Trusses can be constructed with smaller sized lumber than rafters and often their cost is not significantly higher than normal rafters.
Roof truss span 40 feet 6 12 pitch.
24 28 30 32 34 36 38 40 42 44 48 50 60 truss.
Roof truss span tables alpine engineered products 15.
The vertical rise of the top chord per 12 horizontal inches is the roof pitch or slope.
The steeper the roof the more expensive the trusses get because the longer the boards get and the more roof area increases.
For example 4 12 pitch means 4 inches of rise in 12 inches of run.
Truss capacity is listed by pounds per square foot based on the following load rating criteria.
Bottom chords is at least 3 12 or the bottom chord pitch is no more than half the top chord pitch.
Over 51 sizes styles in stock.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
Up to 40 open framing for plumbing.
Depending on your roof slope add 4 to 5 inches for heel height.
Pitch this is the incline of the roof expressed as a fraction.
6 12 2 12 40 43 59 42 49 62 45 56 66 48 57 71 6 12 2 5 12 37 38 52 38 44 57 41 50 61 44 52 66.
Top chord live load snow and other temporary loads top chord dead load roofing materials weight of the truss itself other permanent items attached to the roof bottom chord live load storage and bottom chord dead load insulation ceiling materials ceiling fans etc.
The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.
Shop roof trusses spacer floor truss.
If you can t get the heel height most residential trusses will have a 3 top cord.
While pitch and slope are used interchangeably they are not the same span also known as gable width this is based on the total footprint of the house and refers to the distance between two exterior walls.
Use of manufactured roof trusses can dramatically cut labor costs when framing a gable roof compared to building rafters.
For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.