Plumbing Inspection Before Buying a Home: Your Complete Checklist

A pre-purchase inspection helps you understand the apparent condition of a property, but it does not automatically reveal everything happening inside the pipes, beneath the slab or between the house and the municipal sewer. When a plumbing problem is suspected, a specialized assessment can complement the building inspector’s work and clarify the risk before the deadlines specified in the promise to purchase expire.

This plumbing inspection checklist for buying a home shows you what to examine, which documents to request and when a camera drain inspection may be appropriate. It also helps you distinguish between an observation, a diagnosis and a work estimate so you can make a decision based on facts rather than impressions.

Building inspection or specialized plumbing inspection?

A general pre-purchase inspection remains the first step. According to the requirements presented by the OACIQ, the broker must recommend a complete inspection performed by a professional or inspector who holds liability insurance, uses a recognized service agreement, follows a recognized standard of practice and provides a written report. This inspection covers accessible systems and components according to the agreed scope.

A specialized plumbing inspection answers a more specific question. It may include observations, authorized testing, identification of components, a video inspection of a pipe or an estimate for corrective work. It becomes useful when the general inspector recommends further assessment, when the seller’s declarations disclose a previous issue or when concrete signs require a more detailed diagnosis.

Before booking a service, ask what is included and excluded: sanitary system only or stormwater system as well, distance travelled, surface location, video recording, written report, preliminary cleaning and work estimate. The word “inspection” does not guarantee a uniform scope.

Which documents should you request before the inspection?

The best inspection begins before the technical visit. Available documents direct the service provider toward higher-risk areas and help you avoid paying for a poorly defined assignment.

Seller’s declarations and previous reports

Read the Seller’s Declarations regarding the immovable form in full when it applies. Note any references to backups, water infiltration, low pressure, freezing, leaks, pipe replacement, French drains, sump pumps, backwater valves and insurance claims. The OACIQ also states that the existence of a previous inspection report must be disclosed and that the report must be provided to the buyer upon request, subject to the handling of personal information.

A vague answer deserves a written follow-up question. “Repaired” does not specify the cause, contractor or scope of the work. Request the invoice, date, warranty, available photos and any camera report. Determine whether the problem occurred only once or returned after heavy rainfall.

Invoices, permits and technical information

• Water heater: invoice, installation date, model and warranty.
• Water service and sewer: replacement invoices, plans, permits and proof identifying the portion repaired.
• Backwater valve: location, type, installation date and documented maintenance.
• Sump pump: model, age, backup power supply and replacement history.
• Claims: nature of the damage, confirmed cause, drying work and permanent corrective measures.

The property description and declarations do not replace an inspection, but they determine which questions should be asked. A pipe described as “new” may refer to only a short section. Ask for the starting and ending points of the work to be specified.

Checklist: water supply and visible piping

Locate the water service and main shutoff valve

Locate where the water supply enters the building and identify the main shutoff valve. Check whether access is clear, the handle is present and visible signs of oxidation or leakage exist. Do not force an old valve or operate it without authorization: a seized component may begin leaking when disturbed. The service provider should determine whether testing it is reasonable.

Identify materials without drawing premature conclusions

Record the visible materials: copper, PEX, CPVC, galvanized steel, cast iron, ABS or PVC, depending on the section of the system. A house may contain several generations of piping. What is visible near the meter or in the mechanical room does not prove that the same material is present behind every wall or beneath the slab.

Pay particular attention to:

• improvised or difficult-to-access connections;
• white deposits, verdigris or rust streaks;
• deformed, poorly supported or freeze-exposed pipes;
• repaired ceilings beneath a bathroom;
• missing, corroded or inaccessible shutoff valves;
• recent moisture marks around floor penetrations.

A dry mark does not establish whether a leak is active. A moisture meter, an authorized exploratory opening or another test may be recommended. For an existing leak, visit our water leak detection and repair service page.

Compare pressure and flow systematically

Low flow at one faucet may be caused by the aerator or faucet itself. A widespread reduction may be related to the main valve, available pressure, an undersized or obstructed pipe, a pressure-reducing valve or another restriction. Opening several fixtures at the same time provides an indication, but not a diagnosis. If pressure is a concern, request a measurement with a pressure gauge and an interpretation suited to the building.

