Nov 10, 2026  •  7 min read  •  HexoTech Engineering

Water Leaking Into a New Home in Ontario: What the Tarion Warranty Covers

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Water is the most common reason homeowners contact us. A stain on a ceiling, a damp basement wall, a sump pump that never stops running, a window that leaks in a north wind. In a home less than seven years old, the first question is usually the same: is this covered by the Tarion warranty?

The answer depends on how old the home is, where the water is getting in, and above all on why. This guide explains each of those.

Which warranty applies depends on the age of the home

Ontario's new home warranty runs in three periods, all counted from your date of possession.

The practical lesson: the second anniversary of possession is the date that matters most for water. A leak reported at 23 months falls under a warranty written for it. The same leak reported at 25 months has to meet the structural defect test, which most water problems will not. We explain that test in our guide to Major Structural Defect claims.

If water is coming in right now

Tarion treats some conditions as emergencies, including water penetration through interior walls or ceilings, a pool of standing water inside the home, and a plumbing leak that requires the whole water supply to be shut off. If that is your situation:

  1. Call your builder's emergency number.
  2. If you cannot reach the builder, or the problem is not corrected within 24 hours, contact Tarion.
  3. Do not repair the resulting damage yourself. If you have no option but to stop the leak, fix only the emergency condition.
  4. Photograph everything, before and after, and keep every receipt.
  5. Submit Tarion's Emergency Form as soon as you can, with a copy to the builder.

If you live in a condominium, tell the board or property manager as well. The source may be in the common elements, in which case the claim belongs to the condominium corporation and not to you.

Why the cause matters more than the damage

A warranty claim is about a defect, and a wet ceiling is only its result. Builders often attribute water to something outside the warranty: an unusual storm, ice damming, condensation from how the home is lived in, landscaping the owner changed, or a lack of maintenance. Some of those explanations are right. Many are not, and it is hard for a homeowner to tell the difference.

Finding the real path of the water is engineering work. It can involve moisture mapping, controlled water testing of a window or wall, opening a small section of drywall, checking the grading and drainage around the foundation, and comparing what was built against the drawings and the Building Code. The result should be a written explanation of where the water enters, why, and what repair will actually stop it.

That last point matters after the claim is accepted too. A repair that treats the symptom, such as patching a stain or re-caulking a joint, often fails after the warranty has expired. Before you accept a repair as complete, ask what the cause was and how the builder confirmed it was fixed.

How a water claim proceeds

When to bring in an engineer

HexoTech provides independent investigations for homeowners: a site inspection, a root-cause report written for Tarion, your builder and your lawyer, and attendance at the conciliation where it helps. Read more about our Tarion warranty claim support and forensic engineering investigations.

Frequently Asked Questions

Does the Tarion warranty cover water leaks in a new home?

Often, yes. In the first year, defects in work and materials are covered generally. For two years from possession, the warranty specifically covers water penetration through the basement or foundation walls and defects that allow water into the building envelope, as well as defects in the plumbing system. After two years, only the narrower Major Structural Defect warranty remains.

How long is water penetration covered under the Tarion warranty?

Two years from the date of possession for water penetration through the basement or foundation walls and into the building envelope. Report the problem to your builder and Tarion on a warranty form before the second anniversary.

What should I do if water is leaking into my new home right now?

Call your builder's emergency number. If you cannot reach the builder or the problem is not corrected within 24 hours, contact Tarion. Do not repair the resulting damage yourself, photograph everything before and after, keep receipts, and submit Tarion's Emergency Form as soon as possible.

My builder says the water is from condensation or weather. What can I do?

Ask for the explanation in writing, then have the cause independently investigated. An engineer can trace how the water is entering and whether it results from a defect in work or materials. That evidence can be presented to the builder and to Tarion at conciliation.

How much does a Tarion conciliation cost a homeowner?

$250 plus HST, refunded if Tarion determines that at least one of the items assessed is covered by the warranty.

Water problem in a home under seven years old?

Send us the address, your possession date and a few photos. We will tell you which warranty period applies, what an investigation would involve, and what it would cost.

Request a Water Investigation →

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