Rough dead-weight of an 80-foot span wood-truss for roof?

[KnarfMan]

Hi,
Was hoping someone could tell me what an 80-foot span wood roof truss might weigh? The truss is for a gable roof with a 4/12 pitch. Would appreciate any "ballpark" estimates or site-links. TIA

 

[MiketheEngineer]

What size chord members are you using. ??

Check Alpine's Encyclopedia of Trusses - they have estimated weights or call your local truss supplier.

 

[KnarfMan]

I am only designing the foundations for the structure, so all I wanted was some "rough" dead-weights for the roof trusses. The trusses will be 2-ft c/c spacing with 19 psf snow load and 20 psf wind-uplift. I am going to assume a dead weight of 1100 lbs/truss (includes bridging members). Roof sheathing, shingles, etc. will be calculated separately.

 

[csd72]

80 foot is a long span for a roof truss. You may want to check with the building engineer that this is the way they want to go.

 

[KnarfMan]

found a somewhat useful web-site for my original question

just thought I would share it

http://www.sbcindustry.com/technical.php

 

[MiketheEngineer]

I have found that a 10 psf top chord dead load works quite well. If you have insulation and ceiling - add another 10 psf. If not - 4 psf is usually good enough.

So you are looking at about 40 psf total load - down. Wind is another problem.

Fairly typically for non-comercial here in the mid-west. Commercial is usually about 50 psf.