By Mary Ellen Polson

Part of the charm of an old floor lies in its minor imperfections: the familiar creak of a floorboard, a gentle undulation in the hall, the gouge mark so ancient that the scar has a patina. While any old house can be expected to have ßoors that squeak, sag, or slope, in most cases these ßaws arenÕt structural. With a little know-how, you can easily silence faulty ßoorboards and repair minor damage. WeÕll also give you tips on what to do about those pesky cracks that open up as the seasons change. 5 The good news is that when ßooring problems are the result of old age, itÕs a good bet that conditions have stabilized. (In other words, they probably wonÕt get worseÑat least while you live in the house.) You can trouble-shoot your own ßoors by talking a walk around the room.

Squeaks, Creaks, Springy SpotsyouÕre likely to hear problem spots before seeing them. A squeak usually means a ßoorboard isnÕt making adequate contact with the supporting joist below. A deeper-sounding creak probably means the joist is inadequate. Spongy spots can result from either condition. The solution is to reattach loosened boards using a pair of nails driven into the heart of the squeak, or by anchoring them with screws (see ÒStopping a Squeak,Ó this page).

Gaps Between Boards
both plank and tongue-and-groove floors can develop unsightly gaps as the ßoor ages. This is caused by compression shrinkage. During periods of high humidity, a ßoorboard will expand and compress its neighbors. When dry air returns, the boards shrink, but donÕt fully decompress.

Since the shrink/swell pattern persists even in the oldest ßoors, the best remedy is to do nothing, particularly if the gaps tend to close up during the humid months. If the gaps are especially large or pronounced at certain times of the year, consider the following alternatives.

 ¥ For gaps that appear during dry, cold weather, try increasing the humidity level in the house by running a humidiÞer. This may encourage shrunken boards to expand.
 ¥ Fill gaps with a ßexible paste or Þber Þller that can adapt to the shrink/swell pattern of the ßoor. Homemade remedies include mixing sawdust with a binder such as varnish, shellac, or white glue, or hemp rope soaked in linseed oil or glue. The sawdust mixture is simply pressed into the gap; pack the soaked hemp rope into the crack using a large ßathead screwdriver or small putty knife. (Apply two layers if the crack is deep.)
¥ Gun in an elastic caulk that cures to rubber. A ßexible marine or silicone caulk should only be applied when the cracks are halfway through their shrink/swell cycle (normally in spring or fall). Carefully mask the edges of the crack to keep the caulk off the ßoorboards. You may need to partially Þll very wide cracks with a pliable backing material, such as cloth or weatherstripping.
¥ For wide gaps that persist throughout the year, itÕs possible to Þll in the cracks with wood strips ripped to a slight taper on a table saw. Be aware, though, that introducing new wood into the situation can compound the problem. Glue or toenail the strips with brads to each board, or face-nail them to the joists or subfloor. The repair may need to be hand-planed or sanded to match the level of the ßoor.

Minor floorboard repairs
to replace one or two bad boards, begin by finding replacement wood that closely matches the sound condition of the original flooring. Some tips for matching wood:

 ¥ Look for wood of similar species, age, and size (width, depth, and proÞling). Likely candidates will also have a similar ring pattern (rings spaced closely or loosely together). They should also be cut the same way: ßat-cut (ßat-grain) boards have annual growth rings that run parallel to the face of the board. The rings on rift-cut (and quartersawn or vertical grain) ßooring are usually vertical to the face of the grain, and are much more uniform.
 ¥ Unless you have rare or unusually Þne ßooring, look for sources close to home. A local salvage house, or even your own closet or attic, may yield the best match.

Replacing a floorboard Most ßoors in older homes are composed of individual (plank) or interlocking (tongue-and-groove) boards laid together. Replacing one bad section on a plank ßoorboard is a relatively simple repair, but there are some caveats. First, the boards tend to run the full length of the room, so a small patch may stick out like a stubbed toe. Second, there may be no subßoor, so any repair should span at least one joist and share support on another. (Fastening a sturdy block of wood, or cleat, next to the joist to support the new board is one such method of Òsharing.Ó) To remove a bad ßoorboard, see ÒCut it out,Ó this page.

Before making any repairs, Þrst determine whether the ßoorboards are face-nailed (heads exposed) or blind-nailed (heads concealed between boards, usually driven at an angle). Use the same method for repairs.

Surface Repairs
minor holes and gouges can be Þlled with wood putty (see illustrations, p. 70). To repair a crack in an otherwise sound board, glue down any long splinters, then Þll the crack with wood Þller or wood putty.

Treating Stains
chlorine, oxalic acid, and hydrogen peroxide are the most effective stain removers for wood floors. All three work primarily by bleaching; each is most effective only on certain types of stains. Before you apply any strong agent, test it in a spot that doesnÕt show.

¥ Chlorine Effective on stains containing aniline dyes and ink stains. Use common laundry bleach (a weak solution of about 5% sodium hypochlorite) or dry swimming-pool chlorine mixed with hot water. Even low concentrations of chlorine can burn the skin and eyes, so wear long rubber gloves, eye protection, and allow for plenty of ventilation.
¥ oxalic acid Mixed with warm water and as concentrated as possible, this organic acid removes blue-black water stains, iron stains on oak, and lye-blackened wood stains. ItÕs usually available in dry crystalline form at hardware stores or wood Þnishing suppliers. Dissolve the crystals in hot water until you get a saturated solutionÑi.e., the crystals wonÕt dissolve any more. Oxalic acid is poisonous and should be used with care.
¥ peroxide Sold as a caustic solution with a concentration of up to 30%, hydrogen peroxide is effective for lightening woods (ÒblondingÓ) and last-chance stains.