Brick & Masonry Cleaning in Portland, ME

Brick and masonry cleaning in Portland puts us on some of the oldest building material in the city. After the Great Fire of 1866 destroyed about 1,800 buildings, Portland was rebuilt within roughly two years, with commercial and multi-family buildings mostly in brick and granite. That brick, and the lime-based mortar between it, is softer than modern masonry and easy to scar with too much pressure.

The National Park Service approach

Preservation Brief 1, the National Park Service paper on cleaning historic masonry, calls for the gentlest means possible. For water cleaning it recommends starting at very low pressure, 100 psi or below, and generally going no higher than 300 to 400 psi. It warns that high pressure can etch some types of brick and erode mortar joints, especially lime mortar, and that sand or grit in the runoff is a sign the pressure is too high. We follow that approach on older brick fronts, chimneys, foundations and garden walls.

Test patches come first

Every brick and stone reacts differently. Before cleaning a whole wall we test a small, inconspicuous area with the planned solution and pressure, let it dry, and look at it with you. If the test shows any surface loss or uneven color, we change the method or stop.

What we clean off masonry

• Dirt and soot: general grime on street-facing brick, removed with water, mild cleaner and soft brushes
• Algae, moss and mildew: green growth on shaded walls and foundations, treated with a biological cleaner
• Efflorescence: the white powder left when water carries salts to the surface; often brushed and rinsed, sometimes needing repeat treatment
• Rust and organic stains: from railings, downspouts and leaves, treated locally

Efflorescence is a symptom

White salt deposits mean water is moving through the wall. Cleaning removes them, but they come back if the water source is not fixed: a leaking gutter, a missing cap, failed mortar or splashback from a downspout. Preservation Brief 1 also notes that cleaning itself can draw salts to the surface, so a light return of efflorescence after a wash is normal. We point out likely water sources when we see them.

Weather limits

Masonry holds water. The NPS warns that water cleaning should never be done if there is any chance of frost or freezing, because trapped water can crack and spall brick, and that a wall may take more than a week to dry. Chemical cleaners should not be used below 40 degrees. With January highs around 32 degrees and frost often arriving in early fall, we schedule masonry in the warm months and stop well before cold nights return.

Painted brick and repointing

Painted brick on older buildings may carry lead paint, and high-pressure washing of old paint is not something we do. If mortar joints are crumbling or open, cleaning should wait until a mason repoints them; water forced into open joints can do more harm than the dirt. If that is what we find, we will say so.