertical batten to allow a slight sag in the vapour barrier for condensation to go and the horizontal gives the depth of fixing needed as there are no purlins under the roof.

http://www.britmet.co.uk/downloads/installers_guide.pdf

@jimw @jam-bo – Thanks, I would have gone for the corrugated stuff or rubber if we didn’t have a cat, not convinced it would hold up to her launching 5kgs of herself onto it multiple times a day or claws.

The metal sheets I’ve got are 0.9mm thick, so plenty stiff enough with just two rows of fixings.

i would also do edpm

I re-did the roof of my shed (8×6) a couple of years back with the corrugated bitumen stuff – coroline, I think.

Is great stuff and would go up easily on your shed roof. Just take the felt off and lay it onto the timber.

The previous owner had removed the roof and replaced it with clear corrugated plastic so it worked as a potting shed, but a massive hail storm put multiple holes in it, and it annoyed me that everything in there got bleached by the sun.
In our shed there are only long beams of timber going the full length; one at the top, one halfway down each side of the roof and one at the bottom on each side.
The corrugated stuff is plenty strong enough. We get cats traipsing all over it as well as squirrels.
I like it as it has a lot of flex, so it’s unlikely to be easily broken. I think it’s basically a fibrous material impregnated with bitumen. It’s even easy to cut with a cheap hand saw. You need to clean the blade now and again, but a quick spray of gt85 and a wipe cleans it straight off.

EPDM is slightly more than a bit of rubber
at about 4:30 in

I did the roof of my 13′ x 7′ shed with corrugated galvanized steel. I just added the steel sheets over the top of the existing felt. You can get moulded filling pieces to block off the undulations to prevent birds etc visiting.

It’s been no problem even with 10″ of snow on top of it.

@paton – Cool video, I hadn’t realised it was so tough.

Didn’t pass the the other half approval test unfortunately when I showed her, she would prefer more traditional regular felt or something that looks looks tiled.

@fruitbat – No condensation/damp problems that you noticed, the manufacturer was pretty keen on having a decent air gap and not laying directly on the roof?

The slot in filters do look really neat, I’ve got plastic combs which look to achieve the same thing.

Currently 50:50 on trying it out, but will look to see if I can use less wood supports to make it a bit lighter.

EPDM – single sheet rolled over and glued down with fastenings in about 2 hours and 30 years of life. Light enough for one person to handle and tough enough for branches the thickness of you arm to drop 40feet onto it and just bounce off

Can’t see any issues with using metal for that. It’s not that heavy. The existing felt will likely be fine as a vapour barrier if it isn’t too damaged. Not need for battens but you could put some horizontal ones in to make fixing easier.

@fruitbat – No condensation/damp problems that you noticed, the manufacturer was pretty keen on having a decent air gap and not laying directly on the roof?

No problems here – the sheets are sitting directly on the original roofing felt which is on 16mm T@G roofing. I guess there would be some condensation issues if there was nothing between the inside of the shed and the sheet metal roof.

PS – I’m in Central Scotland so always a good bit of cold moist air around!

I redid the roof of our similarly shaped shed five years ago using onduline corrugated roofing. It’s coped very happily with me standing on it so there shouldn’t be any issues with a cat. Our two are off and on it several times a day and it’s showing no signs of damage. Just make sure to use the appropriate fixing and ridge pieces.

Ps I didn’t strip the old felt off, I left it as another layer of protection and just nailed through it. Shed is dryer than an Arabs sandal inside still.

Spoke to the manufacturer, they need a vertical batten to allow a slight sag in the vapour barrier for condensation to go and the horizontal gives the depth of fixing needed as there are no purlins under the roof.

Hmmm, sounds like they’re being quite… particular, but fair play, you’ve done your research and you might as well follow their advice and do it properly.

I was going to suggest corrugated bitumen, as a few others have done. I’m about to use some on a covered deck/shed I’m building. Comes in black, green, red, and brown I think, and I reckon will look pretty good. You can get heavier weight stuff (Awnapol) in green and black too.

