Applying Interior Finishes



The application of the finishes is practically the last step in the long process of renovation. By now you may be so happy that the project is nearing completion that the time spent in the application of the finishes may go unnoticed. On the other hand, you may be so tired of construction work that fussing with the finishes will become a hassle. Keep in mind that finishes are the most visible part of all the work.

This section includes a discussion of installation methods for some of the most common finish materials, such as gypsum board, wood-strip floor, resilient tile, and ceramic tile. Our discussion of plaster is limited to small repair work. We feel that major plaster and restoration work is best left to the professional plasterer. In addition, we’ve incorporated a section on the installation of insulation and vapor barriers.

Materials:

The materials necessary for the various finishing jobs include:

FOR THE APPLICATION OF BLANKET INSU LATION and VAPOR BARRIER

FOR THE APPLICATION OF WOOD-STRIP FLOORS

• Tongue-and-groove wood strips

Flooring nails

Building paper

Baseboard and molding

FOR THE APPLICATION OF RESILIENT TILE

Adhesive (unless tile is self-adhesive)

Baseboard

Tile

• Blanket insulation

Polyurethane sheets (where needed)

FOR THE APPLICATION OF GYPSUM BOARD

FOR THE INSTALLATION OF CERAMIC TILE

Cementitious board (for walls)

Tile

Cementitious board (where required)

Joint tape (calculate 75’ of tape per 200 square feet of surface)

Ready-mix joint compound (approximately 1 gallon per 200 sq. ft.)

1 power-driven drywall screws

Corner beads

J moldings

FOR THE APPLICATION OF PLASTER

Ready-mix joint compound

• Gauging plaster with perlite aggregate

Gauging plaster and lime

Metal lath

• Gypsum-board panels

• Adhesive

Grout

Tools:

Here is a list of tools you’ll need to install the various finishes:

Spackle knives (in 4”, 6”, and 10” widths) for applying compound

• Hawk

• Wood straightedge

BLANKET INSULATION and VAPOR BARRIER

• Stapler

• Knife

• Gloves

• Approved respirator or mask

GYPSUM BOARD

• Chalk line

• Screw gun

• Pocketknife or utility knife

• Rule or steel tape

• Keyhole saw

• Crimper

• Rubber mallet

• Spackle knives (in 4”, 6”, and 10” widths) for applying compound

• Sandpaper

• Ladder

• Approved respirator or mask

• Pencil

PLASTER

WOOD-STRIP FLOORING

•Saw

• Nailer or hammer (for small jobs)

• Chalk

• Nail set (if using hammer)

RESILIENT TILE

• Utility knife

• Notched trowel

CERAMIC TILE

• Notched trowel

• Squeegee or sponge

• Carpenter’s level

• Tile or glass cutter

• Nippers

• File

INSTALLING THE BLANKET INSULATION and VAPOR BARRIER

Blanket insulation is made up of glass fibers. During the installation you should make every at tempt to protect your skin and lungs from coming into contact with these fibers; wear long sleeves, gloves, and an approved respirator. The application of blanket insulation is simple. Starting at one corner of the walls, measure and cut the blanket insulation to the proper length. Tack-staple one side of the insulation to the stud at large intervals. Once you are sure it fits, go back and staple it at 6” intervals. If there is a vapor barrier attached to the insulation, make sure that it is

facing the predominantly warm side (normally the interior). Once the full length is in place, grab the opposite edge and stretch it well. This side can now be stapled to the stud. With both edges stapled, the top and bottom edges are secured to the floor and ceiling members. It is very important that the insulation be continuous. Don’t skimp on joints or edges. It’s preferable to overlap or have extra insulation at the ends than to leave gaps.

Whenever openings have to be provided to accommodate outlet boxes or other fixtures, cut a hole of the appropriate size in the backing.

If the insulation you’re using doesn’t come with a vapor barrier, you must install a polyurethane sheet over the entire area being insulated. This has become a very popular method of condensation control, its main advantage being fewer joints and therefore fewer areas of possible moisture penetration.

