Flush fascia/eaves detail

Markomlm

Hi all,
I am in the process of attempting a new build and am looking for an eaves without a fascia and soffit sticking out, i.e. just a flush finish right up to the gutter. I have looked online for some similar details, but can't find any that suit. Is there any typical detail available anywhere of the kind of thing I'm getting at? I guess I would have to have a vent slate near the bottom of the eaves, since I wont be able to vent under the soffit like is normal.

Penn

Markomlm wrote: »

Hi all,
I am in the process of attempting a new build and am looking for an eaves without a fascia and soffit sticking out, i.e. just a flush finish right up to the gutter. I have looked online for some similar details, but can't find any that suit. Is there any typical detail available anywhere of the kind of thing I'm getting at? I guess I would have to have a vent slate near the bottom of the eaves, since I wont be able to vent under the soffit like is normal.

You need to counter-batten the slates throughout. It's a more common detail over the last few years. Check out the Acceptable Construction Details for an Unventilated Rafter Void - https://www.housing.gov.ie/sites/default/files/migrated-files/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad%2C18751%2Cen.pdf

The ventilation is provided through the gaps in the battens across the whole roof, rather than through the vents in the fascia/soffit.

Markomlm

Penn wrote: »

You need to counter-batten the slates throughout. It's a more common detail over the last few years. Check out the Acceptable Construction Details for an Unventilated Rafter Void -

The ventilation is provided through the gaps in the battens across the whole roof, rather than through the vents in the fascia/soffit.

Is cross battening necessary? I thought that you could get a vent slate and line these along the eaves to act as vent

BryanF

Markomlm wrote: »

Is cross battening necessary? I thought that you could get a vent slate and line these along the eaves to act as vent

What is your roof build up

Layer by layer?

Markomlm

BryanF wrote: »

What is your roof build up

Layer by layer?

From the inside out, I got the following: (its a storey and a half)
62.5 insulated drylining
225 c16 joists with 120mm rafterlock insulation
tyvek felt
battens
torres slate

Calahonda52

As suggest by penn, look closely at the ACDs
Your build up is a sort of mix and match which while fine on paper can be hard to execute on site
My preferred buildup is
slate,
batten
counter batten
tyvek or similar
xx mm over rafter insulation
yy mm full fill between rafter insulation , which by default will be tight against the over rafter insulation

[if not full fill, then its much easier to ensure its tight against the over rafter layer than trying to keep the rafterlock flush with the inside face of the rafters to be tight against the insulated pb: you also don't have a service cavity.]

vapour layer
battens
service cavity.
12.5mm pb - no foil backing
skim

BryanF

Markomlm wrote: »

From the inside out, I got the following: (its a storey and a half)
62.5 insulated drylining
225 c16 joists with 120mm rafterlock insulation
tyvek felt
battens
torres slate

put in a vapour barrier on underside of joists tapes and sealed
Increase insulation to max between rafters
Breathable felt and double batten above

BryanF

As regards flush details, get an arch to design. Get them to detail air-tightness and thermal bridging while their at it. And check over the rest of your spec.

Markomlm

Why do I need a vapour barrier above my internal drylining?

Calahonda52

Markomlm wrote: »

Why do I need a vapour barrier above my internal drylining?

Why do you think not?

Have you looked at the ACDs
https://www.nsai.ie/about/news/publication-of-sr-542014-code-of-practice
Trevor Hickeys Construction technology [ Leaving Cert book]