Timely thread! I was about to reroof my garden shed with corrugated galvanised sheets because that’s what’s in the local farm supplies store. I’d never seen the bitumen version before – what’s the benefit of them over galvanised? It’s for a small shed with an apex, garden storage not bike storage so there’s no need for any epic security standards etc. Just no holes in the roof!

pics because I’m rather proud of my Sunday project (all done with waste wood from having my house roof replaced!)

@thenorthwind – You are probably right about them being overly cautious, I think when it’s used for full sized buildings the condensation risk must be pretty high especially for centrally heated ones that might not be sealed properly.

Thanks for all the suggestions for the corrugated bitumen sheeting, the heavier duty Awnapol looks to be a nice option as a backup. I would need the battens laid out for that anyway given the number/depth of the fixings it requires.

Nice work Hannah! I guess the advantage of bitumen is it won’t rust (galvanised shouldn’t but probably will eventually, or if it gets dinged) and it looks better (for my money, subjective, obviously). Probably less rain noise if that’s a concern.

One thing to mention about the bitumen sheets, because I’ve been shopping for them recently, is that the sheets are pretty cheap, but the ridges, edging and fittings are all expensive. So factor that in. I’m not bothering with any edging, don’t have a ridge, and I’m just going to source some alternative fixings – 50pack of proper screws and covers is £23, need 20 per sheet 😯

@stwhannah – Nice project for a Sunday! 👍

The main benefits of the corrugated bitumen are that you can cut it with a handsaw so no messing about with tin snips/hefty jigsaw/metal nibbler to cut to size. Condensation underneath less of an issue so you don’t need a membrane underneath it.

The fixing depth for the corrugated bitumen is pretty deep though, I think you would need extra timber inside or battens on the top since each sheet needs a lot more fixings (one in each peak across the bottom/top and intermediate fixings).

@kimura54321 a perfect informative answer, thanks. STW – come for the bikes, stay for the life advice!

Regarding the bitumen sheets….

I didn’t think the extra bits were too expensive, given that you don’t need that many of them – I think I only needed 3 ridge pieces for my shed – I think it’s 8×6.

I didn’t use the ‘proper’ nails/covers; I got some from Screwfix & they were screws, rather than nails which seemed like a better solution for me. I put way too many of them in, as I bought way more than needed. I figured there was no real harm in over-doing the fixings.

Regarding the finishing bits, I wasn’t looking for a perfect finish. The shed will need replacing in a few years & it didn’t seem sensible to spend a ton of money on tarting it up; I just wanted it waterproof.
I put new timbers at each end of the roofline on the outside (the sloping fascia bits, can’t remember what they are called), then used a heatgun to straighten the corrugations of the bitumen where it overlapped the edge of the shed. I bent it downwards & screwed it to the timber, then trimmed it flush.

@thenorthwind – I don’t know where you have been looking for the parts, but the fixing price you quote is very high.
eroofs.co.uk have the screws for £8.28 for 100 or 400 of the nail fixings for £20.74

Screws

Nails

I used these screwfix ones (link below) as I didn’t find any screw versions of the official product, but had I seen the ones I’ve linked to, I’d have got those ones. The clear tops of the Screwfix ones, look a bit conspicuous.

Screwfix roof screws

I’ll try to upload some pics at some point.

Hey there,

Why just re-felt the roof with some new felt? It would probably be half the cost and better. Not sure about corrugated bitumen, it didn’t last that long on my last shed and in the end I re -roofed the shed with Sterling board and felted on top, that was after I bitumen painted the Sterling board for good measure. One question on the guttering on the side of the shed? Sure you need it?
Actually I think if you wanted a super strong waterproof roof I would use waterproof sterling board on top of the existing roof then felt.