To prevent air leakage through cracks in the framing, stuff bulk insulation in the spaces left between door and window frames and the studs. In addition, stuff bulk insulation against any space left between the header and sill plate and the subflooring in all perimeter walls. Be careful not to pack these spaces too tightly, since the effectiveness of the insulation depends on dead air spaces.

Basement ceilings, crawl spaces, and attics are similarly insulated, the difference being that the insulation strips are stapled to the bottom of the ceiling joists rather than the studs and that ceilings and floors over non-air-conditioned areas get thicker insulation, usually 7 1/2” or 9 1/2”.

INSTALLING GYPSUM-BOARD PANELS

The installation of gypsum board, although not difficult, requires lots of muscle and tender care. The muscle is needed because gypsum-board panels are heavy (a 1/2” panel weighs about 2 pounds per square foot; thus a 4’ X 8’ panel weighs 64 pounds). The care is needed because the seams must be “invisible” at the end of the job, requiring great skill in installing tape and joint compound. For both these reasons be sure to have at least one or two other people on hand while installing the drywall, as well as ample time to spend on your jointwork.

The erection of the gypsum board starts with the ceiling panels both because it’s harder to in stall the ceiling than the walls and because the joints between the ceiling panels and the wall framing can be hidden while installing the wall panels. Of course, this requires leaving a gap of ‘/2” or less between the ceiling panels and the wall.

Start by checking to see that the corner of the ceiling where you plan to begin is square. If it’s out of square, take measurements between the center of the joist where you are planning to screw the panel and the top plate along the wall. This will give you the angle at which the panel should be cut. Transfer these dimensions to the panel and cut it to fit the corner.* With the panel cut, you’re ready to lift it in place. Butt the panel against the wall. As one person holds one side, screw the other one to the underside of the joists at approximately every 6” * Remember that all joints must be centered over wood. the screws a little below the surface of the panel without tearing through the paper. The idea is to be able to cover the indentation with spackle in order to obtain a smooth finish at the end. The remainder of the ceiling panels are installed similarly, making sure the edges butt against each other.

To cut gypsum board, mark the panel where it must be cut and place a straightedge on the mark. Score the surface of the paper with a sharp knife, trying to press hard enough to cut into the gypsum core. Cut slowly; a quick cut could get out of control and you can slice your hand instead of the panel.

Once the ceiling is complete, the wall panels are erected. Any small inaccuracies that have been left at the edges of the ceiling panels can now be covered. Begin the installation at one corner. The first step is to check whether the corner is plumb. Cut the panel to match the corner where necessary.

Gypsum board may be installed either vertically or horizontally. Because the jointwork is difficult, it's wise to apply the panels in which ever manner will result in fewer or no butt joints. In rooms with 8’ or less ceiling height, it's better to install the boards vertically. When rooms are taller than 8’ (or than the longest available gypsum-board panel) horizontal applications may result in fewer butt joints. Try to avoid vertical joints at the top of doors and the top or bottom of windows by staggering the panel pieces.

For horizontal applications, start by installing the top panels 4 (There’s no way you can do this without the aid of another person.) Butt the panel up against the ceiling and tack-screw it in place. Go back and screw it every 6” around the perimeter and every 12” in the middle. The lower board is then cut to fit the floor. Any gaps or inaccuracies left between the panels and the sub- floor are covered by the baseboard.

For vertical installations, check the corner for plumbness and cut the panel as needed. Butt the panel well against the corner and screw it in place.

Openings must be provided in the panels to allow for outlets, switches, etc. Determine the exact location of the opening and mark it on the face of the panel. Poke holes at the corners of the projected opening with the tip of a keyhole saw, then cut out the remainder.

Bend the board backward until you break the core. Slice the back of the paper with a knife and smooth the edges.

Some builders put a nailing strip on the ceiling perpendicular to the ceiling joists. This furring can be adjusted in the event that a joist has more crown than the ones next to it.

Butt joints at the ceiling are difficult to finish. Stagger the panels or try to use (when possible) sheets of gypsum board that are as long as the room is wide. You will, of course, have to enlist some extra help to handle such large sheets.

