Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
Roof ridge beam sizing chart.
Engineered wood products ewp lvl span and size charts.
Look at it this way say 40 inch load at the ridge look at your 3 4 sheathed roof as a big 8 ft high 3 8 thick beam laid flat down to a 4 12 slope an eyeball number you better check shows that a less than 1000psi plywood would be sufficient with staggered middle edges and 2x6 rafters to keep em flat however you then have about 6000.
Loading conditions are detailed below.
Fv does not change when you double the thickness.
If you size a roof beam like a structural ridge that has a l 240 limitation you would multiply the minimum e value by 0 666 785 000 x 0 666 522 810 in this case.
Tables providing size selections for various beam spans and loading combinations for southern pine dimension lumber and southern pine glued laminated timber are available for the following applications.
Here we have a wood framed gable roof.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
Floor beam span tables of residential structural design we will now look at roof rafter and beam design.
Window door garage door headers supporting roof loads only.
If there is are any questions about anything else then you should contact your supplier or an engineer.
It has been my experience to never use a beam smaller than a two ply 2 x 8.
Loads are calculated in accordance with table 3 1 of as nzs 1170 1 2002.
Timber steel framing manual single span ridge beam.
Versa lam lvl size chart laminated beam span tables charts.
Rafter to ridge beam connection framing roof ceiling construction structural ridge beam absolute deflection in a ridge beam structural ridge beam tricks of the trade.
Live load 30 psf dead load 14 psf dead load manually increased for roof slope total load 44 psf span is 16 0 to center of posts supporting ridge beam.
Duration of load is 1 15 snow.
Let s consider a basic gable wood roof framing design.
Our versa lam lvl is manufactured in either alexandria lena louisiana in eastern united states or in white city oregon for the western united states.
This calculator matches up with 90 of the applications in the 2012 international residential code book.
This is set by the roof use you selected in the previous screen and cannot be modified.
Make sure the shear value fv for the species and grade you use exceeds the fv listed in the span table.
The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.
Live load overhang kpa.
Most interior beams need to include the roof load.