A thorough inspection of each surface and related areas is necessary to determine what repairs are needed. The following information should be compiled with each inspection:
During your investigation, thoroughly analyze each area's current condition and consider the following important factors:
Note: It is the sole responsibility of the applicator and/or building owner to determine the soundness of the building structure, roof support system, surface and suitability of the substrate for coating. No coating products should be used to try and correct structural defects or compensate for severe problems that may warrant a new roof system.
During the roof inspection you may discover breaks or cracks, open joints or splits, fish mouthing along seams, blisters or standing water - often clear indications of active leaks. Interior stains or discoloration, wet insulation or underlying areas and trapped moisture are also signs of active leaking, as well as corners and junctures where the roof meets a parapet wall or chimney, inadequate flashings, poorly adhered rolled roofing and felts, deteriorated fasteners or corrosion.
It is very important to locate exactly where leaks originate on each roof. Water can and will travel considerable distances between roof layers, through insulation, along joists, beams, ribs or electrical conduit. Therefore, interior water damage is often far removed from the original point of penetration.
It is also important to determine when leaks occur. Leaks that occur during the winter months or during the "spring thaw" season can often be traced to ice and snow build-up on roofs, or to the Freeze/Thaw cycle. Freezing water expands as it turns to ice. This expansion process will widen any existing cracks or breaks on the roof surface and may weaken underlying roof layers, forcing them apart. When the ice thaws, the water is free to penetrate these vulnerable areas on the roof. Moisture problems after heavy or prolonged rain could implicate low spots or corners where ponding water collects. If regular leaking occurs after every rain, look for definite breaks or cracks around vents, mountings, joints or flashings. Trapped moisture in the decking, insulation or sub-layers may not be discovered until the roof is re-sealed and the trapped moisture travels downward to escape.
As a last resort, when the roof is completely dry, water can be poured or sprayed on suspicious areas to pinpoint the exact source of a leak, or a moisture meter can be used. Always be sure to have full permission from a building owner and be sure that the water penetration will not cause damage to internal property when using this method.
Proper surface preparation is imperative for all successful coating applications. Coatings must only be applied to roof surfaces that are sound, clean and dry. Since a coating is only as good as the surface to which it is applied, determining soundness is critical before beginning each application. Failure to do a complete and thorough job of surface preparation, including cleaning, may lead to the failure of the entire repair or recoating job.
A sound surface is one that is stable, in reasonably good condition and firmly fastened, secured or bonded to whatever is underneath. If the roof surface has old coatings or previous layers of material, a thorough inspection is needed to determine the soundness and adhesion of these layers to the roof deck and to each other. If these older layers weaken and lose adhesion, the top coating will come off as well! Coating over a roof with this condition will not solve the underlying problem. If there are doubts about the soundness of the previous coatings, apply a test area.
In addition to good adhesion to the roof decking, or sub-layers, the surface must be stable. To check for stability, look for signs of stress and movement. An unstable roof has a dynamic surface that often moves or shifts dramatically in response to temperature changes, building shifts or other external factors. Liquid asphalt products can move and shift dramatically in response to changing temperatures and may even liquify during extreme heat. TKOWC's non-reactive coatings, which are not affected by shifts in temperature, should not be applied to these types of asphalt surfaces until the underlying asphalt base has stabilized. Always apply a test area to determine whether or not the surface is sound and stable.
All screws, nails and fasteners should be checked, tightened and replaced if necessary. This is also the time to replace worn-out flashings, rusted hardware, broken drains or any other roofing accessories that may become the source for water penetration and leaks if not repaired or replaced.
Thoroughly clean the surface area by either sweeping, brushing, brooming, blowing or water-blasting.
Caution: Do not water-blast if roof decking or underlying material or insulation may become saturated or damaged. Trapped moisture will migrate downward once the roof has been coated and sealed. Remove any oily, greasy or slick surface film by washing with a strong de-greasing detergent. Remove all traces of mold or mildew by scrubbing the surface with a bleach solution or suitable fungicide. Remove cleansing agents by rinsing thoroughly. Allow the roof to dry completely before beginning any repairs. Surface moisture will create a barrier between the coating and the surface, preventing proper adhesion and resulting in an unsuccessful application.
Note: Trapped moisture within the roof system or insulation may not be detected through normal inspection procedures. If trapped moisture is suspected, a professional roofing inspection may be necessary to locate areas of trapped moisture. TKO Waterproof Coatings, LLP cannot be responsible for coating performance or longevity in situations where underlying moisture is present prior to the application of its patching and coating products.
For maximum protection, all leaks, cracks, seams, joints, splits and breakpoints discovered during the initial inspection in Step 1 should be patched with Tuffglass Fabric and either Tuff-kote, Roof-kote or Metal-Patch, depending on the recommended specifications. Tuffglass Fabric is available in a wide variety of lengths and widths, up to 3' wide, to handle nearly any patching situation.
Once all preparation and patching have been completed, the selected coating may be applied. There are several acceptable methods of application, and it is very important to consider the size and type of surface to determine which will be most suitable. The most effective methods of application are as follows:
For jobs over several thousand square feet, spraying TKOWC coatings is generally more efficient, as it will reduce labor costs versus manual spreading, and allow greater control over spread rates and finish. For more information on sprayer models, pump and tip sizes, consult Spraying Specifications.
Use a large roofing brush to apply TKOWC products on wide, open areas, and smaller hand brushes for patching, touch-ups and flashing. Brushing is best suited for smaller-sized jobs, rough surfaces or difficult to reach areas.
Use a squeegee on wide, flat areas with relatively smooth surfaces. A squeegee may also be used in conjunction with brushes and rollers to help smooth the surface. Dip the squeegee in mineral spirits or paint thinner, shake off excess, then pull across the surface lightly to smooth out ridges and brush marks from rollers and brushes.
Rollers are frequently a popular choice for coating applications. The unique formulas of TKOWC products have a thick adhesive nature and rollers may not be the most suitable application tools for many jobs. Choose a low-nap roller, preferably of a foam type, and push the material to spread it rather than trying to roll it in a conventional way. "Rolling" may lead to difficulty in spreading, as the material will stick to the roller rather than to the roof surface. Continued efforts to "roll" and overwork the product can also result in the material picking itself back up off of the surface. For best results, use a very light pushing action when using a roller.
Note: Continuously "dipping" the applicator can be time consuming and may lead to insufficient mil thickness. For best results (except with spraying), pour out the contents of each can (remember to mix thoroughly!) and spread it evenly to the appropriate mil thickness. Be sure to work the material back and forth into crevices, rough or uneven surfaces. Check the application regularly with a mil thickness gauge to help maintain a uniform and sufficient surface thickness.
For further technical support, contact our Technical Services Department via phone (815.338.2006), fax (815.338.9105) or email (tech@tkocoatings.com).
General Information & Application Guidelines | Five Basic Steps to Roof Repair | How to Avoid Common Roofing Problems