Service Bulletin | Due to recent improvements in both the Liquid Roof and Liquid Rubber we have improved the cure time greatly. By doing this we have noticed a shorter pot life after the catalyst is incorporated into the base material. Once the catalyst is added the reaction period begins. The working time to apply Liquid Rubber and Liquid Roof is between two hours and four hours depending on the temperature. The higher the temperature the shorter the working time. Once the catalyst is mixed into the EPDM it must be used. Pro Guard does not warrant catalyzed product that is not used within the proper time frame.
Choosing the right product for your application requires some knowledge of the strengths and weaknesses of each type of product available on the market today.
Liquid roof coatings are aftermarket products designed to extend life, seal leaks, provide a heat reflective or aesthetic function over existing roof surfaces. There are many products on the market ranging from asphalt based products, rubber solution [Hypalon, Neoprene, Silicone], water based Acrylic and other emulsions, and chemically curing systems such as Urethanes and now Liquid Roof®.
• Can be applied over most roofing materials [except asphalt]
• UV and ozone resistant
• Excellent against standing/ponding water
• Waterproofs immediately upon application
• Not damaged by freezing
• Has long term flexibility
• Final cured product not damaged by adverse conditions
• Does not chalk or shrink
• One coat application
RV manufacturers have been using white single ply EPDM rubber for many years. These units are now experiencing chalking and occasional damage. Liquid Roof® is the best and most cost effective product on the market for solving these problems.
Damaged areas require Butyl Tape and Poly Fabric in addition to Liquid Roof® to make repairs.
Given all of the available information, Liquid Roof® is the best product for your roofing needs.
“GOES ON LIKE PAINT – WORKS LIKE MAGIC”
Now you too can enjoy the many benefits of a weather-tight rubber roof. LIQUID ROOF® forms a 100% chemically
The most widely used liquid coatings by the RV industry are Acrylic elastomeric products. The weakness of these products, however, comes from the fact that they are water-based emulsions, which makes them vulnerable to sudden showers or freezing temperatures soon after application. They have inherently poor resistance to standing/ponding water. Another drawback for the Acrylic products is that they do not work over single ply EPDM membranes.
Liquid Roof® is a true EPDM rubber and therefore could be described as a liquid version of the single ply EPDM membrane that has established an outstanding performance record for over 30 years. The EPDM chemistry has two unique features not possessed by any other rubber: It is unaffected by ultra-violet and ozone, and can tolerate continuous exposure at temperatures over 300 degrees F. This feature is what gives EPDM rubbers the best aging properties [retain flexibility longer] of all the elastomers.
Liquid Roof® is the only liquid EPDM product currently on the market.
Liquid Roof® provides more benefits to the RV industry than any other liquid coating on the market.
LIQUID ROOF’S® SIMPLE ONE-COAT APPLICATION BY BRUSH OR ROLLER
Seals and protects your RV from water damage and expensive fuel loss due to drafts. No other product can match the
All these features in a single product
* Chemical resistant * Ease of application * Long-term durability * UV and Ozone resistance *
CAN BE USED OVER:
Liquid Roof® is a true EPDM rubber and therefore could be described as a liquid version of the single ply EPDM membrane that has established an outstanding performance record for over 30 years. The EPDM chemistry has two unique features not possessed by any other rubber: It is unaffected by ultraviolet and ozone, and can tolerate continuous exposure at temperatures over 300° F. This feature is what gives EPDM rubbers the best aging properties (retain flexibility longer) of all the elastomers.
Liquid Roof ® will cover up to 46 square feet per gallon on a very smooth surface. Normal coverage is 40-42 square feet per gallon on an average substrate. The required 20-mil film thickness will be achieved when the above spreading rate is used.
The cure rate of Liquid Roof® is temperature dependent; i.e. higher temperatures will accelerate the cure and lower temperatures will retard it. Contact with air is another requirement. If, for example, a rain shower develops before material has cured (material may still be wet) and water collects on the surface the following condition will prevail. Material that is still wet will prevent water from penetrating the film; however, the curing process will not begin unless material is exposed to air. The material under water will remain uncured until the water has evaporated and the surface again becomes exposed to air, at which time the curing process will begin.
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®.
