Many newer houses have been built using engineered floor joists. These are sometimes called MWJ (manufactured wood joist). Houses with engineered floor joists usually have an OSB plywood band board covering the rim of the house. This material is not designed to support a deck ledger board.
Many builders prefer to build a free standing deck by adding a beam and a row of footings near the house in these situations. If this is not an option you will need to install 2x blocking in between the engineered joists inside the house behind the plywood rim to create a solid surface to attach your ledger board. You may be able to access the floor joists from an unfinished basement. You will need to cut the 2x blocking to the correct size and nail into the sides of the engineered trusses. Then install the ledger board using 1/2" carriage bolts. Bolt through the ledger board, OSB rim, and 2x blocking. Install the washers and nuts to the carriage bolts from inside to finish the job.
Always consult with your local building inspector before attempting to attach a ledger board to a house with engineered floor trusses. You should also contact the manufacturer of the floor trusses for information about attaching deck ledger boards.
