Modern prefinished flooring is often made with a “microbevel” at the top edges that downplays minor differences in height and allows boards to be installed without later sanding.
Q: How do you patch strip flooring?
A:While old-house strip floors occasionally suffer isolated damage from deep burns to animal gouges that require a small, surgical repair, the more common scenario is an in-fill patch—that is, adding new flooring to cover the space of a removed wall, say, or a large duct hole cut in the floor. Here the most unobtrusive repair involves not only matching the wood and cut of the old flooring as closely as possible, but also blending the repair into the existing installation by “fingering in” new boards so they match the spacing of the rest of the floor as closely as possible. To do this, you must cut back selected boards at varying positions, then splice in new boards—all without disturbing the flooring you want to keep.
Start by thoughtfully planning your repair. Measure the offset of the joints in your existing floor, then plot out a similar pattern in the area you need to patch. Do your best to take advantage of the joints already in your favor so that you minimize the work and loss of good materials, while making most effective use of your repair stock (which may be limited if you are recycling flooring). Typically, you want to have boards no shorter than about 24″ and a minimum cutback of 9″ to 12″ to maintain the structural integrity of the tongue-and-groove system.
Next, mark the boards you plan to remove and scribe cut lines at right angles across the boards where you will make a joint. Bore a 3/4″ hole in each board on the waste side of the line, positioning it in the center of the board to avoid any flooring nails. Then, starting from the hole, cross-cut the board with a saber saw, working tangent to the circle circumference. To avoid cutting the subfloor underneath, shorten the saber-saw blade by snapping it with pliers so that its maximum travel just reaches the bottom of the finished flooring.
Afterwards, working from the hole, saw two kerfs down the center of the board to cut out a relief strip—wood that once removed allows you to pry out the groove and tongue sides of the board without damaging the adjacent flooring. Make these blind cuts with a circular saw, setting the blade depth to just about the thickness of the flooring.
Blotchy floors—particularly endemic with softwoods and flat-sawn boards—are the result of uneven stain absorption. (Photo: Andy Olenick)
Q: How do you get new boards into the tongues and grooves?
A: With an in-fill repair, you can often slide some of the new flooring into place between the existing tongues and grooves. Where this is not possible, though, you have to “cheat in” the new board around the system. One method is to cut off the bottom groove shoulder of your patch board so you can nose the tongue into place (usually with a little planing of the bottom corner of the board), then pop the groove over the existing tongue. To secure the board, you either face-nail the board with finishing nails (which are set and filled) or you can glue the board to the cut-off portion of the shoulder that you have put in place beforehand. Q: What about strip floors that are basically sound but squeaky?
A: Squeaks and springy spots in old floors are, strictly speaking, not normal. Solutions vary with the construction of the floor and the cause—generally, insufficient contact with the subfloor. If you can get below the floor, first have someone walk around on top so you can identify the location and source of problems—often shrunken or poorly supported subfloor boards. Try adding support by nailing a cleat (a 1″ or 2″ stick) alongside a joist, or driving a wood screw up through the subfloor to secure a loose floorboard. Where you have no access from below, or the problem stems from a loose-fitting tongue and groove, try driving two ribbed finish nails at opposing angles—preferably into a joist—to secure the floorboards.
Q: After taking the finish off an old floor, can you stain the wood?
A: Yes, but you should know what you’re getting into first. Many an old-house owner has stained a freshly sanded floor and returned to find that, contrary to their expectations of a mellow grain pattern, the floor has become a mess of blotchy patches. This is the result of uneven stain absorption. What’s the reason? Though most bare wood takes stain in varying degrees depending upon what part of the grain structure is exposed—the very effect desired with stain—a newly sanded old floor presents a different scenario. Here, some areas of wood are exposed much as they would be newly milled wood, while others still retain old finish that has deeply penetrated the surface, effectively sealing the wood pores from stain penetration. Extreme conditions like sunk-and-filled nails or spot repairs exacerbate the difference. What’s the solution? Test the effects of the stain first in a limited, out-of-the-way area, and if you anticipate any problems, prepare the surface first with a stain controller—a finishing product that evens the absorption of the wood.