The cheapest masonry repair I have ever done cost $140 and took an afternoon: two downspout extensions and a wheelbarrow of soil regraded away from the west wall. The efflorescence band that had been coming back every spring for six years has not returned since.
The bottom three feet is where walls die
Walk any older street in Westville and the damage is concentrated in a band from grade up to about waist height. That is not coincidence. Four things converge there:
- Splash-back. Rain hitting a hard surface next to the wall throws water and grit back onto the masonry, repeatedly, at the same height. On a paved path the splash zone reaches 12 to 18 inches; on gravel, less.
- Rising damp. Old walls have no damp-proof course. Groundwater wicks up through the pore structure until evaporation balances the rise, typically a foot or two.
- Snow storage. Shoveled snow piled against a wall keeps it saturated for weeks and delivers de-icing salt at the same time.
- Ground contact. Soil or mulch banked above the base of the wall keeps that masonry permanently damp and hides the damage.
Every one of these is a drainage problem rather than a masonry problem, and every one is cheaper to fix than the wall.
The fixes, in order of value per dollar
1. Downspouts that discharge away. Six to ten feet from the foundation, onto something that will not erode. A single downspout dumping at the base of a wall delivers hundreds of gallons in one storm to one spot. Extensions cost $15 to $40 each.
2. Gutters that work. Clean, correctly pitched, joints sealed. A gutter overflowing at one joint puts a vertical stripe of damage down a wall that people then diagnose as a wall problem.
3. Grade falling away. Six inches of fall in the first ten feet is the standard target. Where that is impossible, a swale or a shallow drain to carry water around the building.
4. Get soil off the masonry. The finished grade should sit below the base of the wall or below any damp-proof course. Raised beds against a house wall are a slow way to destroy it.
5. Break the splash zone. A band of gravel 18 inches wide against the wall, or a drip edge on paving that slopes away. Cheap and surprisingly effective.
6. Only then, drainage below ground. A French drain or a footing drain, $80 to $200 per linear foot, once the surface work has been done and the problem persists.
Doing them in that order matters, because the expensive interventions frequently turn out to be unnecessary once the cheap ones are in place. Where the house has a stone foundation, the interior side of the problem is covered in basement water in a stone-foundation house, and the flood and drainage guidance published by FEMA is worth reading for anything on a low-lying lot.
What it looks like when it is working
Give it a full year. A wall that has been chronically wet takes months to dry, and lime mortar and old brick hold a lot of water. The signs it is working: the efflorescence band stops recurring in spring, moss and algae at the base recede, and interior humidity in the basement drops.
What will not resolve on its own is damage that has already happened. Spalled brick faces and eroded joints still need repointing. But repointing a wall whose water source is still live is money spent on the same repair twice.
Frequently asked questions
How far should a downspout discharge from the house? Six feet is the common minimum, ten is better on clay soils or where the grade is nearly flat. Buried lines to a pop-up emitter work well but need cleaning access, because a blocked buried line delivers all that water directly to the foundation with no warning.
Is a gravel bed against the wall a good idea? For breaking splash-back, yes. It should sit below the base of the wall, not against masonry above it, and it works better with the surrounding grade sloping away — otherwise you have built a trench that collects water.
My neighbor’s grade slopes toward my wall. What are my options? Practically, a swale or a shallow drain on your side to intercept the flow before it reaches the wall. Legally it varies by jurisdiction and by whether the grade was altered. Intercepting the water is usually faster and cheaper than resolving the question of who caused it.