Weeping tile collects water at the footing and slopes it to a pit set into the basement floor. When the water in the pit rises, a float switch starts an electric pump that lifts it through a check valve and out of the house. Tile without a working outlet fills and backs up, and a pump without tile only drains what seeps into the pit itself.
- The tile is the collector and the sump is the outlet; a basement stays dry only while both work.
- Part 9 sets a sump pit at no less than 750 mm deep and 0.25 m² in area, with a cover that resists removal by children and is airtight.
- A sump pump can run without weeping tile, but it only relieves the water that reaches the pit directly.
- Discharge has to land where it cannot soak back down to the tile: Calgary asks for water to clear the foundation backfill, Toronto for at least 2 m from the wall.
01 /How does water get from the weeping tile into the sump?
By gravity. The tile loop around the footing is laid with a gentle fall toward the pit, and the pipe enters the side of the pit liner below the basement floor. Water that seeps into the tile anywhere around the house runs along it and pours into the pit. On a house with exterior tile, the connection usually passes under or through the footing; with an interior system, the new pipe beside the footing inside simply ends at the pit.
The City of Edmonton’s homeowner guide draws the typical post-1988 arrangement as a weeping tile loop joined with a tee and led into the sump pit, with the pump discharge carried out to a splash pad or a foundation service standpipe. Older houses in the same guide have no pit at all: their tile runs by gravity into the sanitary service. If you are not sure which you have, the what is weeping tile guide walks through the checks.
02 /What does the sump pump do, step by step?
- The pit fills
Water from the tile raises the level in the pit.
- The float trips
A float on a tether or a vertical rod rises with the water and closes a switch at the "on" level.
- The pump lifts
The impeller pushes water up the discharge pipe, through the check valve and out through the wall.
- The float drops
When the level falls to the "off" point the switch opens and the pump stops.
- The check valve closes
It holds the column of water in the discharge pipe so it does not fall back into the pit and restart the pump.
In wet weather the cycle can repeat many times an hour; in a dry month it may not run at all. A pump that cycles every few seconds usually has a float set too close together, a failed check valve, or a pit too small for the inflow. A pump that runs non-stop in dry weather is either sitting in a high water table or pumping the same water around in a loop because its discharge soaks straight back to the tile. The Weeping Tile Problem Finder uses exactly those patterns.
03 /Can you have a sump pump without weeping tile?
Yes. The City of Calgary’s lot drainage guide notes that sump pumps may be installed with or without weeping tile, and that water can reach the pit either through a piped system or naturally through seepage under the foundation. A pit on its own acts like a small well in the floor. It lowers the water right around it and is useful in a basement with a wet spot near one corner or with water rising under the slab.
What it cannot do is reach water at the far side of the house. Without tile to collect along the footing, a leak at the opposite wall still reaches the floor before it reaches the pit. That is why a pump-only fix is common as an emergency measure and rarely the final answer in a basement that leaks along several walls.
04 /Can weeping tile work without a sump pump?
Yes, when it can drain by gravity. Tile on a lot that falls away steeply, or in a neighbourhood with a storm or foundation service lower than the footing, can drain without a pump. The Part 9 wording lets foundation drains discharge to a sewer, a drainage ditch or a dry well, and calls for an automatic sump pump only where gravity drainage is not practical. Dry wells are limited to places where the natural water table sits below them and must be at least 5 m from the foundation.
Many older houses drain without a pump for a less welcome reason: the tile was tied into the house drain. That arrangement adds groundwater to the sanitary sewer and exposes the tile to sewer surges. Why cities now want those connections cut, and what programs help pay, are in weeping tile connected to the sanitary sewer.
05 /What size should a sump pit be?
The Part 9 minimums are simple: at least 750 mm deep and at least 0.25 m² in area, which the Edmonton guide translates to a round pit about 0.56 m across. The cover must be designed to resist removal by children and to be airtight, which also keeps soil gas out of the basement. A pit much smaller than that fills in seconds, so the pump short-cycles, which wears the switch and motor.
| Item | What the sources say | Source |
|---|---|---|
| Pit depth | Not less than 750 mm | Part 9, 9.14.5.2 |
| Pit area | Not less than 0.25 m² | Part 9, 9.14.5.2 |
| Cover | Resists removal by children; airtight | Part 9, 9.14.5.2 |
| Pump size | Minimum 1/3 hp recommended | Edmonton guide |
| Pumping head | About 10 to 12 ft from pit level to the pipe exit | Edmonton guide |
| Solids | Pass stones up to 10 mm | Edmonton guide |
| Discharge line | 1-1/4 inch pipe | Edmonton guide |
| Check valve, backup or alarm | Recommended | Edmonton guide |
| Expected life | A good pump around 10 years | Edmonton guide; Calgary suggests replacing every 10 years or sooner |
Choosing the pump, the backup and the alarm is its own decision; see sump pump choice and backup.