Checklist: plumbing fixtures and drainage

Test fixtures with authorization from the owner or their representative and observe each area before, during and after water flows. A proper inspection does more than determine whether “the water goes down.”

Kitchen and bathrooms

• Run the hot and cold water and look beneath the sinks.
• Check around the faucets, toilet bases and accessible seals.
• Observe drainage speed, water backing up and gurgling.
• Look for swollen cabinetry, deteriorated caulking and recent repairs.
• Inspect the ceiling beneath fixtures when accessible.
• Note persistent odours without immediately assigning a cause.

One slow drain may indicate a local blockage. Several slow fixtures, a toilet that changes the water level in a floor drain or gurgling throughout the house may justify investigating the main system. However, the absence of symptoms during a brief visit does not rule out an intermittent defect.

Laundry area and connected appliances

Examine the washing-machine faucets and hoses, discharge drain and floor for signs of leakage. Also check the connections for the dishwasher, refrigerator and any water-supplied appliance. Ask whether a leak-detection device or automatic shutoff valve is installed without presenting such equipment as a substitute for maintenance.

Checklist: water heater and risk of water damage

Photograph the rating plate and record the brand, model, serial number and capacity. Serial-number decoding methods vary by manufacturer, so avoid universal formulas. The invoice or manufacturer’s tool will generally confirm the date more reliably.

Hydro-Québec states that an ECOPEAK water heater lasts approximately 12 years from the date shown on its rating plate, while also noting that insurance-policy conditions may influence replacement timing. For other models as well, ask the insurer directly which limits and documentation would apply to the property.

Points to observe

• moisture, corrosion or deposits around the base and connections;
• condition of the drain pan and its drainage, when present;
• presence and route of the pipe connected to the safety valve;
• clearance around the unit and access to components;
• signs of previous leakage on the floor or walls;
• consistency between the capacity, household needs and electrical installation.

Do not operate the safety valve simply “to see whether it works” without considering its condition and the risks. An older valve may not close properly after testing. To assess an existing unit or prepare for replacement, visit the page about water heater installation, repair and replacement.

Checklist: basement, backwater valve and sump pump

The basement often contains the most useful clues: floor drains, main pipes, the sump pit, sump pump, water heater and signs left by previous losses. Examine baseboards, the bottom of walls, concrete, raised storage and differences in finishes that may correspond to repairs.

Backwater valve

Locate the access covers and ask which fixtures or systems are protected. The appropriate type and location depend on the system configuration and applicable requirements. Do not assume that one visible cover automatically protects the entire house. Maintenance also matters: a valve that is inaccessible, blocked by debris or never inspected may not provide the expected protection.

The CMMTQ notes that sewer-backup protection must be designed according to the system. An inspection can document the existing installation; it does not certify overall compliance without verifying the relevant conditions. For more information, visit our backwater-valve installation and inspection service page.

Sump pump and sump pit

• Check accessibility and the condition of the cover.
• Ask about its age, maintenance history and most recent replacement date.
• Identify the route of the discharge pipe and its discharge point.
• Ask whether an alarm or backup power supply is present.
• Have functional testing performed by a competent person with authorization.

A pump that starts during the visit is not necessarily reliable during heavy rain or a power outage. Incoming flow, discharge height, the check valve, power supply and discharge point influence performance. Our page about sump pump service explains the details that should be confirmed.

Do not confuse the sanitary sewer with the French drain

The sewer connection carries wastewater away from the building. The French drain instead manages water around the foundation. A camera inserted into the sanitary sewer does not automatically show the French drain. That system requires suitable access and a separate assignment; certain sections may remain inaccessible. The RBQ also specifies that French-drain installation does not fall under the same subclass as plumbing work involving the water-supply, drainage and venting systems of plumbing fixtures.

When should you request a camera drain inspection?

A camera can be very useful, but the age of the property alone does not create an automatic rule. The decision should be based on the risk, history and potential consequences of an undetected defect.

