Re roofing my workshop

[paulrbarnard]

Time for a new surface on the roof. Starting to get some leaks. It’s a nailed on felt roof tile job at the moment. I’m intending to use coroline sheets. Can I get away with just putting it on top or should I rip the old felt off first? Of course I’m being a bit lazy but also suffer terrible vertigo so I’m not looking forward to it.

 

[Blister]

Time for a new surface on the roof. Starting to get some leaks. It’s a nailed on felt roof tile job at the moment. I’m intending to use coroline sheets. Can I get away with just putting it on top or should I rip the old felt off first? Of course I’m being a bit lazy but also suffer terrible vertigo so I’m not looking forward to it.

Depends on what condition the boards are in under the felt , If rotten it will be a big job.

 

[paulrbarnard]

Depends on what condition the boards are in under the felt , If rotten it will be a big job.

Fortunately the boards are solid. The felt is only five years old and the leaking was very recent along with driving rain.

 

[Bristol_Rob]

I'd just over sheet if the structure can handle the additional weight.

 

[Bingy man]

For what it costs a coat of bitumen over the existing felt can’t hurt then as you describe the actual boards as solid then just cover with your Coroline sheets and it’s job done - if you don’t like heights then get a willing helper to do the roof sheets as your safety is more important.

 

[Ollie78]

I vote epdm, pull off old felt maybe fix some 9mm ply or osb down and glue the rubber on. It`s quite easy to do and should last 20 years.
Or metal sheets which can just be screwed down with tek screws with gaskets, will last ages with zero upkeep, again dead easy to do.
If you don`t like the job, do it once well rather than having to get up there again in 5 years.

Ollie

 

[Fergie 307]

Go for it. The only problem with the bitumen corrugated sheets is that they tend to sag between the supports if they are more than about a foot apart, not a problem in your case. On my very exposed garden shed they are still in good nick after twenty odd years.

 

[TheUnicorn]

an obvious step up in terms of cost, but I saw a youtube shed build recently that roofed with a premade roofing board / system that was essentially an insulation panel (like kingspan) sandwiched between a corrugated metal roof and an interior cladding. cost vs time seemed to be a worthwhile system, was suprised to see him walk on it with no ill effects.

 

[paulrbarnard]

Go for it. The only problem with the bitumen corrugated sheets is that they tend to sag between the supports if they are more than about a foot apart, not a problem in your case. On my very exposed garden shed they are still in good nick after twenty odd years.

I used them on my workshop at the previous house and they were still as good as new when I left after about eight years hence wanting to go this way again.

@the unicorn I’ve had a look at the insulated steel panels and they look great but a bit more costly.

Biggest problem is finding someone to do the job. Tried three companies locally already and no interest in such bc a small job.

 

[Ollie78]

an obvious step up in terms of cost, but I saw a youtube shed build recently that roofed with a premade roofing board / system that was essentially an insulation panel (like kingspan) sandwiched between a corrugated metal roof and an interior cladding. cost vs time seemed to be a worthwhile system, was suprised to see him walk on it with no ill effects.

My mum has a log cabin thing with the insulated roof panels, they work well though there is some sagging over time. I think this is because there is quite a gap between the big joists in that particular design.

 

[TheUnicorn]

Go for it. The only problem with the bitumen corrugated sheets is that they tend to sag between the supports if they are more than about a foot apart, not a problem in your case. On my very exposed garden shed they are still in good nick after twenty odd years.

I found similar on a neighbours outbilding, an almost flat roof, that often sits wet, I think technically it mets the angle rquirement of the sheeting, but I think it wants a really good angle and a lot of support against sagging

 

[Spectric]

I’m intending to use coroline sheets.

I used this on a shed, I chose the mini profile as it looked less industrial and it also cuts easily.

 

[XTiffy]

I have used the bitumen corrugated sheets extensively in the past and would echo the comment that they need loads of supprt or they sag. Somebody mentioned a log cabin. We had one installed in our garden (10Mx3M) and the normal was bitumen felt or the bitumen shingles beloved by our friends across the pond! I instead used fibre cement slates that look so much nicer (on top of rigid foam to form a warm roof). Very glad I did can be used down to a 15 degree pitch and looks still looks great after seven years

 

[dvddvd]

They seemed to have changed the construction of the bitumen panels over the year for the worse.
I used some 20 years ago from Wickes and still water tight after all those years.
I bought some more a couple of years so and they seem to actually soak up the water..
In the end I bought plastic coated metal box profile sheets..10x better and not expensive

 

[paulrbarnard]

They seemed to have changed the construction of the bitumen panels over the year for the worse.
I used some 20 years ago from Wickes and still water tight after all those years.
I bought some more a couple of years so and they seem to actually soak up the water..
In the end I bought plastic coated metal box profile sheets..10x better and not expensive

Oh that is concerning. Was that Coroline/Onduline or some Wicks own brand?

 

[dvddvd]

Not sure it was the stuff Wickes sell, the metal roofing is not that much more expensive than the coroline. what pitch is the roof ?

 

[dvddvd]

The Coroline needs a decent pitch as any sitting water just soaks into the new variation. When it gets wet that's when it sags and then when it dries it buckles.
I used to think it was great...but won't use it anymore.
You can buy the metal roofing either new or used from ebay..depending on size needed

 

[paulrbarnard]

Not sure it was the stuff Wickes sell, the metal roofing is not that much more expensive than the coroline. what pitch is the roof ?

Pretty shallow. About 10 degrees. Coroline is supposed to be good down to 5 degrees but needs a big overlap at that angle.

 

[paulrbarnard]

The Coroline needs a decent pitch as any sitting water just soaks into the new variation. When it gets wet that's when it sags and then when it dries it buckles.
I used to think it was great...but won't use it anymore.
You can buy the metal roofing either new or used from ebay..depending on size needed

Beginning to sound like I should rethink this and go for the metal sheets. Might be the opportunity to put insulated boards on.

It does mean I’ll need to take the felt tiles off. I’m assuming a shovel if the best option for that as it should knock the nails out at the same time.

 

[Tris]

My favourite tool for that job:

https://www.screwfix.com/p/roughneck-big-mutt-pro-multi-use-building-decorating-tool-7-/36715

Although I'd look for the wooden handle version