If you learn anything after buying a house, it’s this: Water is your enemy. Every day, in a surprisingly wide variety of ways, water is infiltrating your house and trying to erode, rust, and wash away everything inside it, including you. That’s why the folks who built your house have taken steps to anticipate and deal with water infiltration—steps many new homeowners are sometimes surprised to learn about.
For example, if your house has a brick exterior, you may notice that there are regular gaps in the mortar—literal holes in your home’s exterior. It’s easy to be alarmed by this—holes in your house are usually bad news. But regularly-spaced holes in brick are perfectly normal. They’re called weep holes, and they serve an important purpose—and need some specific attention from you.
Moisture control
Brick and mortar are porous materials, meaning water gets into them pretty easily. That’s fine as long as the water has a way to drain away; if it gets trapped behind the brick, it will inevitably undermine its structural integrity, and if water sits against the inner lining of your house too long, it can cause serious damage.
That’s why brick exteriors have weep holes. When bricks absorb water, it eventually runs down behind them, seeking an escape. Masons purposefully introduce small openings in the wall that allow that water to safely drip out away from your house. These weep holes also allow air circulation, which allows the brickwork to dry out in-between rain storms and discourages the development of mold. The flashing used on the exterior of your house is designed to direct moisture to those weep holes, preventing your house from rotting away in a surprisingly short time.
Weep hole covers
Because of their essential function in protecting your house from insidious water damage, it’s vital that you never, under any circumstances, block up weep holes. However, this creates a whole new problem: Pests.
Insects and small critters like mice can sometimes use those weep holes as an invasion vector. Once behind the brick, they can sometimes find or create openings into the walls, and from there set up shop in your house. This is one reason why homeowners sometimes make the disastrous choice to plug up their weep holes—no one likes the idea of weep holes acting like invitations to every invasive species in your neighborhood. Sometimes people will advise you to stuff steel wool into the weep holes to prevent pests from getting into them, but this is a bad idea as it can restrict air and moisture flow too much.
Instead of blocking up your weep holes, you should install weep hole covers. These are metal or plastic pieces designed to slide into the opening and create a barrier to pests. They’re easy to install—many can simply be pinched and inserted, though sometimes you’ll need to trim them to fit your exact opening, and it’s sometimes a good idea to use a bit of silicon to secure them in place. There’s a wide variety of weep hole cover products out there, and they all work the same way, so it’s hard to go wrong.
It’s important to note that weep hole covers won’t stop smaller insects like ants; they need to allow air and moisture to pass through them, so tiny bugs can still make it in. But they’re very effective at stopping rodents and larger insects like roaches from entering your house, while still allowing the weep hole to do its job.