Flooring adhesive
Two pails, and between them they cover most glue-down wood jobs in this catalogue. Both are one-component adhesives that also inhibit moisture coming up through a concrete slab, so the bond and the moisture barrier are the same troweled layer.
The short answer
For glue-down wood over concrete you want a moisture-cure or MS-polymer adhesive rated to control slab moisture, troweled at the heavier spread rate the maker gives for that job. The lighter rate bonds the floor only. Get the slab tested first: the moisture reading is what decides which adhesive is allowed, and it is the one number no product page can tell you.
Side by side, from each maker's data sheet
Every figure below is the manufacturer's own, extracted from their published technical data sheet. A dash means the maker does not publish that figure for that product, and we do not supply one.
| Specification | Bostik Wood-Grip Plus Hardwood Flooring Adhesive | Shaw TotalWorx 3-in-1 Ultra Hardwood Flooring Adhesive |
|---|---|---|
| What it is | One-part AXIOS Tri-Linking Polymer, moisture-cure wood flooring adhesive and moisture control membrane in one product. Colour beige; density 14.25 lbs/gallon | One-component, 100% solids, cross-linking MS-polymer hardwood flooring adhesive that also acts as a concrete moisture inhibitor, sound reduction system and crack isolation layer. Solvent and isocyanate free, non-flammable, low odour. Off-white medium paste; working time about 50-70 minutes; one year shelf life unopened at 70F |
| What it is for | All engineered, solid, bamboo, cork and parquet wood flooring, with no restriction on board width or length; also plywood, and ceramic, marble and stone inlays in residential or light commercial use. Below grade is limited to engineered hardwood. Not for exterior or wet areas | Interior installation of Shaw hardwood products and mineral-core resilient flooring |
| Moisture control | Unlimited moisture vapour protection. Water vapour permeability below 0.4 (ASTM E-96). ASTM 1869 and ASTM 2170 subfloor limits: none, dry to the touch. Bridges cracks up to 1/8" (3 mm). Requires 100% substrate coverage and adhesive transfer | Rated for concrete below 3 lbs per 1,000 sq ft per 24 hours (ASTM F-1869) or below 75% relative humidity (ASTM F-2170), and wood subfloors below 12% moisture. Requires the specified substrate preparation: 45 day cure, CSP 1-3 profile, intact below-slab vapour retarder, flat to 3/16" in 10 ft |
| Coverage | As adhesive and moisture membrane: 30-35 sq ft/gallon for solid, engineered or bamboo up to 5/8" thick; 20 sq ft/gallon over 5/8" or plywood. As adhesive only: 80 sq ft/gallon (parquet to 1/2", cork underlayment), 50 (engineered to 1/2"), 40 (engineered over 1/2", solid or bamboo to 1/2", parquet to 3/4"), 35 (solid or bamboo over 1/2", plywood) | Moisture and sound plus wood installation: 30-35 sq ft/gallon. Adhesive only: 60-70 sq ft/gallon for engineered 3/8"-1/2" thick up to 5" wide; 50-60 for engineered over 5" wide and 1/2" thick; up to 80 for engineered 1/4" thick. Shaw states coverage is approximate and varies with subfloor porosity, trowel angle, temperature and installer technique |
| Trowel notch | Adhesive plus membrane: 1/4" x 1/4" V-notch or 1/4" x 1/4" x 1/4" square notch up to 5/8" thick; 1/2" x 15/32" V-notch or 1/4" x 3/8" x 1/4" square notch over 5/8" or plywood. Adhesive only: 3/16" x 5/32" V-notch, or 1/8", 1/4" x 1/4" x 1/8" and 1/4" x 1/4" x 1/4" square notches by flooring type | 3/16" x 1/4" x 1/2" flat V-notch with spacers (trowel included) for the moisture and sound application; 3/16" x 1/4" x 5/16" flat V-notch for engineered over 1/2" thick. Replace the blade with each pail as the spacers wear |
| Sound reduction | Not rated: Bostik's data sheet lists ASTM E492 IIC, ASTM E2179 delta-IIC and ASTM E90 STC as not applicable for this product | Shaw states it meets IIC and STC building code requirements for sound reduction. No numeric IIC, STC or delta-IIC values are published for it, so none are quoted here |
| VOC | Zero VOC as calculated per SCAQMD Rule 1168 (0 g/L); contains no water. May contribute to LEED NC-v2.2 EQ 4.1, Low-Emitting Materials | VOC content 0.5 grams per litre; meets USGBC LEED EQ credit 4.1. Shaw's brand page states low odour, low VOC and Greenguard certification for indoor air quality |
| Container | 4 gallon plastic pail (36 pails per pallet) | 4 gallon pail, trowel blade included |
Order a pail
Both carry a published price you can order against. Neither is available as a sample.
The rest of the glue-down job
Trim, mouldings and underlayment
Transitions, stair nosing and acoustic underlayment, listed as their own department.
The floors these go under
Engineered, solid and parquet wood — the adhesive you need follows the board, its thickness and the slab.
How thick a wear layer you need
Not an adhesive question, but the one most often asked in the same breath.
Get the quantity checked
Send the floor, the area and the subfloor and we will work the pails out with you.
Questions installers ask
- What is a 3-in-1 flooring adhesive?
- One troweled layer doing three jobs: bonding the floor, inhibiting moisture coming up through a concrete slab, and acting as a sound and crack-isolation layer. It is not three products and it is not an underlayment. Which jobs you get depends on the trowel and the spread rate, which is why the same pail covers roughly half the area when it is used as a moisture barrier as when it is used as adhesive alone.
- Do I still need a moisture test on a concrete slab?
- Read the data sheet for the product you are using, because the two we stock answer this differently and one of them has answered it differently over time. Bostik states unlimited moisture vapour protection with no ASTM 1869 or ASTM 2170 subfloor limit when the slab is dry to the touch and it gets full coverage with adhesive transfer. Shaw's current specification limits 3-in-1 Ultra to engineered wood when used as a moisture control adhesive, and Shaw's current warranty requires substrate moisture testing. Where a maker's own documents conflict, we quote the current ones and leave the decision with your installer.
- How much adhesive will my floor need?
- Take the coverage figure for the job you are doing — adhesive only, or adhesive plus moisture membrane — and divide your square footage by it, then round up to whole pails. Both makers state that coverage is approximate and moves with subfloor porosity, trowel angle, temperature and installer technique, so order the next pail up rather than the exact figure. Tell us the floor and the area on a quote and we will do the arithmetic with you.
- Can I use wood flooring adhesive below grade?
- It depends on the floor, not the glue. Bostik restricts below-grade use to engineered hardwood, and neither product is for exterior or wet areas. A basement slab is a moisture question first: get the slab tested, then choose the adhesive that covers the reading.
- Do you sell adhesive on its own, without flooring?
- Yes. Both pails have a published price you can order against on their own product pages, and neither is sold as a sample — a swatch of adhesive would tell you nothing.