Be sure to purchase- an asbestos-free spackle compound and wear a respirator or approved mask.

Tape and Spackle

Taping and spackling involve skill and meticulous work. One of our friends, an experienced carpenter and all-around builder, just completed an extension to his house. Whereas pouring the foundation and the carpentry, roofing, heating, and electrical work did not bother him, he complained at the prospect of having to fuss with taping and spackling. He screwed the gypsum panels in place but brought in a pro to do the jointwork.

While we don’t think that taping and spackling are impossible for the amateur to handle, we must make you aware that it's the type of job that requires good, neat workmanship and lots of patience.

You’ll be wise to minimize the sanding of the joints by applying the tape and joint compound carefully. Although mistakes can be partially fixed by sanding, they can't be totally corrected. An alternative to sanding the joints is to even them out with a sponge before they dry.*

There are contractors who prefer to start the application from the bottom.

Before beginning the taping and spackling, in stall the corner beads at all outside corners. Cut them out to the required lengths. Hold them in position and secure in place with a crimper and mallet. Install 1-molding where gypsum board requires a finished edge or where it abuts a dissimilar surface.

The jointwork requires several precise steps. Once the joint compound dries, it becomes tough to work with. First, with a scraper, apply a small amount of compound over the joint. Start at one end and move all the way to the other. Try to do this in as long and even a stroke as you can. Short strokes give you a rough surface which is hard to smooth out later on.

Once the first layer of compound is applied, take the roll of tape and center it over the joint. Hold the tape with one hand while with the other hand you press the tape into the compound with the scraper. The tape shouldn’t wrinkle. Where wrinkles appear, lift the tape to a spot before the wrinkles begin and apply the tape over again. Sometimes the tape starts to slant away from the joint. Cut it out and start a new strip. It should be directly over the joint. Scrape over the entire length of tape, removing any excess joint com pound.

The second step is to cover the tape with an other layer of compound. It should be a thin, smooth layer wider (about 6”) than the tape. Be sure to cover all exposed nailheads and exposed corner beads with compound. Leave the com pound until it has thoroughly dried (approximately twenty-four hours).

With a wider scraper (about 10”), apply an other layer of compound. This layer should be thin and very evenly applied. Once again, give it time to dry. Small irregularities may be wet- sanded (although we prefer feathering and smoothing to wet-sanding). The wall is now ready to receive the primer.

MAKING MINOR PLASTER REPAIRS

The main problem in working with plaster is that it dries very quickly, making it difficult to correct mistakes. For this reason, most amateur renovators prefer to use joint compound for minor plaster repairs. Since it sets slowly, mistakes are easy to correct. The main disadvantage of compound is that it shrinks considerably as it dries.

There are essentially three types of minor plaster repairs: cracks, holes, and failing plaster.

Cracks

Open up the crack by chipping it out with a small chisel, a pointed trowel, or a pointed can opener. With a trowel apply plaster or joint compound over the opened crack. Unless you are quite skilled, you will most likely have to apply more than one coat.

Holes

You will need to patch holes that were created by chopping for electrical wire or plumbing or simply by failed plaster. The application of plaster is done in three layers or coats: the scratch, the brown, and the white coat. The first two coats are done with gauging plaster with perlite. This type of plaster is lighter and takes longer to dry than plaster of Paris (making it easier for the amateur). The “white” or finish coat is done with gauging plaster and lime since it has good workability.

Mixing plaster isn't easy. You will most likely get the best advice on mixtures and proportions from your supplier. We are including a few tips that may be of help:

  • • Mixing plaster in a plastic pan simplifies cleanup.
  • • Use as much water (cold) as the volume of plaster you want to end up with.
  • • Sift the plaster through your fingers into the pan until all water has been absorbed.
  • • Don’t stir the plaster and the water since it speeds the setup.
  • • When mixing lime and plaster, wet the lime a couple of days in advance.
  • • Amateur plasterers generally use 5 parts of lime to 1 part of plaster.

