The signs that yours has gone: water pooling against the foundation or in a window well after rain, a musty basement or crawl space that never clears, white efflorescence on the basement wall, foundation cracks that weep in wet weather, or a drain scope during a sale that comes back collapsed or root filled. One of those is reason enough to scope the line. Two or more usually means the ring rather than one length of it.
We replace failing perimeter drains from the outside: we excavate down to the footing, take the old pipe out, and install a new system built to the Code minimums set out below. This is the permanent fix, and it is the only approach that lets us confirm what actually failed.
Perimeter drain, foundation perimeter drain, perimeter footing drain, perimeter French drain and weeping tile are five names for that one system. BC Building Code Article 9.14.2.1 calls it foundation drainage and requires the bottom of every exterior foundation wall to be drained by pipe laid around the exterior of the foundation, or by a layer of gravel. We replace failing perimeter drains on Greater Victoria homes.
What a perimeter drain is, in plain terms
A perimeter drain is a perforated pipe laid in clean crushed rock at footing level, running around the outside of the foundation. Groundwater moving through the surrounding soil drains into the perforations instead of building pressure against the wall, and the pipe carries it off to a sewer, a ditch, or a dry well.
The Code gives two acceptable ways to drain a foundation. Article 9.14.2.1 says the bottom of every exterior foundation wall shall be drained by drainage tile or pipe laid around the exterior of the foundation, or by a layer of gravel or crushed rock, unless it can be shown to be unnecessary. Pipe is what nearly every Victoria house has, because the gravel-only version needs a graded excavation draining to a sump.
One point homeowners are rarely told: the system is yours. The District of Saanich sets out that the perimeter drains and roof drains on a property are private and the owner is responsible for maintaining them, right up to the point they connect to the municipal system.
Perimeter drain, footing drain, weeping tile, French drain: which is which
These are mostly the same thing under different names. The difference that actually matters is where the pipe sits, not what it is made of.
| Name | Who uses it | What it refers to | Same as a perimeter drain? |
|---|---|---|---|
| Perimeter drain | BC homeowners, contractors, drain-scope reports | The perforated pipe around the outside of the footing | Yes. This is the common BC name |
| Foundation drain, foundation perimeter drain | Building officials, engineers, the Code | The same pipe, named for what it protects | Yes |
| Footing drain, perimeter footing drain | Trades, US building codes | The same pipe, named for where it sits | Yes |
| Weeping tile | Older BC and Ontario usage | The pipe itself, from the clay tile it used to be made of | Yes, though it names the pipe rather than the whole system |
| Perimeter French drain | Homeowners searching online | A French drain built as a ring around the foundation | Yes, when it is down at footing level |
| French drain | Landscapers and drainage trades | Any gravel trench with a perforated pipe, anywhere on the lot | No. Only if it is at the footing |
| Subsoil drainage pipe | The BC Plumbing Code and the Building Code Appeal Board | The regulator term, and explicitly not part of a storm drainage system | Yes, and that distinction has consequences |
What the BC Building Code actually requires
The requirements are short, specific and public. They are also most of the reason a replacement costs what it does, because meeting them means getting down to the footing.
- Pipe size: drain tile or pipe used for foundation drainage shall be not less than 100 mm in diameter (Article 9.14.3.2).
- Gravel cover: the top and sides of the pipe take not less than 150 mm of crushed stone or other coarse clean granular material, containing not more than 10% of material that will pass a 4 mm sieve (Article 9.14.3.3).
- Joints: pipe laid with butt joints gets 6 mm to 10 mm open joints, and the top half of each joint is covered with sheathing paper, polyethylene or saturated felt so soil cannot wash in (Article 9.14.3.3).
- Position: the pipe is laid on undisturbed or well-compacted soil, with its top below the bottom of the basement slab or the crawl-space ground cover. That is why it has to sit at the footing.
- The gravel alternative: a granular drainage layer runs to a minimum depth of not less than 125 mm beneath the footing and extends not less than 300 mm beyond its outside edge (Article 9.14.4.2).
