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Brick and stone are porous materials and can absorb and store water. The inclusion of weep holes in masonry walls is intended to serve two purposes:
- Drainage: They provide an opening that allows the drainage of any moisture that may reach the back of a wall, or the inside leaf of a wall (such as a cavity in cavitywall construction) from the outside through penetration, capillary action, condensation, leakage or flooding.
- Ventilation: They allow ventilating air to the back of a wall to help prevent mildew, dry rot and damp which might otherwise reduce the life or performance of buildingmaterials such as cavity wall-ties, cavityinsulation and so on.
The Masonry Design Manual describes weep holes as, ‘Openings placed in mortar joints of facing materials at the level of flashing, to permit the escape of moisture, or openings in retaining walls to permit water to escape.’
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. The recommended distance between weep holes is 450mm.
 Types of weep holes
 Open head joints
These are formed by omitting mortar from the vertical joint between bricks. Holes are created that are the same size as the typical joint spacing. The spacing between open head joints is typically done at 24 inch (61cm) intervals. They may include plastic weep vents which incorporate a baffle structure to prevent rain from penetrating through the hole and preventing insects from entering the cavity. They may also include a drip at the front lip to aid drainage.
 Cotton rope wicking
A rope of up to 12 inches (30cm) in length is placed in the joints and the other end is extended up into the cavity wall. The moisture inside the wall is absorbed by the cotton and wicked to the outside where is evaporates. This process is slower than with ordinary weep holes.
Tubes made of hollow plastic or metal can be used as weep holes, spaced around 16 inches (41cm) apart. They are placed at a slight angle to allow water egress. Care must be taken to ensure the angle is not too steep or too flat.
Alternatively, oiled rods or ropes can be placed and mortared into the joints. The oil prevents mortar bond and the rods or ropes are removed after setting which leaves a hole similar to that of a tube. The advantage of these techniques is that they are less conspicuous.
 Problems with Weep Holes
 Pest entry
Weep holes can provide access to the wall cavity for unwanted pests such as rodents and insects. Penetrations such as down lights, extractor fans and holes for plumbing or electronics then serve as an internal entry point. Baffled vents can help prevent this problem.
 Trash mortar
As mortar is squeezed out from between successive courses of brick, droppings can fall behind the wall and build up. This can result in weep holes becoming partially, or totally, blocked by trash mortar. Mortar collection devices can be installed to try and alleviate this problem.
 Obstruction of air flow
Measures to try and combat the problems above, as well as make weep holes more aesthetically pleasing, can result in them not providing the necessary flow of air to properly ventilate the internal brick wall.
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Everything you Need to Know About Weeping Tile
The symptoms of a drainage problem can often be elusive and difficult to uncover. You might only notice puddles during rainstorms or water problems may develop over time. In fact, many issues go undetected for years; only becoming obvious when a foundation crack appears. Once it’s been determined that you have a real drainage issue, it’s important to act quickly. You’ll not only be protecting your property but also your health.
While it’s possible to take care of some waterproofing jobs on your own, installing weeping tile is very labor-intensive and may require the expertise a professional waterproofing company can provide. Below is a guide explaining everything you need to know about weeping tile. By understanding the terminology and the process, you can make educated decisions on how best to proceed.
1. WHAT ARE WEEPING TILES
Weeping tiles are porous 4-inch pipes used to discharge underground water. They were originally named at a time when terracotta tiles were used for drain pipes. Today’s products are plastic pipes with weep holes or small slits designed to redirect water away from the home. The weeping tile system was developed by Henry Flagg French from Massachusetts. He wrote a book about the subject in 1859 and earned notoriety for solving the drain clogging problem of the era.
2. HOW DOES WEEPING TILE WORK
The concept for how weeping tiles work is actually quite simple. The plastic pipes are placed, holes side up, into a trench around the outside perimeter of the home or inside under the basement floor. As ground water rises, it flows through the holes into the pipe. It then follows the pipe’s incline to discharge away from the house or to a sump pump where it is pumped away.
