Pre-Engineered Flooring Installation Guidelines
OVERVIEW
Congratulations on your new wide plank floors. Installing wide plank floors is a skill and should not be treated like standard strip flooring. READ THIS ENTIRE DOCUMENT THOROUGHLY BEFORE RECEIVING YOUR FLOORING and follow throughout the installation process. Failure to do so will void the warranty.
Acclimation - Engineered Flooring
Ensure that the flooring has been properly acclimated to the site conditions prior to installation. Permanent HVAC should be on and operational and maintained between 60-75°F with relative humidity of 35%-55% for a minimum of 7 days prior to delivery, as well as during and after installation of the flooring. Humidity levels below 35% may cause movement in the flooring, including gapping between pieces and possible cupping and cracking in the face. Use of a humidification / dehumidification system may be required to maintain proper humidity levels, particularly over radiant heat.
The flooring must be delivered to the jobsite and the packages opened a minimum of 5 days prior to the start of the installation. Additional special requirements apply when installing over radiant heat. See below under ‘Radiant Heat Systems’ for details.
Subfloor Prep
Subfloors must be level, clean and dry. Improper subfloor preparation can make the floor unstable and cause premature damage. See further instructions below.
NWFA Guidelines
This installation guide is provided as a reference. In addition to these instructions, all flooring must be installed in accordance with NWFA (National Wood Flooring Association Guidelines). NWFA Guidelines provide additional information on job site requirements, acclimation, moisture testing, subfloor guidelines and specifications, installation instructions, safety guidelines, fastening scheduled, wood terminology and a job site checklist.
Receiving
Orders are shipped freight prepaid by Common Carrier or truckload Carrier. If your order arrives damaged due to shipping, note the damage on the freight bill before signing the bill of lading and contact your supplier immediately. Notify the Carrier of the damage and have them sign the bill of lading that identifies damage. Do not un-bundle your order and do not proceed with installation.
Storage, Acclimation & Jobsite Requirements
Storage & Acclimation
Store materials in clean, dry area indoors on flat, level surface. Do not store materials directly on concrete or near outside wall. These floors need adequate acclimation for moisture equalization prior to installation. If possible, leave engineered wood flooring in their sealed packaging until time of actual installation. Do not remove from packaging and acclimate like solid hardwood flooring. If packaging was removed as a necessity to unload materials upon delivery, restack bundles onto the pallet in the installation area for storage/acclimation.
Store the flooring in the properly conditioned installation area for a minimum of 72 hours before installation to allow flooring to adjust to room temperature. See jobsite requirements below for proper conditioning of installation area.
Jobsite Requirements
Prior to installation, the installer must ensure that the jobsite and subfloor meet the requirements of these instructions and the recommendations of the NWFA. Bayshore Wood Flooring accepts no responsibility for flooring failure resulting from unsatisfactory jobsite conditions and/or subfloor conditions.
All work involving water or moisture should be completed before installing hardwood flooring. For any new construction or remodeling project, hardwood flooring should be one of the last items installed.
HVAC systems must be operational and controlling site temperature and humidity. Area to receive flooring [and adhesive] must be properly conditioned at normal occupancy temperature (60-70ºF (15-21ºC), and humidity levels (35-55% humidity), maintained for a minimum of one week prior to installation as well as during and continuously following installation. Do not install in areas subject to moisture, such as bathrooms or laundry rooms.
Acclimation, Moisture Testing & Subfloor Prep Acclimation
Besides acclimating the wood flooring to the installation area as described in the previous section, Acclimation also refers to the moisture content of the wood flooring and the subfloor.
Upon delivery, check wood flooring moisture content with a moisture meter to establish a baseline for required acclimation. Check the moisture content of multiple boards. A good representative sample is typically 40 boards for every 1,000 square feet of flooring. Acclimate to moisture content % appropriate for your area — see NWFA Guidelines – Appendix D for a map of the USA and recommended MC% by state.
Moisture Testing
FOR WOOD SUBFLOORS:
Perform tests so that each test area does not exceed 200 square feet (18.6 sq. m), and perform no fewer than two tests in each installation area and with test areas evenly spaced in installation areas – minimum 20 testing locations per 1,000 square feet for wood subfloors.
