Is It Safe to Pressure Wash a Brick Home in Ontario?

Brick homes are common in Kitchener-Waterloo — from the old-growth brick of Galt's heritage district to the decorative brick facing on modern builds in newer subdivisions. When these surfaces get dirty, the question of pressure washing comes up. The answer is yes, but technique matters significantly more than it does for non-masonry surfaces.

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Yes — With the Right Approach

Brick itself is quite durable and can tolerate pressure washing when the correct settings and technique are used. The critical variable is mortar — the compound between bricks is significantly softer and more porous than the brick face and can be damaged by excessive pressure or a direct perpendicular spray. Technique and pressure setting are what determine whether a brick cleaning goes well or causes damage.

The Mortar Risk

New mortar (under 10 years) is reasonably robust. Original mortar on older brick homes — particularly homes built before 1960 in KW's heritage neighbourhoods — can be quite soft, especially if it has already been compromised by water infiltration or freeze-thaw cycling. Very old soft mortar can be damaged by moderate pressure. Before pressure washing an older brick home, tap along the mortar joints with a small tool and listen for hollow sounds — this indicates existing mortar failure that pressure washing would worsen.

Correct Pressure Settings

Maximum recommended pressure for brick washing: 1200–1500 PSI with a 40-degree fan tip. Spray at a 45-degree angle to the surface, not perpendicular. Keep the nozzle at least 30 cm from the brick face. Never use a rotating/turbo nozzle on brick. Work from top to bottom in overlapping passes. Pre-wet the surface before applying cleaning solution, and rinse thoroughly after.

When Soft Washing Is Better

For older brick, brick with visible mortar damage, or brick with biological growth (algae, moss, mould), soft washing is often the better choice. Soft washing uses very low pressure with biodegradable chemical cleaning agents that kill and remove organic growth without any mechanical stress on mortar joints. It's the professional standard for heritage and older masonry.

After Washing

After pressure or soft washing brick, allow to fully dry (48–72 hours) before inspecting mortar condition. Any mortar that was marginally intact before washing may now be visibly loose. This is an opportunity to tuck-point (re-apply mortar) before winter. Contact D&D Home Services for professional brick washing across KW.

Devon Moore, Operations Lead Co-Founder & Operations Lead — D&D Home Services

Devon Moore is the co-founder and Operations Lead at D&D Home Services, with hands-on experience cleaning hundreds of homes across Kitchener-Waterloo, Cambridge, and Guelph.