Sooner or later, most homeowners will face the prospect of replacing rotten wood around the exterior of the house. Cornices, exterior window and door trim, and wood siding all take a beating year round from the ravages of sun, wind, and rain, and given enough time some of this wood is sure to decay to the point that it requires replacement. The longevity of exterior wood is dependant upon how well the house was built by the original carpenters, as well has how thoroughly seams were caulked and paint was applied by the painter. Tight-fitting joints, well-caulked seams, and properly applied paint coats are the key to preventative maintenance and long-lasting exterior wood.
Rain gutters on the cornices of a house are also frequently a culprit in contributing to wood rot, especially of fascia boards. If gutters are not kept clear of leaves and debris, they back up and water running behind them eventually rots out the fascia boards to which they are fastened.
Having a professional replace your rotten exterior wood is expensive. You can do it yourself with the proper tools and a few tips. First of all, if the wood to be replaced is on a high cornice or other high part of your house, you will need a proper ladder that you can safely work off of. Some situations might require scaffolding, which can be rented from a home-improvement store. To remove the damaged wood, you will need a wrecking bar (often called a “crow” bar), a hammer, screwdrivers, saws, and perhaps a sharp wood chisel. As far as saws are concerned, it helps to have a power circular saw and a power jigsaw or reciprocating saw with a narrow blade to cut out areas where the circular saw cannot reach. Different handsaws might also be handy for certain applications.
In most cases, you can pry off the rotten pieces of wood with the wrecking bar and a big screwdriver. If possible, it’s best to remove entire pieces of fascia board, soffit, or trim so that they can be brought to the ground, even if the entire length of the board is not rotten. This way you can measure and make an accurate cut to remove the damaged part of each board. If you intend to reuse the good parts of the boards you remove, you must take in to account the underlying framing to which it was fastened, and plan your cut so that the joint where new wood will join the old falls on a framing member. This is essential so there will be a place to nail the ends of the two pieces solidly to the house.
In some severe cases of rot, you find after removing fascia and other trim that the underlying framing is also damaged. Since you can not replace an entire rafter, wall stud, or joist without practically tearing down that part of the house, the usual fix is to cut a piece of new wood of the same dimension and nail it on along side the rotten frame member to provide a new place to nail the trim.
After all the rotten wood is cut away and the extent of the damage can be seen, you can then make a trip to the building supply store to buy materials of the correct dimensions to make the replacement parts. Cutting and fitting the replacement parts is a simple matter of making accurate measurements and cutting out parts that duplicate the ones you removed. Nail these parts in place, and carefully seal the joints and seams with a good-quality exterior caulk. Allow the caulk to dry and then seal the new wood with a coat of primer. Once this is done, you may paint your repaired areas to match the rest of the house.
Prevent future rotting problems by staying on top of routine maintenance, such as keeping gutters cleaned out and keeping a solid coat of paint on all exterior wood.
