Here are some questions you should consider when thinking about foundation drains and weeping tiles:
Does my home have a foundation drain?
An assessment of whether or not your home has a foundation drain should be conducted during the detailed plumbing investigation of your home (see Option 3). Older Canadian homes, for example those built before the 1940s or 1950s, may not have foundation drains. If you find that your home does not have a foundation drain, you should consider having one installed. Make sure that you have the proper permits from your municipal government and that the work is undertaken by licensed trades people. This will likely be an expensive job; however, it can have a substantial impact on reducing water damage in your basement.
Are there any problems with the foundation drain?
Over time, weeping tiles may become clogged with debris or may collapse in some sections. When weeping tiles are not in good working order, they will not be able to effectively remove water from the foundation. A review of the foundation drainage should be included as part of the detailed plumbing investigation of the home (see Option 3).
If the home has older weeping tiles made of clay or concrete, the replacement of the entire system with new perforated plastic pipes may be necessary, as older weeping tiles are more susceptible to collapsing and blockages. If replacing the entire weeping tile is not possible, patch-work replacements of sections of the tile could be completed.
For a simple blockage due to a build up of soil or debris, and if there are no significant blockages or collapses in the weeping tile, a professional plumber or contractor might be able to flush the system from smaller access points, which can be dug from around the foundation walls. If the weeping tile must be replaced, installation of a clean-out port with access from the surface should be considered to allow easier maintenance in the future.
What is the weeping tile connected to?
It used to be a common practice in many Canadian communities to connect weeping tiles to a home’s sanitary sewer lateral. This allowed water to drain away from the foundation without the need for a sump-pump. However, over time, it became apparent that this practice contributed a substantial amount of water to municipal sanitary sewer systems, contributing to sewer backup problems.
Disconnecting your weeping tile from the sanitary or storm sewer can help to reduce the amount of water that enters the municipal sewer system during a heavy rainfall event. This can help reduce the chances that you and your neighbours will experience sewer backup, and can also reduce the risk of structural damage to the home.
If the weeping tile is connected to the storm sewer lateral, water can be pushed back into the weeping tile during a storm sewer surcharge. This can result in both structural damage to the home (including cracking or heaving in foundation walls and basement floors) and increased rates of infiltration flooding.
Other flood reduction options, including Option 10 and Option 12 in this handbook, can have an impact on foundation drainage. During a heavy rainfall event, or in instances where the water table is very high, a substantial amount of water can enter the weeping tile. Also, poor lot grading that directs water toward the home, backfill problems and poorly maintained eavestroughs and downspouts can increase the flow of water into the weeping tile.
Disconnection of the weeping tile from the municipal sewer system requires the installation of a sump-pit and sump-pump.
Sump-pits and sump-pumps
Water from the weeping tile should be directed to a sump-pit, and then pumped out of the sump-pit using a sump-pump. The location of the sump-pit depends on how weeping tiles are connected to the pit under the basement floor. Sump-pits are normally located where service connections enter the home (for example, where the sanitary sewer lateral enters the home).
In many cases, water from the weeping tile should be pumped to the surface of the home’s lot. If water is to be pumped onto the lot, the same precautions should be taken for the sump-pump discharge pipe as the downspout extension (Option 12):
• Ensure that the discharge point is at least 1.8 metres away from the home.
• Use a splash pad at the discharge point.
Care must be taken to ensure that this water does not affect neighbouring properties. Where lot sizes are too small or where lots cannot be graded in a manner that will keep water away from homes, a pipe may be used to carry the discharge away from neighbouring properties to municipal conveyance systems that can handle weeping tile discharge. Some municipalities may allow you to direct this water to the municipal sewer system to prevent ice build up in the winter. Talk to your municipal government to make sure that water is pumped to the right place.
Sump-pumps are usually designed to pump a low volume of water at a slow rate. While they can effectively remove water from weeping tiles, they will not be able to pump water out of the basement fast enough to prevent damage when the basement is flooding.
Maintenance
Sump-pumps are prone to blockage and possible failure if they are not routinely inspected and maintained. On-going maintenance will help to ensure the sump-pump will continue to operate over a long time period. A homeowner can inspect the sump-pump by pouring water into the sump-pit, and seeing whether or not the pump starts automatically. Check the manufacturer’s instructions for the pump or talk to your municipal government about proper maintenance and inspections for the pump.
Backup sump-pumps and power supplies
Most sump-pumps rely on electricity and will not operate during a power outage. It is also possible that a sump-pump could have a mechanical failure when it is most needed. If a sump-pump stops running during a storm, water from the weeping tile could flood the basement.
Backup sump-pumps and backup power supplies can help to make sure that sump-pumps operate during a power outage. Here are some backup options to consider:
- Install a backup battery powered sump-pump in the sump-pit along with the main sump-pump. The main sump-pump can be set to run when the water in the sump-pit is at a relatively low level, and the battery powered pump can be set to automatically run when the water in the sump-pit is at a higher level.
- Install a backup sump-pump that uses the municipal drinking water system for power. This unit can be connected to your home drinking water system, and as long as there is water pressure in your home, this type of sump-pump will continue to operate. As with the battery powered backup pump, this type of pump may be installed in the same sump-pit as the main sump-pump.
- Consider installing a generator to provide backup power. A generator must be specially wired into your home’s electrical system and must be located outside of the home. Generators may use propane, diesel or gasoline for fuel. Some generators can be connected to the home’s natural gas connection, ensuring that it will not run out of fuel when it is running for extended periods. The backup generator system can also be used to power other electronic appliances in your home, for example, fridges and freezers.
If you are thinking about installing a backup generator, you should thoroughly review your options. Talk to your municipal government, your electric utility provider and a licensed electrician about this option. The generator should be installed in a manner that is consistent with relevant electrical codes in your area and all relevant building and electrical permits should be attained before you proceed with this work.
