Rake construction

[AlecJames]

I'm after some construction advice -

I've made several repairs over the years to the roof overhang but it's too rotten now so I'm going to replace at least the lower 5m.

If I look up the line of the roof, see inset in the picture, I can see that the rake slopes down - I've labelled this as "low". This is probably because of the rot.

What should this slope be - or should it be level?

Googling around I've come across a "drip edge". There is nothing like it fitted at the moment, should I fit one? I was woondering whether the rot was agrevated by water running along the undercloak into the wood work.

Thanks
A

Roof rake

• AlecJames
• 21 Jul 2012
• 1

Roof question

 

[noseall]

The verge tiles should overhang any timberwork or fascia by about 50mm. These tiles are then either bedded in mortar or secured with a plastic dry verge unit (dry verge). The overhang is also assisted via the undercloak, which supports mortar bedding.

The overhang should weather the timberwork but more exposed gables will encourage painted timberwork to suffer.

The end rafter is usually supported on a noggin ladder fixed through the wall onto the last internal rafter. Care needs to be taken (at the initial building stage) when building up the masonry under this 'ladder' to ensure the masonry does not either lift the end rafter or indeed fall short and allow it to drop.

Some roofs are designed with the ridge, purlins and the wall plate protruding beyond the masonry as a feature and a support for the end rafter. I think this idea is pants as the end grain and lack of maintenance always encourages rot

It could be that the noggins have rotted and the whole overhang has become tired. Replacement may just mean replacing the end rafter or if the noggins are rotten, repairs could be considerable.

 

[AlecJames]

Thanks for the advice.

Some of the noggins rotted and were replaced before I bought the house (long ago). Extra noggins have been added as well. I'm pretty sure this was done without removing the end rafter so as a result the end rafter may have dropped.
The rafter has rotted where it meets the tiles - this also causes the tiles to slope so water runs off the edge. (This is why I'm replacing it.)

The part I'm not sure about is - should the tiles over the end rafter be raised to encourage water to flow back onto the roof or sloped away from the roof (as they are now) so water runs off the edge. (Or true to the rest of the roof).

When I fit the new end rafer I can choose height which could give a lateral slope to the tiles above. My instinct is no lateral slope - true to the rest of the roof.

(The tiles overhang by about 25mm bedded in cement on an undercloak. This side of the house gets the weather and suffers as a result.)

Thanks
A