If the lath is in place, start by cutting back any loose plaster and thoroughly wetting both the lath and the surrounding plaster. You can then apply the scratch coat to the existing lath (as the plaster oozes into the lath it forms a “key”). While the plaster dries, take the tip of the trowel and make diagonal scratch marks. This rough surface provides a bond for the brown coat. Allow the plaster to dry thoroughly between coats. Trowel in the brown coat. To even out bumps and valleys, run a straight board over the patch (long enough to span it). The brown coat should be recessed about 1/8” from the adjacent plaster surfaces. Once it sets, apply the finish coat of plaster. This coat should be built out flush with the adjacent surfaces. The last step is to polish the surface out with water and a trowel.

In those cases where the lath has failed, start by making the hole large enough so that you can securely fasten the new wire lath to existing wood lath or framing. Cut a piece of wire lath the shape of the hole. The wire lath can be attached to the existing wood lath or framing by screwing either to the studs or the wood lath. You must be careful not to loosen the surrounding plaster. For very small holes requiring small pieces of lath, a short cut approach can be used, in which you mix some plaster and attach the wire lath to the wood lath with the plaster. If you already have metal lath in the walls, you can attach the wire lath with wire. Orient the blades of the wire lath so that they are diagonally facing up and away from the wall.

This provides a good hold for the plaster. With the lath in place, proceed with the application of plaster as described above.

Failing Plaster

When plaster is relatively intact (the three coats and the “keys” are together) but the lath is pulling loose from the beams and causing sagging, you can often use plaster anchors (washers) to fasten it back to the structure. The plaster is pressed back into position, a hole is driven through the plaster and into the supports, and then the anchor is screwed in place. For ceiling applications, make a T brace support out of 2 X 4’s and push the ceiling into position. The screws hold best when you can screw into the framing. If you have to screw into wood lath, drive the screws very slowly to prevent them from strip ping through the wood. Once the washers are in place, skim over them with a layer or two of joint compound.

INSTALLING FLOORING

The floor is installed last to prevent its being dam aged during the application of other finishes. Before putting in the new finish floor you must first remove the existing floor and then make sure that the subfloor is well nailed, level, and clean.

Removing Existing Flooring

Be it linoleum, carpet, tile, or wood, the existing floor surface has to be removed before the installation of the new floor can begin. There’s not much advice to be given for carpet, linoleum, or vinyl tile removal.* Removal of tongue-and- groove wood flooring and ceramic tile is more difficult. For the removal of tongue-and-groove wood floors (this includes parquet flooring), use the procedure described for removal of tongue- and -groove siding.

Removing ceramic tile requires a good amount of physical strength. Most likely you will be dealing with tile that was installed in cement. In the past, wall tile was installed by applying a gob of cement to the back of the tile. The tile was then stuck onto a wall which had been coated with cement. As a result, this covering must be removed practically tile by tile. With a cold chisel and a sledgehammer, smash the tiles (or take an end tile and put the chisel behind it). Chisel them off one at a time. Floor tiles are removed by hit ting them with a hammer, breaking them into pieces, and chiseling them off.

We must point out that asbestos fiber may have been used in linoleum backing, vinyl tiles, and even wood backing. Have an asbestos inspection and analysis of the material before proceeding with the demolition. If the flooring contains asbestos, have a licensed asbestos-removal company do the job.

Installing Wood-Strip Flooring

A layer of building paper is customarily laid over the subfloor as the first step in the installation of strip flooring. The building paper prevents dust from passing through to the joists and reduces the risk of squeaking caused by flooring moving against subflooring. It’s a good idea to snap chalk lines over the building paper to indicate the location of the joists below.

Strip flooring is installed at right angles to the floor joists. Older houses may have wood planks as the subfloor instead of plywood. If this is the case, the wood strips are installed at right angles to the subflooring (which will make them parallel to the joists). An alternative is to install the wood-strip flooring on the diagonal. Diagonal installation, though, entails more waste and difficulty in cutting. The strips are matched and grooved on both sides and at either end to provide an easy fit. Keep in mind that wood expands and contracts with the amount of moisture present in the air. Enough room (approximately 1/4”) should be left between the strips and the wall for this movement to take place. The strips will otherwise buckle, damaging the floor.

