Numerous flooring materials now available may be used over a variety of floor systems. Each has a property that adapts it to a particular usage. Of the practical properties, perhaps durability and ease of maintenance are the most important. However, initial cost, comfort, and appearance must also be considered. Specific service requirements may call for special properties, such as resistance to hard wear in warehouses and on loading platforms, or comfort to users in offices and shops.
There is a wide selection of wood materials used for flooring. Hardwoods and softwoods are available as strip flooring in a variety of widths and thicknesses, and as random-width planks and block flooring. Other materials include linoleum, asphalt, rubber, cork vinyl, and tile and sheet forms. Tile flooring is also available in a particleboard, which is manufactured with small wood particles combined with resin and formed under high pressure. In many areas, ceramic tile and carpeting are used in ways not thought practical a few years ago. Plastic floor coverings used over concrete or a stable wood subfloor are another variation in the types of finishes available.
Softwood finish flooring costs less than most hardwood species and is often used to good advantage in bedroom and closet areas where traffic is light. However, it is less dense than the hardwoods, less wear-resistant, and shows surface abrasions more readily. Softwoods most commonly used for flooring are southern pine, Douglas fir, redwood, and western hemlock.
Softwood flooring has tongue-and-groove edges and may be hollow-backed or grooved. Some types are also end-matched. Vertical-grain flooring generally has better wearing qualities than flat-grain flooring under hard usage.
Hardwoods most commonly used for flooring are red and white oak, beech, birch, maple, and pecan, any of which can be prefinished or unfinished.
Hardwood strip flooring is available in widths ranging from 1 1/2 to 3 1/4 inches. Standard thicknesses include 3/8, 1/2, and 3/4 inch. A useful feature of hardwood strip flooring is the undercut. There is a wide groove on the bottom of each piece that enables it to lay flat and stable, even when the subfloor surface is slightly uneven.
These strips are laid lengthwise in a room and normally at right angles to the floor joists. A subfloor of diagonal boards or plywood is normally used under the finish floor. The strips are tongue and groove and end-matched (fig. 6-1, view A). Strips are random length and may vary from 2 to more than 16 feet. The top is slightly wider than the bottom so that tight joints result when flooring is laid. The tongue fits tightly into the groove to prevent movement and floor squeaks.
Figure 6-1.Types of strip flooring.
Thin strip flooring (fig. 6-1. view B) is made of 3/8-by 2-inch strips. This flooring is commonly used for remodeling work or when the subfloor is edge-blocked or thick enough to provide very little deflection under loads.
Square-edged strip flooring (fig. 6-1, view C) is also occasionally used. The strips are usually 3/8 inch by 2 inches and laid over a substantial subfloor. Face-nailing is required for this type of flooring.
Plank floors are usually laid in random widths. The pieces are bored and plugged to simulate wooden pegs originally used to fasten them in place. Today, this type of floor has tongue-and-groove edges. It is laid similar to regular strip flooring. Solid planks are usually 3/4 inch thick. Widths range from 3 to 9 inches in multiples of 1 inch.
Flooring should be laid after drywall, plastering, or other interior wall and ceiling finish is completed and dried out. Windows and exterior doors should be in place, and most of the interior trim, except base, casing, and jambs, should be installed to prevent damage by wetting or construction activity.
Board subfloors should be clean and level and covered with felt or heavy building paper. The felt or paper stops a certain amount of dust, somewhat deadens sound, and, where a crawl space is used, increases the warmth of the floor by preventing air infiltration. As a guide to provide nailing into the joists, wherever possible, mark with a chalk line the location of the joists on the paper. Plywood subflooring does not normally require building paper.
Strip flooring should normally be laid crosswise to the floor joists (fig. 6-2, view A). In conventional structures, the floor joists span the width of the building over a center-supporting beam or wall. Thus, the finish flooring of the entire floor areas of a rectangular structure will be laid in the same direction. Flooring with "L"- or "I-shaped plans will usually have a direction change, depending on joist direction. As joists usually span the short way in a room, the flooring will be laid lengthwise to the room. This layout has a pleasing appearance and also reduces shrinkage and swelling of the flooring during seasonal changes.
Figure 6-2.Application of strip flooring.
When the flooring is delivered, store it in the warmest and driest place available in the building. Moisture absorbed after delivery to the building site is the most common cause of open joints between flooring strips that appear after several months of the heating season.
