What Is Weep Holes?
A weep hole, also known as a weep brick, is a small opening that allows water to drain from a structure. The weeps are placed on the bottom of the object to enable drainage; these holes must be large enough to overcome surface pressure. The weeps could also be needed for a retaining wall to allow water to escape from the retained soil, lowering the hydrostatic load on the wall and avoiding moisture damage from freeze/thaw cycles.
In such cases, the weep is made up of small diameter rubber, clay, or metal pipes that reach through the wall to a layer of porous backfill. Weeps are often arranged automatically for water that has penetrated an assembly from under the surface.
To stop interstate condensation, it will be designed with metal windows and glazed curtain walls. Weep Holes are found in earth-retaining buildings such as retaining walls, underpasses, wing walls, and other below-ground drainage structures.
Importance of Weep Holes
- Internal wall cavity ventilation: Without ventilation, mildew, dry rot, and damp shorten the life of the internal wall studs and other structural materials inside the cavity. The major cause of “Leaky Building Syndrome” is inadequate ventilation.
- Drainage : Water which reaches the cavity by capillary action, condensation, injury, or accidental flooding must find a way out. Flowing water through weep holes in the walls on the dominant side of well-built brick houses during a ‘gully raker’ or monsoonal storm isn’t really uncommon in tropical and sub-tropical Australia..
- Weep holes extend the life of your brick veneer home : They are also helpful to the strength and longevity of your home in the long term. It helps to avoid interior damage to your house by keeping the wall frame dry. Weep holes will assist you in making your home last longer.
Function of Weep Holes
Here, the function of weep holes are as follows.
- In these systems, a weep hole is created to alleviate hydrostatic pressure or water pressure on the walls.
- Reduced water pressure on the walls reduces the structural design demand of the water or earth resisting wall by minimizing thickness and strengthening requirements.
- Weep holes also minimise buoyancy and uplift on surfaces, allowing for the construction of lightweight buildings with no uplift-related stability problems.
- Since there is no chance of water collecting behind the wall if the system is situated near the water desk, a weep hole is not needed.
- That being said, if the structure is located just below water table and there is additional water pressure mostly on framework works that is greater than the saturated pleasures or stress of the earth, a weep hole is needed.
Case 1 : The water table is under the structure, so no weep holes are needed.
- Since the water table is well below the foundation, only ground pressure is taken into account when building it.
Case 2 : The water table should be above the framework and there are no weep holes.
- Once water is combined with dirt, the saturated pleasures as well as earth pressure submerge, which really is less than the saturated pressure, however the water pressure is greater.
- As a result, when planning, this sort of construction, soil, and water pressure should all be taken into account.
Case 3 : The water table is higher than the structure, and weep holes are provided.
- If the water table is above the structure, but weep holes are given.
- The weep hole eliminates the majority of the water pressure, and the water pressure relieves the pores.
- The height of the weep hole is significant because the greater the system is pressurized by water, the higher the height of the weep hole.
- To ensure the correct operation of the weep holes, sand gravel trains are used.
- The variety of holes is determined largely by the structure’s proportions and the height of the water table.
- The weep hole’s height is determined by the maximum possible height of the water’s construction or the actual groundwater table.
Types of Weep Holes
The type of weep holes depends on the nature of the use of the holes:
1. Open Head Joint Weep Holes
Weep holes are created by removing the mortar from the vertical joint between the bricks. The exact space between the open hand joints is performed at 21-inch intervals, and these walls are the same height as the usual joint spacing.
This is the most popular and reliable procedure for removing water from the cavity. This is accomplished by using a weathered plastic structure to avoid rain and penetration into the pores; drip is used on the front lip to aid drainage.
One limitation of this strategy would be that the open head joints produce large gaps that might not be visually pleasing. Any repair staff can even fix such holes unwittingly while noticing they are weep holes. Some materials, such as aluminum vents and plastic grids, can be placed into weep gaps to render holes less visible.
2. Cotton Rope Wicking Weep Holes
Weeps can be made of cotton wicks. In the joints, a rope up to 12 inches (30 cm) in length is mounted. The rope’s other end is stretched up through the cavity stone.
Cotton can trap moisture inside the wall and wick it to the outside, and cotton rope can wick a slight amount of moisture from the outside to the inside of the wall. The evaporation rate is slower than with weep holes. Furthermore, the cotton could catch fire.
3. Tubes Weep Holes
The tube weep holes are made from hollow plastic or metal pipes that are 16 inches long. The tube is angled at a slight angle to enable water to drain; however, the angle must not be too smooth. If indeed the angle becomes too steep, the gap hole within the wall cavity would be too wide to allow water to escape.
If indeed the angle becomes too shallow, the mortar sometimes used lay the bricks can fall into the cavity and clog the tubes. To save mortar from clogging the channels, a thin coat of gravel is often laid. The plastic tube’s thickness, no matter how thin, can form a small barrier, allowing water to collect within the wall cavity.
Instead of using permanent tubing stock, oiled rods or ropes may be used to shape tubes. The oiled rods or ropes would be inserted in the joints and mortared. The oil stops mortar bonding, and the rods or ropes may be withdrawn after the mortar has hardened, forming a hole similar to that of a tube.
The tube style has the benefit of being less noticeable. However, the small holes can not allow enough air to circulate and vent the moisture.
4. Corrugated Channels
A more recent weep technology employs corrugated plastic to create weep channels/tunnels that form the bottom side of the mortar bed joint. These tunnels quickly conduct water out of the wall through several weep hole openings, ensuring that water exits at the lowest point in the wall.
Corrugated plastic weeps mix into mortar and are less noticeable than rope weeps.
Advantages & Disadvantages of Weep Holes
Advantages of Weep Holes
Here, the different pros of weep holes are as follows.
- Weep holes create a gap that allows moisture to drain from the back of the wall through infiltration, capillary action, or leakage.
- It is built in brick masonry to shield the air behind the wall from mildew, dry rot, and damp, which reduces the building’s life and efficiency.
- They are mostly located inside the exterior masonry of cavity walls, but they can also be found above the home windows and doors.
- They are provided at regular intervals to allow moisture to escape, with a suggested distance of 450 mm between row holes.
- From an engineering standpoint, weep holes reduce hydrostatic pressure or water pressure on the walls.
- By reducing the thickness and strengthening needed, this decreases the structural construction requirement for water and earth strain.
- The weep hole further reduces buoyancy and uplift on the frame, allowing for the construction of a lighter structure with no uplift-related stabilization problems.
Here, the different cons of weep holes are as follows.
- Blockage of Weep Holes Due to Trash Mortar: When weep holes are constructed in brick masonry, mortars wedge between successive courses of bricks and fall into the weep cavity. This will help to avoid weep holes by scratching the mortar.
- Pest Infiltration Through Weep Holes: Pests such as rats and insects may gain entry via weep holes. The interior of the building can be accessed through ventilator fans and holes for plumbing and electrical purposes underneath the lights.
- Baffled vents can be installed to solve this issue.
- Obstruction in Airflow: To address the above issues of insect invasion and garbage mortar, as well as to make the weep hole more appealing, the weep hole does not have the requisite flow of air to adequately ventilate the internal brick wall.