[G-Sun]

You're just fantastic!

Wolffman:

Originally Posted by Wolffman

As it happens designing roof trusses, wall frames and structual beams etc is my day job so i might be able to help out with some ideas.

Welcome aboard! Some professional advise is most certainly welcome.

From what i've read in this thread and on your blog site you plan to build a new set of wallframes inside the existing ones, and a new pitched ceiling under the existing ceiling, in one end of your shed, measuring aprox 4420mm x 3390mm, is that right ?

Yes, that's right. Although I think it's going to be something like 4420mm x 3900mm.

I see your going to move and or replace an internal wall to create the new space, also i'm not sure from looking at the pictures but do you also have to remove the ceiling in this area as well ?

Yes.

If so you could use this new wall to tie your external walls together, there fore retaining the structual integrity of the building.

Absolutely

Originally Posted by Wolffman

Hi fellas,

I've done a drawing of the method i described in my previous post,
the blue represents the existing building.

I hope this drawing makes things a little clearer.

Very helpful indeed! Especially for me who has a poor understanding of English building-terms

The Ridge beam doubles as a new support to hold up the existing rafters and to take the lateral load off the external loadbearing walls after the removal of the ceiling joists, as well as giving a place to connect the new internal rafters ( which are only carring ceiling load and are essentially non structual ) which will form the new studio ceiling.

Please note that i've drawn this using commom size material used here in Australia which may be very different from what is available to you, so these drawings are to be taken as a concept only

I've attached a pdf so you can zoom in for more detail etc.

Very good drawings

Connect existing rafters to new ridge beam
with metal fasteners of some kind
your local hardware should be able to advise
the correct one for the job

First image: The connection of the inner ridge to the outer ridge ruins the decoupling of inner/outer structure, but it's maybe necessary?
I also see you recommend fasten inner/outer in the corners, right?

Second image: Brilliant idea. I'll just need to calculate (or get someone to help me) the strength of the ridge beam with supporting studs.
(Is it a deal-breaker not fastening it upwards?)

Note: The inner structure will need to support 1-2 layers of 15mm fire-rated gypsum-boards (heavy), some insulation, together with sound-absorbing-ceiling-cloud and lights.