building an extension with warm roof tieing into a pitched cold roof

[catlad]

Once you have taken a few course of slates away to reveal the wall plate for your new roof joists to sit on, you will then have to lay some board up the rafter slope approx 1 foot which you will then have to slate down to.
A few pictures may help.

 

[2020c]

Materials needed.

9x2s
osb sheets 22mm(or18mm) for under the insulation.
Vapor barrier.
Insulation 140mm.
250mm galvanised screws with plastic washers.
wall straps.
fillets.
nails.
fascia board.
soffit board.
guttering.
EPDM (or other material)

Am i forgetting anything?

 

[2020c]

"Cut" the battens?

From NHBC, showing the principle.

That first tile batten does not need to be notched if its not fitted on the extended plyboard

Yes i see now. TY. This is what i was thinking how to do it.

 

[2020c]

Once you have taken a few course of slates away to reveal the wall plate for your new roof joists to sit on, you will then have to lay some board up the rafter slope approx 1 foot which you will then have to slate down to.
A few pictures may help.

Im just doing up my material list for now for the whole build for the extension. I will get pics when the build is going up. The house is a basic dormer bungalow and ill be adding an extension with the flat roof tied into the bottom of the 40d pitched slatted roof.

 

[catlad]

Large box of 100mm screws, rubber is a good choice as it makes a good tarp, especially at this time of year! 11mm osb will suffice over the joists and up the roof. You will need to go further up your rafters with the osb being a warm roof.
I always use 18mm t&g for the top deck.

 

[2020c]

Is it possible to get firings in 8m lengths to create a slope or will i have to make my own up for that length?

 

[catlad]

No you will have to make your own.

 

[2020c]

No you will have to make your own.

How is this done to get them exact?

 

[catlad]

Well what are you planning to use for joists? you could create your fall that way and level you ceiling.

 

[2020c]

Well what are you planning to use for joists? you could create your fall that way and level you ceiling.

I had this in mind. Maybe a 2x2 batten under the 9x2 joists on one end should give me enough fall. What would you recommend for leveling out the ceiling. would 4x1 screwd to the underside of the joists be to thin to screw into. If so then a 4x2 would definitely do. I cant think of any other method just now. Seems an awful lot of extra work other than a firing strip though.

 

[catlad]

Yes it will have to be done one way or the other, I have seen joists ripped down to create the fall. 9x2" won't span 8m

 

[2020c]

Yes it will have to be done one way or the other, I have seen joists ripped down to create the fall. 9x2" won't span 8m

It is a long span to create a fall. Maybe if i threw it the other direction, where it meets the old roof is where itll take 2 different angles i might have issues with.

 

[2020c]

Question i have about the lead work where the flat roof meets the pitched roof. This picture has been taking from the net. The question i have about it is, is there any need for the lead to be sitting on top of the ply. Would this not have issues with the vapor barrier and the EPDM when installed on top.