Waterproofing chimney masonry after repairs in Bermuda Riviera

Treatments wear and need renewal

Penetrating repellents last a good while, but they do not last forever. Sunlight, weather and wear gradually reduce their effect, and brick industry guidance treats reapplication as part of their use. When the effect fades, the brick starts to absorb water again.

We do not attach a lifespan to the treatment, because it depends on the product, the masonry and the exposure. The written record notes the product and when it was applied. A later maintenance visit can check whether the brick still sheds water and whether renewal makes sense.

Broken and flaking brick goes first

Brick with cracked or flaking faces lets water straight in, and a repellent cannot seal it. Brick industry guidance lists replacing such units among the repairs that should come before any clear coating.

We mark the damaged bricks during the inspection and list their replacement as a separate item. The treatment is then planned for the sound masonry that remains. If most of a face is damaged, we say so, because a larger masonry repair changes whether treatment makes sense at all.

Staining on treated masonry

Brick industry guidance notes that if staining appears on masonry after a clear treatment, it can be harder to remove than it would have been from untreated brick. The treatment holds some stains near the surface.

That is one reason cleaning comes first. The source of any staining, such as rusting metal or runoff from the roof, should also be dealt with before treatment. We point out stain sources during the inspection. Removing them first keeps them from being locked in.

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