Home › Blog › Sandblasting Brick in Grand Rapids
August 9, 2026 · Historic Restoration
Brick comes out of the kiln with its hardest, densest surface on the outside. Sandblasting grinds that fired skin off and leaves the soft core exposed. The wall then drinks water it used to shed, and in a climate that freezes and thaws forty to sixty times a winter, that is how a hundred-year-old brick house starts crumbling.
We get called to look at these walls two or three times a year, and the conversation is always the same. Somebody bought a beautiful old brick house, hired a crew to "clean it up," and now the brick is rough to the touch and shedding orange dust into the flower beds. It looked fine the week the scaffolding came down. Two winters later it does not.
There is no undoing it. That is the hard part of this trade to explain to a homeowner. So this one is written mostly to be read before the decision instead of after.
A brick is a clay product baked in a kiln, and the outside of the brick sits closest to the heat. That outer layer vitrifies. It becomes denser and harder than the inside of the same brick, and it is the reason a brick wall can stand in the rain for a century without dissolving. Masons call it the fire skin. It is maybe a sixteenth of an inch of material doing most of the work.
The Preservation Brief 6, Dangers of Abrasive Cleaning to Historic Buildings puts the consequence plainly: when brick is cleaned abrasively, the hard outer layer is eroded, leaving the soft inner core exposed and susceptible to accelerated weathering. The same document notes that grit blasting increases the water permeability of a brick wall, because the impact of the particles erodes the bond between mortar and brick and opens cracks where water can enter.
That brief was written in 1979. Nothing since has argued with it. The Secretary of the Interior's Standards say it in one sentence: surface cleaning shall be undertaken with the gentlest means possible, and sandblasting and other cleaning methods that will damage historic building materials shall not be undertaken.
Blasted brick is a bad idea in Phoenix too. It is a much faster problem here.
The National Weather Service Grand Rapids forecast office tracks roughly 40 to 60 days each winter where the temperature crosses the freezing mark. Every crossing is a chance for water sitting inside a brick to expand and push outward on a face that no longer has its hard skin holding it together. A sound brick sheds most of that water before it ever gets in. A blasted brick soaks it up.
The result shows up as spalling: faces flaking, popping, and eventually crumbling off the wall. We wrote a full field guide on what causes brick spalling and how to fix it, and abrasive cleaning history is one of the first things we ask about when we see it on a pre-war house.
There is a second, quieter problem. Erosion and pitting leave a rougher surface with more area for dirt and pollutants to collect. The wall gets dirty faster than it used to, which tempts the next owner into cleaning it again.
Most of the blasting we see was done to strip paint. It is worth knowing that the method frequently fails at the one job it was hired for.
The Park Service brief documents exactly this: the entire outer surface layer of the brick gets blasted away while spots of paint still cling in the crevices. Grit follows the flat planes and skips the low spots. You are left with pitted brick and a patchy paint job, which usually leads to a second pass, which takes more brick.
Worth saying too: plenty of nineteenth-century brick was painted on purpose, either because the brick was poor quality and needed the protection or because the fashion of the day called for it. Stripping a house back to bare brick is not always a restoration. Sometimes it removes a finish that was original and protective. The brief is blunt that large painted areas of brick are usually best left painted, or repainted.
"Low pressure" means completely different things to a commercial cleaning contractor and to an architectural conservator, and that gap is where old houses get wrecked. From the same NPS guidance:
| Context | Typical pressure |
|---|---|
| Careful abrasive cleaning of historic fabric | 20 to 100 psi, nozzle 3 to 12 inches away, very fine grit |
| Micro-abrasive work on carved detail | around 40 psi, pencil-sized instrument |
| Firms cleaning historic masonry commercially | 200 to 1,500 psi depending on the company |
| Industrial chemical cleaning | 1,000 to 2,500 psi |
| What the trade calls high-pressure water | over 5,000 psi, sometimes 10,000 to 15,000 |
So a contractor can tell you in complete good faith that he is using low pressure and still be running twenty times what your 1912 brick can take. Ask for the number, not the adjective.
One more wrinkle the brief raises that almost nobody accounts for: line drop. Pressure at the nozzle falls off with distance from the compressor, so the bottom of a two-story wall gets hit harder than the top even when the operator is doing everything right. Uniform treatment of a whole facade is largely a fiction.
