Flat Roof Construction

[Geps]

Hi,

I've had my flat lead bay window roof stolen - I've currently managed to make it whether tight and secure with felt and ply but looking to do a proper job this weekend. I'm trying to establish how you finish the edges of the roof - would anyone have a cross sectional diagram at all?

I've looked on alot of (insulation) manufacturers websites and they have diagrams for the warm deck and where to fix to the wall but not when it comes to the soffits and fascias.

Cheers,

 

[Zeberdee]

Dont bother going down the felt roof way! Go for the EPDM (rubber) roof covering way.

Easier to do and will outlast the felt by a mile.

 

[Geps]

I will be - the felt was only because it was easy to get just to hold off until the weekend.

But I'm still unsure as to how to finish the edges.....?

 

[freddiemercurystwin]

http://www.diydata.com/projects/flatroof/flatroof.php

 

[Geps]

Thanks but it's still not clear.

On a warm deck roof, the EPDM is secured to timber that runs behind the fascia....I'm trying to work out what this timber fixes to on the top of the insulation as there is only an 18mm board from what I can see and so nothing substantial to fix to.

 

[^woody^]

The insulation would not go all the way to the roof edge, rather, a timber would run around the perimeter to fix the fascia to. Then you need another timber around the top of the fascia to form the drip to allow the water to run off the roof not down the fascia

 

[Geps]

Thanks Woody,

Am I right in thinking this is how it goes together.

Where the orange is 18mm WBP ply, the green is insulation, the black is the wood joists and the blue is the bay window roof.

http://img3.imageshack.us/img3/3123/flatroof.png

(EPDM, drip battern, fascias and soffits left off!)

 

[freddiemercurystwin]

For a domestic flat roof covering the principal is largely the same whatever the material http://www.chesterfelt.co.uk/assets/pdfs/Drawing No. 3 - Eaves with gutter.pdf

 

[Geps]

Excellent thanks very much.