"In-use" Moisture Content.
Differences of more than
4% between the expected in-use average moisture content
of flooring and the in-use average moisture content
of underfloor construction are likely to cause
problems such as cupping. The greater the difference
the more severe the problems. A significant difference
of 8% or more may result in buckling of the floor
when the underfloor is the higher moisture content.
Finishing should proceed 1-3 weeks after installation is
completed. Longer periods of exposure to job site conditions
can result in future problems. Finishing immediately
after installation does not allow the flooring
adequate time to acclimate to its new environment.
Work from left to right. In laying strip flooring you'll
find it easier to work from your left to your right. Left
is determined by having your back to the wall where
the starting course is laid. When necessary to cut a
strip to fit to the right wall, use a strip long enough
so the cut-off piece is 8in or longer and start the next
course on the left wall with this piece.
Short pieces. For best appearance always use long
flooring strips at entrances and doorways. Incorporate
as many short pieces as possible at random in the floor.
Do not group them in one area.
Put a "frame" around obstructions.
You can give a
much more professional and finished look to a strip
flooring installation if you "frame" hearths and other
obstructions, using mitered joints at the corners.
Reversing direction of strip flooring.
Sometimes it's necessary to reverse the direction of the flooring
to extend it into a closet or hallway. To do this, join
groove edge to groove edge, using a slip tongue available
from flooring distributors. Glue slip tongue in
place and blind nail that edge. Proceed in the opposite
direction nailing in the conventional manner.
Use only sound, straight boards for subfloors.
The quality of the subflooring will affect the finish
flooring. Use only square edge 3/4in dressed boards no
wider than 6in. Boards which have been used for concrete
form work are often warped and damp and
should not be used.
Don't pour concrete after flooring is installed.
Concrete basement floors are sometimes poured after
hardwood flooring has been installed. However, many
gallons of water from drying concrete are evaporated
into the house atmosphere where it may be absorbed
by hardwood flooring and other wood components.
This is not a recommended building practice since
excessive moisture will cause problems with wood
floors and other woodwork. Wood flooring should not
be installed until after all concrete and plaster work
are completed and dry.
Doorways, Stair Treads, and High Traffic Areas.
If flooring direction changes, always use slip tongues or
engage the flooring end matching into groove side of flooring
to prevent movement and give a solid transition.
Put voids between screeds to good use.
Masonry insulation fill, normally used in hollow concrete blocks,
can be poured between the screeds of a slab installation
to give additional moisture protection and deaden
the drumming sound that sometimes occurs from
foot traffic.
Sound deadening in multi-story building.
Noise transmission from an upper to a lower floor can be
reduced. Nail subfloor to the joists in the normal manner
and cover this with 1/2in or thicker cork or insulation
board laid in mastic. Cover this with another 3/4in
plywood subfloor also laid in mastic. Nail the finish
strip or plank floor to the plywood, or lay block or parquetry
floors in mastic on the plywood. In the case of
parquet the second subfloor plywood can be 1/2in tongue-and-groove type. Note that specifications for some
high-rise apartment buildings call for other types of
sound-deadening construction.
Mastics and trowels. There are several types of mastics
available that are satisfactory for use in laying
hardwood floors. Hot asphalt is generally used only
for laying screeds on concrete and the screeds must
be positioned immediately on pouring the mastic. Cutback
asphalt, chlorinated solvent and petroleum-based
solvent mastics are all applied cold and are used for
laying tongue and grooved block and parquet floors.
Cut back asphalt mastic can be used to hold a recommended
vapor retarder and/or to glue a plywood subfloor
to the slab. Follow manufacturers' instructions
on coverage, drying time and ventilation.
Trowels usually have both straight and notched edges.
The notched edge is for use where a correct mastic thickness
is specified. Both mastic and trowels may be available
from flooring manufacturers and distributors.
Different Manufacturers Products.
Do not randomly mix different manufacturers' products. Use
transition areas such as doorways to separate the different
manufacturers.
Flooring Installation Guide :: Index
1) Installation Introduction
2) Handling & Storage
3) Job Site Conditions
3.1) Installing over Concrete
3.2) Testing Concrete for Excessive Moisture
3.3) Concrete Slab Preparation Prior to Installation
4) Laying & Fastening
5) Plank Flooring
6) Laying a New Strip Floor Over an Old Floor
7) Parquet, Block Herringbone & Similar Flooring
8) Special Construction Situations
9) Tips for Easier & Better Flooring Installations
10) Strip Flooring on Walls & Ceilings
11) Installation of Gymnasium Floors over a Concrete Slab
Installation content courtesy of NOFMA. FloorMall.com is a Proud Member of NWFA.
