New extension roof

[awaitcall]

Advice needed please

New kitchen extension {rear} full witdh of terraced house about 17feet and projecting out about 16 to 17 feet.

Having a lean to tiled roof with a sky light window.

Q. is there a minimum or maximum degrees should the roof be taking into consideration of the projection?

Any other ideas would be greatly apreciated

flat firestone roof would be ideal costing wise would have difficulty with planning permission

 

[jeds]

In theory you can have any pitch you like but the materials and construction must be suitable for the pitch. There are concrete interlocking tiles that will go down to less than 10° - e.g. Forticrete Centurion which I've used on several jobs. You are also right to watch out for planning. They tend to want materials to match the existing building so if your house has a tiled pitch roof a sheet material on the extension is going to be a no-no. Also bear in mind that openable roof lights aren't practical at low pitches.

 

[freddiemercurystwin]

The pitch of any roof will be determined by the type of roof covering, for instance slates will go down to about 20° whereas rosemary's will go down to 35. There are other tiles that will go down to about 10° but you're quite limited and they probably may not match your existing and personally I think tiled roofs at very low pitches look pretty awful. Usually pitched extension roofs have the same type of roof tiles as the main house. With deeper extensions you are often limited in pitch if you have first floor windows that you need to keep beneath although this can be overcome if necessary.

With regards to a flat roof a zinc standing seam roof looks a lot more attractive than a nasty firestone job. Looks a more contemporary than a typical flatty. More expensive than firestone of course but a hellova lot nicer and will last a lot longer. Depends of course on the house its going on, if you like that kind of thing, some think they look too commercial etc. Some planners will like them some will not. Also a lot nice to look down on from upstairs windows. (You can probably tell I like them)

If you want to fit a standard Velux or similar type of rooflight bear in mind that standard rooflights need a minimum pitch of 15° so you need to build an upstand to accommodate this.

//www.diynot.com/network/hardmetalking/ seems to know his stuff (and works all over I think) so if you want to chat with an expert on zinc so you could send him a PM.

//www.diynot.com/forums/roofin...-pitch-ground-floor-extension.296089/#2156755

 

[^woody^]

Unless there is a specific planning policy or design guide preventing flat roofs, then there should be no reason why a flat roof with Firestone epdm could not be used

 

[awaitcall]

Thanx for the replies

I rang the council and I was told that they dont usually approve a flat roof

The terraced house is slate roof. What is the minimum height from the floor to the ceiling in the new extension kitchen. It's just that I'm thinking due to the projection of the extension could I consider making the first floor windows smaller with doing that I can get a good lean to roof with a sky light and looks good

 

[freddiemercurystwin]

Firstly you should check your local authority's actual guidance ie read it yourself rather than take a duty officer's word for it. That depth sounds pretty big for a terrace too so you may find it is too deep aswell.

If you went with a pitched slate roof based on a depth of 17' and a pitch of about 17.5° assuming an eaves level of 2100 above FFL 150 above ground level and say a 150 deep 150 high fascia you would need your window cills to be about 4250 above ground level. All assuming the ground is level.

 

[noseall]

A 5m, shallow pitch, lean-to roof is never going to 'look good'.

Barely acceptable - maybe.

Would hipping the roof not help deal with the existing windows issue.

 

[awaitcall]

I have read the guidance and it states that flat roofs is approval problem

So please I know it's a simple extension but the roofing is baffling me
Any help and support will be greatly apreciated

 

[freddiemercurystwin]

What exactly is baffling you?

 

[awaitcall]

Due to the size of the projection the roof which will get a approval

I can take a risk and submit a flat roof but I dnt want to go through refusal and resubmission. I want to get it right the first time


Thanx

 

[freddiemercurystwin]

Are you doing your own drawings/submission or are you employing someone to do it?

When you submit an application you (or your designer) needs to make contact as soon as the case officer is will permit (there is little point until they have begun looking at your application) in order to assess whether they are likely to support your application or not. At the end of the application period if you have negotiated well the application will be supported by them (of course this depends if you can live with their requirements/whims). This may be with a pitched roof or less deep or whatever. Even if it is turned down you can always re-submit under the same fee.

My own gut feeling is that it will be too deep anyway and would be turned down for that reason alone. If it were less deep of course a pitched roof may be more practical.

You could always apply for formal Pre-application advice if you council offers it.