Situations that make the test more relevant

• a disclosed sewer backup or overflow, even if it was cleaned up;
• repeated blockages or frequent unclogging of the main drain;
• several slow or noisy fixtures at the same time;
• mature trees near the presumed route of the service connection;
• an older pipe, unknown material or partial repairs;
• settling ground or previous excavation work;
• a previous report mentioning roots, a crack, misalignment or reverse slope;
• the high cost of repairs beneath a finished slab or recent landscaping.

The City of Montréal also requires a specialized inspection during certain procedures involving a sewer connection to establish the nature of the problem and characteristics of the pipe. This municipal requirement in a repair context does not mean that a camera inspection is legally mandatory for every real-estate purchase; rather, it demonstrates the value of technical evidence when a defect must be attributed and located.

What a camera can show

When the pipe is accessible and sufficiently clear, the video may reveal roots, a displaced joint, visible cracking, deformation, deposits, an object, buildup or a section retaining water. A locating transmitter may help mark the approximate position of an abnormality on the ground, depending on the equipment and conditions.

What it cannot guarantee

• the complete watertightness of the entire pipe;
• the exact remaining service life of the system;
• the condition of potable-water supply pipes;
• the condition of every branch the camera cannot enter;
• the cause of water infiltration through the foundation;
• the condition of the French drain without suitable access and a separate inspection;
• the compliance of all plumbing throughout the property.

A blocked pipe may need to be cleaned before the camera can pass. Cloudy water, access that is too narrow, tight bends or a collapsed pipe can limit the distance travelled and quality of the images. The report should identify these limitations rather than presenting an unseen section as sound.

To understand the procedure and its limitations, visit our camera drain and pipe inspection service page and our guide explaining how a sewer-camera inspection is performed.

What should a good camera-inspection report contain?

A video without context is difficult to use for negotiation, planning work or comparing estimates. Before the appointment, ask whether the deliverables will include:

• the address, date and portion of the system inspected;
• the access point used and direction of travel;
• the distance travelled and inaccessible sections;
• a clear video or screenshots of abnormalities;
• a description of observations without overstating their certainty;
• the approximate location of abnormalities, if included in the assignment;
• limitations related to water, deposits, bends or a blockage;
• recommended next steps: cleaning, a second pass, testing or an estimate.

Also ask whether the service provider clearly distinguishes an observation from a conclusion. For example, an area of standing water may be consistent with a reverse slope, but the exact geometry and cause may require locating or further testing. The report should help you understand what was seen, where it is located and what remains uncertain.

What should you do if the inspection reveals a problem?

Begin by classifying the findings according to urgency and level of certainty:

1. Observation: what was seen or measured.
2. Diagnosis to be confirmed: the probable cause and any additional testing required.
3. Proposed corrective measure: localized repair, maintenance, replacement or monitoring.
4. Documented cost: a written estimate specifying the scope and exclusions.

An estimate should correspond to the identified problem. The price of a complete replacement should not be used as leverage when the report cannot yet distinguish between a blockage and a damaged pipe. Conversely, a recommendation to “monitor” may not be sufficient when the video shows that the camera cannot pass or when a loss has occurred repeatedly.

Renegotiation or withdrawal: nothing is automatic

The OACIQ specifies that discovering a defect does not automatically allow a buyer to cancel a promise to purchase. Under common inspection clauses, the objective significance of the issue, its effect on value, the deadlines, the notice delivered and the copy of the report may be determining factors. The seller may accept a price reduction, propose repairs, grant an extension or refuse a request to renegotiate.

Do not assume that a plumbing report is enough to withdraw the offer “without penalty.” Contact your broker promptly and, depending on the situation, your notary or legal adviser. Follow the clause you actually signed rather than a deadline found in a general article. The OACIQ states that the inspection period written into the promise to purchase normally begins on the day after acceptance and is calculated in consecutive calendar days; your document and any signed amendments remain the reference.

A sale without legal warranty of quality requires increased caution. The OACIQ notes that an exclusion may limit the buyer’s future remedies without protecting a seller who intentionally conceals a defect. Have the clause and its consequences explained by the appropriate professionals.

To put the work into perspective, use our page about plumbing service costs, then request an estimate corresponding specifically to the building and assignment.

How should you choose a provider for the specialized inspection?