Floor squeaks are usually caused by the movement of one board against another. Such movement can occur for a number of reasons: floor joists too light, causing excessive deflection; sleepers over concrete slabs not held down tightly; loose fitting tongues; or poor nailing. Adequate nailing is an important means of minimizing squeaks. Another is to apply the finish floors only after the joists have dried to 12-percent moisture content or less. A much better job results when it is possible to nail through the finish floor, through the subfloor, and into the joists than if the finish floor is nailed only to the subfloor.
Various types of nails are used in nailing different thicknesses of flooring. Before using any type of nail, you should check with the floor manufacturers recommendations as to size and diameter for specific uses. Flooring brads are also available with blunted points to prevent splitting the tongue.
Figure 6-2, view B, shows how to nail the first strip of flooring. This strip should be placed 1/2 to 5/8 inch away from the wall. The space is to allow for expansion of the flooring when moisture content increases. The first nails should be driven straight down, through the board at the groove edge. The nails should be driven into the joist and near enough to the edge so that they will be covered by the base or shoe molding. The first strip of flooring can also be nailed through the tongue (fig, 6-3, view A). This figure shows in detail how nails should be driven into the tongue of the flooring at an angle of 45° to 50°. Dont drive the nails flush; this prevents damaging the edge by the hammerhead (fig. 6-3 view B). These nails should be set with a nail set.
Figure 6-3.Nailing wood flooring.
To prevent splitting the flooring, predrill through the tongue, especially at the ends of the strip. For the second course of flooring from the wall, select pieces so that the butt joints are well separated from those in the first course. Under normal conditions, each board should be driven up tightly against the previous board. Cracked pieces may require wedging to force them into alignment or may be cut and used at the ends of the course or in closets. In completing the flooring, you should provide a 1/2- to 5/8-inch space between the wall and the last flooring strip. This strip should be face-nailed ust like the first strip so that the base or shoe covers the set nailheads (fig. 6-2, view B).
Installation over Concrete
One of the most critical factors in applying wood flooring over concrete is the use of a good vapor barrier under the slab to resist ground moisture. The vapor barrier should be placed under the slab during construction. However, an alternate method must be used when the concrete is already in place (shown in fig. 6-4).
Figure 6-4.Floor detail for existing concrete construction.
A system of preparing a base for wood flooring when there is a vapor barrier under the slab is shown in figure 6-5. Treated 1-by 4-inch furring strips should be anchored to the existing slab. Shims can be used, when necessary, to provide a level base. Strips should be spaced no more than 16 inches on center (OC). A good waterproof or water-vapor resistant coating on the concrete before the treated strips are installed is usually recommended to aid in further reducing moisture movement. A vapor barrier, such as a 4-mil polyethylene or similar membrane, is then laid over the anchored 1- by 4-inch wood strips and a second set of 1 by 4s nailed to the first. Use 1 1/2-inch-long nails spaced 12 to 16 inches apart in a staggered pattern. The moisture content of these second members should be approximately the same as that of the strip flooring to be applied. Strip flooring can then be installed as previously described.
Figure 6-5.Base for wood flooring on a slab with vapor barrier.
When other types of finish floor, such as a resilient tile, are used, plywood underpayment is placed over the 1 by 4s as a base.
WOOD BLOCK FLOORING
Wood block (parquet) flooring (fig. 6-6) is used to produce a variety of elaborate designs formed by small wood block units. A block unit consists of short lengths of flooring, held together with glue, metal splines, or other fasteners. Square and rectangular units are produced. Generally, each block is laid with its grain at right angles to the surrounding units.
Figure 6-6.Wind block (parquet) laminated flooring.
Blocks, called laminated units, are produced by gluing together several layers of wood. Unit blocks are commonly produced in 3/4-inch thicknesses. Dimensions (length and width) are in multiples of the widths of the strips from which they are made. For example, squares assembled from 2 1/4-inch strips are 6 3/4 by 6 3/4 inches, 9 by 9 inches, or 11 1/4 by 11 1/4 inches. Wood block flooring is usually tongue and groove.
Flooring materials, such as asphalt, vinyl, linoleum, and rubber, usually reveal rough or irregular surfaces in the flooring structure upon which they are laid. Conventional subflooring does not provide a satisfactory surface. An underpayment of plywood or hardboard is required. On concrete floors, a special mastic material is sometimes used when the existing surface is not suitable as a base for the finish flooring.
