Surface Preparation
This
is the most important step in attaining a quality tiling job.
The surface to be tiled must be firm (doesn't flex when weight
is applied), flat, level, and clean. For professional results,
install tile only on the surfaces described in this brochure.
If you find that your surface is a material other than one of
those mentioned below, replace it with an approved surface.
FLOORS
Wood Subfloors:
Check to see that your floor joists (studs) are no more than 16
inches on center.
Anything more than this will not provide a stiff surface to tile.
A double wood
floor of 1-1/4 inch thickness (two 5/8 inch sheets of exterior
grade plywood) is the construction recommendation. These two layers
should
be overlapped with offset joints. In some installations, subfloors
may be stiffened
with a 1/2 inch cement backer board. This should be placed with
8d (1-1/2 inch
minimum) cement coated nails or screws every 6 inches around the
perimeter, and
every 8 inches in all directions across the floor. Space sheets
with 1/8 inch gaps a
nd offset sheets so joints do not coincide with plywood subfloor.
Surface should
not dip or rise more than 1/8 inch over any 10 foot span. (see
diagram below)
Concrete
Subfloors:
Concrete
must be clean and free from waxes, sealers, curing compounds, etc.
If any of these are present, the tile will not adhere to the surface.
To test for
these agents, place a few drops of water on the surface. If the
water beads, one of the above contaminants is present and must
be removed with a floor stripper.
Check the
surface for flatness by laying a straight edge that is at least
four feet long on the floor. The floor should not dip or rise
more than 1/8 inch in a 10 foot span. Larger depressions can be
leveled using a self leveling cement filler or latex fortified
patching compound.
Existing
Ceramic Tile Floors:
Check to see that all existing tile is well bonded. Make sure
that it is clean and free of
all loose materials and remove any soap or wax residue with a
strong degreasing agent
(such as TSP). The new floor you lay down will only be as good
as the surface on
which you tile. Never set tile over a loose or dirty surface.
Asphalt
Tiles, Sheet Vinyl Or Linoleum Floors:
Existing floors of this nature can be used as a substrate as long
as the tiles or sheets are
solidly adhered to the floor, and that there is proper firmness
and flatness throughout.
If the floor
is sound, firm and in good condition, strip floor of all sealers,
waxes and dirt
with a floor stripper. Caution! Never sand or abrade vinyl asbestos
tiles.
Expansion
Joints:
Expansion joints must be left around the perimeter to allow for
floor movement. Leave
a space of 1/4" between the wall and the subfloor/adhesive/tile.
Areas larger than
24" x 24" require expansion joints within tiled area. This space
is then sealed with a
flexible sealant.
WALLS
Standard framing is fine to support a tiled wall. The wall must
be strong enough to hold
up with the additional weight of tile, adhesive and grout. Use
plaster, gypsum board or
moisture resistant portland cement backer boards for most tiling
jobs. Plywood and
Gypsum based products are not recommended for wet areas.
COUNTERTOPS
Plywood
Underlayment:
Total thickness must be at least 3/4 inch and securely bonded.
If a new or additional
surface is needed to increase the thickness to 3/4 inch, use approved
underlayment grade
plywood or cement backer board. Fasten at 6 inch intervals along
the edges and studs
with 1-1/2 inch galvanized roofing nails for cement backer boards
or 1-1/4 inch (minimum)
underlayment nails or screws for plywood.
Check old
or newly applied surface for loose areas and reinforce with appropriate
fasteners.
