Restore vs Reroof
The goal of the Elastek Sustainable Roof System™ is to cover the entire exposed roof surface with a continuous, fully adhered, built-in-place polymer and fabric membrane that protects the existing roof surface from exposure to the elements.
Low-slope roofs (3:12 inches or less) of built-up asphalt (BUR) or wood decks with a smooth felt or granulated capsheet surface qualify for a Sustainable Roof System. Pavers, aggregates, or cast granules are not suitable. Roof must be in good-to-serviceable condition and not previously re-covered, well-attached, with deck substrate in good condition, and roof insulation must be dry. System should be installed by a factory-trained, licensed contractor.
SPF foam roofs may be satisfactory for a Sustainable Roof System if the foam is in excellent condition, the surface is smooth, and no moisture intrusion has occurred. The Sustainable Roof System membrane gives foam additional resistance to hail, UV damage, and foot traffic. A moisture scan would be appropriate in any case where moisture intrusion is a possibility.
The applicator must determine if moisture control and venting are adequate. Roofs that are badly deteriorated, drain poorly, delaminating, have extensive blisters, buckles, ridges, or surface contamination, are structurally weak, in need of extensive repairs, or otherwise unsound are not acceptable candidates for a Sustainable Roof System. Qualifying roofs must be fully repaired prior to installing the system.
Applicator is responsible for determining suitability of roof substrate. Property owners are advised to have their roofs inspected by a qualified roofing professional before proceeding. Sustainable Roof Systems are intended for roofs located in warm Sunbelt climates.
Generally, Sustainable Roof Systems would be considered a repair or refurbishment and not a re-roof. However, applicators are responsible for determining if local codes pertain to installing a Sustainable Roof System.
The following are general instructions for building a Sustainable Roof System. These steps noted must be followed to qualify for a warranty. The applicator will need to make judgments on specific issues that pertain to a given roof. Applicator must read and follow the instructions found on Elastek product pails and/or in product information sheets found on our website as well as the instructions provided herein. Please contact us with questions.
Roof Size: The actual number of square feet to be coated needs to be determined accurately. Take the length times the width of the total roof or each section of the roof. Calculate a total number of square feet for all. Add the total of the length and width of non-horizontal surfaces (such as parapet walls and base flashings attached to parapets) and add this to the square-foot total. A sketch is helpful in figuring requirements for more complex roofs. Order coatings at the rate of 100 square feet of coverage per gallon.
The named Elastek coatings and sealants must be used. Warranty is voided when other brands of coating are used or if unspecified grades/types of Elastek products are substituted without our written permission.
To satisfy warranty requirements, the applicator must keep records that document the coatings used, invoices to substantiate purchase of coatings, information regarding cleaning and repairs to the roof, and dates of coating applications along with weather conditions on those days. Records of wet-gauge testing of coating thickness could be helpful. The roof should be fully repaired prior to applying the Sustainable Roof System.
Follow product label instructions. There should be no standing water on the roof for 48 hours after coating application. Staging fabric requires minimal wind conditions. Full coating cure takes 7 days or more. Drying time is 3-to-6 hours for coatings in warm weather, longer in cool weather or when fabric has been embedded in the coating. When using a 3-course application (coating/fabric/coating), allow a minimum 24 hours before applying additional coating.
Follow Elastek basic product label instructions. Check coating thickness with a wet-mil gauge periodically (20 mils wet for topcoats).
Coating can be spray-applied by airless pump capable of 2-3000 PSI, 1-3 GPM using a 6-31 or 8-31 reversible tip. Coating may be diluted at the maximum rate of one-quart of clean water per 5-gallons of roof coating to improve spray-ability. Diluting will require slightly more coating be applied to maintain dry-mil thickness. Paint rollers, push brooms, or roof brushes will be needed to completely wet fabric with coating.
A maintenance coating of asphalt emulsion should be used for roofs with rough texture, badly worn surface, or in need of resealing. Use a premium quality product and follow manufacturer’s application instructions.
Steps to building a Sustainable Roof System
1. Clean roof surface
Dirt, chalky coatings, loose stones, granules, peeling materials, oil, grease, rust, silicone caulks, and other contaminants must be removed. Clean roof and bare metal surfaces with TSP and water (or more environmentally friendly TSP Substitute). Rinse thoroughly and allow drying. Badly contaminated surfaces may require steam cleaning. Mildewed areas should be treated with chlorine bleach; rust should be removed, and affected areas coated with quality rustproof primer.
Ensure the roof is clean and dry before applying each coat.
2. Repair roof
Repair any loose or damaged flashing, drip edge, lap seams, roof penetration, parapet sides and tops, splits, holes, gaps, tears in roof membrane, or other deficiencies. Where elastomeric coatings are not suitable for repairs, applicator should use customary professional roofing products and practices. Areas that could hold standing water more than 48 hours in dry weather must be eliminated (NRCA Roofing & Waterproofing Manual, 5th Edition).
3. Caulk & seal
Reinforce joints around chimneys, vents, stacks, roof jacks, curbs, HVAC ductwork, plumbing, parapets tops, coping seams, and open-ply seams, etc. using Elastek Crack & Joint Sealant and polyester roof fabric. A wet coat of 1/8-inch or more of Sealant is applied to gaps and open seams; then polyester fabric is immediately embedded in the coating. A second thick coat of Sealant is applied over the fabric (4-inch and 6-inch wide fabric is used for this purpose). Allow at least 24 hours for drying.
