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Larry Caldwell

In article .com,
) says...
question on trusses. contractor is building a stand-alone garage
24'x30'. 2nd floor is for storage. he's using 2x8 lumber for the floor
joists, mated in the middle with a gusset plate.

is this sufficient for bearing weight on the 2nd floor for storage?
some reason I thought wood-composite i-beams were better. he said the
gusset-type should be fine.

yes? no? opinions?

As long as there is a bearing wall or heavy beam under the joists where
they meet in the middle, it will be fine. Otherwise, forget it.

Let me guess: either you live in some backwoods community with no
building codes, or you are trying to bootleg a building in without a
permit. What you are describing would never pass a structural plan
check or inspection.

Do a quick structural calc. Suppose you want to load just the center
12' of the upstairs with something fairly heavy, say 100 psf. If the
joists are 16" on center, that means each joist has to support 1560 lbs,
plus the weight of the lumber and decking. Divide by 2 (two joists)
times 12' of lever arm, divided by 2/3 of a foot (8 inch joist) gives
14,040 lbs. of tension on the bottom edge of that gusset plate. Now how
do you think it's going to work?

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