weep holes in brick walls

Got weep holes in your brick wall? Do you know why? When your veneer walls don’t have adequate ventilation and drainage, you face issues like moisture, rot, and mold. Today we will tell you some common reasons for blocking the weep holes in brick walls. Blocks can happen due to mud, drains buried by backfills, and insects/bugs.

We will explain the importance of proper drainage in the veneer walls. But first, let’s see more about weep holes.

What is a weep hole?

Weep holes are the holes or gaps in the bottom side of the veneer that serves as a drainage system. And it also helps in ventilation while keeping the interior wall dry after any rain. If the interior walls remain wet, they rot and get ruined. It will eventually affect the building’s life.

You can spot the holes above windows or doors in the exterior wall. These holes are at regular intervals and reduce the water pressure on buildings. And contribute to diminishing the structural demand for water. These holes also assist in making lighter structures without any stability problems.

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.

Hence weep holes are provided in all houses with brick sidings as it drains the waters. But these holes aren’t opened to your home’s interior. These weep holes are 4-4.5 inches in depth. You can insert scales to check their width yourself!

When do you need to weep holes in brick walls?

The function of weep holes is to keep the interior walls dry and eliminate moisture. When the water level is below the structure, there is no need for weep holes. There won’t be any water intrusion.

But weep holes are necessary when the water level is above the structure. The holes will eliminate the water pressure. The number of weep holes gets decided by the size of the house. And the height of these holes depends on the water level.

Why flashings are used in the weep holes?

Flashing used directs the water to these holes. These flashings keep the water from seeping inside the walls and damaging them.

The flashings are made of rubber or metal sheets and block water from rotting the interior walls.

You can spot flashings under the lowest brick row. The flashings are connected to sheaths at an angle to ensure that the moisture/water will eventually run down and exit through the weep holes. The weep holes are on the row of bricks that are above the flashings.

Types of weep holes

These weep holes get created using ropes 10-12 inches long. One end of this rope extends to the cavity wall. The holes get placed in the joints. The moisture in the interior wall gets absorbed by the cotton and evaporates from the other.

But this process is way slower than the usual weep holes in brick walls.

Open head joint weep holes

The mortars from the vertical joints between bricks get removed to create these weep holes. The standard distance between the open-head joint holes is 21 inches. Plastic weep baffles get used to prevent rain and insects from entering these spaces.

Tube weep holes

The tube weep holes are made by inserting hollow tubes of plastic and metal. They get spaced around 16 inches away from each other. These holes are placed at slight angles to drain the water.

Therefore angles shouldn’t be too steep or flat.¬†

Problems with weep holes

Weep holes are essential to keep your interior walls safe, but there are a few problems with the weep holes.

Pest entry from holes

The pest can enter these weep holes. These bugs and rodents can access the interior of the building through ventilator fans or electrical and plumbing holes. However, you can stop these insects by using plastic baffled vents.

Trash mortar

Often in brick masonry, the mortar squeezes between two bricks. Eventually, they drop down in the weep holes and block them. It is called blockage due to trash mortar.

Barriers to the airflow 

To prevent the above problem, like the entry of pests in the holes, you may use vents that affect the airflow. The trash mortar gets stuck in the weep holes therefore the ventilation gets ruined. Finally, this barrier won’t allow proper ventilation, and internal bricks can rot.