Wood Subfloors must have a moisture content under 12% and within 2% of the moisture content of the flooring material. If you record excessively high readings in one or more areas, do not proceed with installation until the origin of the moisture is identified and moisture problems are remedied. Pay special attention to exterior and plumbing walls. See NWFA guidelines – Chapter 3 – for accectable vapor retarders over a wood subfloor. Do not use an impermeable vapor retarder material with a perm rating of .7 or less at it may trap moisture on or in the wood subfloor.
FOR CONCRETE SUBFLOORS:
Test concrete floors for moisture vapor emission using a Calcium Chloride Test per ASTM F 1869 or Calcium Carbide (CM) Test per ASTM (modified) D 4944-04. Before moisture testing begins, a concrete slab must be fully cured for at least 30 days. It is recommended that you first perform an electrical impedance and electrical resistance test with a moisture meter specifically designed for concrete (such as Tramex). These tests are not for the purpose of accepting or rejecting the subfloor, but rather are useful survey tools to select locations for further Calcium Chloride or CM testing.
** NOTE: A “DRY” SLAB, AS DEFINED BY THESE TESTS CAN BE WET AT OTHER TIMES OF THE YEAR. THIS TEST DOES NOT GUARANTEE A DRY SLAB. Roots Wood Products LLC is not responsible for site related moisture issues.
Calcium Chloride Test (ASTM F 1869)/Calcium Carbide (CM) Test (ASTM (modified) D 4944-04)
Follow all NWFA testing guidelines and test manufacturer’s guidelines. Perform a minimum of 3 tests per 1,000 square feet and one additional test for each 1,000 square feet thereafter. For concrete slabs reading less than 3 lbs per 1,000 square feet (15 g/m2) in 24 hours using the Calcium Chloride Test OR less than 2.5% using the CM Test, we recommend using SikaBond T-21 all-in-one adhesive and vapor retarder (perm rating of 0.4 when properly installed). Visit www.SikaBondT21.com for product information including the latest Technical Data Sheet, MSDS, and application instructions. For concrete slabs reading over 3 lbs and up to 7 lbs using the Calcium Chloride Test OR over 2.5% and up to 4% using the CM Test OR if there is any concern about the slab remaining “dry” year-round, a direct glue-down application (SikaBond-T35/ SikaBond-T21/ SikaBond-T55) is recommended only in combination with a vapor barrier (Sika Primer MB) with a perm rating of 0.15 or less. A concrete slab with a reading over 7 lbs using the Calcium Chloride Test OR over 4% using the CM Test is not acceptable for wood flooring installation. Keep detailed documentation of test results and all test location(s).
If directly gluing to concrete, use recommended Sika adhesive ONLY and follow all of Sika’s instructions.
ON-GRADE OR BELOW-GRADE INSTALLATIONS
Due to the concern of moisture, for on-grade or below-grade installation, we recommend installing a vapor barrier and a plywood sub-floor over the concrete. If slab conditions are not adequate for a direct glue down application, building in a subfloor is common. An impermeable vapor barrier with a perm rating of .15 or less, such as a 6 mil polyethylene film or Sika Primer MB, is required over the concrete slab prior to building the subfloor. Gluing/Screwing down a plywood deck prior to installing the wood floor is one option. Plywood and adhesives MUST be rated for this application. A floated subfloor is another option. Additionally, installing sleepers then a nailed down plywood deck is another approach to the creating a subfloor condition where wood flooring can be nailed down, or glued and nailed to the deck. See NWFA Guidelines, Chapter 6 for additional information on installing a subfloor over conrete.
NOTE: Installing a plywood subfloor over the concrete is our recommendation for installation over concrete on- or below-grade. However, if you choose to perform a direct glue-down installations on-grade or below-grade, a vapor barrier (such as Sika Primer MB) with a perm rating below .15 is always required.
Do not use a concrete sealer nor install over one. The concrete must be high compressive strength (3,000 psi or greater). For weak concrete substrate or gypsum-based substrate use Sika Primer MB as a surface consolidator. All concrete sub-floors should be tested for moisture content. Visual checks are not reliable.
See NWFA Installation Guidelines, Chapter 3 for additional information on moisture testing.
Subfloor Preparation
Acceptable Subfloor Types
- 3/4” or thicker exterior plywood, 5/8” minimum thickness, installed with the long edge forming a right angle to the floor joists.
- 1” x 4” to 6” wide, square edged, kiln dried coniferous lumber, laid diagonally over 16” on center on wooden joists. The ends of all boards are to be cut parallel to the center of the joists for solid bearing.
- 3/4” minimum O.S.B. on 19.2” center floor joists system properly nailed.
