Roof/box gutter interface

[Bancroft]

Our architect has proposed the attached solution for our roof/guttering interface.

 

He’s suggesting the roof stop short of the external edge of the ICF wall.  This is to allow the downpipe from the box guttering to be inside the cladding (which will mean cutting 60mm into the ICF outer foam to accommodate the downpipe behind the cladding). 

 

I get the feeling this is all for aesthetic purposes rather than practical.

 

To my mind, this just builds in added complexity and risks the watertight integrity of the roof system.  Any leaks in the box guttering over time could result in water ingress into the wooden elements at the top of the ICF wall – which may go unnoticed for years and thus create rot.

 

My proposal is that we extend the roof out beyond the outer edge of the ICF and locate the box guttering external to the outer edge of the ICF too.  This would result in the downpipes being outside the cladding but I don’t see that as an issue.

 

Any thoughts on the architect's proposal?  Any thoughts on my proposal?  Am I being too sensitive about potential water ingress?

 

[G and J]

Our architects practice suggested something similar, albeit on a timber frame build, Geoff's view was "not keen" for similar reasons, apthough he accepted it looked very neat, but when we sat down with the senior partner to do the final sign off his view "do you really want to do that" and so reverted to external box gutters

[torre]

Occasionally you see this done so cleanly that wall and roof meet seamlessly enough to make the aesthetics worth the risk of issues.

 

Here though it looks like complexity and risk for limited aesthetic value as you've still got a separate fascia at that junction anyway.

 

Personally I'd aim for something like your proposal and try and do it with an off the shelf hidden gutter system. Maybe you can still run the downpipes behind the cladding? From below I'm not sure you'll notice any difference.

[Dave Jones]

add another block to the inside skin and have a normal gutter.

 

box gutters = ongoing maintenance every year, clearing moss/leaves.

 

it wont be the architect who does that.

[Russell griffiths]

I like roofs to shed the water off the building, box gutters keep the water in board and in my opinion are a recipe for disaster 

 

extend the rafters have a facia outside the wall edge and stick a nice looking gutter on it. 
these details look lovely on paper, but a year after you move in you will never look up there again.