An underpayment also prevents the finish flooring materials from checking or cracking when slight movements take place in a wood subfloor. When used for carpeting and resilient materials, the underpayment is usually installed as soon as wall and ceiling surfaces are complete.
Hardboard and Particleboard
Hardboard and particleboard both meet the requirements of an underpayment board. The standard thickness for hardboard is 1/4 inch. Particleboard thicknesses range from 1/4 to 3/4 inch.
This type of underpayment material will bridge small cups, gaps, and cracks. Larger irregularities should be repaired before the underlayment is applied. High spots should be sanded down and low areas filled. Panels should be unwrapped and placed separately around the room for at least 24 hours before they are installed. This equalizes the moisture content of the panels before they are installed.
Figure 6-7.Fasteners for underpayment.
Plywood is preferred by many for underpayment. It is dimensionally stable, and spacing between joints is not critical. Since a range of thicknesses is available, alignment of the surfaces of various finish flooring materials is easy. An example of aligning resilient flooring with wood strip flooring is shown in figure 6-8.
Figure 6-8.A1ignment of finish flooring materials.
To install plywood underpayment, follow the same general procedures described for hardboard. Turn the grain of the face-ply at right angles to the framing supports. Stagger the end joints. Nails may be spaced farther apart for plywood but should not exceed a field spacing of 10 inches (8 inches for 1/4- and 3/8-inch thicknesses) and an edge spacing of 6 inches OC. You should use ring-grooved or cement-coated nails to install plywood underpayment.
RESILIENT FLOOR TILE
After the underpayment is securely fastened, sweep and vacuum the surface carefully. Check to see that surfaces are smooth and joints level. Rough edges should be removed with sandpaper or a block plane.
The smoothness of the surface is extremely important, especially under the more pliable materials (vinyl, rubber, linoleum). Over a period of time, these materials will "telegraph" (show on the surface) even the slightest irregularities or rough surfaces. Linoleum is especially susceptible. For this reason, a base layer of felt is often applied over the underpayment when linoleum, either in tile or sheet form, is installed.
Because of the many resilient flooring materials on the market, it is essential that each application be made according to the recommendations and instructions furnished by the manufacturer of the product.
Installing Resilient Tile
Start a floor tile layout by locating the center of the end walls of the room. Disregard any breaks or irregularities in the contour. Establish a main centerline by snapping a chalk line between these two points. When snapping long lines, remember to hold the line at various intervals and snap only short sections.
Next, lay out another center line at right angles to the main center line. This line should be established by using a framing square or set up a right triangle (fig. 6-9) with length 3 feet, height 4 feet, and hypotenuse 5 feet. In a large room, a 10-foot triangle can be used. To establish this triangle, you can either use a chalk line or draw the line along a straightedge.
Figure 6-9.Establishing center for laying floor tile.
With the centerlines established, make a trial layout of tile along the center lines. Measure the distance between the wall and last tile. If the distance is less than 2 inches or more than 8 inches, move the centerline half the width of the tile (4 1/2 inches for a 9 by 9 tile) closer to the wall. This adjustment eliminates the need to install border tiles that are too narrow. (As you will learn shortly, border tiles are installed as a separate operation-after the main area has been tiled.) Check the layout along the other center line in the same way. Since the original center line is moved exactly half the tile size, the border tile will remain uniform on opposite sides of the room. After establishing the layout, you are now ready to spread the adhesive.
Estimating Floor Tile Materials
Use table 6-1 when estimating resilient floor tile materials. This table gives you approximate square feet coverage per gallon of different types of primer and adhesives. Be sure to read and follow the manufacturers directions. Table 6-2 provides figures for estimating the two sizes of tile most commonly used. After calculating the square feet of the area to be tiled, refer to the table to find the number of tiles needed, then add the waste factor.
Table 6-1.Estimating Adhesive for Floor Tile
Table 6-2.Estimating Floor Tile
To find the number of tiles required for an area not shown in this table, such as the number of 9- by 9-inch tiles required for an area of 550 square feet, add the number of tiles needed for 50 square feet to the number of tile needed for 500 square feet. The result will be 979 tiles, to which you must add 5 percent for waste. The total number of tiles required is 1,028.
When tiling large areas, work from several different boxes of tile. This will avoid concentrating one color shade variation in one area of the floor.
SHEET VINYL FLOORING
Because of its flexibility, vinyl flooring is very easy to install. Since sheets are available in 6- to 12-foot widths, many installations can be made free of seams. Flexible vinyl flooring is fastened down only around the edges and at seams. It can be installed over concrete, plywood, or old linoleum.