Lay out parts of the floor before beginning the installation. Mix long and short wood lengths. Long lengths can be used at the center of the rooms with short ones left for areas close to the walls. Avoid using all the long strips in one area and all the short strips in another. The floor should look homogeneous. Remember to stagger the joints.

Lay the first strip about 1/4” from the edge of the wall, placing the groove side toward the wall. With the aid of a nailer and mallet, nail through the top of the tongue into the subfloor and the joist below. Hook the groove side of the second strip to the tongue of the first. These strips should be driven tightly against each other. You can do this by using a piece of scrap flooring as a driving board.

The remaining strips are installed in the same manner. You may have to cut the last strip lengthwise to fit the room. Here again a gap of approximately 1/4” should be left to allow for expansion. Joints between the butt ends of the strip and the wall aren't that critical, since most of the expansion and contraction occurs along the width rather than the length. Keep a few things in mind. Butt joints should be staggered, with joints no closer than 6” from each other. In addition, be particularly careful to keep the boards straight. If they aren't aligned, you’ll have a problem when you reach the other wall.

Thresholds and saddles are nailed in place once the floor is completely laid. The baseboard is the last of the trimming to be installed. It is usually made up of a precut molding or a 1” X 4” or 1” X 6” piece of wood and a decorative cap. A quarter-round molding is then added at the floor. The molding is nailed to the floor, not the base board. Its purpose is to cover any cracks between the baseboard and the floor due to unevenness.

Installing Resilient Tile

Resilient tile, unlike wood-strip flooring, does not add to the strength of the floor. For this reason, the use of resilient tile requires a minimum of 3/4” of plywood to avoid springy floors.

Install the underlayment using ring-shanked nails every 6” o.c. at the edges of the panels and approximately 12” o.c. at the intermediate joists. Any indentations in the underlayment should be filled with a floor-leveling compound. Check with your supplier. Joints between underlayment sections should also be filled. The reason for doing this is that the type of tile used for residential installation is thin. Defects in the underlayment could show through and eventually damage the tile itself.

Most resilient-tile adhesives aren't compatible with particle board.

One way of applying tile is to start at one corner of the room and work your way into the other. A better way is to find the center line of the room and determine how many tiles need to be installed on either side. E.g., a room that's 17’-4” wide will require eight full (1’ X 1’) tiles to both the right and the left of the center line. The edge tile at both ends of the room will be 8”. The same system is used for the length. The center line can be adjusted slightly to accommodate various conditions. For instance, if the room was 16’-4”, the edge tile would be a skimpy 2”. By moving the center line to 7’-8” and 8’-8” the edge tile can become 8”.

If the type of tile you are using is self-adhesive, be careful. Once it’s laid down it's quite difficult to lift. When the adhesive is separate, follow the instructions on the can. Adhesive application should be done with a notched trowel.

Start laying the tile by applying adhesive up to one of the center lines. Allow the adhesive to set to the proper dryness. Line up the tile with the pencil line and press it firmly against the adhesive. The following tile is butted tightly against the first. The remaining tiles are similarly in stalled. Don’t try to push tiles into place once you’ve laid them. Lift and relocate them instead. To cut and fit tiles to walls and other features, place a tile on top of the nearest full installed tile. With the aid of another tile scribe up against the wall and transfer the dimensions to the top tile. This tile is then removed, cut with a lath knife and straightedge, and installed in the same manner as full tiles. When all the tiles are laid, the baseboard is installed.

Installing Ceramic Tile

There are two ways in which ceramic tile can be installed: with mortar or adhesive. We generally recommend mortar over adhesive since it offers a more durable installation. Mortar installation can be the traditional “mud” job or thin-set. Traditional Portland cement or “mud” jobs involve a thick bed of mortar, about 3/4” to 1 1/4” thick (de pending on whether it's for floors or walls). There are tiles that because of their irregularity can only be installed in cement. These generally include handmade tiles such as Mexican tiles. This type of installation involves quite a bit of time and skill. Should your tiles require a cement or “mud” installation, hire a good tile person.

