Chimney waterproofing that lets the brick breathe in The Hammocks

What a repellent can and cannot bridge

Penetrating repellents work in the pores of brick and mortar, not across gaps. Some product data allows for very fine shrinkage cracks, but anything wider is beyond what the treatment can close. Brick industry guidance also notes limited effect against wind-driven rain through cracks.

We look closely at the cracks on your chimney before recommending treatment. Hairline crazing may be within what the product tolerates. Open cracks, separated joints and gaps at the crown are not. Those are listed for repair, and the estimate explains which cracks were judged which way.

Gloss on the brick points to a film

If a chimney has a glossy or wet look after an earlier treatment, it may have been coated with a film-forming product. That shine can be a sign that the coating is sitting on the surface rather than in the pores.

We check any earlier treatment before recommending another. A film over the brick can prevent a penetrating repellent from working and may be trapping moisture. The findings describe what we see, and removing an old coating, if needed, is a separate step with its own test.

Questions to ask about a sealing proposal

A proposal to seal or waterproof a chimney should answer a few basic questions. These help you check any quote, including ours.

If a quote cannot answer these, it is worth asking why. Our estimate addresses each in writing, and we are glad to go through them in person.

• Does the product penetrate or form a film
• Which repairs will be done before it goes on
• Will a test area be done first
• What happens to glass, roofing and plants nearby

Reaching the chimney for treatment

Treating a chimney means reaching every face to be treated, usually from the roof and sometimes from ladders or staging on the ground for an outside chimney. Access depends on the roof pitch, height and surface.

Mention anything that sits under the chimney, such as a patio, flower beds or a skylight, so we can plan where ladders stand. Gates, dogs and parked cars matter too. We sort out access before the application day, so the dry weather window is not spent setting up.