Surface preparation

All surfaces to be coated should be clean and dry. Remove peeling paint and brittle caulking. Heavy build ups of asphalt roof cement should also be removed. Tighten any loose fasteners and replace those which are severely corroded. Repair or replace roof panels damaged by storms. Remove heavy rust with abrasive discs or wire brushes. Power wash all surfaces to be coated and allow to dry thoroughly. Caulk all gaps wider than 1/16 inch which are not expansion and contraction slip surfaces.

Treating rusted areas

It is recommended that a corrosion inhibitive primer first be applied to areas where severe rusting has occurred. Liquid Rubber™™ does not contain any corrosion inhibiting pigments but it is such an effective moisture barrier that it may be directly applied over light rust without a primer.

Going over existing coatings

[1] Original mill finish
If still tightly adhering , it can be top coated directly with Liquid Rubber™. Corrosion inhibitive primer should still be used on severely corroded areas.

[2] Alkyd paints
Aged alkyd paints that were applied over the original mill finish should be checked for adhesion. If coating is brittle and can be scraped off easily , it must be removed before Liquid Rubber™ can be applied . If removal can be accomplished with high pressure water spray, that should be the method of choice. If removal is spotty, the roof should be allowed to weather another year before removal is again attempted. Brittle alkyd paint will continue to lose adhesion over time and will result in predictable failure if not removed.

[3] Asphalt based coatings
Liquid Rubber™™ should not be applied directly over an asphalt based coating. Water based acrylic elastomeric coatings may be used as intermediate coats before applying Liquid Rubber™. Asphalts should be considered as being unstable materials and are excluded from warranty coverage by Pro Guard Coatings. Caution-Latex house paints can not be substituted in place of the acrylic elastomeric coating.

[4] Acrylic elastomeric coatings
Liquid Rubber™™ bonds very well to these coatings. Some of the earlier acrylic elastomeric formulations were prone to the development of under film corrosion. There usually is little visual evidence of this on the surface of the acrylic so small sections of coating must be removed from different parts of the roof to determine whether the condition exists and how severe it is. A visual inspection of the underside of the roof panels can reveal total penetration in the most severe cases.

The decision of whether to apply Liquid Rubber™ over an area with severe under film corrosion becomes an economic one. The recommendation should be to replace the corroded panels. However , if this is not an economically viable solution and removal of the coating is equally impractical, then application of the Liquid Rubber™™ may be justified as being the best of the available alternatives. No warranty would apply in such a case.

Application of Liquid Rubber™

Airless or Air Atomized spraying is the only feasible application method for corrugated or standing seam roofs. Airless equipment needs only one hose from pump to gun but must generate 3500-4000 psi pressure and is limited in the length of hose which can be used because of high pressure drops. Air atomized equipment requires two hoses to the gun making it more cumbersome to maneuver plus the addition of a compressor.

Liquid Rubber™™ will produce greater line drops and spray with narrower fan than most other coatings. Some solvent [xylene or mineral spirits] may be used to thin the product to make it spray easier. This dilution should not exceed 2 quarts solvent per 5 gallon pail. The recommended procedure is to spray apply and roll back with a short nap roller to obtain an even film and complete surface coverage. Application should be at rate of 40 square feet per gallon. This will produce a 20 mil dry film . The chemical and physical properties of Liquid Rubber™ make it possible to achieve a 20 mil dry film on sloped or vertical surfaces with one evenly applied coat.

Spray-on followed by rolling where surfaces configuration permits will produce an even film. Roller marks will level out in a few minutes.

Fasteners

Caulking around fasteners is usually not necessary. The physical properties of the EPDM rubber [Liquid Rubber™] will produce a longer lasting seal around fasteners than caulks can because the latter will embitter with age causing loss of adhesion and cracking.

It is good practice to brush the rubber into the fasteners after spray application to ensure complete coverage. This procedure will still be less time consuming than caulking.

Fabric reinforcing of seams and overlaps

Tight overlaps and standing seam joints do not need to be reinforced.

Overlaps with gaps greater than 1/16 inch and corroded edges should receive fabric reinforcing. Apply a light coat of Liquid Rubber™, center the fabric on the overlap and roll it out taking care not to create wrinkles; press fabric down with squeegee or wide spatula; spray apply a full coat of Liquid Rubber™ to seal top surface of fabric and roll back over to ensure coverage.