Verify who will perform the assignment, who will issue the report and who would be authorized to complete any resulting work. The RBQ recommends checking its registry before hiring a contractor. For plumbing work, the licence must include the appropriate subclass, generally 15.5 — Plumbing Contractor. The CMMTQ directory can also be used to verify the company and its specialties.

Before authorizing the service, ask for:

• the company’s legal name and licence number;
• the written scope and price of the assignment;
• possible fees if cleaning or a second camera pass is required;
• the report format and delivery time;
• whether the video will be retained;
• known access limitations;
• whether a separate estimate will be provided if an abnormality is found.

SOS Plombiers is a referral platform. We receive the request and direct it to a local partner based on the service area, type of work and availability. The partner confirms the scope, price, appointment and technical conclusions directly. To arrange a specialized assessment, send information about the property and your inspection deadlines.

Final checklist before removing the inspection condition

• I have read the seller’s declarations and requested previous reports.
• I have obtained available invoices for water damage and plumbing work.
• The inspector identified accessible components and recommended assessments.
• The valves, visible materials, fixtures and signs of moisture were examined.
• The age of the water heater was confirmed using a reliable source.
• The backwater valve and sump pump were located and documented.
• The relevance of a camera inspection was assessed according to actual risks.
• The report describes the portions inspected, abnormalities and limitations of the assignment.
• The anticipated costs are based on a written scope rather than a generic estimate.
• My broker or adviser verified the deadlines and notices required by the promise to purchase.

Frequently asked questions about pre-purchase plumbing inspections

Is a plumbing inspection mandatory before buying a house in Quebec?

A separate plumbing assessment is not automatically mandatory for every purchase. A general pre-purchase inspection is strongly recommended, and a specialized assessment may be appropriate when a problem, previous history or limitation of the general inspection justifies it. The conditions of your promise to purchase determine the procedures and deadlines applicable to your transaction.

Does the building inspector automatically inspect drains with a camera?

No. A sewer-camera inspection should not be assumed to be included in a general inspection. The inspector assesses accessible components according to the service agreement and standard of practice. They may recommend a specialized assessment when signs require more detailed testing.

Does an older house always require a camera inspection?

No. Age is one factor among several. Previous sewer backups, repeated blockages, materials, trees, partial repairs and the potential cost of excavation are often more revealing. A newer house may also justify a camera inspection when symptoms or questionable work are reported.

Can a camera inspect the French drain?

Only when the French drain has suitable access and the assignment specifically covers that system. A camera inserted into the sanitary sewer does not automatically enter the foundation drainage system. Even with access, certain portions may remain out of reach or difficult to interpret.

How much does a camera drain inspection cost?

The price depends in part on access, length, diameter, the need to clean the pipe, surface locating and the type of report requested. Ask for a written scope specifying the camera pass, recording, report and fees for a possible second appointment.

How much time should be allowed?

The duration varies according to the number of components, access, condition of the pipe and authorized testing. A simple video inspection may be cut short by a blockage, while a complete pre-purchase assignment may require several checks and a subsequent report. Schedule it early enough to receive and understand the findings before the contractual deadline.

How can the age of the water heater be confirmed?

Begin with the rating plate and invoice. The serial-number structure varies by brand; use the manufacturer’s tool or contact the company rather than applying a universal formula. Then verify the specific conditions of the prospective insurer.

Can I cancel my offer if the inspection reveals a plumbing problem?

Not automatically. The answer depends on the clause you signed, the objective significance of the problem, the deadlines and how the notice and report are delivered. A minor defect may not be sufficient. Consult your broker, notary or legal adviser promptly before making a decision.

Turn the inspection into an informed decision

A good pre-purchase plumbing inspection does not attempt to declare a house “perfect.” It documents accessible components, targets costly uncertainties and allows you to estimate the next steps. The most useful result is a coherent file: the seller’s declarations, observations, video when appropriate, report, limitations of the assignment and a suitable estimate.

If the inspector recommends further assessment or the property has a history of sewer backups, slow drains or poorly documented repairs, contact SOS Plombiers. We will direct the request to a partner in the area so the company can confirm its availability and the appropriate scope before your deadlines expire.