- Where the water goes: foundation drains shall drain to a sewer, a drainage ditch or a dry well, and a dry well has to sit at least 5 m from the foundation with drainage running away from the building (Articles 9.14.5.1 and 9.14.5.3).
- When gravity will not do it: a sump pit is not less than 750 mm deep, not less than 0.25 m2 in area, and covered, with an automatic sump pump where gravity drainage is not practical (Article 9.14.5.2).
The rule most pages skip: a perimeter drain is not a storm drain
This is the part that surprises people, and it is written down. In Appeal Board decision #1226, the BC Building Code Appeal Board held that foundation perimeter drains are perforated subsoil drainage pipes, that the Plumbing Code definition of a drainage system specifically excludes subsoil drainage pipes, and that area drains serving a driveway therefore cannot be connected to them. Those have to run to the storm sewer in approved solid pipe.
That ruling explains a large share of the perimeter drains failing across Greater Victoria right now. Downspouts and driveway drains tied into the perforated ring push roof and surface water, plus everything it carries, through a pipe designed only to collect groundwater seeping slowly out of soil. The pipe silts up from the inside and the failure gets blamed on age. When we replace a drain, roof and surface water gets its own solid line and the subsoil pipe is left to do the one job it is rated for.
It is worth checking before you spend anything. If your downspouts disappear into the ground beside the foundation, where they go is a question a camera answers in an afternoon.
Who is allowed to replace a house perimeter drain, and what a permit buys you
One job, two sets of rules, and the seam between them is where quotes stop matching each other. The perforated ring at the footing is subsoil drainage. The line that carries its water out to the street is plumbing, and it is regulated as plumbing.
The District of Saanich puts the split in writing: anyone can install perimeter foundation drainage, but storm laterals, sanitary sewer lines, rain water leader systems and water lines can only be done by a certified plumber holding a trades qualification number, by an indentured apprentice supervised by a journeyman certified plumber, or by the registered owner and occupant of the building, working from an isometric drawing approved by the plumbing official.
That is worth knowing before you compare two numbers. A quote that stops at the footing is doing less work than a quote that also replaces a failed storm lateral, and the second one carries regulated trade time the first does not. Ask which side of that line your scope ends on, and get the answer in writing.
The permit is also what puts an inspector in the trench. Foundation drainage can only be verified in the window between the drain rock going in and the backfill going back, because once the trench is closed nobody can confirm that the pipe sits below the underside of the slab or that it carries its full 150 mm of cover (Article 9.14.3.3). We work to that window rather than around it.
Where the water is allowed to go, and why the outlet decides the price
Every replacement has to end somewhere, and the Code is specific about where. Foundation drains shall discharge to a sewer, a drainage ditch or a dry well (Article 9.14.5.1). A dry well has to sit at least 5 m from the foundation with the ground draining away from the building (Article 9.14.5.3), which quietly rules it out on a lot of narrow Victoria lots. Where the ground will not carry water off by gravity, the Code allows a sump pit not less than 750 mm deep and not less than 0.25 m2 in area, covered, with an automatic pump (Article 9.14.5.2).
The municipal side is a separate permission and a separate ownership boundary. The City of Victoria maintains roughly 5,700 storm drains and its drainage crews clear them, but that system starts at the street. Saanich states the other half plainly: perimeter drains and roof drains on a property are private, and the owner maintains them right up to the municipal connection.
So the pipe is yours, the main is theirs, and the join between them is where responsibility changes hands. This is the single most useful thing to establish from a drain-scope video before anyone quotes. A failure inside your property line is your replacement. A failure at the connection is a different conversation, and a different number.
