Fix Brick Staining from Overflowing Eavestroughs in Ottawa

Those dark streaks running down your brick are a telltale sign that your eavestroughs have been overflowing, and it is a problem Ottawa homeowners deal with constantly thanks to our heavy rainfall, autumn leaf loading, and spring snowmelt volumes. The staining itself is usually a combination of mineral deposits, algae growth, and tannin from decomposing leaves that overflow water carries down the brick face. The good news is that most brick staining from eavestrough overflow is cosmetic and removable — but the real fix is addressing the overflow that caused it.

Cleaning the Stains and Preventing Recurrence

For light staining that has been there less than a year, start with oxygen bleach (sodium percarbonate, sold as OxiClean or similar) mixed with warm water. Apply the solution to the stained brick, let it sit for 15 to 20 minutes, then scrub with a stiff-bristled brush and rinse thoroughly. Oxygen bleach is safer than chlorine bleach for brick because it will not damage the mortar joints or kill surrounding vegetation. For stubborn staining, a dedicated masonry cleaner from a building supply store costs $15 to $30 per container and is formulated specifically for mineral and organic stains on brick.

For severe staining that has built up over multiple seasons — dark black or green streaks that do not respond to scrubbing — you may need professional pressure washing. A professional exterior cleaning service in Ottawa charges $200 to $500 for brick cleaning on a typical home. The pressure must be kept below 1,500 PSI on brick to avoid damaging mortar joints, which is why professional equipment with adjustable pressure and fan-tip nozzles produces better results than most homeowner-grade pressure washers.

However, cleaning the brick without fixing the eavestrough overflow is just treating the symptom. The overflow itself is caused by one or more of these issues: clogged gutters from Ottawa's heavy autumn leaf fall (especially in neighbourhoods like the Glebe, Rockcliffe, and Old Ottawa South), insufficient eavestrough slope that causes standing water, undersized gutters that cannot handle peak flow from steep or large roof areas, or damaged seams and joints that leak water down the fascia.

A professional eavestrough cleaning in Ottawa costs $150 to $350 and should be done at minimum twice per year — once in late November after all leaves have fallen and once in spring after the thaw. If your home is surrounded by mature trees, installing gutter guards at $10 to $25 per linear foot eliminates the primary cause of clogging and overflow. Also check that your eavestrough slope is at least one-quarter inch per 10 feet toward the nearest downspout — insufficient slope causes water to pool and overflow during heavy rain.

To find eavestrough professionals who can diagnose and fix the overflow problem at its source, browse the Ottawa Construction Network directory at justynrookcontracting.com and look for contractors experienced with gutter maintenance and repair.