Proper incorporation and thorough mixing of the catalyst is critical to achieving desired cured film properties and should, therefore, be done with great care. Container is filled low to allow room for mixing as well as the addition of the catalyst. Insert mixing paddle in Liquid Roof® and mix for approximately one minute so that material is moving uniformly and has formed a vortex. Slowly add catalyst into this vortex at a rate, which allows it to be incorporated without puddling. DO NOT pour catalyst on top of Liquid Roof® prior to starting mixer. After all the catalyst has been added, the mixer (if hand held) should be moved in a circular fashion around the periphery of the pail as well as up and down to insure that the catalyst is completely and uniformly mixed. Periodically scrape the sides with a rubber or metal spatula to incorporate the stagnant layer of material adhering to walls of pail.
|Spreading Rate:||A 20 mil dry film will result when liquid is applied at the rate of 46 sq ft per gallon on a smooth surface. A rate of 40-42 sq ft per gallon allows for average surface roughness.|
|Theoretical Coverage:||1020 sq ft per gallon at 1 mil dry|
|Weight/ Gallon:||8 pounds (mixed)|
|Brittle Point:||-62 degrees F.|
|Weatherometr:||2000 hours (ASTM D4459-8-03|
|Peel Adhesion:||4.85 pounds per linear inch on Firestone EPDM.|
|Pot Life:||4-10 hours depending on temperature.|
|Cure rate at 70° F:||7-8 hours to touch|
|24-30 hours to walk on|
|5-7 days full cure|
|Thinner:||Most aliphatic and aromatic hydrocarbon solvent (Mineral Spirits, VMaP Naphtha, Xylol). Weaker solvents should be used when coating EPDM rubber sheet to minimize distortion.|
|Chemical Resistance:||Cured EPDM rubber is resistant to acids, alkalis and polar solvents (Alcohols, Ketones, Glycols). Oils and fats will soften the rubber and should be avoided.|
|Cure System:||Two component Peroxide initiated free radical cure|
|Heat Resistance:||302° F (150 C) continuous exposure|
|VOC:||2.46 pounds per gallon (295/ grams liter)|
The information presented herein is furnished free of charge and is based on technical data that Pro Guard believes to be reliable. It is intended for use by persons having technical skill and is at their own discretion and risk. Since conditions of use are outside our control we make no warranties, express or implied, and assume no liability in connection with any use of this information. Nothing herein is to be taken as a license to operate or a recommendation to infringe any patents.
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 with adhesive Butyl Tape. 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.
Liquid Roof ® will cover up to 46 square feet per gallon on a very smooth surface. Normal coverage is 40-42 square feet per gallon on an average substrate. The required 20 mil film thickness will be achieved when the above spreading rate is used. If you are uncertain how to calculate the amount of material you will need, please contact Pro Guard Coatings at (800-735-4399) M-F 8-4:30 EST.
The container is under filled to allow for the addition of the pre-measured catalyst that is included. A drill, and a mixer (shown at left) will be needed to incorporate the catalyst. For a 1 gallon can a short mixer will suffice. For 4 or 5 gallon pails you MUST use a long shaft mixer.
The catalyst will be inside the box for 1 gallon and 1 gallon repair kits. The catalyst will be located under the lid in 4 and 5 gallon pails.
Mix rubber material in can/pail until uniform; center mixer shaft in pail or can and begin mixing until a vortex is formed. Slowly pour all of catalyst into vortex . Move mixer up and down and in a circular motion for 2-3 minutes until all portions of can/pail are uniformly mixed
By brush, roller or squeegee. A combination of methods might be most effective. For example, on a flat roof, pour a serpentine bead of material, distribute with squeegee, finish with a short nap roll to press air out of cracks and even out wet film. Product will self level when sufficient material has been applied. Working time is 4-6 hours depending on temperature. A single application of Liquid Roof is preferable to multiple coats. Apply with brush around flashings 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. Touch-ups may be applied as desired after initial film has cured and surface is first wiped with solvent.
Liquid Roof® may be applied at any temperature that permits it being spread onto the 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 film. 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.
WARNING: Please read all directions completely before beginning the application process. Please make sure all safety precautions are followed and appropriate safety equipment is used. Please read can/pail for complete precautions and instructions.
The information presented herein is furnished free of charge and is based on technical data that Pro Guard believes to be reliable. It is intended for use by persons having technical skill and is at their own discretion and risk. Since conditions of use are outside our control we make no warranties, express or implied, and assume no liability in connection with any use of this information. Nothing herein is to be taken as a license to operate or a recommendation to infringe any patents
When properly applied, Liquid Roof® can be expected to provide many years of reliable roof protection. EPDM Rubbers have proven themselves to be one of the most durable roofing materials made.
