Waterproofing chimney masonry after repairs in Riverland

Stone on the chimney

Natural stone varies. Some stones, such as limestone and marble, react badly with certain repellents, and product data may rule them out. Other stones need testing to confirm the result. Manufactured stone behaves differently again.

We identify the stone where we can and check the product data against it. A test area is especially important on stone. If the product is not suited, we say so rather than applying it anyway. Stone repairs, if needed, are a separate item that comes first.

Stains from rust or copper

Rust from a cap or old flashing, or green runoff from copper, can stain the brick below. A repellent applied over those stains may make them harder to remove later, because treated masonry holds stains differently.

We clean stains before treatment where the masonry allows it, using methods suited to the stain and the brick. The source of the staining is noted, because a rusting cap will keep staining the new work. If the metal needs attention, that is its own item.

Removing paint to treat the brick

If a chimney is painted and you would like a breathable repellent instead, the paint has to come off first. Paint removal from brick is a job with its own risks. Harsh methods can damage the face of the brick and leave it more absorbent than before.

We explain whether removal is realistic on your chimney and what method would suit it. It is priced as its own item, with a test on a small area first. In some cases, keeping and maintaining the paint is the better choice, and we say so.

What a repellent will not do

It helps to be clear about the limits of a treatment before paying for one. A penetrating repellent is not a repair, and the list below covers what it leaves untouched.

Each of those needs its own repair. Our estimate lists them separately, so nobody expects the treatment to do a job it was not made for.

• Close cracks, open joints or gaps at the top
• Strengthen crumbling brick or soft mortar
• Stop rain falling down an open flue
• Fix water getting in at the roof junction