A rotted sill - What now?

We recently decided to replace the outdoor deck on our house. When we pulled off the ledger board that had been attached to the house, we discovered the builder had neglected to use flashing. The wood siding seems to be rotten and we're not sure how far the damage goes. What now?

It's disheartening to think a builder would overlook something so basic as flashing. To be charitable, your deck builder might have been a previous homeowner who just didn't realize how important flashing is.

But whatever the reason, you may be forced to deal with rotten sills -- an unfortunate fact of life in many old houses.

Your first step should be to peel away damaged material and find out how extensive the problem is. My own old-house adventures have taught me there's usually more rot than first appears, and all of it has got to come out before you can rebuild.

Mold and insects both prosper in wet wood. And, just as troubling, decaying wood has virtually no structural strength. It can lead to a variety of unpleasant symptoms around your house, including floors that bounce and sag when you walk across them and crooked door and window openings. Water damage is really not something you can afford to be casual about.

That's the bad news.

The good news is that repairs are simple if the damage is limited to siding and sheathing. Really.

Take off enough siding to completely expose the damaged sheathing, then cut back whatever sheathing appears rotten. Make the cuts with a circular saw over a stud so you