All the best
JeZ

@stumpy01 Good find, thanks for that. I was looking at roofin.co.uk where they have standard Corrapol for about a tenner a sheet, but the only screw fixings (sod nails) they have are the screw cap ones: https://roofin.co.uk/shop/corrapol-bt-corrugated-bitumen-screw-cap-fixings-black-50-pack/ Even the nails aren’t that cheap. I found those Screwfix ones too, but the ones you link are actually cheaper in that quantity. The screw head isn’t covered but I can probably live with that.

Corrapol do an edge piece which looks like it would be really easy to fit and neat, but it’s £30 for a 2m length: i.e. 3x the price of the sheet it’s edging: https://roofin.co.uk/shop/corrapol-bt-rock-n-lock-black/ Doesn’t look like there’s an equivalent on eroofs. Will probably either leave mine open, or construct some sort of timber edge.

@jezzep – Good question on the felt, I had hoped the metal roofing would be a “do it once option” and be tougher so not needing replacement in another 4-5 years.

Guttering round the side was because the barge boards don’t project as much as I would like, so it means the drips are caught and means the exposed end of the shed gets less wet from the rain. Might be slightly overkill but I had some spare guttering anyway.

@thenorthwind – those edging strips look good. I didn’t see them, but would probably have given them a miss based on the cost.

I would go for the screw option I linked to rather than the screwfix ones with clear caps. They really stick out and are a bit of an eyesore.

I have put some pics on flickr.
Like I said in my earlier post, I heated the panel at the edge, folded it over and screwed it down. If I hadn’t been rushing I would have added a piece of timber over the top of the sheet to neaten it up before screwing it down (sandwich it in place) .
The ridge piece needs trimming. At the moment it overhangs and looks messy. But it’s dry inside which was the main criteria!

Inside of the shed has no sheet timber on the roof as the previous owner took it out. I added an extra run of timber at the ridge on both sides and also at the bottom edge as I needed something to screw into.

[url=https://flic.kr/p/2kVnLf4]PXL_20210428_102510296[/url] by STW stumpy01, on Flickr

You can see here the folded over edge screwed down onto a new piece of timber here. You can easily fold it and I trimmed it with a Stanley knife to remove the excess.

[url=https://flic.kr/p/2kVreJq]PXL_20210428_102440069[/url] by STW stumpy01, on Flickr

[url=https://flic.kr/p/2kVnLfV]PXL_20210428_102426139[/url] by STW stumpy01, on Flickr

@stumpy01 Thanks for all that. Good to know it can be bent (in line with the corrugations) and cut easily. Thought it would be too brittle to bend.

Agree the clear screw caps stick out a bit. I don’t think they’re that bad but will go for the ones you linked if I order the sheets from there (otherwise postage is £8). If you really wanted, you could just replace the screw caps with something like this https://www.screwfix.com/p/snap-caps-brown-polypropylene-6-8ga-100-pack/61091 You’d still have to take the screws out, but one at a time it would be half an hour, an hour’s work.

Just a bit of an update, bottled fitting the metal roofing sheets myself and sold on locally at a loss to someone who could use them.

Got an actual roofer in to do it instead, he used torch on house grade roofing felt and cleared next doors gutters when he was over for a very good price all in. Glad I had reinforced the roof though and thankfully he must have weighed <50kg, he was not shy about clambering on it! 😂

Looks like a nice felt job that.
I’m all over DIY but sometimes it’s worth buying your life back.

Lawn needs scarifying. (You can pay someone for that too)

@goldfish24 – You are right, it does need a bit of attention. Did make me giggle though as I only cut it yesterday after neglecting it in the rainy weather!

Coincidentally I actually bought a more robust rake online yesterday as my current one is a bit flimsy and not getting the old bits out properly. Will try that and some lawn feed, it’s only a small lawn and I use a push along manual mower.

My folks never did any of that with theirs and somehow managed to always have the most lush and verdant grass without really trying. Might be a bit cooler and shadier though, as it was Liverpool and not London.

https://www.cromwell.co.uk/shop/cutting-tools/rakes/springbok-lawn-rakes/f/4869?query=Rake