Assume that i have an attic which currently has 2x6 joists on 16 inch centers.
Floor joist rule of thumb.
Mike standard deck framing for joists of various depths you don t give the depth nor span of your porch floor joists are in the article above.
A joist is a horizontal structural member used in framing to span an open space often between beams that subsequently transfer loads to vertical members.
8 2 x 2 12 maximum allowable span for a generic deck floor joist a look at an actual current joist span table will show that depending on the wood species the allowable spans for a 2x8 floor joists with 40 pound live load with deflection limit of span 360 ranges from 10 5 western red cedar to 12 9 doug fir larch.
E is chief operating officer of structural affiliates international inc in nashville.
Many building departments limit joist cantilevers to 24 maximum.
The rule of thumb for the depth of common joists is to take half span in feet.
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If i sister a 2x8 to each 2x6 meaning that the bottoms of the joists line up but the top of the 2x8 is approximately 2 inches above the top of the 2x6 is there a span table for such a situation or any rule of thumb for estimating strength as per code.
E g for a span of 18 feet half this is 9 add 2 which giv.
For each additional 2 of depth add 2 of span up to 12 deep.
Follow the rules to keep your floor solid.
Light gauge steel joists or trusses 6 deep span 10.
You must use at least five framing nails to attach the rim joist to the ends of your joists.
If your home is more than 20 years old your floor joists are most likely solid wood 2x8s 2x10s or 2x12s.
Just specifying 12 oc joist spacing is not enough to even make a wild guess at spans allowed.
To this number add 2 for the depth of the joist in inches.
The american wood council states that cantilevers are limited to 1 4 the span of the joists.
Steel construction rules of thumb.