Help/guidance please - roof design for workshop

KAYPEE

Hi Folks,

I’m looking desperately for some guidance on a self build workshop. My background is the cars that go in them, not the building itself so I feel a little out of my depth!

I’m currently starting a build of a 30’ X 50’ cavity built block workshop. The insulated slab is in and il be getting the block work done shortly. The rest, I hope to mainly do myself.

My main headache that’s been keeping me up at night is the roof. I will be using 60mm kingspan insulated panels. It will be a shallow apex of 12-15deg to keep the overall height down, across the 30’ span.
I have been totally overwhelmed with the amount of options/opinions on Trusses and how to do the roof. So, here is where im looking for some advice.

My initial plan was:

· Both gable ends built up with solid blocks in a step format
· 3 x A-frames built from 3” angle, resting on the wall, 4 solids on their flat 12.5 ft apart (50’/4).
· Timber purlins 3 lengths each side of the apex so 6 overall with a main timber spine along the top.
· 60mm insulated panels 16ft long mounted to the purlins at 12-15deg.

Could anyone give me advice on this, how I should mount it to the walls, tell me im mad, if im on the right path etc?

Any help appreciated, cheers!

Calahonda52

Snow load and wind uplift would be my concerns

BryanF

please read the forum charter, we can’t offer structural advice

landcrzr

In short i think you need an engineer. You did mention an insulated slab though and that this garage is for cars.
Be careful if fitting a post lift, especially a 2 post type. You need a good depth of reinforced slab and punching shear could be a concern if the insulation is not load bearing, again, you really should get an engineer onboard before going further.