EPDM Pitched Roof

[JohnMactabish]

Hi all,

 

I'm designing an extension to the rear of my house and was planning a very shallow pitched roof with a couple of roof lights.

 

Having struggled to find the exact detail online I've drawn up the detail below indicating the roof junction, skylight & hidden gutter.

 

I have little experience in construction and would appreciate any comments/potential problem areas.

 

Many thanks,

JM

 

 

[Jeremy Harris]

Have you looked at doing this with GRP, rather than EPDM? 

 

I think it may well be easier to construct with a GRP covering, and may also be longer lasting, especially given some of the shapes around the hidden gutter.  Worth investigating I think.

[JohnMactabish]

Thank for the tip - I'll have a look into GRP - always thought EPDM may be more likely to leak at junctions so GRP could be a good call.

[Ferdinand]

I do not like the look of that gutter liner finishing on the inside face of the wall.

 

That could drive water down the inside of your wall if eg it is filled with leaves or if snow settles.

 

It needs to be mortared 25mm into a joint in or taken over the top, surely?

 

How are you going to access and maintain it (and the bigger roof above)? I would want to make the shallow pitched roof walkable-on. OK with GRP if you avoid the joints; not sure about EPDM - perhaps with deck shoes.

 

Ferdinand

 

Edited March 19, 2018 by Ferdinand

[JohnMactabish]

Hi Ferdinand - many thanks for the comments. 

 

The detail of the gutter lining finishing definitely needs further development - as you suggest I was planning to mortar into the brick joint.

 

You raise a very good point about access and maintenance, there are two existing windows roughly above the gutters at either end of the proposed roof. These would be ok for cleaning the gutters, although if repairs were required it would obviously be preferable for the roof to be able to support someone. 

 

The proposed roof has two large skylights so if the additional weight of a person has to be factored in then maybe I need to run it past a structural engineer before taking it any further.

 

Thanks again,

JM 

[joe90]

I also agree about using GRP , I have used it often and it’s great. You can get a grey top coat type paint that makes it look like lead. I would extend the GRP over the top of the external wall, you can finish it with made up sections so no change of ragged edges. Look at u tube, loads of vids about how to do it. One word of warning, make sure everything is dry, if damp or wet it will go bad on you.