All substrates must be clean, dry, structurally sound, properly cured and free of dirt, oil, paint, old adhesive, wax, sealers and curing agents. General scouring with 20 grit or #3 1/2 open-coat sandpaper will remove most compounds. All loose materials must be vacuumed from the surface after scouring. The subfloor must be flat to a tolerance of 3/16” in a 10’ radius. Hollow spots, popping spots and squeaks are related to unevenness in the subfloor. Grinding concrete floors is preferred over the use of filling compounds. If filling/flattening compounds are used, they must be Portland-based cementitious material and have a compressive strength equal to or greater than 3000 psi when cured. Use of adhesive over light weight concrete and all gypsum-based materials requires the use of a primer prior to application of adhesive. Remove all existing base, shoe molding and door thresholds prior to continuing the installation. All door casings must be undercut with either a jamb saw or a hand saw. Use a piece of the flooring as a guide to determine the thickness needed.
Installation of Wood Flooring
Titebond 821 Premium can be installed using the “wet lay” or “flashed” methods, depending on your preference and the environment of your installation. In the “wet lay” method you do not flash the adhesive. Once the adhesive has been troweled, the wood flooring may be installed immediately into the wet adhesive. To reduce slippage, secure the first starter row with Titebond Tape. Remaining planks must be placed firmly into adhesive. Planks which are not flat should be weighted for several hours. In the wet lay method, you should not work on top of the wood. The “flashed”* method is when the adhesive is allowed to flash for the recommended amount of time prior to installing the wood flooring. While using this method, you are advised to trowel out larger sections of the room so that you spend most of your time laying wood rather than flashing adhesive. Be careful not to exceed 821 Premium’s open time of 90 minutes and do not trowel more adhesive than you can comfortably cover with the flooring in 90 minutes.
Re-sealing and Re-opening Partial Pail
* The recommended flash time for Titebond 821 Premium is 30 minutes, depending upon subfloor moisture and humidity.
Scrape sides of pail (this will aid in removal of adhesive later). Place plastic trash bag over unused adhesive, working out any air pockets. Replace lid on pail and tightly seal. Upon re-opening pail, remove trash bag. Material should be ready for use.
Gluing Plywood Over Concrete
1. Use 5/8" CD Exposure 1 Plywood subfloor panels, 4' x 8' sheets; cut sheets into 2' x 8' or 4' x 4' sections
2. Score the back of the panels half the thickness of the panel on a 12" x 12" grid in order to relieve tension in plywood
3. Use a 1/4" x 1/4" square-notched trowel to apply adhesive to concrete
4. Lay sections in a staggered joint pattern in the adhesive, with 1/8" spacing between sheets, and 3/4" minimum expansion space at walls and all vertical obstructions
5. Add weight as necessary to ensure adhesive remains in contact with plywood as it cures
6. Allow adhesive to dry overnight before proceeding with flooring installation
As the pre-finished flooring is being installed, immediately wipe any wet adhesive from the flooring, tools and equipment with mineral spirits. Do not allow adhesive to cure on surface of the flooring, tools or equipment. Follow solvent manufacturer’s directions when working with solvents. Cured adhesive will be difficult to remove.
Do not sand, scour or abrade any material that is suspected of containing asbestos fibers. Asbestos is known to cause cancer. Federal law requires that asbestos be handled by a licensed and certified hazardous materials contractor.
The recommended flash time for Titebond 821 Premium Wood Flooring Adhesive is 30 minutes
, depending upon subfloor moisture and humidity. Specific questions regarding "flash time" should be directed to Franklin Technical Service at 1.800.347.4583.