2.1 TYPES OF WEEPING TILE SYSTEMS
a) Exterior weeping tile or French drains manage water at ground level before it can get into your basement. The system consists of a trench that is sloped away from the house, gravel and pipe. Surface water soaks into the ground, filtered through the gravel, through the holes in the pipe and channeled away from the house.
b) Interior weeping tile is often used when an exterior weeping system has failed. This system is installed under the basement floor where water is directed to a sump pump, through the pipes and to an exterior storm sewer. Installing a French drain beneath the basement floor is similar to installing a sump pump. A 12-inch wide by 12-inch deep trench is cut around the entire perimeter of the basement. A pipe is placed inside, filled with course gravel and covered with concrete.
3. EXTERIOR WEEPING TILE INSTALLATION PROCESS
Installing weeping tile can be back-breaking work so engaging a professional is definitely recommended. In addition to having the proper equipment, a waterproofing company can determine the proper slope, materials needed plus offer a warranty if any problems arise later on. The information listed here will give you a better understanding of the process and help you plan for any preliminary work requirements:
STEP 1 – DIG A TRENCH
A 12-inch wide trench must be dug around the outside perimeter of your home. It should slope one inch for every eight feet and extend down to the footings. You’ll need to relocate plants and shrubs in the dig area and also determine where any excavated soil should be placed. As the tile and gravel take up a good portion of the trench, you’ll have a significant amount remaining after the job. Talk to your contractor about how to dispose of excess soil.
STEP 2 – POUR THE GRAVEL
Two or three inches of washed gravel should line the bottom of the trench. Granite or river gravel, less than an inch in size, are best as they won’t break down over time. This natural filter will allow water to drain without clogging from organic material.
STEP 3 – LAY THE PIPE
Rigid PVC pipe with pre-drilled holes is the most popular for its durability and easy maintenance. Covering the stone or wrapping the pipe with landscape fabric will keep it root- and obstruction-free. Leaving a clean-out joint that remains above ground will help in future maintenance.
STEP 4 – BACKFILL THE TRENCH
Covering the pipe and filling the trench with gravel or a combination of sand and gravel will allow easy access. Adding gravel, then dirt with sod will conceal the weeping tile completely and provide a base for landscaping.
3.1 INTERIOR WEEPING TILE INSTALLATION PROCESS
STEP 1 – CUT THROUGH THE CONCRETE FLOOR AND DIG A TRENCH
Using a circular saw with concrete blade and chipping hammer, the basement floor is cut out. The opening should be approximately 12 inches wide and run around the entire foundation. Remove all concrete slabs sections to access the gravel below. Then dig a trench one to two feet deep where the concrete has been removed. Stop digging when you get to the footer.
STEP 2 – POUR THE GRAVEL
There will be some gravel below the concrete floor, but you’ll need to add enough washed gravel to fill the bottom of the excavation area.
STEP 3 – LAY THE PIPE
Similar to an exterior installation, a fabric-covered PVC pipe should be used with holes or slits to allow for drainage but resist clogging. Place the slits upward, install sufficient weeping tile to cover the entire perimeter and end it at your sump pump.
STEP 4 – BACKFILL AND REPLACE THE CONCRETE FLOOR
Once the tile has been connected to the sump pit, cover the entire trench area with gravel. Let it settle for a day, pour the concrete and smooth it with a trowel.
As you can see, both exterior and interior weeping tile installations are labor-intensive. Unfortunately, that also means it can be costly. An exterior, full-perimeter job can run between $8,000 and $15,000 with sump pump and accessories. Luckily, a four-wall project is not always needed and can reduce the cost significantly. Interior weeping tile can be installed for half the price of exterior and will eliminate the need for removing landscaping or other obstructions. The good news is that once the work is complete, you can enjoy a dry, trouble-free basement for years.
