DO-IT-YOURSELF : Know When to Mend Fences for Harmony

Because fences are exposed to all kinds of weather, it’s a good idea to inspect them for damage periodically. This is especially true for wood fences, although metal fences are not immune to weather damage.

Here’s what to look for and what to do about the problems:

* Check all sections for splits, loose nails, rot and termite infestation.

* When replacing any part, or adding repair pieces to a wood fence, use pressure-treated wood from a lumber yard. Remove nails with a nail puller and pry pickets off with a flat pry bar.

* Inspect the posts for decay below and at ground level, along areas where rails are attached to the posts and at the tops of the posts. Also look for rot where pickets and boards are attached to rails.

* To steady a post that has decay underground, sink a new, shorter post next to it in concrete and bolt them together. Saw through the old post two inches above the soil line and remove the decayed wood.

* If a 6-by-6 post is rotted above ground, saw top or part of the post off below the damaged area. Make a new section from pressure-treated wood. Cut a half-lap joint by sawing the old post and the new piece to half their thickness so they interlock and are flush when joined. Then bolt the two sections together with carriage bolts.

* To replace part of a rotted or splintered rail, make a half-lap joint by cutting out the damaged area and a matching part of the new rail. Glue, screw or bolt the pieces together.

* If there is ground-level rot in a post set in concrete, chisel away the decayed wood below the soil. (You may have to chisel away the concrete, too.) Drive three large nails halfway into each side of the post. Make a plywood form several inches higher than the old footing to surround the old footing; coat its inside with motor oil. Mix concrete and fill the form. Tamp the concrete down, then slope it so water will run off. When the concrete has set, remove the form.

* If a post has an uncovered flat top, trim it to form an angle to let water drain off or add a metal or wood cap or a continuous top rail.

* If a post has been heaved up, drive it back down into alignment. If it’s out of plumb, straighten it and tamp down the earth. If the fence is exposed to severe wind, the post may have to be secured with steadying wires known as guy wires, or by driving a six-foot steel pipe into the ground and strapping the post to it. To reduce wind pressure on a solid fence, remove some of the siding so that it’s partially open.

* To replace a rail, saw off the old one as close as possible to the posts at either end. Cut a new piece to the exact length required. Join it to the posts with L-brackets at each end. Then caulk the joints with sealing compound.

* Instead of topping off a hollow metal fence post with an expensive metal cap, cram it with added newspaper or styrene chips. Then fill the top with two inches of concrete.

* To repair a metal pipe post that has been damaged above ground, cut off the damaged section. Get a pipe post that will fit into or over the old post. Drill aligned holes into the new piece and the anchored post. Insert the new pipe 24 to 30 inches, then bolt together.

* To treat an already-painted fence post with a wood preservative, drill holes at a sharp angle on all four sides at the top, middle and bottom of the post. Use the longest drill bit you have--at least 10 inches. Pour wood preservative into the holes until it overflows and let it soak in for a few hours. Then patch the holes with wood putty.

Here are some painting tips:

* If you are spray-painting a fence, protect plants and your lawn by dragging a large piece of cardboard along the fence as a backdrop. A large appliance carton is ideal.

* When painting a fence with a roller, hold an old dustpan at the bottom of the posts to keep the roller from touching the ground and picking up dirt. If necessary, use a shoe polish dauber to touch up the posts at ground level.

Another idea:

* In the spring, you can provide a low-cost alternative to conventional fencing by planting a living screen of fast-growing flowering vines. Dig a strip two-feet-wide along the perimeter of the area you want to enclose. Set rough poles at six-foot intervals along the center line. Staple a strip of chicken wire or plastic netting from the top to the bottom.

Around the base of each pole, plant several seeds of a fast-growing flowering vines. As the tendrils grow, fasten them to the wires with twist ties.