Quick Answer: Most Canadian mattress warranties require visible sagging of 1 to 1.5 inches (measured without body weight) before a claim is accepted. Stains, improper foundations, or removed law labels typically void coverage. Prorated warranties reduce the manufacturer's payout over time. To file a claim, measure the sag with a straight edge, photograph it, and contact the manufacturer with your original receipt and serial number.
In This Guide
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What Mattress Warranties in Canada Actually Cover
A mattress warranty covers manufacturing defects, not comfort changes. That distinction is the most important thing to understand before reading any warranty document, because manufacturers know that most people conflate the two.
If you buy a mattress and it feels firmer or softer than it did in the showroom after three years, that is not a warranty issue. It is normal foam compression and wear. If you buy a mattress and the spring breaks through the cover, or the foam cracks vertically, or the mattress develops a permanent indentation that exceeds the warranty's stated threshold without any external cause, those are warranty issues.
Canadian warranties typically cover:
- Broken or exposed coils or springs in innerspring mattresses
- Visible sagging or body impressions that exceed the stated depth threshold (measured without weight)
- Foam cracking, splitting, or deteriorating in ways inconsistent with normal wear
- Cover fabric defects, stitching failures, or zipper failures where the cover is part of the mattress (not a separate protector)
- Structural failures in the mattress foundation or base unit if that component was sold as part of the set
Why Foam Sags: The Science Behind Body Impressions
Foam sagging is a function of foam fatigue, not a mystery. Polyurethane foam is a polymer network with open cells. Each time you compress the foam (every night, under your body weight), you stress those polymer chains. In lower-density foam, fewer chains share the load, so each chain fatigues faster. In higher-density foam, more chains distribute the stress, and degradation is slower. The zones that degrade fastest are directly under your heaviest body points: hips and shoulders for side sleepers, lumbar for back sleepers. This is why body impressions look like valleys where you sleep. Jacobson et al. (2008) in the Journal of Chiropractic Medicine confirmed that mattress firmness changes due to compression are associated with back pain increases, which is why the warranty threshold matters practically, not just contractually.
The Sagging Threshold System: 1 Inch, 1.5 Inches, 2 Inches
The sagging threshold is the line in the warranty that matters most. It tells you how much the mattress has to visibly sink before the manufacturer will consider a claim.
In Canada, the most common thresholds are:
- 1 inch (25mm): More consumer-friendly threshold. Less common. Some mid-range specialty brands use this to differentiate their warranty as stronger.
- 1.5 inches (38mm): The most common threshold in Canadian retail mattress warranties, including most major brands sold through brick-and-mortar stores. This is the threshold used in most Restonic warranties.
- 2 inches (50mm): Used by some budget brands and a few online-direct brands. At two inches, a mattress is significantly degraded. This threshold is difficult to reach without the comfort layer being genuinely exhausted, which is why consumer advocates consider it a weak warranty.
There is an additional nuance that catches people: the measurement is taken without body weight. Many warranty inspection processes require measuring the sag while the mattress is empty and supported by its foundation. A sag that looks like 2.5 inches when you are lying in it might only measure 1.2 inches with the mattress empty and unloaded. The measurement conditions are everything.
This is an honest frustration with the industry. A mattress that has softened so much that your hips sink deeply and cause back pain every morning may not technically qualify for a claim if the unweighted depression is only 1.2 inches on a 1.5-inch threshold warranty. The mattress has failed you functionally but not contractually.
How to Measure and Document Sagging
Measuring Mattress Sag: Step by Step
Step 1: Remove All Bedding
Strip the mattress completely: sheets, protector, topper if any. The measurement must be of the mattress alone, not any additional layers. If a topper is permanently part of the mattress, it stays.
Step 2: Find the Deepest Depression
Stand at the foot of the bed and look along the surface from sleeping height. The valleys will be visible near where your hips and shoulders rest. Identify the deepest visible area.
Step 3: Place a Straight Edge Across the Depression
Lay a long straight object (a broomstick handle, level, or long ruler) across the mattress so it bridges the depression. The straight edge should rest on the highest undepressed areas on either side of the valley.
Step 4: Measure the Gap
Using a ruler or tape measure, measure the vertical distance from the straight edge down to the bottom of the depression at its deepest point. This is your sag measurement in millimetres or inches.
Step 5: Photograph Everything
Take multiple photographs: one from the foot of the bed showing the overall surface, one close-up with the straight edge in place and the ruler measuring the gap, and one showing the mattress label with the model name and serial number. Good photos are the difference between a smooth and a difficult claim process.
The Most Common Warranty Voiding Conditions
These are the conditions that manufacturers most commonly cite when denying claims in Canada. Some are reasonable. A few border on predatory.
Warranty Voiding Conditions to Know
- Stains: Many warranties explicitly state that any stain on the mattress voids coverage entirely, regardless of the stain's size or cause. This is one reason why a waterproof mattress protector is not optional. A single stain from a water glass, perspiration, or a toddler accident can void a 10-year warranty. Keep the protector on at all times.
- Improper foundation: Using a slatted bed frame with slats more than 3 inches apart, a box spring in poor condition, or any base not approved by the manufacturer can void the warranty. Most warranties specify the required foundation type. Check your warranty document before setting up your bed.
- Removed law label: The law label is the tag that says "Do Not Remove Under Penalty of Law." Removing it can void the warranty because it contains the mattress's material identification information needed for a claim. Leave it on.
