Titebond® 821-Step Adhesive, Moisture & Sound Control combines the superior properties of a moisture cure adhesive with the ability to be used as a moisture and sound control system. This high-performance formula is ideal for bonding engineered, solid plank, cork underlayment and bamboo flooring to common underlayments and subfloors.
Its non-slumping characteristics allow the troweled ridges to bridge normal gaps between the wood flooring and the subfloor, virtually eliminating hollow and popping spots. This product also allows the installer to protect the wood floor with a glue down all-in-one application with unlimited moisture warranty, saving labor and time. Once cured, the product is water-resistant. It offers excellent green grab and develops a superior bond that will remain flexible for the lifetime of the floor.
Alternatively, Titebond 821-Step can simply be used as an adhesive by using a different sized trowl. Please see specific application guidelines in this document for details and instructions. It can also be combined with Titebond 531 or Titebond 531 PLUS Moisture Control Systems to achieve unlimited moisture protection. It has unparalleled green grab, strength development and spreads easily. This mold and mildew resistant formula delivers exceptional performance characteristics that exceed the expectations of professional installers.
All substrates must be clean, dry, structurally sound, properly cured and free of dirt, oil, paint, old adhesive, wax, sealers, curing agents and any material that may inhibit bonding. General scouring with 20 grit or #3 1/2 paper 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/leveling compounds are used, they must be Portland cement based and have a compressive strength equal to or greater than 3000 psi when cured. Moisture level in concrete subfloor will fluctuate. Any cementitious material used must be rated for the highest moisture content possible. Consult the cementitious material manufacturer’s application directions. Use of product over light weight concrete and all gypsum based materials requires the use of Titebond Concrete Primer or equivalent prior to application of adhesive
MOISTURE CONTENT LIMITATIONS
Titebond 821-Step may be used as an adhesive and moisture control system for concrete slabs with elevated moisture levels. Calcium chloride or in-situ RH testing is NOT necessary. To ensure a proper bond and full moisture control, it is essential that the concrete be dry to the touch and fully cured before installation. For flooring adhesive only application method, concrete subfloor moisture cannot be greater than 3 lbs./1000 sq.ft./24 hours on a Calcium Chloride Test or greater than a reading of 4.5 on a Tramex Concrete Moisture Encounter or 75% relative humidity per an in-situ probe test.
INSTALLATION: ONE-STEP ADHESIVE, MOISTURE AND SOUND CONTROL METHOD
When using this method, follow all previous instructions for subfloor preparations. Be sure to obtain the correct trowel. Trowel product with the correct trowel and immediately install the wood flooring into the wet adhesive. To reduce slippage, secure the first two starter rows with starting blocks fastened to the substrate or wedges against starting wall. Remaining planks must be placed firmly into adhesive. Planks that are not flat should be weighted for several hours. 100% adhesive coverage, with no voids, is required to qualify for the all-in-one installation warranty. Open time depends on relative humidity and is usually around 90 minutes. Be sure to seat the flooring into the adhesive firmly. Any low or high spots may cause voids in the adhesive and void the warranty
IF INSTALLING ON CONCRETE - MOISTURE BARRIER SHOULD BE APPLIED
Titebond® 531 PLUS Concrete Moisture Control System solves the challenges of moisture transfer from concrete subfloors to wood and resilient flooring by reducing the transmission rate of moisture. The system consists of two pre-measured components that are mixed together to form a coating that is applied to the concrete surface. The easy-to-use formula will reduce the moisture vapor transmission rate from most concrete subfloors by 75%-90%. When used as directed with recommended wood flooring and resilient flooring adhesives, Titebond 531 PLUS is fully warranted. It dries fast and is tack-free in less than two hours under most conditions, allowing for same-day installation of flooring. The product has low odor and eliminates the need for bead blasting or other inconvenient measures. It has zero VOCs, meeting the most stringent national regulations. In addition, it helps reduce the potential for mold and mildew growth caused by subfloor moisture. Titebond 531 PLUS provides the professional installer with a cost-effective, convenient system designed to reduce concrete subfloor moisture transfer to wood and resilient flooring.