- Concrete Slab – minimum 3,000 psi (glue-down only)
- Sheet vinyl (glue-down only)
NOTE: Direct glue-down of Bayshore engineered wood flooring over a Gypcrete subfloor is not recommended due to the possibility of shearing/cracking of the Gypcrete caused by the adhesive pulling on the subfloor as the wood naturally expands/contracts with changes to temperature & humidity. If working with a Gypcrete subfloor, we recommend building a plywood deck prior to installing the wood floor. Plywood MUST be rated for this application. Additionally, installing sleepers then a nailed down plywood deck is another approach to the creating a subfloor condition where wood flooring can be nailed down, or glued and nailed to the deck. Consult NWFA for recommendations on constructing a subfloor over Grycrete.
Bayshore Wood Flooring is not responsible for any flooring failure caused by subfloor conditions.
All Sub-Floors Must Be:
- Structurally Sound
- Dry and remain dry year-round.
- Clean: swept (or vacuumed with industrial vacuum if using glue-down method) thoroughly and free of all debris. If using glue-down installation, subfloor must also be free of wax, grease, paint, sealers and old adhesives which can be removed with sanding. A simple way to test for the presence of sealers on concrete is to pour a small amount of water on the concrete slab – the concrete should be porous and the water should seep into the concrete. If the water is beading, this would indicate the presence of a sealer which needs to be sanded prior to beginning the installation.
- Level: flat to within 3/16” in 10 feet or 1/8” in 6 foot radius.
Grind and fill sub-floor using methods and materials appropriate to the sub-floor construction to eliminate humps and depressions exceeding 1/8 (3 mm) inch in 6 feet (1830 mm) radius or 3/16 inch in 10 feet. If necessary, level down any irregularities using #20 grit paper and fill any uneven spots with cementitious leveling compound – we recommend SikaLevel-125, SikaLevel-315 or Sika Level SkimCoat (see next page for additional information). Remove all paint, wax, oil, plaster, sheetrock mud, protruding fasteners and previous or existing glues and adhesives. Grind concrete with #3 1/2 grit sandpaper if needed then sweep or vacuum thoroughly. Clean surfaces thoroughly prior to installation.
Wood Sub-Floor Must Be:
- Flat, clean, dry, structurally sound, well secured, free of squeaks, free of protruding fasteners and with a moisture content under 12% and within 2% of the moisture content of the flooring material.
- Nailed down or screwed down every 6” along the joist to avoid squeaking.
- Leave an 1/8” gap around perimeter to allow for expansion.
- Leveled by sanding down high spots and filling in low spots with a Portland based leveling patch as necessary. For installations using mechanical fasteners of 1 •••” and longer, the subfloor should be flat to within •••” in 10 feet or 3/16” in 6 foot radius. For glue-down installations and installations using mechanical fasteners of less than 1 •••”, the subfloor should be flat to within 3/16” in 10 feet or 1/8” in 6 foot radius.
Concrete Sub-Floor Must Be:
- Fully cured for at least 30 days
- Installed properly with minimum 6-mil polyfilm between concrete and ground.
- Dry all year round. Do not install over concrete if you are not sure it will remain dry.
- Tested for moisture by using Calcium Chloride Test or CM Test (see moisture testing above)
- High Compression Strength – Minimum 3,000 psi (20 MPa)
Sheet Vinyl Must Be:
- Well bonded to the floor.
- In good condition.
- Clean and level, no debris.
- Do not install over vinyl tiles.
Installation
Bayshore Engineered Wood Flooring can be installed above-grade on-grade, or below grade. It may be glued down over a plywood or concrete sub-floor. It also may be simply nailed down or stapled down over a plywood floor using specially designed hardwood floor nailers. Knot holes or other defects can be filled with a clear two part epoxy, wood filler, or clear adhesive. Note: this may take extra time when working with reclaimed wood. All cracks, open knot holes and large nail holes are normal with reclaimed wood and will require filling.
PLEASE NOTE: It is the duty of the installer to judge the suitability of any piece for placement in an obvious area of the room. If you feel a piece is not suitable, either do not install it or install it in an inconspicuous place.
Preparing for Installation
Be sure to follow proper subfloor prep and moisture testing as outlined in the previous section. Undercut or notch-out door casings to fit flooring underneath by placing a piece of flooring on the sub-floor as a height guide for sawing. Remove door thresholds and base moldings and replace after flooring installation. Always leave at least 1/2” expansion space between flooring and all walls and vertical objects. Use wood or plastic spacers during installation to maintain this 1/2” expansion space.
