Our Process
How chimney waterproofing is done in Lake Charm
How a siloxane water repellent works
According to Technical Note 6A, siloxanes form a chemical bond with the silica and alumina in brick and mortar, and that bond is what makes the treated masonry repel water. SaverSystems' data sheet for its water-based ChimneySaver repellent describes a hydrophobic zone beneath the surface that keeps water molecules out while water vapor moves freely.
Because the reaction happens inside the pores, the surface texture and color are meant to stay much as they were. The same chemistry is why these products bond to glass that has not been protected, so masking nearby windows is part of the job on your Lake Charm home.
The cracks a repellent cannot bridge
Penetrating repellents line the pores. They do not fill gaps. Technical Note 6A says they seldom stop water penetration through cracks more than 0.02 inch wide, roughly the thickness of five sheets of copy paper, and that their effectiveness under wind-driven rain is limited.
Cracks wider than that need a repair of their own, whether that is repointing, brick replacement or stucco repair. Our specialists look for them on every face during the free inspection, because a repellent sprayed over an open crack leaves the water path in place. Where a hairline sits in otherwise sound mortar, we explain whether it needs work or can be left alone.
Waiting for new masonry and repairs to cure
Fresh masonry and fresh mortar need time before a repellent goes on. For best results, the maker of one water-based siloxane repellent wants new masonry cured for 28 days or more, and a wait of at least 72 hours after repairs or tuckpointing, before the product is applied.
When your Lake Charm chimney needs both repairs and waterproofing, we schedule the treatment after the waiting period the product calls for, often as a second visit. Both steps appear on the written estimate, so you know the sequence before any work starts.
The crown needs its own protection
The crown is a flat, exposed cap of concrete or mortar, and it is handled differently from the brick walls below it. The company behind one chimney wall repellent makes a separate brushable elastomeric coating for crowns, and its data sheet describes it curing into a flexible waterproof membrane over the crown.
A wall repellent sprayed across a cracked crown will not close the cracks. When your Lake Charm chimney's crown needs attention, crown repair or sealing is priced as its own line next to the waterproofing, so each part of the top gets the treatment made for it.