Repair, reline or replace: which one is your quote actually for
Not every failing drain needs the full ring dug out. The honest answer depends on how much of the pipe has gone and why, which is what a camera is for. Published BC ranges for each path sit below, so you can see roughly where a quote should land before you get one.
| What you are buying | What is done | When it fits | Published range |
|---|---|---|---|
| Camera inspection | A scope run through the existing drain to find the break, the silt line or the roots | Before anything else, and before you accept a replacement quote | $250 to $500 (HydroPro) |
| Spot repair | Digging one short run and replacing the failed length only | A single collapse or root intrusion in otherwise sound pipe | $3,000 to $8,000 (HydroPro) |
| Full exterior replacement | Excavating to the footing and rebuilding the ring to Code, with the outlet corrected | Original clay or early perforated pipe that has silted or collapsed in more than one place | $8,000 to $25,000 (HydroPro), or $15,000 to $25,000 on an existing home (Back 40) |
| Drainage on a new build | The same system, installed before there is anything on top of it | New construction, where nothing has to be put back afterwards | $10,000 to $20,000 (Back 40) |
- A camera first is almost always the cheaper order of operations, because it is the only thing that tells you whether you are in the spot-repair range or the replacement range.
- The gap between the new-build range and the existing-home range is restoration, not drainage. Digging is predictable. Putting a patio, a driveway or a mature garden back is not.
- A quote that does not say what happens to the outlet has not priced the part most likely to surprise both of you.
Signs your perimeter drains are failing
Perimeter drains fail slowly, so the early signs are easy to miss until water shows up inside.
- Water pooling against the foundation or in window wells after heavy rain
- A damp, musty smell in the basement or crawl space that will not clear
- Efflorescence (white chalky staining) or dark water lines on basement walls
- Cracks in the foundation that weep during wet weather
- A drain-scope report during a sale that flags collapsed or root-filled pipe
- Soggy ground or slow-draining low spots right beside the house
What the replacement process looks like
A full exterior replacement follows the same sequence on almost every property, and each stage exists to satisfy one of the Code requirements above.
- Site assessment: we look at grade, downspouts, soil, and where water is showing up, then put the scope and price in writing.
- Excavation: we dig down to the footing around the affected sides of the house, protecting landscaping where we can.
- Remove and inspect: the old weeping tile comes out and we confirm what failed, including whether surface water was being fed into it.
- New system: we lay new perforated pipe on a proper slope, wrap it in filter fabric, and bed and cover it in clean drain rock to the Code minimums.
- Outlet: we confirm the drain runs to a sewer, ditch or dry well, and separate any roof or surface water onto its own solid line.
- Waterproofing: while the foundation is exposed we can re-membrane the wall and seal cracks.
- Backfill and restore: we backfill, re-grade so water runs away from the house, and tidy the site.
What a perimeter drain replacement costs
We do not publish a flat price, because the site sets the number and a quote is a commitment we can only make after seeing the property. Published third-party ranges are still worth knowing before you call anyone. HydroPro Plumbing puts full perimeter drain replacement in Metro Vancouver at $8,000 to $25,000 for 2026, partial spot repairs at $3,000 to $8,000, and a camera inspection to diagnose first at $250 to $500.
Back 40 Landscaping publishes a different set for the same region: $15,000 to $25,000 for a perimeter drain on an existing home, and $10,000 to $20,000 on a new build where there is no landscaping to put back. Both are Lower Mainland numbers rather than Victoria ones, and they disagree at the bottom of the range. The gap is restoration. Digging out the pipe is the predictable part of the job. Putting back a patio, a driveway or a mature garden is where two quotes on the same street separate.
Our Victoria cost guide works through the parts of that number that are actually published, including the metered disposal rate and the permit.
- How much of the perimeter needs to be dug (one wall versus the full footprint)
- Excavation depth and how deep the footing sits
- Access: tight side yards, decks, patios, or mature landscaping to work around
- Soil and water conditions (heavy clay and high water tables take longer)
- Whether the drain has a working outlet, or a new one has to be run
- Whether you add foundation waterproofing while the wall is open
- Restoration: replacing concrete, walkways, or planting beds that had to come out
Why Victoria homes need this more than most
Two things put Greater Victoria foundations under pressure. First, the soil: much of the region sits on dense marine clay that holds water instead of letting it drain, so it pushes moisture toward the foundation and keeps the drain working year round. Second, the rain: our wet coastal winters mean months of steady water load against the house rather than a few storms. Original clay tile and early perforated pipe were not built for that combination. When we replace a drain here, we design it for clay and for a wet winter.
