Brick houses are not immune to termites. While termites can’t eat through brick or mortar, every brick home contains wood framing, floor joists, roof trusses, baseboards, and other structural lumber that termites target. The brick is just a veneer. Termites reach the wood inside by exploiting tiny gaps in the foundation, and they can squeeze through cracks as small as 0.03 inches (less than 1 millimeter). Knowing what to look for on both the exterior and interior of your brick home can help you catch an infestation before serious structural damage sets in.
How Termites Get Into a Brick House
Subterranean termites, the most destructive and common type in the U.S., live in soil colonies and build upward to reach wood. In a brick home, they don’t go through the brick itself. They go around it or behind it, using the many small openings that exist in any foundation. Common entry points include cracks in concrete slabs, expansion joints, gaps around plumbing pipes where they penetrate the foundation wall, the interior of hollow concrete blocks, and the narrow space between the brick veneer and the wood-framed wall behind it.
Weep holes are a particular vulnerability. These small gaps left in the bottom course of brickwork allow moisture to drain from behind the veneer, but they also provide a direct path for termites to travel from the soil into the wall cavity, completely hidden from view. Once inside that cavity, termites can access wood framing without ever building a visible tube on the outside of your house.
Mud Tubes on Foundation Walls
The most recognizable sign of subterranean termites is the mud shelter tube: a narrow, pencil-width tunnel made of soil, saliva, and waste that termites build to travel between their underground colony and the wood they’re feeding on. On a brick house, look for these tubes running vertically up the exterior foundation wall, along mortar joints, inside the crawl space on support piers, and along plumbing pipes under the house. They’re typically brown or tan and blend in easily with dirt-stained brick, so you may need to look closely.
If you find mud tubes higher up on the building, on exterior walls near the soffit or fascia boards, or on interior walls and ceilings, that often signals a Formosan termite infestation. Formosan colonies are much larger and more aggressive than native subterranean species.
To check whether a mud tube is active, break off a one-inch section and check back in a few days. If you see live termites immediately, or if the tube has been repaired when you return, the infestation is active.
Discarded Wings Near Windows and Doors
Termite colonies produce winged reproductive adults, called swarmers, that fly out in large numbers to start new colonies. This typically happens in spring or early summer for most subterranean species. After landing, swarmers shed their wings. Finding piles of small, translucent, equal-length wings on windowsills, near exterior doors, around light fixtures, or collected in spider webs near your foundation is a strong indicator that a colony is living in or very near your home.
Swarmers are often confused with flying ants. The key difference: termite swarmers have straight, beaded antennae, a thick waist, and two pairs of wings that are the same size. Flying ants have elbowed antennae, a pinched waist, and front wings noticeably longer than the back pair.
Interior Warning Signs
Because brick homes hide so much of their wood structure behind walls, interior signs are often the first thing homeowners notice. Watch for these:
- Bubbling or peeling paint on walls. Termites feeding behind drywall produce moisture that can cause paint to blister or wallpaper to bubble, mimicking minor water damage.
- Hollow-sounding wood. Tap on baseboards, door frames, and window trim with your knuckle. Wood that sounds hollow or papery has likely been eaten from the inside out. Termites consume wood along the grain, leaving a thin outer shell intact.
- Sagging or warped floors. If floor joists or subflooring have been compromised, you may notice soft spots, a slight bounce, or visible sagging in areas near exterior walls.
- Tight-fitting doors and windows. As termites eat through framing members, the structure can shift slightly, causing doors and windows to stick or not close properly.
- Small holes in drywall with soil-like material. Termites sometimes breach the surface of drywall, leaving tiny pinholes surrounded by bits of mud or frass (termite waste).
- Mud tubes on interior walls. In heavier infestations, shelter tubes can appear on the inside of walls, along baseboards, or even running across ceilings.
Where to Inspect a Brick Home
Start outside. Walk the full perimeter of your foundation with a flashlight, looking at the base of the brick where it meets the ground or the concrete slab. Pay close attention to areas where soil, mulch, or landscaping beds sit against the brick, as these provide moisture and cover that termites prefer. Check around exterior plumbing penetrations, air conditioning lines, and where concrete porches or patios abut the house wall.
If your home has a crawl space, inspect the interior foundation walls, support piers, and any plumbing running from the ground up into the floor. Mud tubes are often more visible here than on the exterior because they’re protected from rain and wind. Look at the floor joists and sill plate (the first piece of wood that sits on top of the foundation) for signs of damage, mud, or active tubes.
Inside the house, focus on ground-floor rooms closest to exterior walls. Check baseboards, closets built against exterior walls, bathroom floors, and the area around your water heater or furnace where pipes come through the slab.
Drywood vs. Subterranean Termite Signs
Most termite problems in brick homes involve subterranean termites, but in coastal and southern regions, drywood termites can also infest the wood inside your walls. The signs differ. Drywood termites don’t build mud tubes because they don’t need soil contact. Instead, they live entirely inside the wood they’re eating and push their waste out through small “kick holes.” This waste, called frass, looks like tiny, six-sided pellets, often resembling coarse sand or sawdust in a small pile beneath the infested wood. Finding these pellets on a windowsill or along a baseboard is the hallmark of a drywood infestation.
Subterranean termites, by contrast, leave mud as their calling card. If you see soil-like material in places where soil shouldn’t be, along a wall, inside a crack in your slab, or packed into a joint between brick and trim, subterranean termites are the likely cause.
What Treatment Looks Like for Brick Homes
Treating a brick home for subterranean termites typically involves creating a chemical barrier in the soil around and beneath the foundation. For slab-on-grade brick homes, this often means drilling through the concrete slab at roughly 12-inch intervals along interior perimeter walls and injecting liquid termiticide into the soil below. Exterior treatment involves trenching along the foundation and applying termiticide to the soil. These treatments typically require well over 100 gallons of solution depending on the size of the home, making it a professional job rather than a DIY project.
Bait station systems are the other common approach. Small stations are installed in the ground around the perimeter of your home at regular intervals. Termites feed on the bait and carry it back to the colony, gradually eliminating it. Bait systems require ongoing monitoring, usually on a quarterly schedule.
For homes with hollow block foundations, treatment can be more involved. If the blocks aren’t capped with at least 4 inches of reinforced poured concrete, or if the joints aren’t fully filled with mortar, termites can travel through the voids inside the blocks. In these cases, the voids themselves may need to be treated, and gaps around pipes or columns should be sealed with dense cement mortar.
Brick homes often give a false sense of security because the exterior looks impervious. The reality is that every brick house has a wooden skeleton, and termites only need a fraction of a millimeter to find it. Regular inspections, at least once a year, are the most reliable way to catch a problem early.