Abrasive Action: First step to preparing the chimney crown surface is to scrub it down with a heavy duty wire brush, a wire brush can increase the surface area of the chimney crown by 300%, this fact gives the crown coat solution more area to attach itself to ensure property adhesion. The brushing process ensures the removal any debris and or microbial that may have attached themselves to the chimney crown. Sometimes a chimney crown / bricks will get moss buildup which then will leave a residue once removed, so it is very important to really get down to the surface area of the crown by scratching into the concrete.
High PSI Air Blower: After the surface penetration is complete it is time to clear the area of dust debris caused from the brushing process. This high pressure air blower will clear a great percentage of the dust away to accommodate the next step in the process of sealing the chimney crown.
Water Treatment : This final step in the prepping process is key for the fact that neither a brush nor by using high pressure air will completely remove all leftover dust molecules. This step is commonly missed by many masons. Our outlook on this is that every step matters for proper adhesion. When water pressure is applied it completely clears the surface area of the chimney crown, by opening up all the surface pours. A great analogy if this step is skipped, is like sticking a peace of tape on the dusty floor before using it.
Applying Crown Coat: After all steps are complete, we must mist crown with a water sprayer to facilitate proper adhesion. Next we use a 1" China Bristle brush to apply the first coat, let stand a few minutes, then continue to apply as many layers as needed to achieve the desired results. Let stand 2 hour to cure, after this point your chimney crown is now maintenance free .
Chimneys require special attention and maintenance to prevent damage from water penetration. Chimneys are considerably vulnerable to the 90 plus freeze thaw cycles our Minnesota seasons put our homes through. Chimney Saver, is a product developed specifically for chimneys. Chimney Savor has been used successfully for nearly 20 years, It reduces water penetration of masonry by 99.9%, according to ASTM tests conducted at the University of Wyoming. Chimney Saver Water Repellent is also 100% vapor permeable, this translates to the fact it will not trap water vapors that may pass through the bricks, when the chimney is in its working stages, causing condensation. Some products actually form a vapor barrier when applied to a masonry chimney, which leads to water damage.
Solvent (Mineral Spirits) and water-based formulas are both available. The water-based formula is the favorable choice of most chimney Contractors however, if your working with a chimney that has already been sprayed previously with a water repellent, its strongly recommended to us the solvent-based formula. Moisture is always present in concrete/masonry structures, with that being said by trapping water vapors inside, water resistant surface film type sealants are highly frowned upon among chimney contractors. If vapors can't escape, they will play a huge part in the spalling, scaling and deterioration process during the Minnesota Weather cycles. Chimney Saver is a non film-forming water repellent that penetrates and bonds into masonry pores.
Check out this great video strait from manufacture. Chimney Saver water repellent.
Check out this great video of Chimney Savers Crown Coat.