Fixing Rotten Wood
In writing about exterior painting ( http://hubpages.com/hub/Paint-Like-a-Pro-Exterior ) , I must address the topic of rotten wood. Not everyone will encounter this problem, so I made a separate article to address this issue.
At first glance, you may not even know that you have rotten wood. There are common areas that are susceptible to this problem. Window sill, trim around windows, soffit, door trim, and facia. To check the integrity of your wood, try and press the corner of a stiff putty knife into the wood. If it gives way easily, or worse, pokes into the wood - you have a little work to do before you can paint.
Don't just replace the bad wood. Wood does not just rot by itself. Sunlight, water, or bugs can rot wood. You must determine what is causing the problem and fix it, or it will just happen again.
The easiest problem to fix is simple sunlight deterioration. Wood that was never painted in the first place will get dried out and cracked and water can get in and rot it. If that is truly the cause, just replace the piece and make sure it gets sealed and painted this time.
More likely, water is getting on the wood. When water is constantly present, it finds it's way under the paint and works on the wood to rot it. The paint may still be there, but the wood underneath rots away.
You must find the source of the water. A leaky gutter above? Improper angle of window sill? Leaky air conditioner? Whatever the cause - find it and stop it. Then worry about the wood.
Some water causes cannot be helped. Door trim near the ground is subject to alot of moisture. Porch posts are famous for rotting where they touch the concrete porch.
Once the water source is found and fixed, it's time to replace the wood.
Removing the old piece properly can make for less of a job.
- decide if you will replace entire piece, or splice in a new section
- cut caulk, or run razor knife along edge that touches house to cut paint
- cut caulk, or run razor knife along edge that touches door jamb to cut paint
- cut out piece to be replaced with box saw, or remove entire piece
- cut to fit new piece
- prime, allow to dry
- caulk in new piece
The same procedure works for window trim.
Soffit boards are more complicated. Find seams of original piece with rotten section in it. Determine method of original installation. If soffit fits into mitre in facia, tap facia board out away from house to allow soffit to drop down and out. It soffit is nailed to fur strips or directly to rafter tails, wreck it out and cut new piece to fit, prime, replace, caulk, paint.
Facia boards are often behind gutters. Gutters must be removed, any metal trim removed carefully from facia. Drip edge may have to be replaced. It is often difficult to remove the facia without damaging this metal piece. Pry off old board. Cut new board to fit. Prime. Re-install. Re-attach/install new drip edge. Caulk. Paint. Re-attach gutters.
Porch posts can be completely replaced, or new wood may be scabbed in, depending on your budget, time constraints, if you care about the place alot or not. The main thing is to keep the new post/new piece from resting directly on the concrete. Metal post feet are made for this purpose. You might think that you could fashion your own if you have a hand brake and some spare flashing, but the store-bought ones are made of thick-gauge galvanized steel and are designed to bear a load. Place the steel cups under the post and re-attach or scab in.
Siding usually rots near the ground, which is good, since this is the easiest piece to replace. If somehow you find rot in the middle of a wall - you must decide if you will replace full pieces or blend in a patch. Bottom piece: out with the old, in with the new. Mid-wall: I vote for the patch. Cut out section a few inches bigger than rotten area. Check for rot in sheathing/studs. If you have time/it's not raining/you care, let this dry before you put the new piece in. Cut pieces of new siding to fit as close to exactly in the space you have created.It's best to go from stud to stud, with old siding resting on half a stud and new siding fitting on other half. Install new siding pieces in hole. Last/top piece will be hardest! You may have to loosen existing old piece to get last piece in. Once secure, grind down edges where they meet. Fill with wood putty to hide joint. Sand, prime, paint. You'll have to paint the whole wall to hide repair (but that is likely the plan anyway). TIP: to make a better joint between new and old and prevent cracking of wood putty, use the powder type of wood putty and mix with liquid latex instead of water.
Now you are ready to paint!