Proper attention and preparation of the jobsite will ensure successful hardwood flooring installation.
Wood flooring by design is not to be used to strengthen/stiffen a subfloor and will not do so. If movement of the subfloor occurs prior to installation and is not corrected, that same movement will occur after installation is complete.
Minimum Jobsite Requirements
A. Wood flooring should be one of the last jobs completed on the construction project. Limit foot traffic on finished wood flooring.
B. Evaluate the jobsite for potential problems before installation begins, and before wood flooring is delivered to the jobsite.
C. Installation constitutes acceptance of flooring material, subfloor/substrate, the jobsite itself including the ambient temperature and relative humidity at the time of installation, and all impacting variables that may affect a wood floor. For warranty and/or hold harmless agreements, check with legal counsel.
- Exterior surface drainage should direct water away from the building.
- Do not deliver wood flooring to the jobsite or install wood flooring until the building is enclosed.
- If heating and/or air conditioning is in operating condition, it needs to be operating. If it is not possible for the permanent heating and/or air conditioning system to be operating before, during and after installation, a temporary heating and/or dehumidification system that mimics normal temperature and humidity conditions can enable the installation to proceed until the permanent heating and/or air conditioning system is operating.
- Do not deliver wood flooring to the jobsite or install wood flooring until appropriate temperature and humidity conditions have been achieved. Appropriate temperature and humidity conditions are defined as those conditions to be experienced in the building after occupancy.
- Do not deliver wood flooring to the jobsite or install wood flooring until all concrete, masonry, plastering, drywall, texturing and painting primer coats are completed.
- Basements and crawl spaces must be dry. If power washing is required in the basement, do so before wood flooring is installed and allow subfloor and basement to dry before installing wood flooring.
- Crawl space should be a minimum of 18" (457mm) from ground to underside of joists.
- Crawl space earth (or thin concrete slab) should be covered 100 percent by a vapor retarder of black polyethylene (minimum 6 mil) or any recommended puncture-resistant membrane, such as Class C, meeting ASTM D1745. Click on Figure 1-1 to enlarge. Check local codes.
Crawl Space Conditions
- Where a proper ground covering is in place and when venting is required by local building codes, the crawl space should have perimeter venting equal to a minimum of 1.5 square feet per 100 square feet of crawl space square footage, unless local building codes differ from this specification. Note: Local building codes may differ. Follow local building codes.
- For crawl spaces without ventilation openings, vapor retarder joints must overlap a minimum of 6 inches and be sealed or taped. The vapor retarder should also extend at least 6 inches up the stem wall and be attached and sealed to the stem wall. Continuously operated mechanical exhaust and perimeter wall insulation or conditioned air supply and insulation must be provided.
- Note the grade level so that the correct type of flooring and system can be specified for the job. Engineered and floating floors can be appropriate for above-grade, on-grade and below-grade installations. Solid wood flooring can be appropriate for above-grade and on grade installations, but not for below grade installations. If the soil surrounding a structure is 3 inches or more above the floor of any level, consider that level below grade. This includes walk-out basements. In addition, the surrounding soil should be sloped away from the structure. See Figure 1-2.
- Subfloors (wood or concrete) should be checked by an appropriate method for establishing moisture content. Average subfloor moisture content should be within the range as specified for the product by the product manufacturer. See Moisture Testing. See Figure 1-2.
- Where the minimum jobsite conditions are present, the flooring can be delivered and stored in the rooms in which it will be installed. See >Acclimation and Conditioning of Wood Flooring.
Additional Jobsite Conditions for Factory-Finished Flooring
A. All finished wall coverings and painting should be completed. Note: Base and shoe mold may be installed after the flooring installation.
B. After installation, if you choose to protectively cover the floor, cover the floor completely, since some species are light-sensitive and uncovered areas may change color. However, covering a glue-down application may not allow some adhesives to properly cure. Follow the flooring and adhesive manufacturer's recommendations. Use a covering material with a vapor permeance (perm rating) of 1 perm or more (tested in accordance with ASTM E96) to avoid trapping moisture/vapor on or within the floor. Any covering should be taped, using a lowadhesion tape, to base or shoe moldings. Do not tape to finished flooring. When taping paper or sheets together, tape them to each other, not to the floor. As in all installations, at completion of job, inspect flooring from a standing position.
See Appendix M.
Be aware of the most current EPA regulations for lead paint dust as well as asbestos (www.epa.gov).