3.2 HOW TO USE WEEPING TILE FOR BACKYARD DRAINAGE
Basements aren’t the only areas where water collects and causes problems. If your property looks more like a pond than a yard after a rainstorm, or if your sidewalk remains flooded days after the storm has passed, you may be able to solve these issues with a French drain system. Using a similar concept to eliminating basement flooding, the French drain is placed about a foot below the ground’s surface. A gravel-filled trench is cut on a slight slope. Weeping tile is installed then a layer of gravel and coarse sand is placed on top. As water filters through the sand, it drains into the pipe and away from the area.
3.3 WINDOW WELL WEEPING TILE
Window wells are designed to allow sunlight and fresh air into the basement of your home while creating an air pocket around the window itself. However, without proper drainage, your window wells can fill up with water or snow and flood your basement. It is possible to use a weeping tile system here as well to divert water away from the foundation.
- Remove the window well form.
- Excavate the dirt from the well area. Dig down to the horizontal weeping tile system.
- Use a utility knife to cut the pipe in half and insert a 4-inch T-connection directly below the window. The long end of the T should point up.
- Attach a 4-inch diameter PVC pipe to the T-connection. It should be long enough to reach the lower edge of the windowsill.
- Attach a drain cover to the top of the pipe and backfill the excavation area and pipe completely with gravel. Cover the gravel with 3-inches of soil but stay 1-inch below the windowsill.
- Replace the window well form. It should be re-attached to the foundation.
- Fill the window well with at least one foot of gravel to stabilize the pipe and provide continuous drainage.
4. WEEPING TILE MAINTENANCE
To keep your weeping tile system working properly, regular plumbing checks and maintenance are needed.
- Clean out leaves and debris from gutters and re-direct downspouts away from the house.
- Do the same for window wells and consider adding a cover.
- Make sure your sump pump is operating properly or add a battery back-up.
- Have any slow-draining sinks or toilets checked by a licensed plumber for clogs.
- Walk your property to check for spongy soil or pooling water.
Sometimes simple concerns are symptoms of larger problems. Be sure to address issues as soon as you discover them.
4.1 HOW TO TELL IF YOUR WEEPING TILE IS PLUGGED
The PVC pipe that comprises the drainage system for your home can become blocked by tree roots or soil. If this happens, water doesn’t drain away from your home fast enough and presses against the foundation. The added pressure can lead to cracks and leaks. A thorough inspection of your home and property can help alert you to plugged weeping tile before it becomes a major concern.
- Look for horizontal, vertical or diagonal cracks in your basement or crawlspace walls.
- Search for damp areas or pools of water under basement windows or floor.
- Pay attention to a strong, musty odor – a sign of mold or mildew.
- Look for stained or peeling drywall; mold or mildew on walls and flooring.
- Run a garden hose near your exterior foundation wall. Watch your sump pump pit. If the weeping tile is working properly, the pit should fill with water. If not, it’s likely blocked or broken.
4.2 HOW TO CLEAN WEEPING TILE
Occasionally, debris in your weeping tile will cause water to back-up or leave a bad odor. You can clean it with soapy water and a plunger.
- Firmly wedge a large plunger head into the sewer floor drain in your basement.
- Connect a hose to a sink or washer faucet.
- Completely fill the catch basin and weeping tile with water and liquid soap. Be careful not to allow the water to overflow.
- Leave the soapy water there for 30 minutes to neutralize the odor.
- Pull the plunger out to allow the water to drain.
- Repeat several times and then rinse with clean water to remove soap residue
Now that you’re familiar with the advantages of weeping tile, its installation and maintenance, it’s time to contact a professional waterproofing company for a consultation. Aquamaster Drain, Plumbing & Waterproofing, Inc. can provide high-quality, permanent waterproofing solutions to protect your property and health. Call us today for a free, no-obligation estimate.
About Aquamaster Plumbing
Aquamaster Drain, Plumbing & Waterproofing Inc. is your full-service plumbing and basement waterproofing company assisting the Greater Toronto Area residents. We offer services such as drain repair, drain cleaning, basement waterproofing, sump pump installation, and more.
Everything you Need to Know About Weeping Tile The symptoms of a drainage problem can often be elusive and difficult to uncover. You might only notice puddles during rainstorms or water problems