Gentlest means possible is not a slogan, it is a work sequence. You start at the bottom and stop as soon as the wall is acceptable.
Timing matters here as much as method. Any wet cleaning on masonry in Michigan needs to happen in warm weather with a long stretch of frost-free days ahead of it, so the wall can dry all the way through. Water left in the masonry when the first hard freeze arrives can spall the face and leave you worse off than the dirt did. That means late spring through early fall in Kent County, not October.
While the wall is being looked at, the joints are worth looking at too. Cleaning is a poor use of money on a wall with failing mortar, and our notes on tuckpointing versus repointing explain which one a given wall actually needs. On pre-1950 brick the mortar mix itself is a decision, not a default, which we cover in historic mortar matching for Grand Rapids brick.
You cannot put the fire skin back. What you can do is slow the water down.
First, get the mortar joints sound and the drainage working, because a blasted wall with open joints deteriorates several times faster than a blasted wall with good ones. Then comes the coating question, and it is the one people get wrong. A film-forming sealer looks like the obvious answer and is usually the wrong one: it slows the evaporation of moisture out of the wall, salts then crystallize behind the face, and the brick spalls anyway. The Park Service brief notes that painting is generally preferable to a transparent sealer for exactly this reason. Our post on whether to seal or paint exterior brick works through the tradeoff in detail.
Where damage has gone past coatings, the options narrow to selective brick replacement or, in bad cases, stucco. Neither is cheap, which is the real argument for never letting a blaster near the house in the first place.
If the house sits in Heritage Hill or another locally designated district, this is not only a technical question. Exterior work in a district generally goes through the Historic Preservation Commission before it starts, and cleaning methods and coatings are squarely the kind of change that review exists to catch. Abrasive blasting is not going to get approved. Our walkthrough of the Historic Preservation Commission masonry review process covers how the application works and what the commission wants to see.
The broader guidance behind all of this is public and readable. The National Park Service Preservation Briefs cover cleaning, repointing, and coatings for masonry in plain language, and Brief 6 is the one specifically about abrasive damage.
Have someone look at the wall before anyone quotes a cleaning method on it. We will tell you what the soiling actually is, whether it needs to come off at all, and what the gentlest thing that works looks like on your particular brick. If the wall has already been blasted, we will tell you honestly what can and cannot be recovered. See our historic masonry restoration work, or request a free estimate or call (616) 345-5247.
Yes, on almost every house. Brick is fired hardest at its outer surface, and blasting grinds that skin off and leaves the soft, porous core exposed. The National Park Service documents that abrasive cleaning makes brick weather faster and increases how much water a wall takes on. In a freeze-thaw climate that is the setup for spalling.
Not reliably. The National Park Service notes that abrasive blasting often erases the brick surface while paint still clings in the low spots and crevices, so you end up with damaged brick and a patchy result. Removing paint from masonry without any damage is close to impossible, which is why repainting is frequently the better call.
Far lower than most contractors assume. NPS guidance describes careful abrasive work on historic fabric in the range of 20 to 100 psi at a nozzle distance of 3 to 12 inches with very fine grit. Commercial cleaning firms often work at 1,000 psi and up, and industry high-pressure water can run past 5,000 psi.
Start with the gentlest thing that works. A low-pressure water wash and a natural bristle brush, never a wire brush, handles most soiling. Steam is a step up. A masonry-safe chemical cleaner or a poultice handles stains that water will not touch. Test a small patch in a hidden spot before doing the whole wall.
You are managing it rather than reversing it, because the fired skin does not grow back. The wall needs sound mortar joints, working drainage, and usually a breathable coating or paint to slow water uptake. Avoid film-forming sealers, which trap moisture behind the face and make spalling worse.
If your home sits in Heritage Hill or another locally designated district, exterior work generally goes through the Historic Preservation Commission before it starts. Cleaning methods and coatings are exactly the kind of change the review looks at, and abrasive blasting is not going to be approved. Ask before scheduling anything.
About Masonry Grand Rapids. We are a West Michigan masonry contractor working on brick, block, and stone across Grand Rapids, Wyoming, Kentwood, Rockford, Holland, Muskegon, Kalamazoo, and Lansing. Tuckpointing, chimney work, brick repair, retaining walls, and historic restoration. 500 Fulton St E #234, Grand Rapids, MI 49503. (616) 345-5247.