Box guttering with warm roof, is it possible?

[Tuppers]

Hi all,

 

The person doing our plans is on holiday at the moment and I wanted to try and get some advice on something I noticed following a comment on my intro post (https://forum.buildhub.org.uk/topic/42202-extension-slightly-large-and-renovation-in-cambridgeshire/). We're on the path to getting planning permission so don't have all of the structural/full technical documents created at this time.

 

I'm very keen to have a warm roof on our large single storey rear extension. I'd not noticed that as part of the plans, there is what I understand to be box guttering placed on top of the external skin wall on the attached neighbours side, thus allowing for the extension to go 100% to the boundary. Would you think this would be possible? I've searched to try and see if anyone has mentioned this before and looked online but not found anything, apologies if there is.

 

I'd appreciate any advice anyone can give!

 

Tuppers

[DevilDamo]

Yes, it is possible subject to notifying the neighbour via Certificate B on the Planning application and then again via a Party Wall Notice/Agreement.

[Tuppers]

Thanks for the response and I'm glad to hear it! I've tried drawing it out to help me, but I can't seem to work out how you fit it all the requirements in for a warm roof with the insulation sitting on the rafters, for example where the stop battens would go, how the rafters would sit, etc.

 

 

 

 

[EdHat]

I'm not sure if i understand your question. Do you want to build right up to the boundary and therefore don't have room for a normal gutter?

 

With a warm roof you can form a gutter in the insulation, you only need to achieve a 1:80 fall. Roof manufacturers will have a standard detail for this.

Alternatively is it possible for the roof to fall a different direction and then have a kerb along the boundary side so no need for gutter there?

[DevilDamo]

9 hours ago, Tuppers said:

Thanks for the response and I'm glad to hear it! I've tried drawing it out to help me, but I can't seem to work out how you fit it all the requirements in for a warm roof with the insulation sitting on the rafters, for example where the stop battens would go, how the rafters would sit, etc.

 

 

 

 

Why is a warm pitched roof being proposed? A cold (vented) roof would be more common but you can still achieve a similar detail with a warm roof.