Brick walls are not waterproof and were never designed to be. They are designed to absorb some water, hold it briefly, and then release it as the wall dries. The whole system depends on the wall being able to breathe.
This is why the single worst thing you can do to a brick wall is coat it in a film-forming sealer. Water still gets in, through the joints, around windows, over the top. Now it cannot get out. It sits in the masonry, it freezes, and it takes the face off the brick.
The order of operations
Water repellent is the last step in waterproofing a wall, not the first.
- Fix the joints. Failed mortar is the largest opening in most walls, and no coating bridges a gap.
- Fix the sealant. Window perimeters and control joints.
- Check flashing and weeps. Water that gets into a cavity wall is supposed to drain out through weep holes. Blocked or missing weeps turn the cavity into a reservoir.
- Check the top. Chimney crowns, parapet caps and sills are horizontal, and horizontal masonry is where water gets in.
- Then, if it is warranted, apply a repellent.
What we apply
A penetrating siloxane water repellent. It soaks into the masonry and lines the pores so liquid water beads and runs off, while water vapor still passes through freely. Applied to a dry wall at the correct rate and in the right weather, it typically holds up for seven to ten years.
The part that is usually not masonry at all
If the complaint is a wet basement, the cause is frequently not the wall. It is a downspout discharging next to the foundation, ground sloping toward the house, or a patio pitched the wrong way.
We will tell you when that is what we are looking at. Regrading and extending a downspout costs very little compared to masonry work, and on a lot of houses it is the fix.
Signs you need this work
- Damp patches on interior walls after heavy rain
- Efflorescence returning again and again
- Musty smell in the basement or lower level
- Brick that stays visibly dark for days after rain
- Peeling interior paint on an exterior wall
- Water in the basement along a particular wall
What's included
- Diagnosis of where water is actually entering, before anything is applied
- Repointing and sealant repairs as the first line of defense
- Flashing and weep hole inspection and correction
- Breathable siloxane water repellent, never a film-forming sealer
- Downspout and grading recommendations
- Clear explanation of what a repellent will and will not fix
How we do it
- 1
Find the entry point
Water repellent is the last step, not the first. We identify whether it is joints, a lintel, flashing, the crown, grading or a downspout.
- 2
Fix the path
Repointing, sealant, flashing and weeps come first. A repellent over failed joints is money wasted.
- 3
Apply the repellent
A breathable siloxane, applied at the correct rate to a dry wall, in appropriate weather.
- 4
Address the ground
We will flag grading and downspout issues, which are often the real cause of a wet basement wall.
Common questions
Does waterproofing brick actually work?
A breathable repellent reduces water absorption significantly and is worthwhile on exposed walls. But it will not bridge a failed mortar joint or a leaking lintel. Those have to be fixed first, and if they are, they do most of the work.
What is the difference between a sealer and a repellent?
A film-forming sealer puts a skin over the surface and traps moisture inside the wall, where it freezes and spalls the brick. A breathable siloxane repellent soaks in and lets vapor escape. Only the second type belongs on brick.
How long does a water repellent last?
Typically 7 to 10 years on a vertical wall, less on horizontal surfaces that take standing water.
My basement is wet. Will this fix it?
Possibly not. Wet basements are more often a grading, downspout or drainage problem than a wall problem. We will tell you honestly what we think is going on rather than sell you a treatment that will not help.