Use a hammer and tapping block and tap against the tongue to pull planks together. Never tap against the grove of the plank. When near a wall, use a crow or pull bar to close end joints. Be careful not to damage flooring edge. All of Bayshore’s Engineered Wood Flooring is milled to very exacting standards, so pieces that do not go together easily usually have debris in the groove, the tongue and/or groove has been damaged, or the board is a little bowed and you just need to flatten it out, rather than forcing the pieces together.
Starting Installation
For aesthetic purposes, wood flooring is often laid to the longest wall. However, the building owner/architect/design, upon the advice of the professional installer should make the final decision as to which direction the planks will run. Flooring should be laid at right angles to the floor joists and, if possible, in the direction of the longest dimension of the room. Most professional installers will begin installation next to an outside wall, which is usually the straightest wall, as a reference point in establishing a straight working line. A good way to establish a working line is to measure an equal distance from the wall at both ends and snap a chalk line. Measure distance from the wall at the width of the plank plus another 1/2” for expansion space for establishing your working line. It is advisable to “dry lay” a few rows before permanently laying the floor to confirm your directional layout decision and working line. This will also allow you the opportunity to select the varying colors and grains to create an aesthetically pleasing pattern. Adjustments of the working line may be necessary if the outside wall or other working line reference is out of square. This can be done by scribe cutting the first row of planks to match the wall, thereby creating a straight working line.
Stagger end joints of boards row to row a minimum of 8-10” for 3” to 5” planks, and 10” for planks wider than 5”.
Glue-Down Installation
You can contact Bayshore Wood Flooring. Use of another manufacturer’s adhesive may result in failure and void warranty.
Staple or Nail Down Installation
In general, wood or plywood sub-floors should not exceed 12% moisture content, nor 2% moisture content difference between hardwood flooring and sub-floor.
Use stapler/nailer of your choice that is suited for the material being installed. See NWFA guidelines for fastener schedule.
Before installing, test a sample to make sure that stapling/nailing will not cause “dimpling” (localized raised edges) on the finished floor. If dimpling does occur, STOP and adjust the stapler/nailer shoe and angle/place of staple entry in order to avoid it. Bayshore Wood Flooring is not responsible for dimpling.
Adequate and proper nailing as well as soundness of the sub-floor should be ascertained. Foreign material should be removed from the sub-floor. The clean sub-floor should be covered, wall-to-wall, with 15 lb. asphalt saturated felt. When positioning felt, lap edges at least 4”. Double the felt around any heat ducts in the floor. Basement and crawl spaces must be dry and well ventilated. Crawl space should be a minimum of 18” (457 mm) from ground to underside of joints. Crawl spaces must be 100% covered by a minimum 6 mil black polyethylene vapor barrier below the sub-floor on the ground.
For the first and second starting rows, lay first plank inside chalk line with grooved edge toward wall. Install entire first room in this same manner. Remember to always leave a 1/2” expansion space between flooring and all walls and vertical objects. Use wood or plastic spacers during installation to maintain this expansion space. Make sure that the nail gun’s faceplate does not damage the UV-cured factory finish. 3M Blue tape can be placed on the faceplate to prevent damage.
In order to affix the first rows, as it is difficult to get the nail gun in place next to the wall, you may wish to set these rows in mastic and glue them down rather than face nailing them and leaving unsightly nail holes, which must be filled with putty to match the wood floor. After gluing down these starting rows with the recommended adhesive, set weight on top of these rows and allow them to set BEFORE commencing stapling/nailing the additional rows, as nailing the adjacent rows may cause the starting rows to subsequently move. Make sure the starting rows are straight and drawn tight.
Continue laying subsequent rows using stapler/nailer to blind-nail top inside edge of tongue at a 45º angle. Nail each board every 8” and within 2” of each end. Remember to stagger end joints from row to row at least 8” apart and use a tapping block to fit boards together.
It may be necessary to face-nail in doorways or tight areas where the stapler/nailer cannot fit (or glue-down in these areas and weight them while the mastic sets). The last two rows will need to be face-nailed (or glued-down) in the same manner as the first two rows.
Flooring wider than 7” in nominal width should be face-nailed or equivalent to minimize movement after installation.
Be sure to check the floor as you go to endure that the stapler/nailer is not causing dimpling.