Reusing bricks is straightforward once you know how to clean them properly and match them to the right project. Old bricks from a demolition, renovation, or salvage yard can work for everything from garden paths to structural walls, but the process starts with removing old mortar and checking each brick for damage. Here’s how to do it right.
Removing Old Mortar
The mortar clinging to reclaimed bricks needs to come off before you can do anything useful with them. How easy this is depends almost entirely on what kind of mortar was used originally. Bricks from buildings constructed before the early 1900s typically have lime-based mortar, which is softer and comes off much more easily. Bricks from newer construction usually have Portland cement mortar, which bonds harder and takes more effort to remove.
For lime mortar, a joint raker (a wheeled tool with a nail-like head) rolls along the old mortar joints and scrapes material away quickly. A hammer and plugging chisel also work well. Hold the chisel nearly parallel to the brick face and strike lightly. Hammering too hard or at a steep angle will chip or crack the brick itself. You want to remove roughly half an inch to three-quarters of an inch of mortar from each surface.
For stubborn cement-based mortar, a grinder with a raking bit attachment is more effective. The bit fits most standard drills and grinds the mortar out of the joint. The key risk here is cutting into the brick, so move slowly and keep the bit centered on the mortar line. After mechanical removal, you can soak bricks in water for a day or two to soften any remaining mortar, then knock off the residue with the chisel.
Checking Whether a Brick Is Still Sound
Not every old brick is worth reusing. Cracks, flaking surfaces, and deep chips all signal a brick that may crumble under load or deteriorate quickly when exposed to weather. Start with a visual inspection: reject bricks with visible fractures running through the body, heavy surface spalling (where layers are peeling away), or corners that break off easily by hand.
A simple field test that works surprisingly well is the sound test. Hold a brick in one hand and tap it with another brick or a hammer. A clear, ringing tone indicates a dense, well-fired brick. A dull thud suggests the brick is soft, porous, or internally damaged. Research published in the journal Case Studies in Construction Materials found that visual observation and the pitch of a sound test are effective enough to sort out weak bricks from a batch, even without lab equipment. For a backyard project like a garden path, these two checks are sufficient. For anything structural, like a load-bearing wall, only laboratory compression and freeze-thaw testing can confirm a brick is safe to use.
Choosing the Right Mortar
If you’re laying reclaimed bricks into a wall or any mortared structure, the mortar you use matters more than you might expect. The critical rule is that your mortar should be equal to or weaker in strength than the bricks themselves. Using mortar that’s too strong creates stress concentrations that cause the softer brick to crack and spall over time.
Most reclaimed bricks, especially older ones, pair best with Type O mortar or a lime-based mortar mix. Type O is a low-strength mortar commonly used for interior work and restoration of historic masonry. If your bricks came from a pre-1900s building, they were almost certainly laid with pure lime mortar originally, and using a modern high-strength Portland cement mortar on them is a recipe for damage. The Brick Industry Association recommends that the compressive strength of your repointing or relaying mortar should match or fall below that of the original mortar. When in doubt, go softer.
Project Ideas and What Each Requires
Patios and Walkways
Brick pavers are one of the most popular uses for reclaimed bricks. You’ll need to excavate about four to six inches, lay a compacted gravel base, add a layer of sand, and set the bricks on top. Not all bricks are suitable for ground-level paving, though. Bricks that are too soft or porous will absorb water, crack in freezing temperatures, and deteriorate within a few seasons. Choose bricks that ring clearly when tapped and show no surface flaking. You can leave small gaps between bricks and fill with sand or fine gravel for a permeable surface that lets stormwater drain through rather than pooling or running off.
Garden Walls and Raised Beds
Low garden walls and raised planting beds are forgiving projects for reclaimed brick. A freestanding garden wall under three feet tall doesn’t bear significant load, so even slightly imperfect bricks work fine. For raised beds, you can dry-stack bricks without mortar, which makes rearranging easy and avoids the question of mortar compatibility entirely. If you want a more permanent raised bed, mortar with a lime-based mix. Keep in mind that if your bricks were ever painted, the paint could contain lead, particularly if it was applied before 1978. Avoid using painted bricks for vegetable garden beds unless you’ve confirmed the paint is lead-free.
Retaining Walls
For retaining walls that need to hold back soil, reclaimed brick is often used as a decorative veneer over a structural cinderblock base rather than as the load-bearing element itself. This approach gives you the character of old brick without relying on salvaged material to handle lateral soil pressure. Proper drainage behind any retaining wall is essential to prevent water pressure from building up and pushing the wall outward.
Decorative and Interior Uses
Reclaimed brick makes excellent interior accent walls, fireplace surrounds, and edging for landscaping beds. These applications put almost no structural demand on the brick, so cosmetic imperfections and softer bricks are perfectly acceptable. Thin brick slices cut from full bricks can be adhered directly to an interior wall for the look of exposed brick without the weight of a full masonry wall.
Safety When Working With Old Bricks
Cutting, grinding, and chiseling brick generates crystalline silica dust, which causes serious lung damage with repeated exposure. OSHA identifies brick cutting, sawing, and especially sandblasting as high-risk activities for silica exposure. Wear a respirator rated for silica dust (not just a paper dust mask) whenever you’re removing mortar or cutting bricks. Spraying water on the work area while cutting dramatically reduces airborne dust.
If you’re using a grinder or saw, work outdoors and position yourself upwind. Change out of dusty clothes before going inside, and wash your hands and face before eating or drinking. Avoid dry sweeping brick dust, which just sends it airborne again. A wet cleanup or a vacuum with a HEPA filter is much safer.
Old bricks may also carry lead-based paint, asbestos-containing coatings, or residues from their original use. If your bricks came from an industrial building or were painted before the late 1970s, test for lead before sanding, grinding, or using them in food-growing areas.
Why Reusing Brick Is Worth the Effort
Beyond the aesthetic appeal of weathered brick, reuse has a real environmental payoff. Manufacturing new clay bricks requires firing at temperatures around 1,000°C, which consumes significant energy and produces carbon emissions. Research comparing conventional brick production to methods incorporating reclaimed materials found average energy savings of 21% and a reduction of roughly 2 tonnes of carbon per year at the production level. Every brick you pull from a demolition pile and put back into service skips that manufacturing process entirely. A single pallet of reclaimed bricks keeps several hundred pounds of material out of a landfill while avoiding the full energy cost of producing replacements.
Reclaimed bricks also tend to be denser and harder than many modern bricks, since older manufacturing methods and clay compositions often produced a more durable product. That density, combined with the character of age and weathering, is why salvaged brick commands premium prices in the architectural market and why the effort of cleaning and sorting is usually worth it.