Building garage roof trusses

see where you're coming from @Silver ....

you will only just get your bus in there....,8'6" width, 8' total height,15 degrees pitch gives you a drive thru height of 6'10".....poptop bus 6'8"

Again, don't take my word for it....you know the space you have to deal with and the height of your bus....5 degrees pitch is about as shallow as you can go with steel sheet roofing....do you have the exact dimensions? i can knock up a sketch on sketchup

 

Flat roof!

 

pop up roof ?

 

I think he has the walls up already and has 7', leaving only 1' for the apex height of the truss including the ridge purlins. Knock these off and that leaves 8" to the apex of the truss. If I've read this all correctly I would suggest an 8" joist and cut it to a triangle. Or sit the purlins between the trusses in shoes and retain 1' truss height at the apex, which is still small.

Put your existing dimensions up @Zebedee

 

like amazing spaces....

 

without knowing the length of the building, it's impossible to say whether a flat roof would be tall enough at the far end, even with a tiny pitch

 

Its a concrete sectional garage with panels 7ft high. It originally had steel trusses with a 12.5 degree (not 15 as i thought) pitch which i assume kept it below the maximum 8ft height limit.

The sheets from eaves to ridge is only 4 1/2ft so was thinking of a purlin at the ridge, one at the eaves and one between the two which gives somewhere around 650mm between purlins.

 

big wall plates?

 

Flat roof`s leak...end of...

 

oooh some ones using sketchup.

flat roof is the key. max height shallow fall.

 

They do - you are right but with a height limitation of 2.5 metres (8 ft 2 and bit) a height of 7ft 5 is just about achieveable! Depnds what height you need

 

would an apex on the length work ?? ie middle to front slope and middle to back slope ? not sure on sheet size overlap etc ?? side truss?

 

Fall across width and not length. Standard about 2 to3" fall I reckon.

 

dig deeper...

 

here's a leftfield solution....do your trusses out of Unistrut

 

I can't draw this out but I'm thinking 6" ceiling joists, 6" ridge purlins, 4" intermediate purlins. You will have to cut the ceiling joists to 4" at the plate tapering to the middle purlin position, to keep the eaves height down. You will only have a 7' ceiling across the garage though.

Or mono pitch across the width

Or bend the rules!

 

Mono pitch - almost a flat roof - but better!

 

post your dims @Zebedee ....length, width, height

 

you've got 2.5m (8'2") height to play with, regardless of whether it's apex, pent, flat....(within 2m of a boundary fence)
your walls are 2.1m (7')...is this accurate?
the width of the garage from external side to external side is 2.6m (8'6") is this accurate?
how long is the garage?

 

Yep, those are the dimensions I have.