To install, spread the sheet smoothly over the floor. Let excess material turn up around the edges of the room. Where there are seams, carefully match the pattern. Fasten the two sections to the floor with adhesive. Trim the edges to size by creasing the vinyl sheet material at intersections of the floor and walls and cutting it with a utility knife drawn along a straightedge. Be sure the straightedge is parallel to the wall.
After the edges are trimmed and fitted, secure them with a staple gun, or use a band of double-faced adhesive tape. Always study the manufacturers directions carefully before starting the work.
Wall-to-wall carpeting can make a small room look larger, insulate against drafty floors, and do a certain amount of soundproofing. Carpeting is not difficult to install.
All carpets consist of a surface pile and backing. The surface pile may be nylon, polyester, polypropylene, acrylic, wool, or cotton. Each has its advantages and disadvantages. The type you select depends on your needs. Carpeting can be purchased in 9-, 12-, and 15-foot widths.
Measuring and Estimating
Measure the room in the direction in which the carpet will be hid. To broaden long, narrow rooms, lay patterned or striped carpeting across the width. For conventional y rectangular rooms, measure the room lengthwise. Include the full width of doorframes so the carpet will extend slightly into the adjoining room. When measuring a room with alcoves or numerous wall projections, calculate on the basis of the widest and longest points. This will result in some waste material, but is safer than ordering less than what you need.
Most wall-to-wall carpeting is priced by the square yard. To determine how many square yards you need, multiply the length by the width of the room in feet and divide the result by 9.
Except for so-called "one-piece" and cushion-backed carpeting, underpayment or padding is essential to a good carpet installation. It prolongs the life of the carpeting, increases its soundproofing qualities, and adds to underfoot comfort.
The most common types of carpet padding are latex (rubber), sponge-rubber foams, soft-and-hardback vinyl foams, and felted cushions made of animal hair or of a combination of hair and jute. Of all types, the latex and vinyl foams are generally considered the most practical. Their waffled surface tends to hold the carpet in place. Most carpet padding comes in a standard 4 1/2-foot width.
Cushion-backed carpeting is increasing in popularity, especially with do-it-yourself homeowners. The high-density latex backing is permanently fastened to the carpet, which eliminates the need for a separate underpadding. It is nonskid and heavy enough to hold the carpet in place without the use of tacks. In addition, the foam rubber backing keeps the edges of the carpet from unraveling so that it need not be bound. Foam rubber is mildewproof and unaffected by water, so the carpet can be used in basements and other below-grade installations. It can even be laid directly over unfinished concrete.
The key feature of this backing, however, is the dimensional stability it imparts to the carpet. This added characteristic means the carpet will not stretch, nor will it expand and contract from temperature or humidity changes. Because of this, these carpets can be loose-laid, with no need for adhesive or tacks to give them stability.
Preparing the Floor
To lay carpets successfully on wood floors, you must ensure that the surface is free of warps, and that all nails and tacks are either removed or hammered flush. Nail down any loose floorboards and plane down the ridges of warped boards. Fill wide cracks between floorboards with strips of wood or wood putty. Cover floors that are warped and cracked beyond reasonable repair with hardboard or plywood.
Stone or concrete floors that have surface ridges or cracks should be treated beforehand with a floor-leveling compound to reduce carpet wear. These liquid compounds are also useful for sealing the surface of dusty or powdery floors. A thin layer of the compound, which is floated over the floor, will keep dust from working its way up through the underpayment and into the carpet pile.
The best carpeting for concrete and hard tile surfaces is the indoor-outdoor type. The backing of this carpet is made of a closed-pore type of either latex or vinyl foam, which keeps out most moisture. It is not wise to lay any of the standard paddings on top of floor tiles unless the room is well ventilated and free of condensation. Vinyl and asbestos floor tiles accumulate moisture when carpeting is laid over them. This condensation soaks through into the carpet and eventually causes a musty odor. It can also produce mildew stains.
The standard fastening methods are with tacks or by means of tackless fittings. Carpets can also be loose-hid with only a few tacks at entrances. Carpet tack lengths are 3/4 and 1 inch. The first is long enough to go through a folded carpet hem and anchor it firmly to the floor (fig. 6-11, view A). The 1-inch tacks are used in corners where the folds of the hem make three thicknesses.