- Physical damage: Burns, cuts, tears, or pet damage are not covered. Even accidental damage from moving can fall under this exclusion if it is detectable during inspection.
- Normal softening: All foam softens over time. If your mattress feels softer than it did in year one but does not have a measurable depression above the threshold, that is not covered. The warranty covers structural failure, not comfort preference drift.
- Unsupported use: Using a mattress on the floor (depending on the warranty) or on adjustable bases not listed as compatible can void coverage.
Talia, our showroom specialist, recommends that every customer photograph their bed setup within the first month of purchase: the mattress on its foundation, the foundation type, and the bed frame slat spacing. "If you ever need to make a claim, having that photo of the original setup is much better than trying to prove it later," she says.
Prorated vs Non-Prorated: What the Difference Costs You
A non-prorated warranty means the manufacturer will repair or replace the mattress at no cost to you throughout the warranty period, as long as the defect is covered. This is the better kind of warranty.
A prorated warranty reduces the manufacturer's financial responsibility over time. A typical prorated structure might look like this: full coverage for years 1-2, then 50% coverage in year 3, 40% in year 4, and so on until the warranty expires. In year 8 of a 10-year prorated warranty, you might receive only 20% of the replacement value, meaning you pay 80% of the cost to resolve a manufacturing defect. Prorated warranties sound impressive at 10 years but provide increasingly weak protection after the first few years.
Many brand warranties are hybrid: non-prorated for a certain number of years, then prorated for the remainder. Read the warranty document to understand which years are which.
Mattress Miracle's Warranty Approach in Brantford
At Mattress Miracle, we encourage every customer to read the full warranty document before purchasing, not just the marketing summary. We carry Restonic, Sleep In, products, each with their own warranty terms. Brad walks through the key points with customers who ask, including the sagging threshold, foundation requirements, and what documentation to keep. If you ever have a warranty concern with a mattress purchased from us, call us first at (519) 770-0001. We act as an intermediary with the manufacturer and can often facilitate claims more efficiently than going directly to a call centre. We have been doing this since 1997, and we think helping with warranty issues is part of what we agreed to when you bought from us.
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Call 519-770-0001Frequently Asked Questions
How deep does my mattress have to sag before it's covered under warranty in Canada?
Most Canadian mattress warranties require 1 to 1.5 inches (roughly 25 to 38mm) of visible, measurable sagging when the mattress is unloaded and lying flat on its foundation. Some budget brands require 2 inches. The measurement is taken with a straight edge across the depression, without body weight. A mattress that feels dramatically degraded may still not qualify if the unweighted sag falls below the threshold.
Can a stain really void my entire mattress warranty?
Yes, and this is one of the least consumer-friendly standard terms in the Canadian mattress industry. Many major brand warranties state clearly that any stain voids the warranty, regardless of how minor or unrelated to the claimed defect it is. A waterproof mattress protector is the only reliable defence against this. Always use one from day one, even if you think you do not need it.
What is the difference between a prorated and non-prorated mattress warranty?
A non-prorated warranty means the manufacturer pays for the full repair or replacement throughout the warranty period. A prorated warranty reduces the manufacturer's contribution over time, so in later years you pay a larger share of the replacement cost. A 10-year prorated warranty may offer only 20 to 30% replacement value in years 7 to 10. Non-prorated is always the better protection.
My mattress feels softer than when I bought it. Is that covered?
Generally, no. All foam softens over time as the material compresses. This is considered normal wear unless the softening results in a visible body impression that exceeds the warranty's sagging threshold. Comfort preferences are explicitly excluded from coverage in virtually all Canadian mattress warranties. The warranty addresses structural defects, not the subjective feel of the mattress over time.
Can Mattress Miracle help me with a warranty claim for a mattress I bought from them?
Yes. If you purchased from us at 441 1/2 West Street in Brantford, call (519) 770-0001 when you notice a potential warranty issue. We can advise on whether the situation meets the manufacturer's criteria, help you document the sag properly, and work with the manufacturer on your behalf. We have done this for Brantford customers throughout our nearly 30 years in business. We cannot override manufacturer warranty decisions, but we can advocate effectively.
Sources
- Jacobson, B.H., Boolani, A., & Smith, D.B. (2008). Changes in back pain, sleep quality, and perceived stress after introduction of new bedding systems. Journal of Chiropractic Medicine, 8(1), 1-8. doi.org/10.1016/j.jcme.2008.09.002
- Zhong, Y., Talapatra, B., Lu, B., & Turner, R. (2022). Characterizing the physical and mechanical properties of commercial polyurethane foam mattresses. Polymer Testing, 105, 107427. doi.org/10.1016/j.polymertesting.2021.107427
- Ontario Ministry of Consumer Services. (2002). Consumer Protection Act, 2002, S.O. 2002, c. 30, Sched. A. Ontario Legislature. ontario.ca/laws/statute/02c30
- Radwan, A., Fess, P., James, D., et al. (2015). Effect of different mattress designs on promoting sleep quality, pain reduction, and spinal alignment in adults with or without back pain. Sleep Health, 1(4), 257-267. doi.org/10.1016/j.sleh.2015.08.001
- ASTM International. (2023). ASTM D3574: Standard Test Methods for Flexible Cellular Materials - Slab, Bonded, and Molded Urethane Foams. ASTM International. astm.org/d3574-23
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