Where must weep holes be provided?

Author: Thaddeus Emard  |  Last update: Saturday, March 28, 2026

Weepholes shall be located immediately above the flashing. ❖ Weepholes must be provided directly above the flashing mandated by Section R703. 8.5 to allow for the escape of any moisture that may have penetrated the masonry veneer.

Where should weep holes be placed?

Weep holes are typically found in the outer masonry leaf of cavity walls, just above the flashing. They can also be found above windows, doors or other penetrations. They should be provided at regular intervals so as to allow any moisture collected by cavity trays to escape.

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.

Are weep holes required by 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.

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.

Positioning/Installation of Weep Holes

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.

Can snakes get into a house through weep holes?

small or young snakes can come into a house through the weep holes in the masonry, though assorted insects and small rodents can also get in that way and they (and warmth, if sunlight strikes the wall there) would be a primary reason a snake would enter.

Where are weep vents required?

It's essential that weep vents are placed at regular intervals along the base of the wall at the ground floor, below the DPC level, and must also be provided as part of any cavity tray run, including roof abutment trays, over lintels and continuous cavity tray systems, such as gas protection barrier systems.

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.

Are weep holes mandatory?

Yes, Australian building codes mandate weep holes in masonry to ensure proper drainage and ventilation, safeguarding structural integrity and preventing moisture-related issues in buildings.

What is the problem with weep holes?

Weep holes serve an important role in your home's drainage and ventilation, but they can also provide pests such as mice and cockroaches an easy access point into your home.

Will silicone caulk keep mice out?

Because your home's foundation is close to the ground, it provides easy access for curious mice to enter. Take a walk around your home and look for small cracks and gaps in the foundation. Seal the gaps with silicone caulk, which is tough enough to withstand exterior elements and will keep mice out.

Can you plug a weep hole?

If you plug the weep hole the seal will continue to leak and it will pressure up the cavity between the seal and the pump shaft bearing. This will force the coolant through the bearing and out the other side. So the leak will reappear very quickly just via another route.

Does a house need weep holes?

Brick weep holes are a critical component of any brick home and are incredibly important to maintaining its structural integrity and health. If you're a homeowner who's never heard of brick weeps before, or you're not sure about what exactly they do, read on for a detailed guide about them and their importance.

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.

Do you need weep holes in cavity walls?

Weep holes are a crucial component in the maintenance and longevity of new build homes. They play a vital role in managing moisture levels within wall cavities, preventing the buildup of dampness and mould which can compromise both the structural integrity and the healthiness of the living environment.

Where should weep holes be?

To allow water to drain out of the cavity, weepholes should be provided in the outer leaf immediately above the cavity tray and positioned at a maximum distance of 900mm centres. The tray should dress over any associated flashing or vertical membranes to ensure any water is drained outwards as illustrated in Diagram 3.

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.

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.

Do you need weep holes above windows?

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 water enter 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.

Where are trickle vents required?

Trickle vents are required by Building Regulations when replacing windows that already have trickle vents fitted. For new window frames that are replacing old windows without vents, it must be demonstrated that ventilation will not be made worse by the installation of the new energy-efficient window.

Do snakes like basements?

Basements and crawl spaces are moist, quiet, and damp, which make them very attractive nesting sites for snakes. They enter through cracks in building foundations, gaps in siding, or open windows at the ground level.

How can you tell if snakes are in your walls?

You should cautiously check these areas and behind items like boxes and clutter boxes with a long stick. Many snakes shed their skin as they grow. If you find a dry, scaly sheet of the skin or a crumpled heap somewhere close to an entrance into the walls of your home or small space areas.

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