Wood Beam Depth To Span Ratio

Of a member is influenced not only by the span but by such variables as spacing.

Wood beam depth to span ratio.

E value or modulus of elasticity of the individual elements. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Beams of more than one ply must be fastened together with either nails or bolts. E is a ratio that relates the amount a given load causes a material to deform.

It can be used as a quick check for deflection and initial beam size if your beam span depth ratio is exceeding the ratio limited by the design code then you have to incr. Wood wood joists. The 2012 irc code calls for a minimum of a 32 o c. Staggered pattern with at least a 3 x 120 nail.

9 1 and 9 2 and this. 2 8 2 10 2 12 spaced 12 14 or 16 inches apart maximum slenderness ratio for column l r is 50 steel deflection limit for steel members l 360 for live load only general steel beam depth 1 22 x span depth to span ratio of joists is limited to 1 24 for composite beam to be efficient slab thickness of 4 to 5 1 2 inches. Wall w nominal reinforcing wall w heavy reinforcing concrete structural element structural depth l 30 to l 40 l 40 to l 50 l 25 to l 35 l 35 to l 40 l 10 to l 20. Will provide a stronger and stiffer floor assembly than 2x8 joists of the same grade and species that are spaced 16 inches o c.

Often 2x10 joists spaced 24 inches o c. Conversely the deflection of a beam can be calculated if the value of the abscissa is known. It is the ratio of beam span length to its effective depth depth cover. Wood floor beam joist floor beam vibrating machinery or track support.

Depth of structural members. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Tapered beams deflect as a result of shear deflection in ad dition to bending deflections figs. No mention is made of how the depth was chosen but 1 2 per foot of span seems to be the rule used also a rule which i have used for many years as a preliminary choice of beam depth.

Design a beam depth based on the rule of thumb for estimating the depth of manufactured beams which is to divide the span by 20. Beam depth h0 can be calculated for comparison with that given by the design criteria.