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Cleaning and Sealing Stone Facades

Removing mold mildew

To remove mold and mildew from an area, we recommend using green cleaning chemicals for cleaning the natural stone. CT- Mold Remover penetrates deep into the substrate and attacks the roots of the mold and not just on the surface. The product is not harmful to natural stone and should be diluted 10 parts water to 1 part cleaner. Another advantage of CT -Mold Remover is that it will not damage grass and plant life. This makes the product much safer than using chlorine and bleach which can cause damage to neighboring surfaces as well as vegetation. Do not use acid based cleaners on natural stone. These will likely damage or etch the alkaline based stone.

Cleaner Application

Apply CT- Mold Remover to the surface with a low pressure garden sprayer, or watering can. An airless sprayer works the best for large areas. Applicators should use a spray devise that will not create heavy misting or over spray.

Allow the Mold Remover to remain on the surface for 10 minutes before rinsing with hose or pressure washer. (If remover starts to dry on the surface, dampen with water). Stubborn stains and areas of severe accumulation may need a second application before rinsing. Keep surface damp until rinsed. Rinse the surface thoroughly with clean water. For best results, use a minimum of 80 psi water pressure for rinsing. After washing, the surface should be allowed to dry.

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Long term sealant protection

To seal a stone facade we recommend the use of a fluorosurfactant clear sealer such as PEN55 . This penetrating sealer has outstanding anti adhesion anti fouling properties making the stone surface mildew resistant and highly repellant to water, dirt and oil. PEN55 is penetrating so it will not affect the appearance of the cleaned surface.

Sealer Application

CoverSeal PEN55should be applied using low-pressure (15 to 25 psi) pumping equipment with a wet fan type spray nozzle. Alternate methods include using either a power roller with a 1″ nap or a brush. Do not alter or dilute the material. Do not apply to a wet or damp substrate. A test patch should be applied to the substrate to verify coverage rate, application conditions and desired results. On vertical surfaces, the CoverSeal PEN55 should be applied in a flooding application from the bottom up, so that the material runs down 6 to 8 inches below the spray pattern. On horizontal surfaces, allow the Pen55 liquid to pond on the surface for at least 5 seconds before being absorbed. Coverage rates on vertical surfaces depend on the type of stone or concrete material to be treated.

For sealing a stone facade, the typical application rates are from 250 to 300 ft2/gal. remember to protect glass, metal, plastic, asphalt materials and nonporous substrates from overspray. PEN55 will not etch glass or cured joint sealant but will leave a residue on nonporous surfaces.

CT –Mold Remover and CoverSeal PEN55 are used for the cleaning and sealing stone facade material. They can be obtained direct from CoverTec together with detailed application instructions and technical support. If you are interested in buying these products please email your request or call us at 754-223-2465 to discuss your project.


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