Roof construction - Garage inside Barn

[gost]

Hi all "constructors", I'm going to make a "garage" or plasterboard cell inside an old barn, about 10x6m with a height of 3.6m, the question is how do I make the roof?

The roof will be flat, and needs neither to take snow load nor rain, so I was thinking of a tarp on the top, 95mm insulation is enough, then 13mm as ceiling plasterboard.

The span will be about 6m without the possibility of support, of course as cheap/lightweight as possible.

I don't have a formula collection here with deflection coefficients or whatever it's called, it was 15 years ago since I calculated this kind of stuff in school...

I was thinking 145 or 195 x45 cc 1200 length 6000 then 28X70 cc 400 thereafter plasterboard - do you think this will hold? The only thing I'm going to hang from the ceiling is fluorescent lights...

I know such lengths don't exist but you have to splice them.

 

[prototypen]

Glulam is available in looooooong lengths, but why bother tinkering inside a barn, just tear it down.

Seriously, if the barn is good, frame up the walls and make proper trusses out of what's already there. If you make trusses, then a span of 6 m is no problem, I've done it.

Protte

 

[gost]

Thank you for a very constructive response :S

 

[MaZtoR]

There are finger-jointed 45x195 in 6.5-meter lengths at my nearest lumberyard. Making trusses just to support a ceiling seems unnecessary to me.

 

[v-g]

There is also http://www.skanskabyggvaror.se/produkt/barlina_frontbalk-4092 but maybe it's a bit overkill

But in some cases, you can have it as the middle then regular 2"x6" against it.

 

[gost]

I've changed my mind now, it will be a longitudinal 2x8 in the middle of the garage, 9.6 meters long, which I can support with the existing barn trusses, then hang 2x4s under this beam, but only supported by this beam, for minimal impact on the barn.

 

[prototypen]

If the barn has real trusses, why not hang the ceiling directly on the trusses? As you're currently thinking, you're loading the barn's roof construction with a lot of (expensive) timber. I don't see the point of minimally affecting the barn if it's the barn roof that must support the inner ceiling. Isn't the barn yours?

Protte

 

[v-g]

Barns usually don't have real "trusses"; they are mostly intended to absorb the tensile forces. Sure, they can store a lot of junk on them, but I would think a bit before hanging something very heavy on them. This also, of course, depends on the barn's construction.

It's also perfectly fine to use a steel beam in the middle, to which you can then attach shorter stubs towards the long sides.

 

[prototypen]

"Barn" 10 x 6 meters, it's possible to use a ridge beam but the roof might look like the back of an old horse.

A bit more facts from gost and maybe we can give better advice.

Protte

 

[v-g]

protte:If you can't see it, you can only guess. If you're going to install something new in a building (especially an old one), it must be evaluated on-site from top to bottom to ensure safety.

Quite often, you should cast new piers as the old ones tend to give up over time and become skewed.