White Salt on Your Brick After Roof Day: Ask Each Roofer Who Cleans It

White powder on brick is one of the first things a homeowner notices after a roof comes off, and it is often the last thing anyone writes down. Efflorescence is the salt left behind when water moves through masonry, dissolves minerals inside the brick and mortar, and then evaporates at the surface. It looks alarming, usually does no structural harm on its own, and fades over weeks in dry weather. But it tells you water has been moving through that wall, and it can show up near a roof job for ordinary reasons: a wet week during tear-off, runoff from a roof wash, or water finding a new path while the old flashing is off.

That makes the question of who cleans it a comparison point, not a detail to leave for later. Each roofer will answer it differently, and the difference tells you how they treat your house after the crew leaves. This page covers what to ask, what a clear answer looks like, and where the cleaning line belongs in your bid. Keys Roofing can be reached at (314) 220-2333 if you want to ask these questions directly, and the questions below work with any roofer you are weighing.

Why St. Louis brick gets it

Greater St. Louis has a lot of brick, and the freeze and thaw cycle gives it plenty of reasons to take on water. Brick soaks up moisture through the face, and mortar joints open a little each winter. When a warm spell follows a hard freeze, water wicks outward and evaporates, bringing salts with it. Clay soil around older houses holds water against foundations, and that moisture can climb as well. None of this is a roof failure by itself. The point is that a roof job disturbs the top of the wall, and the top of the wall is where water enters and where the salt tends to show.

Roof day adds a few specific ways for water and chemicals to reach brick. Pressure washing the deck or the eave before a tear-off can push water into open mortar. Some roof-wash products run down the wall if the crew does not protect the brick below the eave. A roof that is opened in rain can send water down the chimney or the wall plate, and that water can exit through brick a few weeks later. A roofer who never mentions the brick below the eave is not necessarily careless, but you should know whether they looked.

Where the cleaning line belongs

Cleaning efflorescence is not part of tear-off or install, so it often does not appear in a roof bid at all. Some roofers treat it as a warranty item if their work caused the water. Others treat it as a change order. Some will say they will look at it when they are back on site, which is not an answer you can compare. Put the question to each roofer in these words: if white salt shows on my brick within sixty days of final walk, who cleans it, what is the method, and what does it cost me? Then write down the answer beside the question.

The best answer names the party, the method and the price basis, and it puts the answer in writing. A clear answer might say the crew will inspect the brick below the eave at pre-start and again at final walk, photograph it with dates, and clean any salt it caused at no charge if the photos show it was there before the crew arrived. Another clear answer might say cleaning is a separate line priced by the hour, but that the company will fix any wall it damaged. Both are fine as long as they are specific. A weak answer is one that says it will be taken care of.

Ask about the method, not just the price

Brick cleaning can do real harm if it is done in the wrong order. Acid cleaners, including some sold for masonry, can etch brick faces and attack mortar joints, and a high-pressure wash can strip the face off soft brick or push water deeper into the wall. Many masonry specialists start with a dry brush, then clean water, and only use a mild, labeled cleaner after a test patch in a hidden spot. Ask each roofer which method they use, whether they test first, and who does the work. If the answer is that they will power wash it, ask for the pressure setting and the product name, and write both down.

Timing also matters. Efflorescence often fades on its own when the wall dries, and cleaning too soon can drive salts back in. A roofer who says they will clean it on day one of a wet week is asking you to accept a weak result. A roofer who says they will wait for three dry days and then return is giving you a plan you can check. Ask how many dry days they need and who decides when the brick is ready.

What to check before the crew leaves

Before the final walk, ask each roofer to show you the brick below the eaves, the chimney and any wall that meets the roof. Take your own photographs from the same spots with a phone that keeps dates. If there is white salt already present, write it down so the cleaning answer covers the existing condition and any new spread. The gap between what was there before and what appears later is where most disagreements start, and a dated photo set settles more of them than memory does.

Look for a line in the closeout paperwork that names the brick, the wall and the expected follow-up. If the closeout packet says nothing about masonry, ask the roofer to add a sentence about it. A crew that will not write one sentence about the walls it worked next to is telling you something about how the rest of the job will be documented.

Questions to put to each roofer

• Did you look at the brick below the eave and the chimney during your site visit, and what did you see?
• What method do you use for efflorescence, and do you test on a hidden patch first?
• If salt shows within sixty days of final walk, who cleans it and who pays?
• Do you use acid cleaners on brick or mortar, and if so, which product and what dilution?
• How many dry days do you need before you clean, and who decides the day?
• Will you put the cleaning answer and the photo set into the contract or closeout packet?

Write each answer on one sheet, with the roofer's name at the top and the date you asked. When two roofers give you very different answers, the one that names the method and the payer is usually easier to hold to later. The one that says it will handle it when it comes up is harder to compare, even if its price is lower.

When the salt is not a masonry problem

Some white marks look like efflorescence and are something else. Hard water residue, roof granule dust, and mineral staining from a dripping gutter can all look similar from a few feet away. If the powder wipes off with a dry cloth and does not return, it may be surface dust rather than salt moving through the wall. If it sits in the mortar joints and returns after cleaning, it is coming from inside the wall, and that points toward a water path that the roof work should address. Ask the roofer to tell you which one they see, and why, before any cleaning starts. A roofer who cannot tell the difference should say so.

If you see white salt along with damp spots, soft mortar, or a smell in the room behind the wall, stop waiting for it to fade. Water in the wall needs a source found, and that is a question about the roof flashing and the wall, not about the brick finish.

Where to start

Start this week by walking the brick below your eaves and your chimney with a phone. Take photos from the same spots you will use after the job. Then send each roofer the same short list of questions and file their replies by date. You will be able to compare them side by side, and the answers will tell you more about how each company handles the wall than a line of marketing copy will. Keys Roofing can be reached at (314) 220-2333 if you would rather ask by phone.