Roof Truss Span Chart - cascade-mfg-co.com

1 Roof Truss Span Tables15 Alpine Engineered ProductsTop Chord2x4 2x6 2x62x4 2x6 2x62x4 2x6 2x62x4 2x6 2x6 Bottom Chord2x4 2x4 2x62x4 2x4 2x62x4 2x4 2x62x4 2x4 2x62/1224 24 3327 27 3731 31 4333 33 29 3933 33 4537 38 5239 40 553/1234 34 4637 39 5340 44 6043 46 39 5341 44 6144 50 6547 52 704/1241 43 5943 49 6446 56 6949 57 745/1244 52 67*46 58 69*49 66 74*53 66 80*6/1246 60* 69*47 67* 71*51 74* 76*55 74* 82*7/1247 67* 70*48* 72* 72*52* 77* 77*56* 80* 83*2/1224 24 3325 27 3827 31 4129 32 29 4029 32 4331 37 4633 37 493/1230 33 4531 37 4734 42 5036 42 37 49*34 41 51*36 46 54*39 46 58*4/1235 41 52*36 45* 54*39 50* 58*42* 49* 62* Other pitch combinations available with these spansFor Example, a 5/12 - 2/12 combination has approx.

2 The same allowable span as a 6/12 - 3/12 Top Chord2x4 2x6 2x62x4 2x6 2x62x4 2x6 2x62x4 2x6 2x6 Bottom Chord2x4 2x4 2x62x4 2x4 2x62x4 2x4 2x62x4 2x4 2x616"23 24 25 25 25 25 25 25 25 25 25 25 18"25 27 2827 27 29 29 29 29 29 29 29 20"27 28 3028 28 3231 30 33 32 31 33 24"29 30 3331 31 3534 33 3835 34 4028"32 32 3634 33 3937 36 4238 37 4430"33 33 3835 35 4038 37 4440 39 4532"34 34 3936 36 4239 39 4541 40 4736"36 36 4239 38 4542 41 4843 43 5042"39 39 4541 41 4844 44 5245 46 5448"40 42 4943 44 5246 47 5646 49 5860"44 47 5546 49 5848 53 6349 55 6572"45 51 6048 54 6451 57 6851 59 69 = Span Limited by length to depth ratio of 24 PitchDepthSpans in feet to out of bearingSpans in feet to out of bearing5/1238* 47* 57*39* 51* 59*42* 56* 63*45* 54* 68*6/12 - 2/12 40 43 59*42 49 62*45 56* 6648 57* 71*6/12 - 37 38 5238 44 57*41 50 61*44 52 66*6/12 - 3/12 33 33 4535 38 5238 43 56*40 46 60*6/12 - 28 28 3832 32 4434 37 5036 39 546/12 - 4/12 22 22 3126 26 3630 30 4132 32 44 Alpine Truss designs areengineered to meet specificspan, configuration and loadconditions.

3 The shapes andspans shown here representonly a fraction of themillions of designs producedby Alpine load(PSF)Duration factorLive load(PSF)Roof **shingle**constructionor rain,not snow rain or load(PSF)Duration factorLive load(PSF)NOTES:These overall spans are based on NDS 01 with 4" nominal bearing each end, 24" , a live load deflection limited to L/240maximum and use lumber properties as follows:2x4 f =2000 psi f=1100 psi E= 2x6f =1750psi f=950 psi f =1900 psi E= . Allowablespans for 2x4 top chord trusses using sheathingother than plywood ( spaced sheathing or 1xboards) may be reduced slightly. Trusses mustbe designed for any special loading such asconcentrated loads from hanging partitions or airconditioning units, and snow loads caused bydrifting near parapet or slide-off from higher achieve maximum indicated spans, trussesmay require six or more panels.

4 Trusses with anasterisk (*) that exceed 14' in height may beshipped in two pieces. Contact your local Alpinetrussmanufacturer or office formore configurations for themost widely designed roof where the roof is required toslope only in one direction. Also in pairswith their high ends abutting onextremely long spans with asupport underneaththe high a cathedral orvaulted ceiling. Most economical when thedifference in slope between the top andbottom chords is at least 3/12 or the bottomchord pitch is no more than half the top most economical flat Truss for aroof is provided when the depth of the Truss ininches is approximately equal to 7% of thespan in inches.