How to put in fascia for slating without blockwork?

[Tin Soldier]

So I'm a bit stuck

 

I have my house kit up,

 

blockwork guy says blockwork goes on after roof to allow for settlement. roof guy says how can you start the slates without the fascia in place?

I'd rather start slating asap as scaffolding is in place and blockwork isn't being done for another month.

 

I hate boxy fascias and overhangs etc so I'm aiming to just have a very simple timber fascia (painted 2x6) to pin the gutter to, or ideally no fascia at all and blockwork all the way up.

 

the current house is shown below in a simple graphic. the roof is as per the green. I have battened it out (the red) and attached sarking board (brown), with a 250mm overhang.

 

The reason for overhang is the 50mm gap and 100mm blockwork to go up, render and along with any timber and the overhand of slate to gutter. I've screwed on the last sarking board so I can take it off and cut to size  or extend if needs be.

 

So how to I start the slating. just start with an imaginary overhang. or do I attach something to the building that allows a temporary fascia/gutter to be put in place?

 

Am I making any sense?

 

Scott

 

[Russell griffiths]

Isn’t you facia fixed to the ends of the rafters. 

[Tin Soldier]

there are no rafter ends, its sips panels,

 

so its very much shaped like the green/light grey

[Jeremy Harris]

Fascias still need to be fixed to the plate at the end of the SIPs roof, though.  I'm not sure what the standard fascia detail is for a SIPs roof but there is bound to be one.

[Tin Soldier]

only photo I've got that kinda shows it

 

battens put on before sarking. (the green roof)

sarking on (the wooden roof)

 

another membrane to go over sarking.

[Jeremy Harris]

There's a detail on page 13 here: www.thermapan.com/pdf/ThermapanInstallationManual-Roofs.pdf and from page 13 here: www.sips.org/downloads/sipafigs-colored.pdf

Edited June 13, 2018 by PeterW
Fixy linky

[Tin Soldier]

architect detail below

[Tin Soldier]

theres no overhang of roof panels at all.

[Jeremy Harris]

That detail has a massive thermal bridge at the eaves, with a risk that there will be condensation in the internal corner.  The proper SIPs eaves details seem to be illustrated pretty well in those links, so I suggest going back to the architect and asking how to mitigate the thermal bridge and provide a fixing for the eaves.  There are a few ways to do this, by adding some triangular fillets to the roof SIPs panel eaves edge, then fitting insulation in to overhang the wall.  It won't be perfect, but will be very much better than the current arrangement.

[Mr Punter]

The architect detail shows the lowest slate resting on the blockwork.  When the building shrinks this may cause a problem.  I think you may need some rafter feet attached to the end of the roof to take your guttering.  In the past I have just attached 50 x 25 batten to this for the over fascia vent to go on and added a further 100 x 25 section below this later after the wall cladding was done.  Overclad the lot in aluminium.

[Tin Soldier]

Jeremy/ mr punter, I'm not understanding, any chance of a drawing?

[Jeremy Harris]

13 minutes ago, Tin Soldier said:

Jeremy/ mr punter, I'm not understanding, any chance of a drawing?

 

 

Take a look at the drawings in the linked pdf files I gave above, as they show several SIPs eaves details.  The eaves details drawings seem to start from page 13 in both those documents.

[Simplysimon]

@Tin Soldier, unless you are intending to put any fascia up in pvc, don't bother. it will just be another thing to maintain, i'm not putting up a fascia. agree with the cold bridge detail, needs sorted.

[Tin Soldier]

I've added some 'rafter feet'/fillets as mentioned above, worked out ok on my test wall.

[Jeremy Harris]

What does the architect say about fixing the massive thermal bridge at the eaves?  It needs resolving, as there is definitely a significant condensation risk there, right where the roof imposes loads on the wall SIPs panel.

[Tin Soldier]

I'm awaiting feedback from him, not holding out much hope in terms of a quality response

[Jeremy Harris]

It should be fairly straightforward to cut wedges of insulation and fill the triangular gap. ideally using low expansion foam to seal and secure the insulation.  If the insulation is extended out beyond the outer edge of the inner SIPs wall then that will help to reduce the geometric thermal bridging, too.  I did this at our eaves, and fitted additional insulation inside the eaves ladder frame overhangs, just to reduce geometric thermal bridging in the inner corners.

[Mr Punter]

Could you not just stuff in some mineral wool along the eaves and maybe hold it there with a strip of breather paper stapled in?

[Jeremy Harris]

Mineral wool is going to have both a lower U value than the SIPs panels and be subject to windwash, so although easy to fit there will still be a thermal bridge at that corner.  Corners really need better insulation than flat areas, because of the hard to avoid geometric thermal bridge they create.