An application of Liquid Roof produces a relatively thin membrane approximately 20 mils thick. This is sufficient to act as a weather shield but not enough to provide any structural strength. Roof maintenance should, therefore, not be limited to only the topmost layer but include the structure that supports it.
CLEANING THE SURFACE
CLEANERS AND SOLVENTS
WHAT NOT TO DO
Universal Repair Method for EPDM Rubber
This Universal Repair Method
Pro Guard Coatings, the manufacturer of Liquid Roof®, has received a number of reports from dealers and private users of Liquid Roof® that have described a condition similar to the following:
…”We applied Liquid Roof® over an existing rubber roof one or two years ago and now it is tacky, leaves are sticking to it, and it has turned gray”…
After some considerable probing we are able to establish that the rubber that has been coated over was of the ALFA brand. The common denominator for the Liquid Roof® starting out appearing normal but then becomes “tacky” after one or two years seems to be the ALPHA brand of rubber.
The technical explanation for the process that is softening the coating and making it tacky is “reverse polymerization”. This is a process of decomposition that slowly reduces the rubber to its starting point composition. The suspect cause for this is the antioxidant used in the ALPHA rubber.
Do not apply Liquid Roof® directly over ALPHA rubber.
Using ProFlex Flexible Primer prior to the application of Liquid Roof will effectively place a barrier between the two incompatible rubbers.
The term electrolysis generally describes a condition where an aluminum or galvanized metal roof skin corrodes from underneath. The metal acts as a catalyst causing the adhesive bonding it to the plywood to decompose. Some of the decomposition products then react with the metal causing pitting and loss of adhesion. This condition will continue at an unpredictable rate until the catalytic effect of the metal is lost or the adhesive completely degrades.
Advanced stages of electrolysis can be recognized visually. Make a 2” T cut and bend the skin back. If there is poor or no adhesion to the plywood and the underside of the skin appears mottled or rough then the electrolysis process has already begun. The beginning stages will be more difficult to recognize but will start with loss of adhesion and then progress to eroding the metal.
DO NOT apply Liquid Roof® to a roof diagnosed or suspected of having active electrolysis. The coating will eventually fail as the skin deteriorates from underneath. Removal of the metal skin is the only way to stop the electrolysis. When pitting or corrosion is only on the topside of the metal, it may be top-coated with Liquid Roof®.
Liquid Roof® over Sheet Rubber:
Liquid Roof® is recommended for application over sheet rubber because it is the same chemistry and has identical flexibility and weathering characteristics. Liquid Roof® does not chalk and can be used to eliminate the chalking of sheet rubber. When a solvent containing product like Liquid Roof® comes in contact with sheet rubber, the applicator should be prepared for a phenomenon which will make it appear as if something has gone radically wrong. Some of the solvent in Liquid Roof® will be absorbed by the sheet rubber and cause it to swell. If the sheet is not glued tightly to the plywood the swelling causes wrinkles or bubbles to form. Depending on the temperature, this condition will persist for days or sometimes weeks. However, as the Liquid Roof® begins its cure process and solvent slowly evaporates, the sheet will shrink and return to its original shape. DO NOT apply Liquid Roof® in a heavy film as this will aggravate the swelling reaction in the sheet.
Liquid Roof® has been used directly over plywood to make a finished roof in situations where expediency and minimal cost were the primary considerations. Although this procedure results in a weaker roof structure, water-tightness can be achieved if the application is performed carefully.
The joint between sheets should be positioned directly over a roof truss and securely fastened to prevent warping. Next, to seal the pores, coat plywood with oil based exterior primer paint. Allow an overnight cure. Seal the joint by bridging it with a 6” wide polyester fabric strip. Apply a light coat of rubber over the joint, lay fabric into wet rubber and smooth out wrinkles. Complete job by applying a liberal coat of LIQUID Roof® over entire roof surface, being especially careful to completely cover the fabric over the joint without skips or pinholes. Using an oil base primer on the wood considerably improves the appearance of a one-coat application of Liquid Roof®.
Recoating Liquid Roof®:
Since Liquid Roof® cures by chemical reaction, a single heavy application will be preferable to multiple thin coats. A second coat will bond to a previous film but that bond will not be as strong as the internal bond within each layer. If a second coat is applied before the first has thoroughly cured, some wrinkling may result as the first coat absorbs solvent and swells. This will, however, recover as the solvent evaporates. It is generally recommended that only a single coat be applied over non-porous surfaces, the thickness of which can be varied as desired. Thicker films will take longer to cure through.