This document has been created as an addendum to the MEL-ROL LM technical datasheet to provide the recommended procedure to use when installing MEL-ROL LM single-component, polymer-modified, cold-applied, water-based, liquid waterproofing membrane from W. R. MEADOWS.
All surfaces must be clean (free of all coatings and curing compounds), free of frost, relatively smooth, and structurally sound. Patch any bug holes, tie holes, large gaps, or cracks with MEADOW-PATCH® 5 or MEADOW-PATCH 20 from W. R. MEADOWS. All loose laitance on the substrates, such as dirt, dust, loose stones, and debris, should be either swept or blown clean. All inside corners should be addressed with a cove of BEM from W. R. MEADOWS prior to application of MEL-ROL LM.
All shrinkage cracks less than 1/16″ (1.6 mm) should be pretreated with a 60-mil coat of MEL-ROL LM 6″ (152.4 mm) wide. All cracks greater than 1/16″ (1.6 mm) should be taped with DETAIL STRIP from W. R. MEADOWS prior to application of the membrane. For specific project recommendations, please contact W. R. MEADOWS technical services.
MEL-ROL LM is designed to be used from the pail or drum with little or no mixing. However, if water appears on the surface, mix thoroughly with a low speed mechanical mixer prior to application.
To reduce blistering on concrete surfaces, a thin coat of MEL-ROL LM diluted with water may be required. (Approximate dilution ratio of MEL-ROL LM to water is between 4:1 and 5:1.)
Thoroughly mix primer with a mechanical mixer. Prime the entire concrete surface to be waterproofed by spraying or rolling on a single coat at a coverage rate of 100 – 150 ft.²/gal. (2.45 – 3.68 m²/L). Allow primer to dry (approximately one hour, depending on temperature and conditions).
After surface preparations are complete, detailing should be addressed. The desired thickness of membrane coverage is 120 mils for inside/outside corners and non-moving and hairline cracks, as well as around drains and penetrations. Request and view the W. R. MEADOWS WATERPROOFING CONTRACTORS HANDBOOK for additional information.
Use DETAIL STRIP from W. R. MEADOWS for impaction sheet coverage. First, fold strips lengthwise and then cut at the fold. Material is then ready to install as 4 ½” (114.3 mm) strips on either side of the rebar. Any excess can be turned down on the face of the footing. Next, fill the voids around rebars in the keyway with BEM. Pour the walls.
Install DETAIL STRIP horizontally along the wall where it meets the footing, placing half the material up the wall and the other half onto the footing. Extend the material 4 ½” (114.3 mm) beyond outside corners. Slit extended portion of DETAIL STRIP lengthwise. Place the horizontal flap out onto the footing and bend the vertical flap around the wall. Repeat this procedure in the opposite direction.
In applications subject to a high water table, WATERSTOP EC PLUS from W. R. MEADOWS (or approved alternative), must be incorporated in the wall design.
MEL-ROL LM can be applied directly from the container using a ¾” (19.1 mm) nap roller. Apply in two coats, each 30 mils thick, allowing first coat to reach initial set prior to application of second coat.
MEL-ROL LM may be sprayed on at a minimum coverage thickness of 60 mils wet (45 mils dry). To obtain 60 mils wet thickness, and to prevent slumping, apply MEL-ROL LM in two coats of 30 wet mils. Apply the second coat after the first coat has dried (approximately one to two hours).
MEL-ROL LM is most effectively applied by using the Graco HydraMax 350 or the Graco GH833 Big Rig.
The Graco heavy-duty texture gun is recommend- ed for use with the following tips: For best results, use the 0.051″ (Graco GHD551) heavy-duty switch tip. For spraying of primer coat, a smaller orifice tip such as the 0.035″ (Graco GHD635) can be used. Tips should be reversible types for easy cleanout. For more complete spraying equipment information, please view INSTALLATION INSTRUCTIONS: SPRAYER EQUIPMENT GUIDELINES FOR W. R. MEADOWS FLUID-APPLIED MEMBRANES.
For horizontal applications, use HYDRALASTIC 836 from W. R. MEADOWS.
Frequently inspect surface area with a wet mil gauge to ensure desired consistent thickness is achieved. Porous substrates or masonry block walls may require additional coats to obtain desired thickness.
Material should not be left in the pump, lines, or gun when finished spraying. CAUTION: Solvents must not come in contact with MEL-ROL LM in the sprayer, as they will break the emulsion and plug up the entire sprayer system. After spraying, promptly flush water only (no soap) through the system until pump and hose are clear [approx. five gallons (18.9 L)]. Aromatic solvents, such as xylene or toluene [approx. two gallons (7.6 L)], should be used for final flushing after water is flushed through the pump and lines.
Mineral spirits, paint thinner, gasoline, etc., must not be used to flush system. NOTE: Water must be flushed through the machine to remove any solvents prior to spraying of MEL-ROL LM.
Allow 24 hours for complete cure of membrane prior to backfilling.