Proper Surface Preparation: Step-by-Step Instructions
Adhesives & Sealants
Before applying high-strength adhesives such as the SikaBond Construction Adhesive, SikaBond Ultimate Grab, or any of the Sika Anchorfix products, all surfaces must be prepped and treated prior to application. All surfaces should also be cleaned and dried as well as free of frost, oil and grease. Any foreign matter or curing compound residues should be thoroughly removed. Priming is not usually necessary.
Before applying polyurethane sealants such as the Sikaflex+ Construction Sealant, Sikaflex+ Mortar Fix, Sikaflex+ Self-Leveling Sealant, Sikaflex+ Concrete Fix, Sikaflex+ Crack Flex Sealant and any sealant accessories, such as the Sika Backer Rod, it is again important to make sure that all surfaces and cracks/joints are cleaned and dried. Before applying a sealant, users are also encouraged to install bond breaker tape or backer rod if needed to prevent bonding at the base of a joint. Once again, priming is not usually necessary. Most substrates only require priming if testing indicates a need.
Concrete/Stucco Repair
Surface preparation for the Sikacryl Ready-Mix Concrete and Stucco Patchers calls for loose particles and excess dirt or dust to be removed with a wire brush. The area of repair should then be able to accept moisture penetration. Also, users may choose to stir the material thoroughly before the repair until a uniform appearance and consistency is achieved.
Before applying the Sikacryl Powerset Instant Concrete Repair, cracks and small cavities or voids that occur in cementitious mortar, concrete or masonry should be mechanically prepared to a clean, sound, dust-free condition. Extremely narrow (i.e. hair line) cracks and voids may need to be notched or routed. Dry substrate conditions are ideal, but damp conditions can be tolerated as long as the cracks, cavities or voids contain no standing water.
The Sikadur Crack Fix also requires that surfaces and cracks be cleaned and free of contaminants. Users can remove dust from cracks by brushing with a wire brush or blowing with an oil-free compressed air.
Surface preparation for liquid products, such as the Sika LiquidWeld Blu and SikaLatex R Concrete Bonding Adhesive/Fortifier, calls for the removal of deteriorated concrete and all other bond-inhibiting materials. Preparation work should be done by high pressure water blast, scabbler, or other appropriate mechanical means. For Sika LiquidWeld Blu, substrates must be dry before application. As for SikaLatex R, saturate the surface with clean water. The substrate should be saturated surface dry (SSD) with no standing water during the application.
Subfloor Covering
In order to prevent any interference regarding the penetration of the SikaLevel Self-Leveling Underlayment and Primer, substrates must be clean, dry, stable and free of oil, paint, wax, dust, and curing or sealing compounds.
Before applying the SikaLevel system, prepare concrete, cement, ceramic, quarry and vinyl tile substrates by mechanical means, such as shotblasting, sandblasting, waterjetting, scarifying or other appropriate methods to achieve an open-textured, fine-gripping surface. Weak concrete should be removed and surface defects such as blowholes and spalls should be fully exposed and repaired. All cracks and holes should be similarly filled to prevent loss of coverage or seepage of the primer through to lower areas. All loose friable material, including preparation residue, must be completely removed using a vacuum. Allowance should also be made for double priming on excessively porous substrates. Old water-soluble adhesives should be removed completely, and old water-resistant adhesives should be mechanically removed as far as possible.
NOTE: Careful consideration should be given to the method of mechanical surface preparation and the timing of applying the primer and underlayment. Immediately following mechanical preparation on some excessively porous substrates, outgassing will increase for a short period of time (around 48 hours) until equilibrium in slab vapor pressure and the ambient environment is reached. Before overall installation begins, Sika recommends the application of several small test patches to determine application requirements and acceptability of final product performance.
Specialty
Using a post hole digger or auger, dig a hole that is to be filled with Sika PostFix Fence Post Mix to the proper depth and diameter. Make sure that the post is adequately positioned in the hole. The post should stand straight and level and be either braced or held before mixing the material. If there is standing water in the hole, backfill partially with soil or gravel until the water is no longer visible. Users can also pump the water out. Keep the material between 65 and 77 °F (18–25 °C) for at least 2 hours before mixing and using.
NOTE: Sika PostFix Fence Post Mix is for outdoor use only and will react faster in warmer temperatures. For coverage and other application information, refer to the Technical Data Sheet.
Insulation
Prior to applying the Sikaflex Insulation Sealant & Adhesive, interior joint surfaces and walls must be cleaned and free of contaminants. For porous substrates, clean by mechanical methods to expose a sound surface free of contamination and laitance. For nonporous substrates, lightly abrade smooth surfaces and remove loose dust and debris. Wipe the surface using a clean white cloth dampened with either Isopropyl Alcohol, Acetone, MEK or Xylene. Follow the solvent wipe with a clean, dry rag wipe. Ensure that the cleaning agent has completely evaporated away prior to the application.
Before installing the Sika Rmax PRO Select Polyiso Insulation Board, vertical joints must be backed by framing or structural sheathing. Taping the joints is acceptable, although not required. Installations utilizing this board must be fully protected on the inhabited side of the building by a thermal barrier, such as a minimum of 1/2” gypsum wallboard. Also, per the IBC, a WRB is required behind the exterior wall veneer. The code also has provisions regarding vapor retarders, type and location, based on the assembly, climate zone and the amount of continuous insulation. It is up to the design professional to specify an assembly that will perform adequately and meet these requirements.
All surfaces that the SikaSeal Clear Insulation Tape (1.88 in. x 164 ft.) will be applied to should be sufficiently cured and free of moisture and other debris that could inhibit adhesion. Any necessary cleaning agents that were used should be completely removed and/or rinsed off and allowed to thoroughly dry. No residues of cleaning agents should be present at the time of tape installation and any wet method of surface preparation must be allowed to thoroughly dry. Users can clean surfaces with a dry cloth as necessary.
Blacktop Repair
Much like other Sikaflex sealants, surface preparation before the use of Sikaflex Asphalt Sealant should ensure that all joints, asphalt and surrounding contact surfaces are clean and free of frost, loose tar, paints, coatings, sealers, rust, and any other contaminants that could prevent adhesion. Concrete substrate preparation should be accomplished by sandblasting, abrasive grinding or another mechanical means. Mask off and protect any adjacent surfaces (e.g. edges of joint) that should not receive contact with Sikaflex Asphalt Sealant. Closed-cell backer rod or bond breaker tape must be installed at the bottom or base of a dynamically working joint prior to the sealant installation to prevent three-sided adhesion. Bond breaker tape, when used in lieu of a closed cell backer rod, should cover the bottom or base of the joint void.
Find What You Need with Sika PRO Select
If you’re looking for the best materials for your next project, remember to choose Sika PRO Select, the brand trusted and used by professionals everywhere. From adhesives and sealants to concrete repair, insulation and much more, find us at your local hardware store or on Amazon.
For more information on the best surface preparation practices, refer to the Technical and Safety Data Sheets on our website.
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