DIY flat roofing options

[harryhotdog]

Hi Guys, I have a small external garage (5M by 3M) that currently has a flat felt roof and has wooden rafters on top of a single skin of bricks. Its in pretty bad shape with a lot of ponding and I've had to patch it twice over the winter with acrypol so I will be replacing it when we get some nicer weather.

I was looking at doing a DIY EPDM roof and also laying a new deck and firrings (quite certain both of need replacing). A relative has kindly offered to help with the replacement but suggested we could do it a lot cheaper with a polycarbonate or bitumin sheets.

Is it possible to fit these sheets as a flat roof or by building one side up to make it slope? I've only ever seen these sheets used for sloping rooves or rooves with ridges, can't see anything only and got the feeling doing it as a flat roof would be a bit cowboy/bodgey.

 

[foxhole]

Bitumen sheet without a good fall get waterlogged and loose shape leading to leaks .

 

[Notch7]

I was looking at doing a DIY EPDM roof and also laying a new deck and firrings (quite certain both of need replacing). A relative has kindly offered to help with the replacement but suggested we could do it a lot cheaper with a polycarbonate or bitumin sheets

You would need to change from a flat roof to a pitched roof.

Ive done a diy epdm roof, 30 sq metres. Its a brilliant system.

My tips:
lay the epdm sheet on the roof for a few days to ease out creases
Scrub the gluing side of tge sheet with a vacuum cleaner to remove as much silver dust
Vac the boarding
Use the white glue on both deck and epdm
Buy a karndean floor laying roller -about £25 from amazon.

 

[catlad]

You could get 3 polycarb sheets that length with 2 glazing bars delivered, that's another option

 

[harryhotdog]

Thank for your advice guys appreciate the ideas.

@Notch7 thank you for your tips, could I you who you bought your roof from and if you reckon the kits that some sites offer are worth it or is it cheaper to buy all the trims, adhesives etc separately?

@catlad sorry if its a daft question, but would I still need some sort of trims/edging as well as the sheets and bars?

 

[catlad]

I would glue say a 50mm angle trim on both sides and top.
There is specific drip edge for the gutter end.

 

[Rad1o]

When we added an extension we changed our flat roof to pitched / tiled. This was not part of the extension but was similar in cost to having it refelted regularly and now I do not get the home insurance pestering me with "Have you got a flat roof?" plus the premium for a bigger house is lower.