For the Building Inspector

The building codes typically require that decks be able to support the same live load as the rooms to which they connect. In a residence, that’s 40 psf. for 300 sq. ft. deck. That’s a total of 12,000 lbs., half of which is supported by the ledger board.

Take, for example, a 2 x 10 Southern Pine deck ledger board attached to the house framing. With a 1/2" diameter bolt and a single shear applied perpendicular to the grain for “normal” duration, the allowable shear load in the bolt is 330 lbs. Of course, the bolt itself could handle many times that load, but what will fail first is the wood; that’s what limits the capacity to 330 lbs.

For a deck with joists spanning 14ft. with 2 x 10’s, 16" on-center and 2 x 6 decking, the weight of the deck itself is approximately 7.3 psf., add this to a design load of 40 psf., and the total is 47.3 psf. One half of this load must be supported by the ledger at the house. Simple math (14 ft. x 20 ft. = 280 sq. ft. x 47.3 psf. x ½ gives the total load of 6622 lbs. along the ledger. Divide that by the ledger length, 20 ft. and you get a total load of 331 lbs. per lineal foot of ledger.

The "Stratton Bracket®" however, virtually eliminates the “shear” of the wood because the wood "sits" in the brackets.

Certified Test Results of the Stratton Bracket®

Two bolts, 16" on-center, top bolt through wall, bottom bolt through bracket and board only.

2,750 lbs./1,375 lbs. each Bolts Pinned against wall.
5,500 lbs./2,750 lbs. each Brackets deflecting and pinned against wall.
15,320 lbs./7,660 lbs. each Bracket failure - Bottom bolts pull through holes, top of brackets break.

test1 test2 test3

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