So do you need a perimeter drain replacement, or a French drain?
The question to answer first is where the water actually is.
- Water in the basement or standing against the foundation wall, in a house built between the 1950s and the 1990s: the ring at the footing is the problem, and the fix is perimeter drain replacement.
- Water pooling in the yard, at the base of a slope, or behind a retaining wall, with a dry basement: that is French drain installation, a separate trench that intercepts water before it ever reaches the house.
- A humid crawl space, or standing water under the house: that is crawl space drainage, usually an interior perimeter running to a sump.
- Both at once, which is common on a sloped Victoria lot: our guide on French drain vs perimeter drain sets the two side by side.
Common questions
Is a perimeter French drain the same as a perimeter drain?
Yes. A perimeter French drain is a French drain built as a ring around the foundation footing, which is exactly what a perimeter drain is. French drain describes the construction, a gravel trench with a perforated pipe, and it can be built anywhere on a property. Perimeter drain describes the location. Someone searching for a perimeter French drain almost always means the drain at the footing.
What is a perimeter footing drain?
The same system again, named for where it sits. The pipe is laid at footing level so it can collect groundwater below the basement floor, which is what the BC Building Code has in mind when it requires the top of the pipe to sit below the bottom of the slab.
How long do perimeter drains last?
A properly installed modern perimeter drain typically lasts 30 to 50 years or more. The original clay or early perforated pipe on many Victoria homes is now well past that, which is why replacement, not repair, is usually the right call once it fails.
Can downspouts be connected to the perimeter drain?
They should not be. The Building Code Appeal Board has held that foundation perimeter drains are subsoil drainage pipes and cannot form part of a storm drainage system, so roof and surface water belongs on its own solid line to the storm sewer. Feeding roof water into perforated pipe is a common cause of premature silting.
Do you need a permit to replace a house perimeter drain?
Treat it as yes and confirm with your municipality. Saanich, for example, requires a plumbing permit for work on a plumbing system and inspects foundation drainage before backfill. Saanich also sets out that anyone may install perimeter foundation drainage, while storm laterals, sanitary sewer lines and rain water leader systems can only be done by a certified plumber, a supervised apprentice, or the registered owner and occupant working from an approved drawing. We handle the permit and the inspection as part of the job.
Who owns the perimeter drain, me or the municipality?
You do. Saanich states that perimeter drains and roof drains on a property are private and the owner is responsible for maintaining them up to the point they connect to the municipal system. The storm main in the street is the municipality. That boundary is what decides who pays when a drain scope finds the failure out near the property line.
Do you have to dig up the whole yard?
Not always. If only one or two sides of the foundation are failing, we can replace just those runs. We confirm the scope during the site assessment so you only pay to dig what needs digging.
How long does the job take?
Most single-family replacements take a few days to about a week, depending on how much of the perimeter is involved, access, and weather. We give you a realistic timeline in the written scope.
Can you replace drains in winter?
Yes. Winter is often when the problem shows up, and we work through the Victoria wet season. Excavation is weather-dependent day to day, but the season does not stop the job.
Sources
- Section 9.14, Drainage, Division B, Part 9, British Columbia Building Code, 2018.
- BCAB #1226, Area Drains, BC Building Code Appeal Board, 1990.
- Stormwater: homeowner responsibilities, District of Saanich, 2026.
- Plumbing permits: who can do plumbing work, District of Saanich, 2026.
- Flood prevention and storm drains, City of Victoria, 2026.
- Perimeter drain replacement cost, HydroPro Plumbing, 2026.
- Perimeter drainage cost in the Fraser Valley, Back 40 Landscaping, 2026.
Estimates vary by property. Book a site assessment for a scope and price specific to your home.