Velux windows - minimum pitch

[nick60]

Afternoon all,

I'm in the early stages of planning a single storey extension to the rear of my house. For various reasons I'd like a roof with a very shallow pitch (less than 15deg), so I won't be doing this in conventional tiles (might go for zinc if I'm feeling rich enough). The problem is that I'm going to need some windows in the roof and therein lies the problem - Velux and other manufacturers I've looked at all seem to be specifying a minimum pitch of 15degs.

Does anyone know of a roof window that can be installed at pitch angles lower than this? I assume the minimum pitch is all about water getting blown back under the flashings .....? Do you think building control would let me breach the installation spec if I took some measures to prevent this?

Any advice appreciated, TIA
Nick

 

[freddiemercurystwin]

You just need to build an upstand to support your rooflight to increase its pitch, not that uncommon. Bit of a crappy image but it was the first one google threw up but you get the gist.

 

[nick60]

I get the gist, thanks FMT

Problem is it's all about aesthetics and I think that's going to spoil the appearance.

I think I might have answered my own question (partly) ...... http://www.sunsquare.co.uk/products/skyview/

However, having looked around this site a bit I might have a new problem .... it seems the planners will be wanting me to match the appearance of the extension to the main house. My neighbours did this and it looks bad - their extension looks big and fat if you know what I mean - it looks like it's all roof, which is why I want to use a different approach. I wonder what it will take to persuade them ..... I'm in an AONB so things are generally tricky planning-wise

 

[simonjay]

Afternoon all,

I'm in the early stages of planning a single storey extension to the rear of my house. For various reasons I'd like a roof with a very shallow pitch (less than 15deg), so I won't be doing this in conventional tiles (might go for zinc if I'm feeling rich enough). The problem is that I'm going to need some windows in the roof and therein lies the problem - Velux and other manufacturers I've looked at all seem to be specifying a minimum pitch of 15degs.

Does anyone know of a roof window that can be installed at pitch angles lower than this? I assume the minimum pitch is all about water getting blown back under the flashings .....? Do you think building control would let me breach the installation spec if I took some measures to prevent this?

Any advice appreciated, TIA
Nick

Forticrete Centurion tiles can be layed down to 11 or 12 degrees. My extension roof is like this and has a sun tunnel fitted with lead flashing without any problems. The tiles have a baffle that stops driven rain, and this also prevents water being blown under the tiles. All tiles should be clipped down to prevent lifting in wind. Looks fine on a monopitch roof.
If you wanted a velux, only a little upstand would be required to get from 12 degrees to the minimum for velux.
If you (or the BCO) is paranoid, flash down over the front of the tile, water will never get up there.
Simon.

 

[nick60]

Thank you Simon. I hadn't heard of the Forticrete tile you mention so will definitely take a look. 11deg is close to what I need.

Main issue now is convincing planning about the aesthetics/matching. I'm convinced that matching the pitch to that of the main roof is simply wrong. Every single storey mono pitch extension I've seen that has been built like that looks too top-heavy.

 

[noseall]

I find it strange that you are concerned about aesthetics but are prepared to build a roof at less than 15 degrees.

Ok, you may have limited pitch options but this automatically limits the complexity of the roof.

What people fail to realise when planning single story extensions with limited roof rise, is that by insisting on fitting a pitched roof means there has to be a compromise.

Shallow pitched, tiled roofs need to be simple uncomplicated slabs.

 

[simonjay]

Thank you Simon. I hadn't heard of the Forticrete tile you mention so will definitely take a look. 11deg is close to what I need.

Main issue now is convincing planning about the aesthetics/matching. I'm convinced that matching the pitch to that of the main roof is simply wrong. Every single storey mono pitch extension I've seen that has been built like that looks too top-heavy.

Any chance of a photo of your house and the neighbours extension ?

Simon.