Stone at dormer edge

[curlewhouse]

Put this in general construction as although it's a SIPs built, it's also a traditional stone outer, and the issue is somewhere between the two.  Anyway, along with the builder we've just realised an issue.  

 

The outer wall buildup is backed off stone, 55mm cavity, then SIPs.  

 

So, no problem with the stone until you reach the dormers - the roof design wraps half around the dormer edges at eaves height, which creates a problem for how the stone above on the dormer edge would be supported. I've attached an annotated picture and an unmarked one.  One suggestion has been to just use wood panelling above, which would look horrible as the window edge would be half stone then panelling, so it's a non starter really. I did wonder about cutting the stone so it's basically cladding and attaching it to some sort of boarding so it would just look exactly the same, but would not be placing it's weight on the thin section the roof wraparound causes - but as the builder points out, you'd then have a 55mm cavity Plus the thickness of the cut off stone (av 170mm) as cavity on those sections.  The sides of the dormers will be panelling, but it would just look wrong on the front like that. 

I'm still not convinced that's impossible, but can anyone see a different solution (we thought about cutting the wraparound off, but it's actually the end of a load bearing beam and concealed beneath the fabric is a whopping screw through into the wooden end of the adjacent SIPs roof panel. ) ?

Any thoughts guys?

Edited August 1, 2017 by curlewhouse

[ProDave]

The unusual detail there is the roof biting half way across that upstand. What is the reason for that?

 

This is our previous house. The two thin pillars were built of cut blocks. It still makes me cringe that these two thin pillars support the lintel and blockwork above the dormers with only the wall ties stopping the whole lot falling over. But they show no signs of distress. It however was a detail I did not wish to repeat on the present house.

 

[curlewhouse]

It's quite literally something the architect or SIPs designer designed in and we didn't pick up the practicalities of until the builder pointed it out TBH. Would be a non issue if the house was just clad or rendered of course, but with a real stone outer it's become an issue. I suspect its been a way of bolting the structural member (its a beam running up the inner edge of the dormer which carries the adjacent SIPs panel) to the adjacent SIPs panel which has a wooden block in that end.

Edited August 1, 2017 by curlewhouse

[PeterW]

Have you got a photo from a little further back, or the architects plans for the dormer ..? Trying to visualise it ..!

[curlewhouse]

I'll try and get a better photograph tomorrow.

But, as you can see from the diagram below of the East elevation, it's actually been the SIPs designer who has added that detail as it's not on the architects plan. The original idea was to have single stone columns up the side of each window, but that look is not in the local vernacular so we want simple stone sides like the rest of the building. Wouldn't have affected this issue either way though as the columns would have had to have a substantial piece cut out to allow for this unexpected wraparound piece severely weakening them. It also robs all the stone above of support of course.

 

1502_108_rev B_ AL (0) proposed roof plan.pdf

Edited August 2, 2017 by curlewhouse

[PeterW]

Can you not cut those roof horns back ..? They look wrong ...

[curlewhouse]

That was our first thought - but each contains a screw bolt attaching that bean tom the adjacent SIPs panel.  I've emailed Clays who did the SIPs to get their view. 

[curlewhouse]

*Update* - got an answer from Clays to the effect they can simply be removed as they are not structural, though also blaming me for not noticing them in their proposals. Actually, whenever their designer kept asking questions and making amendments I asked him to refer to my architect since sometimes I couldn't even understand what the question was! But for some reason he simply would not engage with our architect though.   So anyway, looks like they can come off and that simplifies matters no end (plus we've now got that in writing).

 

Edited August 4, 2017 by curlewhouse

[Ferdinand]

What is a roof horn?

 

Google says it is something to do with sex on the pantiles near the Pamplona bull run.

 

http://www.mirror.co.uk/news/uk-news/randy-tourists-horn-sex-house-10779803