MEL-ROL is a waterproofing membrane designed for application on various substrates including concrete, masonry, wood, insulated wall systems, and metal. Proper installation requires careful substrate preparation, priming, detailing, and protection of the membrane. This article details the installation procedures and precautions based on manufacturer guidelines.
Substrate Preparation
Prior to application, all substrates must be clean, dry, and free of surface irregularities. Masonry walls may necessitate a cementitious parge-coat, applied using MEADOW-PATCH T1 or MEADOW-PATCH SMOOTH GRADE. This parge-coat should be allowed to dry – typically 12 hours at 75° F (24° C) – before priming. The application of a parge-coat results in a smooth, uniform, and well-bonded surface. MEL-PRIME or MEL-PRIME WB should be applied to all areas intended to receive MEL-ROL. When applying to insulated concrete forms, MEL-PRIME WB is required.
Priming Procedures
The appropriate W. R. MEADOWS primer must be applied at the specified coverage rate using a medium nap roller brush. A minimum drying time of 30 minutes at 75° F (24° C) is required, though colder temperatures will extend this duration. The primer should be allowed to dry to a tacky surface before MEL-ROL installation. MEL-PRIME adhesive should be applied to surfaces that will be covered within one working day; if left exposed overnight, additional adhesive is necessary. All instructions and precautions detailed on the primer container must be followed.
Detailing for Corners and Protrusions
Specific detailing procedures are required for inside and outside corners, as well as around drains and protrusions. For inside corners, a vertical DETAIL STRIP should be placed before MEL-ROL application, extending 4 ½” (114.3 mm) beyond each side of the corner and terminating at the footing. The corner should then be finished with POINTING MASTIC or BEM.
For outside corners, the DETAIL STRIP should be bent vertically over the corner, also extending 4 ½” (114.3 mm) beyond each side, and terminating at the footing. This corner should also be finished with POINTING MASTIC or BEM.
All protrusions require a collar of MEL-ROL or DETAIL STRIP applied at least 6″ (152.4 mm) in all directions. All terminations, including those around drains and protrusions, should be sealed with POINTING MASTIC or BEM. Around drains, a bead of POINTING MASTIC or BEM should be applied between the membrane and clamping rings at all terminations.
Footing Details
When dealing with footings, 90° interior angles should be filled with a cove of BEM. MEL-PRIME should be applied to all inside and outside corners prior to installing DETAIL STRIP. The DETAIL STRIP should be installed 4 ½” (114.3 mm) up the wall and onto the footing, extending 4 ½” (114.3 mm) beyond outside corners. The extended portion of the DETAIL STRIP should be slit lengthwise, with the horizontal flap placed onto the footing and the vertical flap bent around the wall. A bead of POINTING MASTIC or BEM should be applied to the exposed edge of the installed DETAIL STRIP at the footing. When using MEL-ROL XLT, POINTING MASTIC should be used in place of BEM.
Membrane Application – Horizontal Surfaces
For horizontal applications, the release paper should be removed from MEL-ROL starting at the top edge of the roll, and the exposed area firmly pressed onto the wall. The release paper should then be removed in a downward direction, pressing the MEL-ROL into place. On edges, the release paper should be removed, and the membrane positioned. The balance of the release paper should be pulled off while running the roll from low to high points to ensure all laps shed water. End laps should be staggered and overlapped by at least 2 ½” (63.5 mm). A double-thickness of the membrane should be applied over construction joints, control joints, expansion joints, and cracks exceeding 1/16” (1.59 mm) in width.
Membrane Application – Vertical Surfaces
When applying MEL-ROL vertically, the membrane should be positioned and immediately hand-rubbed firmly to remove any bubbles or wrinkles. The entire membrane and all laps should then be rolled with a hard rubber hand roller to ensure positive adhesion.
Inspection and Repair
A thorough inspection must be conducted before covering the installed membrane, and any necessary repairs made immediately. Tears and inadequate overlaps should be covered with MEL-ROL. Slit fish mouths should be patched, and the edges of all patches sealed with POINTING MASTIC or BEM. Horizontal applications can be flood-tested for up to 24 hours to identify leaks, which should be marked and repaired after the membrane dries.
Protecting the Membrane
Immediately after installation, the membrane must be protected. This can be achieved by applying PROTECTION COURSE on all vertical and horizontal installations if no drainage system is used, or by applying MEL-DRAIN. PROTECTION COURSE should be secured using POINTING MASTIC or BEM as an adhesive, and/or physically attached at the top edge using a TERMINATION BAR.
When using MEL-DRAIN on a vertical wall, the first roll should be aligned and mechanically fastened. The MEL-DRAIN should then be rolled down the wall, overlapping the footing. The fabric layer of MEL-DRAIN should be pulled away to expose the dimples, and drainage tile installed, with the excess fabric wrapped over the tile. A TERMINATION BAR should be installed and fastened at 12” on center, with a bead of POINTING MASTIC or BEM applied to the top edge of the bar.
Backfilling Procedures
Backfilling should be performed immediately after membrane protection, exercising care and caution to avoid damaging the waterproofing application.
Precautions and Compatibility
MEL-ROL is not recommended for use as a pond or tank liner. It is incompatible with coal tar, polysulfides, polyurethanes, pitches, soft PVC, and most polyether materials. The membrane should not be left exposed to direct sunlight for longer than 45 days. The use of MEL-ROL does not eliminate the need for hydrostatic head relief; a complete drain tile system should be installed around footings and under slabs as required.
Accessory Products
Several accessory products are available for use with MEL-ROL, including:
- MEL-PRIME W/B: A water-based adhesive for preparing surfaces for MEL-ROL application. It can be applied with a manual sprayer or roller and is VOC-compliant. MEL-PRIME W/B is suitable for use at temperatures of 40° F (4° C) and above.
- POINTING MASTIC/BEM: Used for sealing corners, protrusions, and patch edges.
- DETAIL STRIP: Used for detailing corners and footings.
- TERMINATION BAR: Used for mechanically fastening the membrane and providing a secure termination point.
- PROTECTION COURSE (PC-2 or PC-3): Provides a protective layer over the membrane when a drainage system is not used.
- MEL-DRAIN: A drainage membrane used in conjunction with MEL-ROL.
Conclusion
Proper installation of MEL-ROL requires meticulous attention to detail, from substrate preparation and priming to careful detailing and membrane protection. Adhering to the manufacturer’s guidelines ensures a reliable and long-lasting waterproofing solution. The use of appropriate accessory products further enhances the performance and durability of the system.