Expert: Dan Griffin - 12/30/2008

Question
Hi I am building a deck that will be attached to the house.
My ledger board needs attached to the house. I have a cement block foundation. The rim joist inside the house sits too high. The deck at the highest point will be maybe 3 feet off the ground on one end, and flush with the ground at the other end. How do i go about attaching the ledger board to the house? Should I drill all the way through the block and use 1/2 screws and attach washer and nut on the inside? or something else?

thanks

Answer
Ron, you have me well confused.

Cement block foundation.
Rim joist sitting on top of CMU foundation.
Finish floor sitting on rim/floor joits.
I don't know what your exterior finish is, but I assume it covers the joint between CMU and rim.
I assume you want the deck to be at or slightly below finish floor, so your deck's rim joist is almost directly where the interior rim joist is.

The big issue is firm, strong, well flashed attachment of the deck's rim joist to the house rim joist.  The deck's joists will attach to the deck's rim with Simpson strong ties or similar.  This is usually done with lag bolts, but if your interior rim is accessible, bolt and nut connection is great.  The fasteners should be staggered rather than run down the center of the deck rim.  Here is an illustration of my assumptions:
http://www.bestdecksite.com/introLedgerPg1.htm
<ake sure you flash to prevent waer and rot from developing between the  deck rim and the exterior siding.  If I have misunderstood the condition, ask again.