Replace studio corrugated bitumen roof with felt?

[Timmyk86]

Hi all,

I have a small 4.5 x 3m studio with a pitched roof in my garden. The roof is corrugated bitumen sheets. They have now failed and have started to leak. The roof inside & tongue in groove boards.

I need to replace it urgently to address the leak. I've had a quote to replace it with torched on felt, for £650.

What would be the best option to replace the current roof with? Would prefer non-corrugated, but only for aesthetics. I'm a competent DIYer - what would be best if doing myself?

Pictures attached. Thanks very much for the advice!
T

 

[diy_fun_uk]

 

[Timmyk86]

Thank you.

Does the board underneath have to be anything specific? Ie does it have to be 18mm OSB or ply or can it be whatever is there already?

Thanks!

 

[diy_fun_uk]

You'd maybe get away with 11mm OSB3 if laying it directly on the existing tongue & groove, however personally I'd go with 18mm just to be sure.

Note like you, I'm a (hopefully!) competent diy'er so don't take my advice as gospel, however I reckon you'd definitely not go wrong with the 18mm.

 

[Harry Bloomfield]

What would be the best option to replace the current roof with? Would prefer non-corrugated, but only for aesthetics. I'm a competent DIYer - what would be best if doing myself?

Modern, box section, steel. Thin sheet steel, galvanised, then colour coated. It cuts to length with shears, and lasts almost forever, but you must use the correct fixing screws/bolts.

 

[Alastairreid]

You need to watch the additional weight as the trusses look quite far apart. Maybe a couple of purlins or reinforcing.

 

[Timmyk86]

Box section steel sounds good. Screws with neoprene or rubber washers right?

 

[datarebal]

Watch for the condensation

 

[Harry Bloomfield]

Box section steel sounds good. Screws with neoprene or rubber washers right?

Correct! They are hexagon headed, with a built-in washer and seal, and unlike the usual corrugated steel, they go in the bottom of the channel. They do a special, matching 3m long angle for the apex.

 

[Harry Bloomfield]

I just thought I would add a link to what proved to be the cheapest source delivered, for the box section steel I used earlier in the year - The company was called Mighty Structural Products, in Walsal, Staffs. Much cheaper than any local sources I was able to find, despite the delivery distance involved. https://mightystructural.com/

They say/or said, they do not accept credit card payments (due to cost), but do accept debit card payments. They also do numerous similar product lines.

 

[Timmyk86]

Thanks everyone. Did this yesterday. Was a reasonable effort doing it solo! The sheets were slightly long and cutting them down was a total PITA but I muddled through. Goosewing grey as it's the only colour the supplier had that would fit in my car. I think it looks alright.

They are only 172cm in length and I've just used a single row of screws at the top and the bottom of each sheet. They feel solid. Think I need more than that?

Annoyingly I forgot to buy barge flashing and it seems hard to find from local suppliers. Any suggestions on alternatives?

Thanks again
T

 

[Harry Bloomfield]

They are only 172cm in length and I've just used a single row of screws at the top and the bottom of each sheet. They feel solid. Think I need more than that?

Well done, it looks neat. At 1.72m - I would add some more fixings, at least another row along the mid point, every second channel, but maybe two rows. The manufacturers specify fixings no futher apart, than every 400mm.

 

[diy_fun_uk]

Now that I look at it, I wonder if I should consider the corrugated option for my garage. It would essentially be a like for like replacement in that my garage has old cement corrugated sheets that are failing. I was considering doing EPDM however the sheeting option would be quicker and more cost effective.

The only thing I'd wonder about on a near flat roof is noise when it rains medium-heavy. I suppose the corrugated profile would help dissipate noise to an extent (?) however some websites say on installs like garages the metal roofing can be noisy.

 

[Harry Bloomfield]

The only thing I'd wonder about on a near flat roof is noise when it rains medium-heavy. I suppose the corrugated profile would help dissipate noise to an extent (?) however some websites say on installs like garages the metal roofing can be noisy.

It can be noisy when you are inside, but the insulated version can help a lot, if there is no other backing to it, but then how often are you in the garage to even hear it?

It's better than cement corrugations, in that I found the cement allows moss a foothold, the moss then blocks the channels from draining effectively. Nothing sticks to the steel sheets, they are too slippy. I had an issue with birds and squirrels landing on the summerhouse roof, constantly damaging the felt - not now, it's too slippy for them to land.

I have now done my workshop extension to my garage (from original), replaced the garage roof, and most recently the summerhouse with it. All I will say is, order the thicker version, if it has to span the supports, if you intend to step on it, or take care to only step where the supports are - otherwise it can be deformed.

 

[diy_fun_uk]

It can be noisy when you are inside, but the insulated version can help a lot, if there is no other backing to it, but then how often are you in the garage to even hear it?

It's better than cement corrugations, in that I found the cement allows moss a foothold, the moss then blocks the channels from draining effectively. Nothing sticks to the steel sheets, they are too slippy. I had an issue with birds and squirrels landing on the summerhouse roof, constantly damaging the felt - not now, it's too slippy for them to land.

I have now done my workshop extension to my garage (from original), replaced the garage roof, and most recently the summerhouse with it. All I will say is, order the thicker version, if it has to span the supports, if you intend to step on it, or take care to only step where the supports are - otherwise it can be deformed.

Is it noisy outside in medium-heavy e.g. to neighbours?