Hardwood can be sanded down to the raw wood (removing 1/32" to 1/16" of the top layer of your hardwood floor) and refinished with sealing coats of polyurethane (VOC compliance). The sanding brings out the original beauty in the wood, while the polyurethane (VOC compliance) seals and protects the floor, providing a long lasting finish.
Sanding and refinishing a floor is the best way to revitalize a floor, mainly because it is not very expensive, and the results turn out beyond expectation! Some people opt to stain their floors a darker color, such as mahogany. The staining process is done before the polyurethane (VOC compliance), and usually lasts until the floors are sanded again. We offer different types of stain to our customers, but can also create custom stains if you are looking for something unique.
Unlike most flooring products, hardwood is very durable, and carries a long life. However, sanding the floors is not an infinite process, and it is possible to "run out" of sandings. This is normally evident when you can see the installer's nails appearing between the boards of the floor. This is a good sign your floors cannot be sanded again.
Many people have beautiful hardwood hidden underneath their carpets, and even more people have exposed hardwood that has dulled and is unattractive. For those with existing hardwood, sanding and refinishing the floors is a great way to revitalize an old floor.
Methods and Preperation
This monograph discusses sanding methods and preparation of the exposed surface of wood finish flooring prior to the application of finish coatings. This discussion does not include consideration of the finish coatings. Oak, either red or white, is the most commonly used finish flooring wood. However, other hardwoods such as beech, birch and maple are not uncommon, and in some areas, softwood flooring, such as pine and fir, is popular. For special effects, for feature strips, and for tonal quality, elm, walnut, teak, and a variety of exotic woods are occasionally used. Regardless of kind, wood flooring when received from the lumber supplier, is milled but not sanded. Thus, new flooring must be sanded after installation to prepare the surface for finishing.
Sanding should be done just before application of a final finish coat to the base molding, and after all other interior work has been completed. Immediately before the sanding operation is begun, the floor must be swept clean. Use no water.
For unusually fine oak or other hardwood floors, manual sanding is recommended. Requiring considerably more time and hence greater cost, hand sanding produces a much smoother surface than machine sanding.
The floor should be traversed at least three times with a heavy power-driven type-sanding machine. On wood strip flooring, the first cut may be made crosswise to the grain, at a forty-five degree angle. Succeeding cuts must be in the direction of the grain. Where parquet or unit block is installed, the first cut should be made at a forty-five degree angle with the following cut ninety degrees in direction from original cut.
Using the correct grade of sandpaper in the machine, the drum sander should be passed slowly and at an even speed, starting at one wall and moving straight to the opposite wall. The sander is then passed back along the same path with each complete pass (from wall to wall and return) overlapping a previous pass by two or three inches.
To sand close to the wall and any other areas, which cannot be reached with a drum sander, use a disc sander, equipped with the same grit paper as the drum sander.
While three traverses are recommended, acceptable results sometimes are obtained from two. If an especially smooth surface is desired, four or five traverses may be desirable, the fourth with 2/0 (100) sandpaper and the fifth with 3/0 (120). After the final machine-cut, the floor should be buffed by hand using 3/0 (120) sandpaper.
For fine machine sanding work, when the floor is of parquet or unit block style, make the final cut with fine sandpaper using a disc sander. Final sanding should leave floor in a condition that no sanding marks will show through or be brought out by application of the finish.
The first coat of stain, filler or other finish should be applied the same day the final sanding, buffing, and dust removing are completed. If there is a longer interval between the operations, the grain of the wood will rise perceptibly, causing a rough surface. In large areas, this may require more manpower to complete in a day.
After the final sanding, the floor should be swept clean. Windows, windowsills, doors, doorframes and baseboards or any other flat surface as well as the floor should be dusted carefully with power vacuum cleaner. After the final buffing, the floor surface should not be walked on until the stain filler, or first finish coat has been applied. Any footprints that appear must be removed. A reinforced craft paper, lapped at least six inches at edges and ends, can provide surface protection from normal foot traffic.
The following images are examples of how sanded wood changes due to oxidation.