Over spray

If over spray lands on cars, it can be easily removed with Mineral Spirits within 24 hours. Thereafter, stronger solvents such as Xylene will be effective in removing the rubber but may dull some finishes. Black, one foot square test panels should be placed in various parts of the parking area as evidence of over spray in the event later claims are made.

Flushing Spray equipment

Three separate flushes with Xylene are recommended. (Save this solvent for future use) .

When the last of the Liquid Rubber™ is sucked from the pail, add several gallons of Xylene to pail to purge material from line and onto roof. Remove gun from the hose and place end of hose in same bucket as pump suction. Reduce pump delivery pressure and allow solvent to re circulate for five minutes. Remove suction tube from bucket and purge line. Starting with clean solvent or the final flush from a previous cleaning, repeat the procedure two more times.

The gun can be reattached during the final flush for cleaning.

Pail handling and disposal

Pour material from newly mixed pail into the one from which the pump is sucking. Scrape the sides of the just emptied pail into the next one to be mixed. Only a thin film of material should remain. When this procedure is used , the pails can be collapsed and placed in a trash dumpster or taken to a metal recycler.

Rain showers or freezing temperatures.

Unexpected rain showers after application may affect the surface appearance but will not wash material off roof. Temperature drops below freezing will arrest the cure but will not damage Liquid Rubber™. The cure reaction will resume again whenever adequate temperature returns.

General Application Instructions for Liquid Roof™

Before applying, mix the pre-measured catalyst into Liquid Roof™ by following label directions.

Surface preparation

Surface to be coated should be clean, dry and structurally sound. Fasten loose areas with adhesive [contact cement] or pop rivets. Oil or wax must be completely removed with solvent.
Remove loose portions of existing coatings and brittle caulk with scraper and wire brush. Whatever still has good adhesion may remain to be recoated.

Rusty or pitted metal should be wire brushed to remove loose oxide. Tightly adhering corrosion may be directly coated with Liquid Roof™.

Asphalt based aluminum coatings should be removed as much as possible by wire brush or abrasive disc. Roof cements should be removed and replaced with butyl caulk where necessary.

Repair torn rubber by regluing loose areas with contact cement. Coat exposed edges with contact cement to prevent solvent absorption from Liquid Roof™. A rubber patch may be applied over torn area if desired.
Remove chalk from white rubber membrane by brushing with a detergent solution followed by a water rinse or working surface with a stiff brush.

Smooth metal or plastic surfaces should be roughed up to improve adhesion of Liquid Roof™. A deglossing solvent may work on some plastics.

Application:

A single application of Liquid Roof™ is preferable to multiple coats. Touch-ups may be applied as desired after initial film has cured and surface is first wiped with solvent. Apply with brush around flashing's and edges using long, slow strokes. On flat surfaces, material can be poured, spread with a squeegee and then evened out with a short nap roller. Liquid Roof™ will level itself when sufficient material has been applied.

Temperature and Cure Conditions:

Liquid Roof™ may be applied at any temperature that permits it being spread onto surface. It will waterproof immediately upon application. The solvent will evaporate at a rate governed by temperature but will not be affected by relative humidity. Exposure to freezing temperatures before cure has taken place will not damage the films. The time necessary to reach cure should not be a concern as this process will occur automatically. Exposure to sunlight will accelerate the curing process. The final film properties of the cured membrane will be the same regardless of the time required to achieve cure. Liquid Roof™ will provide long term protection even under extreme exposure conditions. Please read all safety precautions and heed all warnings.

CUSTOM COATINGS WITH LIQUID EPDM RUBBER

In the development of new products and processes special requirements will arise which cannot be met by existing coatings. Pro Guard Coatings has the capability to custom design a coating to meet either a specific or a broad range of performance criteria.

The following properties are available from a liquid EPDM coating:

excellent water, vapor and gas barrier;
temperature tolerance from minus 60 degrees F. to plus 300 degrees F.;
elastomeric;
Ozone and UV stability;
broad chemical resistance from strong bases to acids;
high dielectric value;
excellent corrosion protection on steel and aluminum;
not affected by salts;
resists cathodic disbandment ;
easily repairable.