06 /What is the small hole in some sump discharge pipes for?
Some installers drill a small relief hole in the discharge pipe inside the pit, between the pump and the check valve. The usual reason given is air lock: when the pit refills, air trapped in the pump housing below a closed check valve can stop the impeller from priming, so the motor runs without moving water. The hole lets that air escape, and while the pump runs a thin jet of water squirts back into the pit.
Not every pump needs one; some have a built-in vent and some manufacturers say not to add a hole. Follow the instructions for your pump model. If you see a jet of water inside the pit while the pump runs, check whether it is a deliberate weep hole or a crack before you seal anything.
07 /Where should a sump pump discharge?
Outside, onto ground that carries the water away from every foundation, and far enough from your own wall that it does not soak straight back to the tile. The City of Calgary says discharged water should clear the backfill zone of the foundation, directs it through landscaped areas to the front or rear of the property, asks owners to keep sump and downspout outlets at least 2 m from public sidewalks, streets and lanes, and to keep discharge pipes from freezing in winter. Toronto’s subsidy page asks for discharge onto a permeable surface at least 2 m from the foundation wall.
Two outlets are off limits nearly everywhere. The City of Winnipeg says draining a sump into the floor drain is illegal and raises the flood risk for you and your neighbours, and Calgary’s guide says foundation drainage cannot go to the sanitary sewer. Some cities provide a storm or foundation service connection for the discharge; Edmonton’s guide says properties with a separate storm service must send weeping tile discharge to it.
08 /How do you test that the tile and pump are working together?
Edmonton’s guide describes a three-step test that takes five minutes: make sure the pump circuit has power, pour enough water into the pit to start the pump, and go outside to confirm water is actually leaving the discharge line. A pump can hum and turn without moving water if its intake is clogged or its check valve is stuck.
Testing the tile itself is harder. Watch the pit during a long rain: water should arrive through the inlet pipe within hours. A pit that stays dry while the basement floor gets wet suggests the tile is blocked, broken or missing upstream. The next step is a camera run from the pit, described in weeping tile camera inspection and flushing. Planning costs for a new pit and pump are on the cost page.
FAQQuestions people ask
Is weeping tile always connected to the sump pump?
Only when the builder or a later contractor connected it. Many older houses drain the tile by gravity to the house drain or a storm service and have no pit at all.
Does a sump pump need weeping tile to be useful?
No, but without tile it only lowers water near the pit. Tile extends its reach around the whole footing.
Why does my sump pump run when it has not rained?
Common reasons are a high water table, spring melt still working through the soil, a discharge that recirculates back to the tile, or a leaking water line nearby. Time the cycles and check where the discharge lands.
Can a sump pit be too small?
Yes. Below the 750 mm by 0.25 m² minimum in the Part 9 wording, the pump starts and stops far too often, which shortens its life.
Should the sump lid be sealed?
The Part 9 wording calls for a cover that resists removal by children and is airtight. A sealed lid also limits soil gas and humidity entering the basement.
NETWORKGo deeper across the HAUSE Sewer network
How to prevent sewer backup in your basement: a layered plan
How to prevent sewer backup in a basement: keep your lateral clear, maintain a backwater valve, disconnect downspouts, manage weeping tile, plan for storms.
SewerJetting.caHydro jetting weeping tile: how foundation drains are cleaned, and when they cannot be
Hydro jetting weeping tile explained: how foundation drains clog with silt, roots and iron ochre, how they are jetted from the sump, and when to replace them.
PipeCleaning.caCleaning grease out of a kitchen drain line
How to clean a grease-clogged kitchen drain line: how fats build up, why snaking alone fails, when to jet, what to do at home, and how to keep the line clear.
SOURCESSources and further reading
- British Columbia Building Code 2018, Division B, Section 9.14 Drainage (National Building Code Part 9 wording)
- City of Edmonton — The Homeowner’s Guide to Lot Grading and Drainage (April 2020)
- City of Calgary — Guide to Lot Drainage, Residential Development (2019)
- City of Toronto — Basement Flooding Protection Subsidy Program
- City of Winnipeg — Basement and overland flooding