Figure 6-11.Carpet installation.
Tackless fittings (fig. 6-11, view B) are a convenient fastening method. They consist of a 4-foot wooden batten with a number of spikes projecting at a 60° angle. The battens are nailed to the floor around the entire room, end to end and 1/4 inch from the baseboard, with the spikes facing toward the wall. The spikes grip the backing of the carpet to hold it in place. On stone or concrete floors, the battens are glued in place with special adhesives.
Though cushion-backed carpeting can stay in place without fastening, securing with double-face tape is the preferred method. Carpets can also be attached to the floor with Velcro tape where the frequent removability of the carpet for cleaning and maintenance is a factor.
To install a carpet, you will need a hammer, large scissors, a sharp knife, a 3-foot rule, needle and carpet thread, chalk and chalk line, latex adhesive, and carpet tape. The only specialized tool you will need is a carpet stretcher, often called a knee-kicker.
Before starting the job, remove all furniture and any doors that swing into the room. When cutting the carpet, spread it out on a suitable floor space and chalk the exact pattern of the room on the pile surface; then cut along the chalk line with the scissors or sharp knife.
Join unseamed carpet by placing the two pieces so the pile surfaces meet edge to edge. Match patterned carpets carefully. With plain carpets, lay each piece so the piles run the same way. Join the pieces with carpet thread, taking stitches at 18-inch intervals along the seam. Pull the carpet tight after each stitch to take up slack. Sew along the seam between stitches. Tuck any protruding fibers back into the pile. Carpet can also be seamed by cementing carpet tape to the backing threads with latex adhesive.
Open the carpet to room length and position it before starting to putdown the padding. The pile should fall away from windows to avoid uneven shading in daylight. Fold one end of the carpet back halfway and put the padding down on the exposed part of the floor. Do the same at the other end. This avoids wrinkles caused by movement of the padding.
To tack start at the corner of the room that is formed by the two walls with the fewest obstructions. Butt the carpet up against the wall, leaving about 1 1/2 inches up the baseboard for hemming. Attach the carpet temporarily with tacks about 6 inches from the baseboard along these two walls. Use the knee-kicker to stretch the carpet, first along the length, then the width, Start from the middle of the wall, stretching alternately toward opposite comers. When it is smooth, tack down the stretched area temporarily.
Cut slots for pipes, fireplace protrusions, and radiators. Trim back the padding to about 2 inches from the wall to leave a channel for the carpet hem. Fold the hem under and tack the carpet in place with a tack every 5 inches. Be sure the tacks go through the fold
When installing carpet, use tackless fastening strips, as shown in figure 6-12, view A. Position and trim the padding (view B) so that it meets the strip at the wall, but does not overlap the strip. Tack it down so it does not move. Lay out the carpeting and, using a knee-kicker, stretch the carpet over the nails projecting out of the tackless strip (view C). Trim the carpet, leaving a 3/8-inch overlap, which is tucked into place between the wall and the tackless strip (view D). (If you trim too much carpeting, lift the carpeting off the spikes of the tackless strip and use the knee-kicker to restretch the carpet [view E]). Protect the exposed edge of the carpet at doorways with a special metal binder strip or bar (view F). The strip is nailed to the floor at the doorway and the carpet slipped under a metal lip, which is then hammered down to grip the carpet edge.
Figure 6-12.Carpet installation using tackless fastenings.
Tacks can be used as an alternative to a binder strip. Before tacking, tape the exposed edge of woven carpet to prevent fraying if the salvage has been trimmed off. Cement carpet tape to the backing threads with latex adhesive. Nonwoven or latex-backed carpet will not fray, but tape is still advisable to protect exposed edges. Any door that drags should be removed and trimmed.
When installing cushion-backed carpeting, you cart eliminate several steps. For instance, you dont need to use tack strips or a separate padding. Although these instructions apply to most such carpeting, read the manufacturers instructions for any deviation in technique or use of material.
To install a cushioned carpet, apply 2-inch-wide double-face tape flush with the wall around the entire room (fig. 6-13, view A). Roll out and place the carpet. Fold back the carpet and remove the protective paper from the tape. Press the carpet down firmly over the tape and trim away excess (view B). A metal binder strip or an aluminum saddle is generally installed in doorways (view C). If your room is wider than the carpet, you will have to seam two pieces together. Follow the manufacturers recommendations.
Figure 6-13.Installing cushion-backed carpeting.