If lap seams are open or lifting, 4-inch or 6-inch fabric should be used to seal all lap seams. The full membrane will then add strength to all seams.
4. Build the fabric membrane
A single ply of polyester roof fabric is used in the Sustainable Roof System. Fabric is available in rolls of 40” by 324’ (covers 1,000 sq. ft.) and 300’ rolls of 4”, 6”, 12”, and 18” widths. When covering large areas, use the widest practical fabric width.
Begin applying fabric horizontally along the lower edge of the roof, lapping the drip edge if any, and moving from one side to another. Move up the roof with succeeding layers of fabric, overlapping fabric 3-inches at each lap and 6-inches at the end seam. All exposed areas of the roof must be covered with fabric and all fabric seams must overlap.
Fabric should be extended vertically on parapet walls to the counter flashing, the attachment point, or the parapet top if the roof flashing covers this area. It may be easier to apply fabric to the vertical walls first, and then build the horizontal ply.
Additional ply should be installed where greater strength is needed. Deck fabric must overlap and seal the flashing around all roof penetrations and parapets.
A fabric ply is applied directly to a cleaned and repaired roof surface using Elastek High-Tek Basecoat. Use the widest material (40-inch) whenever practical. Starting at the down slope edge, apply a thick coating to an area slightly wider than the fabric roll being used and 5-to-10-feet in length based on coating drying time.
The fabric should immediately be rolled into the base coating while it is still wet. Be sure the bottom side of the fabric is fully embedded in the coating. A second application of coating is applied immediately over the embedded fabric so both coatings merge and dry as one. High roof or air temperature and wind all can reduce coating working time and can make application impractical until conditions improve.
Follow these steps:
- A base coat of High-Tek Basecoat is applied at the rate of approximately 100 sq. ft. per gallon. Elastek PolyTek fabric is immediately embedded into the wet basecoat without tension/ stretching. A paint roller, roof brush, squeegee, or push broom is used to quickly work coating into the fabric, saturating the mesh and eliminating air pockets and wrinkles. All fabric must be fully supported from below. Uniformly work coating into the fabric to avoid air pockets that can cause delamination later.
- A second or saturation coat of High-Tek Basecoat is immediately applied to the laminated area at the rate of approximately 100 sq.ft. per gallon and worked to completely encapsulate the ply fabric so both coatings dry as one.
- Continue applying fabric to the roof. With each new length of fabric, pull back the applied fabric slightly to get a wet overlap of coating with the prior section. Cut the fabric with a sharp scissor when the end of the roof or section is reached.
Note: Fabric can be scissor-cut to fit any roof shape, around dormers, vents, skylights, HVAC units, etc. All fabric seams must overlap. Fabric must overlap from the roof surface onto flashings, tightly sealing the entire roof.
5. Apply topcoat
Once the new ply is fully dry, a reflective coat of Elastek Solar Tek Extreme™ is applied at the rate of 100 sq. ft. per gallon. Allow drying. A second weathering coat of Solar Tek Extreme is applied at the rate not to exceed 100 sq. ft. per gallon. Additional coats of Solar Tek Extreme may be applied to further extend the initial warranty. In most cases, it is beneficial to coat exposed ductwork and repairs with topcoat.
6. Inspect the finished roof
Correct any air pockets, loose fabric, wrinkles, thin coating, areas not covered by the Sustainable Roof System, or other problems.
- Installation Details
- Use enough coating to fully wet fabric and laminate it to the roof. Some roofs may require more coating than our minimum specifications.
- When installing fabric, work only an area that will remain wet with coating long enough to embed fabric.
- When installing fabric, remove air pockets or wrinkles from fabric before proceeding.
- Overlap all coating seams a minimum of 3-inches on lap seams; roll ends 6-inches; and 2-inches on repair seams.
- All fabric must be full adhered to the substrate; never allow fabric to be unattached from the surface.
- Make all lap seams face downward by working up from the bottom of the roof.
- Add one or more additional fabric ply where greater strength or water resistance is needed.
- Allow adequate drying time for the completed fabric to laminate before top coating.
High Traffic Areas
Walkways and service areas around roof-mounted equipment can be given additional durability by adding another ply of fabric using the techniques noted above. 60-mesh silica may be mixed (or broadcast) into the final topcoat applied to provide even greater durability. Final coating may be color tinted to delineate the service lanes.
Application for Warranty
Upon job completion, a warranty application form should be submitted by the contractor to Structural Elastomeric Products Inc. (SEPI)/Elastek. SEPI must be given the opportunity to inspect commercial roofs over 5,000 square feet per roof to determine if Sustainable Roof System standards have been met. Contractors will be given a 30-day period to correct deficiencies.
When SEPI assumes/determines that the completed roof meets Sustainable Roof System standards, a written executed warranty agreement will be provided to the property owner.
Roofs are dynamic surfaces and subject to change. It is necessary to inspect Sustainable Roof System roofs at least once a year and correct any developing problems immediately. Allowing small problems to become major due to lack of annual roof inspections may void coating warranty.
Maintaining Energy Efficiency
Dust, soot, air pollution, etc. will reduce the reflectivity of white roofs over time. Where practical to do so, rinsing the roof with water is recommended annually, particularly before very warm, dry weather sets in.
Renewing a Sustainable Roof System
Most systems can be renewed repeatedly by cleaning the roof, making necessary repairs, and applying one or more top coatings of Elastek elastomeric roof coating. Recoating restores reflectivity, energy efficiency, and extends the service life of the roof.