Where should weep holes be placed?

Author: Ellen Mante  |  Last update: Sunday, June 15, 2025

Gravity draws water to the bottom of the wall, just above the foundation, where weep holes allow it to escape. They are located above all windows, doors, and other openings. Weep holes are also located on window tracks.

Where are weep holes located?

You'll typically find weep holes forming a line of openings at regular intervals close to the bottom of a retaining wall. In higher walls, particularly with older structures, additional rows of weep holes may be seen higher up the wall to improve the retaining wall drainage.

Should weep holes be at ground level?

A potential for rising damp (leading to salt attack and mortar erosion) and flooding of the wall cavity and dwelling is also present. As a general guide weep holes at floor level should be a minimum of 75mm above finished ground levels.

Where should weep vents be located?

Weepholes to cavity walls should be provided:

at least one to the bottom tray in a series of stepped cavity trays, eg at pitched roof abutments. on cavity trays in parapet walls or at horizontal roof abutments at not more than 1m centres.

Where should weep holes be positioned on cavity walls?

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.

Positioning/Installation of Weep Holes

Where should weep holes be installed?

Where are weep holes located ? 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.

What is the code for weep hole spacing?

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.

Do all cavity walls need weep vents?

Weep vents are usually required where there is a cavity between two walls such as in brick veneer or double brick constructions. They are typically installed at the base of the wall above the flashing. Building codes or regulations will state their spacing and required locations.

How far apart should weep holes be placed?

The Weep Vent should be spaced at no greater than 900mm centres to meet N.H.B.C guidelines, which state, “weep holes are recommended to be sited at every 450mm maximum with at least two per opening above all windows and doors.”

Where should trickle vents be fitted?

Through Frame Design

The most common type of trickle vent used in modern window frames. The vent is fitted in the top of the frame and integrated with a staggered design to limit through draughts. At Everest, our trickle vents are integrated into the frame using an 'Up and Over' design.

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.

Where are weep holes not required?

(2) Weepholes are not required in the following locations: Where head openings are less than 1.2 m wide. Beneath window and door sills.

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.

How high should weep holes be?

Weep holes lower than 75mm from the ground are considered invitation to termites and other small pests.

Can water seep through weep holes?

This research demonstrated that even under truly extraordinary conditions water rarely enters the weephole and even if it does it cannot be blown high enough up in the cavity to create internal damp problems. To understand why, it's important to look at the details of a correctly constructed cavity wall.

Can weep holes be raised?

Weep holes should have at least 75mm clearance from the ground and not be blocked or covered and must meet the Australian Standards AS300 for masonry structures. Typical weep hole obstructions could be a raised concrete path, raised garden bed, or decking.

Where should weep vents be installed?

Weep vents are small openings or vents placed in brickwork or masonry walls to allow moisture to escape. They are typically installed at the bottom of walls, above windows, and in other locations where water might accumulate.

Where are weep holes installed?

Weep holes are small but almost invisible openings in masonry walls. These are installed at the base of brickwork or the site of flashing. Despite their small size, they serve a great purpose—they allow moisture trapped within the walls to drain.

What is the minimum size for a weep hole?

Weepholes shall be not less than 3/16 inch (5 mm) in diameter. Weepholes shall be located immediately above the flashing.

Where do I need weep holes?

Brick weep holes

They allow moisture to escape from brick cavity walls, which helps to prevent the buildup of water and condensation. Look at a brick masonry weep wall and you'll find these gaps spaced at intervals specified by building regulations, but you may also find them above windows and around doors.

Why don't old houses have weep vents?

“Not all properties have weep vents, especially old houses as they were built without cavities and weep vents and cavities have become popular over the last few decades as the building industry has evolved and we have become aware of moisture-related issues and building science improved,“ shares David.

Do weep holes let cold air in?

While the first thought may be, “Won't those little holes let cold air in (or warm air out), the reality is these are the window's weep holes. They are designed and placed to drain water out of the window frame, while preventing airflow into your new pole building.

Can you partially cover weep holes?

It is also common to see concrete paths or driveways installed that partially or fully conceal the weep holes. This is particularly troublesome because termites are subterranean and can gain access to your home via these covered weep holes without being detected.

How should weep holes be installed?

Manufacturers recommend installing them at an angle in the mortar of the head joints, spaced 16 inches apart. COTTON WICKS Cotton wicks are used to form another type of weep system. A 1/4 to 3/8 inch diameter rope is installed in joints at 16 inches on center.

How often should weep holes be installed?

weep holes should be provided at a maximum of 450mm intervals. each opening should have at least two weep holes. cavity trays or combined lintels should have stop ends.

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