Deck Framing Design

by ken » Tue Sep 12, 2006 7:36 am

What do you think about this deck framing design?

http://primalkey.com/_blog/img/deckdsn1-012605.jpg

http://primalkey.com/_blog/img/deckdsn2-012605.jpg

http://primalkey.com/_blog/img/deckdsn3-012605.jpg

by ken » Thu Oct 05, 2006 10:21 am

Traditionally, we prefer spanning the deck joist into a ledger bolted to the wall framing at the floor framing level for a more efficient design.

This particular case, the deck joists were framed into center beams. The beams were supported by the ledger which was not getting a positive support at the wall/floor framing system. (i.e. There might be a rim-joist nor a post to support the beam end bearing.)

The deck framing was done by a builder without knowing the structural requirements. And the end result was that he spent an additional 75% of the cost for the repairing. (additional reinforcing required for beams, joists, ledgers and posts/blockings)

by Bruce Pooley » Wed Oct 11, 2006 8:30 pm

The point load at the end of the beams are fairly large and requires a hanger to attach to the ledger. The attachment of the ledger to the rim board or, if no rim board, then to the wall studs or floor joists (possibly floor trusses) would require several lag screws or bolts. The large load transfer can complicate the design and may also result in overstressing the connection.

Post by ken » Fri Oct 13, 2006 12:17 am

The point load created from the beam end reaction indeed caused a very expensive repair cost issue.
Multiple LVL blocks and additional bearing support at posts were added additionally to support each point load.