minimum roof pitch?

[matt73]

does anyone know what is the minimum pitch allowed for a sloping roof to my extension. i've calculated the propsed roof angle at 19-20 degrees. i am not sure if building control will allow this.

also i am woried about rain going under the tiles. any advice would be appreciated.

matt

 

[noseall]

19-20 deg is ok provided youre using interlocking concrete tiles sutch as marley wessex wich can be fitted to a roof as shallow a pitch of 17 deg.

 

[matt73]

just been on marley site. looks like my existing tiles are anglia interlocking concrete only suitable for 30" so it looks like i'll have to go for a different tile of same style.

cheers
matt

 

[hammerswinger]

does anyone know what is the minimum pitch allowed for a sloping roof to my extension. i've calculated the propsed roof angle at 19-20 degrees. i am not sure if building control will allow this.

also i am woried about rain going under the tiles. any advice would be appreciated.

matt

To help stop the rain going under the tiles you would increase the headlap of the tile to 100mm (75mm is standard)

It's also worth bearing in mind that the pitch (angle) of the roof tiles will be a couple of degrees less than the pitch of the rafters, in the case of the Marley Wessex I think it's about 3 degrees less.

 

[freddiemercurystwin]

does anyone know what is the minimum pitch allowed for a sloping roof to my extension. i've calculated the propsed roof angle at 19-20 degrees. i am not sure if building control will allow this.

also i am woried about rain going under the tiles. any advice would be appreciated.

matt

To help stop the rain going under the tiles you would increase the headlap of the tile to 100mm (75mm is standard)

It's also worth bearing in mind that the pitch (angle) of the roof tiles will be a couple of degrees less than the pitch of the rafters, in the case of the Marley Wessex I think it's about 3 degrees less.

The pitches as quoted by manufacturers refer to the pitch of the roof not the actual angle of the tile.

 

[hammerswinger]

The pitches as quoted by manufacturers refer to the pitch of the roof not the actual angle of the tile.

I'll have to take your word on that one as I don't know for sure if that's the case.

 

[hammerswinger]

The pitches as quoted by manufacturers refer to the pitch of the roof not the actual angle of the tile.

I'll have to take your word on that one as I don't know for sure if that's the case.

Just found this so I guess if one manufacture uses that method they all will, so yes you are quite correct, it is rafter pitch.
http://www.monier.co.uk/faq-s/performance-and-appearance.html

That said I would still try to keep the roof at the best (highest ) pitch practical.