Flat roof to pitched

[RKB]

I am the proud owner of a nice little cottage with a 1960's monstrosity extension with a flat roof. Actually is was a garage which has been converted to an office / bedroom.
I'm sure the felting has never been replaced, and consequently leaks like a blo ody seive.
I have planning permission to change the flat to a pitched roof, and have saved my pennies to get the job done. After having no luck getting a builder interested, I've decided to look into seeing if I can do it myself.
Can anybody suggest a website or book which describes how a cut, hipped roof is designed and assembled?
Thank you

 

[masona]

Can anybody suggest a website or book which describes how a cut, hipped roof is designed and assembled?

It would be easier and quicker to have a roof trusses frame made up for you, take the drawing plan with you for the wallplate to wallplate measurement etc. They also come with a easy instruction to fit them.
When I've done away with my flat roof extension to a pitch roof the 4"x2" timber section for me to make came to £780 and the trusses frame was £560 and delivered !

Having said that, is it a pitch roof on it own or lean-to type to the property ?

 

[tim00]

More info. needed:
1. a plan view of the proposal.
2. dimensions
3. pics would help.
4. vertical dimensions from existing roof to any window frames,plumbing or abutments. This will determine your pitch - if possible.
5. why a hip(s)?
All or any of above would help, you might also look up a recent thread on flat roofs for general info.

 

[jofly24]

Can anyone tell me what the fall should be on a pitch roof? I intend removing the concrete slab and replacing it with a sloping roof. my roof is approx 9feet x 9 feet. also is there a good book with diagrams and instruction. You know, a kind of step by step guide?

 

[JerryD]

Can anyone tell me what the fall should be on a pitch roof? I intend removing the concrete slab and replacing it with a sloping roof. my roof is approx 9feet x 9 feet. also is there a good book with diagrams and instruction. You know, a kind of step by step guide?

It all depends what tiles you want to use, some tiles can go a shallow as 15 degrees whereas others need minimum 35 degrees. Surely you have to match the house for tiles type and roof pitch? Don't you have planning permission as this would show the pitch the council have approved.

 

[jofly24]

Plans?

 

[masona]

Plans?

Yes & no but normally building approval which is very straight forward.
Example: Flat roof no higher than 3m and pitch roof no higher than 4m etc, so pop down to your BCO and they will give you the information you need.

 

[jofly24]

many thanks

 

[davelloyd]

RKB,

I read this again and realized that the garage had been converted to an office / bedroom.

The thing is if you were to cut this yourself then you will most likely be able to leave the existing roof / celing joists in place and so not disturb the existing finished ceiling. You would also be able to leave all the roof deck in place and just need to strip off the boards around the edges leaving a sound platform to work off. I've done this on numerous occasions.

However, if it's a hipped end you want to do then you'll find that the hip will most likely interfere with the joists at the ends of the building.

Using trusses you will have to strip off the whole roof for them to sit between the existing joists. They may then interfere with any wiring / pipes / blocking that is between the joists. Also for a hipped end, depending on sizes and the system used, you will probably still have to cut the hip yourself and maybe all the jack rafters too which will call for a sound understanding of roof cutting techniques

As for a book you can try this -

http://www.amazon.co.uk/exec/obidos...651/ref=sr_8_xs_ap_i1_xgl/026-6268020-3416461

Not the most riveting read but all the info is there. It shows several waysto find the lengths and angles. How's your trigonometry?

David Lloyd

 

[masona]

Using trusses you will have to strip off the whole roof for them to sit between the existing joists.

I do see your point, it can be done depending on the angle of the roof and the appearance of the fascia board. The only exsisting flat roof to cut out is all round the edge approx' 300mm.

Have done a quick drawing to give you some idea if you're not sure, save a lot of work if you can do it this way !

Watch this space ! I have e-mail diynot to post the picture for me.

Plan