We recommend that you limit your tilework to thin-set installation. “Thin-set” is a term used to describe various types of mortar compound which offer you the durability of Portland cement and the flexibility of adhesives. These installations can be as thin as 3/32” to 1/8”. All that's required is to spread the compound over the surface (with a large square-toothed trowel) and set the tiles in place. The best recommendation on the type of thin-set compound to use will come from your supplier. Directions for use are on the bag or container. While applying the tile, keep in mind the compound’s drying time. If you apply too much at once, it may be too dry by the time you’re ready to set the tile.

The procedures for walls and floors aren't vastly different. The walls, however, should be done first. (Walls located in moist areas such as showers or tubs should be backed by cementitious board. Moisture-resistant gypsum panels can be used on other bath walls.) Ceramic tile, like resilient tile, should be centered on the wall or floor. You may otherwise wind up with very narrow edge tiles, which, aside from looking awkward, are quite difficult to cut. To center the tile on the wall or floor, use the procedure outlined previously for resilient tile.

Thin-set installation requires that the floor base be level and smooth. Ceramic tile may be cut with tile cutters or with water saws. These tools can generally be rented where you buy the tile and instructions obtained from the dealer. For other than straight cuts (such as when you need to fit tile around a pipe), you will need to use flippers. Nippers are essentially “tile scissors.” Hold the glazed side up and , starting at one edge, make very small cuts until you get the desired shape. Smooth the edges with a file. When a hole is located at the center of a tile, your best bet is to cut the tile in half and , using the flippers, cut out the hole in each half.

Begin the installation of the wall tile by setting up a plumb vertical guideline. (You can use the center line you’ve already drawn on the floor to determine the tile location.) A wood strip is nailed at the edge of the line. (Without the wood strip the line would disappear when you apply the thin-set.) Check to see that the floor is level and start the application of the bottom or cove tile.* Apply the tile in rows, using the level cove tile and the wood strip as guides. Start on one side of the wood strip and work in one direction. When complete, remove the wood strip and repeat the process in the other direction. Some wall tiles are made with concealed tabs which space the tiles with respect to one another. These tabs should be laid in contact with one another. If the tile does not have these features, you will have to insert spacers between horizontal rows of tile in order to prevent them from settling. These are available at tile stores or may be fabricated out of wood. The rows of tile should be checked frequently with a carpenter’s level.

Plot out the installation of the floor tile by placing the guideline and wood strip at the opposite end of the room from the door. The reason for this is that once you install the tile, you can't step on it until it sets. Install the tile in the same manner as described above. (Spacers aren't required for floor installation.) With the aid of a straight edge and ruler, check the lines periodically for correct alignment. Once the tile sets, come back to complete the installation of the far edge.

Tiles are set by pressing them firmly against the thin-set. (A slight twisting motion helps to adhere them to the surface.) Every so often, go back over a few rows and tap them down with a wood board to make sure they’re all on the same plane. Allow tiles to set as recommended by the thin-set manufacturer.

Now is the time to grout the joints. Grout is the material used to fill the joints between the tiles. It comes in a couple of types, the most popular being a powder, which when mixed with water forms a thick paste. Before applying the grout, make sure that all the joints are free of thin-set. With the aid of a squeegee (some people prefer a trowel), pack the grout well into all the joints, going over them a few times. Wipe off excessive grout. Let the grout set for ten or twenty minutes or as directed by the manufacturer. Wipe clean the film of dry grout with a damp (not wet) sponge. Don’t let the grout dry completely before removing the excess. Once it dries, it's quite tough to remove. Most likely, you’ll have to wipe off the tile several times before it’s completely removed. Polish the clean tiles with a dry cloth.

For those who aren't using a cove tile, we suggest you start the installation with the floor and then proceed to the walls.

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