julianf
Member
- Messages
- 7,976
- Location
- devon, uk
I feel like I'm missing somthing here -
Slate roof -
Membrane on top of rafters, then battons, then slate nailed to battens.
I'm aware there are different ways of laying out the batttons, but that's the way it is on this roof.
Then the slate comes down, and there is facia board screwed to the ends of the rafters, pushed up to the bottom of the slate, and then the gutter is mounted on that.
But...
The bit I don't understand -
I know there shouldn't be water running down the membrane, but it still seems sensible that it should be able to drain if it does. If the fascia is up to the bottom of the slate, then the membrane will be higher at that point than when it passed under the last battern.
So you would get a low point and pooling. All be it right on the edge of the roof, but still seems a bad idea? Especially when you get those plastic things to hook under the last course and then bend into the gutter.
I just feel as it should be able to drain and that I'm missing somthing, but maybe that's the accepted way?
Why do I want to know this?
I've got issues with water wicking back on the underside of the slate and running down the facia. There probably should have been more overlap, but theres nothing I can do about that. I want to take off the facia boards (well, I've done that) and slip those plastic things up under the slate to direct the flow better into the gutter. I've got the plastic things, went to fit them and got confused.
There is no water running down the membrane, so it's all a bit hypertherical but it still seems odd to introduce a high point. Is it just that my facia boards need to be moved down the thickness of one battern? Ie a gap of an inch between the top of them and the bottom of the slate? That kind of seems odd too.
Slate roof -
Membrane on top of rafters, then battons, then slate nailed to battens.
I'm aware there are different ways of laying out the batttons, but that's the way it is on this roof.
Then the slate comes down, and there is facia board screwed to the ends of the rafters, pushed up to the bottom of the slate, and then the gutter is mounted on that.
But...
The bit I don't understand -
I know there shouldn't be water running down the membrane, but it still seems sensible that it should be able to drain if it does. If the fascia is up to the bottom of the slate, then the membrane will be higher at that point than when it passed under the last battern.
So you would get a low point and pooling. All be it right on the edge of the roof, but still seems a bad idea? Especially when you get those plastic things to hook under the last course and then bend into the gutter.
I just feel as it should be able to drain and that I'm missing somthing, but maybe that's the accepted way?
Why do I want to know this?
I've got issues with water wicking back on the underside of the slate and running down the facia. There probably should have been more overlap, but theres nothing I can do about that. I want to take off the facia boards (well, I've done that) and slip those plastic things up under the slate to direct the flow better into the gutter. I've got the plastic things, went to fit them and got confused.
There is no water running down the membrane, so it's all a bit hypertherical but it still seems odd to introduce a high point. Is it just that my facia boards need to be moved down the thickness of one battern? Ie a gap of an inch between the top of them and the bottom of the slate? That kind of seems odd too.