Render, facia then roof?

[ragj195]

Hi

I'd like to double check the sequence of events when installing a flat roof on a new extension. I've just had the blockwork completed on a single story rear extension. Joists are on. The flat roof with be VCL>120mm celotex>18mm Plywood>Torch on Felt. Am I right in thinking that because the side trim overhangs the fascia the fascia has to be installed before the roof is done? Also the fascia is installed over the render so before the roof goes on the rendering and the fascia must be installed?

Thx
Richard

 

[clive12345]

Put up the fascia and soffit , felt the roof .
Then render up to the soffit .

 

[ragj195]

Put up the fascia and soffit , felt the roof .
Then render up to the soffit .

Thanks Craig. As the room is a warm roof I'm not planning on having a soffit. Just the fascia almost flush with the wall. Should the fascia still be install before the soffit or should it be rendered right up to the joists then the fascia installed over the render?

 

[theprinceofdarkness]

I would think that the tops of the fascias need to be in so the felt can be made off to them (or some flashing). Else you need to render first, then fit the facias then felt the roof.
If you try to render up the the edge of a fascia board, I think you will have a nasty little crack which will be difficult to seal properly. A better idea would be to fix a 2 X 1 batten along the wall, an inch higher then the bottom edge of the fascia board and fit the facia to it. Then your renderer can render up under the fascia and you can paint the board and it would have a drip edge. Micro soffit?
Frank

 

[ragj195]

I would think that the tops of the fascias need to be in so the felt can be made off to them (or some flashing). Else you need to render first, then fit the facias then felt the roof.
If you try to render up the the edge of a fascia board, I think you will have a nasty little crack which will be difficult to seal properly. A better idea would be to fix a 2 X 1 batten along the wall, an inch higher then the bottom edge of the fascia board and fit the facia to it. Then your renderer can render up under the fascia and you can paint the board and it would have a drip edge. Micro soffit?
Frank

Thanks that makes sense. Fitting a batten and leaving a drip edge will mean there is space to render underneath after the fascia has been fitted. One other question. As it's a warm roof the profile of the board will need to be around 350mm. I want anthracite grey boards but the only ones I can find are freefoam ones that are 410mm and around £80 per board! As I don't need a soffit is there any other cheaper option or as it's UPVC, grey and wide I should expect to pay a good amount?

 

[^woody^]

What does your design detail state?

How the wall meets the roof insulation is important to avoid local condensation problems and that's separate to the fascia fitting.

Any fascia should overhang render to form a drip, not just abut. And then whether the joint should be sealed or left open will depend on the roof edge detail.

In practical terms, the fascia needs to be fitted before the roof cover, which needs to be laid before rendering. Render needs to go up behind the fascia to allow an overlap, but whether the soffit strip can be fitted later depends on how you are constructing it all.