Requirements of Substrate
- Subfloors must be smooth, sound, clean, dry and free of any contaminants which may hinder adhesion.
- Surface treatments or any “friable” areas of the subfloor must be mechanically removed back to a sound base and the substrate repaired with SCHÖNOX repair compounds as required.
- All slabs on or below grade level must be known to have an intact vapor retarder directly beneath the concrete in conformance to the relevant standards. If in doubt, please contact our SCHÖNOX representative for further advise.
- This product is not a vapor barrier and will allow free passage of moisture. Follow the directions of the floor covering manufacturer regarding the maximum allowable substrate moisture content and test the substrate prior to installing SCHÖNOX AST. Where substrate moisture exceeds the maximum allowed then application of SCHÖNOX SDG, SCHÖNOX MR 18 or SCHÖNOX EPA may be used to suppress residual moisture (see data sheet).
- Gypsum screeds should always be dry. Do not use moisture mitigation systems on gypsum substrates.
- Old water-soluble adhesives should be removed completely to the clean substrate, old water-resistant adhesives should be mechanically removed to a thin, well-bonded residue (i.e. using the wetscraping technique as recommended by the Resilient Floor Covering Institute). The complete mechanical removal of cutback (i.e. grinding, sanding, blasting) can be hazardous as old cutback adhesive may contain asbestos. Do not sand or grind adhesive residue. Harmful dust may result. Inhalation of asbestos dust may cause asbestosis or other serious bodily harm. Please consult the adhesive manufacturer and all applicable government agencies for rules and regulations concerning the removal of flooring and adhesives that contain asbestos. Prime remaining adhesive residues accordingly.
- The use of trowelable patching compounds to mask the presence of adhesive residues can be used successfully, but only when the new adhesive to be used does not react with the old residue, and the floor covering to be installed will not be affected by adhesive bleed-through.
- All cement based or wooden substrates must be solid, thoroughly clean and free of oil, wax, grease, asphalt, latex and gypsum compounds, curing compounds, sealers and any contaminant that might act as a bond breaker. If necessary, mechanically clean the floor down to sound, solid surface.
- Solidly bonded non-porous substrates such as ceramic tile and terrazzo must be thoroughly cleaned and abraded including the complete removal of existing waxes and sealers, dust, dirt, debris and any other contaminant that may act as a bond breaker.
- SCHÖNOX AST can be applied over SCHÖNOX EPA without the need of priming. Apply SCHÖNOX AST after the moisture mitigation system has dried accordingly but within the first 72 hours after the moisture mitigation system was applied.
- The requirements of the relevant valid standards, guidelines and data sheets apply.
- Vacuum substrates thoroughly.
- Gypsum substrates (sanded and vacuumed):
- Cement substrates such as:
- ConcretePrime with SCHONOX VD (1:3)
- Non-porous substrates such as:
- Ceramic tiles (thoroughly cleaned and abraded)
- Water-resistant, acrylic adhesive residues (removed as far as possible)No priming required
- Wooden substrates such as:
Limitation of Liability
To the best of our knowledge, the technical data contained herein are true and accurate at the date of issuance but are subject to change without prior notice. We guarantee our product to conform to the specifications contained herein. We make no other warranty or guarantee of any kind, express or implied, including merchantability and fitness for particular purpose. Liability, if any, is limited to replacement of the product or refund of the purchase price. Labor or cost of labor and other consequential damages are hereby excluded. SCHÖNOX does not authorize anyone, including SCHÖNOX Representatives, to make any statements which supersede, modify or supplement the information provided on its printed literature or package labels without written confirmation.