Types and Importance of Weep Holes in the Retaining Walls

Types and Importance of Weep Holes in the Retaining Walls

What are Retaining Walls?

A retaining wall holds soil behind it from eroding or sliding away. This wall can be constructed using several materials, such as concrete, timbers, boulders or rocks.

What Are Weep Holes and Their Purpose?

Weep holes are small circular or rectangular-shaped openings that escape water from the structure. These weep holes are carefully crafted to prevent surface tension.

If the building or structure is constructed on top of the water table. In such a situation, creating weep holes is essential to let the excess water pass through.

They are primarily created in underpasses, wing walls, external brick or retaining walls.

Simply put, there are two main reasons to provide weep holes in a structure:

  • Ventilation of Internal Wall: Without weep holes, mildew, rot or fungi develops inside walls. They reduce the life of building materials as it decays and weakens due to dampness and mildew.
  • Drainage: Water that enters the structure due to rain, condensation or accidental flooding must be escaped.

Functions of Weep Holes

Functions of Weep Holes

There are many functions of weep holes, some of which may include the following:

  • It reduces the hydrostatic pressure acting on the walls or structure.
  • To drain rain or flood water into the cavity of retaining walls.
  • To prevent the formation of mildew, fungus and mould.
  • To prevent dampness as it damages the structure and its material.
  • To provide ventilation for the internal walls.

Types of Weep Holes

Depending on the usage, there are several types of weep holes.

Cotton Rope Wicking Weep Holes

  • As the name refers, these weep holes are created by using ropes.
  • These ropes are no longer than 12 inches.
  • In order to create these weep holes, one end of the rope is placed at the joint and the other end at the cavity wall.
  • Water absorbs from one end of the rope from the back of the wall and evaporates at the other end.
  • Although this method appears to be quite efficient, it is extremely slow compared to other weep holes.

Open Head Joint Weep Holes

  • These are the most commonly used type of weep holes to vaporise water.
  • They are the easiest and are created at the cavity walls’ base.
  • In this type, the weep holes are created in the upper joint, so water can escape only from the wall joint.
  • A plastic drain structure is added around open head joint weep holes to stop insects from entering.
  • Moreover, a 24 inches space is provided between each joint weep hole.

Tube Weep Holes

Tube Weep Holes

  • Tube weep holes are created by using metal or plastic hollow tubes.
  • These tubes are placed at 16 intervals.
  • On top of that, gravel is added to stop water from flowing from the clogged drain.

Corrugated Channel Weep Holes

  • These are designed using the latest technology, which can pump excessive water in numerous ways.

Advantages and Disadvantages of Weep Holes


  • The benefits of weep holes include the following:
  • It allows water to drain from the weep holes.
  • Weep holes prevent dampness and damage from occurring inside the walls.
  • They provide ventilation and help control the moisture


  • If weep holes are installed in the brick walls; trash mortar gets stuck in the weep, causing a total or partial blockage.
  • If the weep holes are not covered properly, they will allow pests, insects and other unwelcomed guests into the building.
Scroll to Top