What does a weep hole look like?

Author: Ayla Harvey  |  Last update: Friday, June 19, 2026

Weep holes in brick walls usually appear as small vertical spaces that are left during construction in the mortar of brickwork. They allow moisture to escape from brick cavity walls, which helps to prevent the buildup of water and condensation.

How do you identify weep holes?

Weep holes are usually located at the base of brick exterior walls. They appear to be vertical gaps in the mortar joints between the bricks. Water may seep through the surface and enter the wall's interior because brick masonry is porous.

Are weep holes really necessary?

Without masonry weep holes, or if the existing drainage system is blocked or broken, capillary action can result in the water becoming trapped inside the cavity wall.

Can water enter a house through weep holes?

Weep holes are often located at the bottom of brick exterior walls. They look like vertical gaps in the mortar joints between bricks. Because brick masonry is porous, water may penetrate the surface and get behind the wall.

How do you know if a weep hole is clogged?

ANSWER - Having wet grout around the drain does suggest that the weep holes at the waterproof membrane level might be plugged.

What Is A Weep Hole And What Do They Do?

How to unclog a weep hole?

To head off costly repairs, follow these maintenance tips: Check weep holes at least once a year, before the rainiest season. If they're clogged, open them up with a brush, a screwdriver or a toothpick.

How do you check a weep hole?

How to identify weep holes
  1. Look for gaps in the mortar between the bricks: Weep holes are typically small gaps in the mortar between the bricks, located near the bottom of the external wall. ...
  2. Check for patterns: Weep holes are usually located in a pattern of one every few feet along the bottom course of the brickwork.

Can you block up weep holes?

Furthermore, if you block your weep holes in an attempt to solve that problem then you will prevent the drainage of that water and the airflow needed to completely dry the cavity. This will likely cause catastrophic problems.

Can I drill my own weep holes?

It is difficult to add weep holes after the walls are constructed. If the weep holes are drilled, they will typically puncture the flashing. This is true even if a special guide is placed on the drill. If the hole does not go all the way through the mortar then it will be ineffective.

What happens if you seal weep holes?

If the weep holes are blocked to prevent drainage from occurring, the water can build up in the extrusion and ultimately leak into the wall cavity if a leakage path is available.

What is the alternative to a weep hole?

As an alternative to weep holes, most new construction will connect the drainage zone to a perforated drainage pipe located behind the base of the wall outfalling to a manhole.

Where are weep holes located?

You can find weep holes in concrete block walls, brick cavity walls, window frames, retaining walls, and many other places where water accumulation is a problem. By allowing water to escape, they can prevent damage to the building or structure.

Can mice get into weep holes?

It's obvious that small pests such as cockroaches and spiders can crawl through weep holes, but vertebrate pests such as lizards, snakes and even mice can also squeeze through a normal weep hole.

What does a weep vent look like?

Weep vents, also commonly known as 'weep holes', are small openings incorporated into the design of many structures, especially masonry walls made of brick or stone. Their primary function is to provide an outlet for water to drain out of and to allow air to enter, helping to prevent damp and moisture build-up.

When did weep holes become code?

Even if you used the code as a basis of the requirement for weep holes, you would be surprised to learn that weep holes were nor mandated in the single family code until 1983 CABO, mandated by the 1985 Kentucky Building Code. Home inspectors are calling out missing weep holed on house built before 1985.

Can bugs get in through weep holes?

Your weep holes are an important part of your home's drainage and ventilation system, but they're also vulnerable to pest infestation. Cockroaches, rodents, and spiders can easily enter your home through these gaps in your brick cavity walls.

Can a house flood through weep holes?

Do I Need To Plug Weep Holes During a Flood? No. Unless your home is a submarine the exterior materials along with doors and windows are not watertight and will succumb to the flood waters.

Why does my house not have weep holes?

Why are there no weep holes? The reasons vary, but the house's builder forgot to include them, or the homeowners didn't want them. Sometimes homeowners don't want weep holes because they retract from the house's appeal – think smoothly rendered brick houses.

Are weep holes code?

Weepholes shall be provided in the outside wythe of masonry walls at a maximum spacing of 33 inches (838 mm) on center. Weepholes shall be not less than 3/16 inch (5 mm) in diameter. Weepholes shall be located immediately above the flashing.

What happens if water gets in weep holes?

You will always spot the weep holes in brick walls because bricks and mortar are porous. It means water can pass through them. This water will run towards the backside of the brick wall, and if there is no drainage, water will settle inside, slowly decaying the walls.

Is it OK to cover weep holes?

While they can provide an entry point for pests, covering weep holes in brick walls is a definite no-no due to the damage this can cause to a building's structure. Instead, high quality screens and covers can be used to keep vermin out whilst maintaining the utility of these very important openings.

What can I use to fill weep holes?

While you should never fill weep holes with solid material—such as caulk, wood, or mortar—you can put strips of fiberglass screen wire or a scouring pad in the weep holes to keep insects out.

What happens if weep holes are blocked?

Blocking your window weep holes predisposes the window structure to water damage, rust, and corrosion ultimately reducing your window's lifespan.

What causes weep hole to leak?

This is because the gear drive of the pump, and the pump bearing, are lubricated with engine oil. The weep hole sits between the oil and coolant seals. If the oil seals are leaking, extra lubricant from the pump bearings will drip out of the housing through the weep hole.

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