Many people move into a new house and discover that their deck was improperly installed. In some cases the ledger board wasn't flashed. Improperly installed ledger boards can allow water to penetrate the house wall and lead to rot and decay. In these cases you should remove the siding to inspect the house sheathing and framing for damage. You may want to hire a professional deck builder to assist you. A qualified deck builder will have experience with deck repairs and know the best course of action. We have seen cases where an entire side of a house has been severely decayed and requires major structural reconstruction costing thousands of dollars.
If there is no damage to the house wall you may just install new flashing under the siding. If you are tearing down the deck and replacing it we recommend removing the ledger board and replacing it. Some deck builders even install a layer of ice and water shield on top of the sheathing behind the ledger board for extra protection.
