How long does a mattress last in New Zealand?

We've been making mattresses in Christchurch since 1939, and the honest answer hasn't changed much: a decent mattress gives you seven to ten years of proper support, a cheap one less, and a well-cared-for one a bit more. The age is only half the story though. Here's how to tell whether yours is actually done, what counts as normal wear, and when it's a warranty job instead.

Why seven to ten years

Every night you compress the comfort layers in the same spot. Foam and fibre slowly lose their bounce, and eventually the layers above the springs stop pushing back. The spring unit itself usually outlasts the comfort layers, which is why an old mattress feels "flat" rather than broken.

How fast that happens depends on what's inside and how it's treated. Our entry beds, like the Sense-A-Tech Backcare, carry a 5 year warranty and are built for spare rooms, flats and kids. As a rough guide, most of our mattresses from about $1,000 for a Queen carry a 10 year warranty, and the Latex Luxury range has a solid organic latex core that holds its shape longer than foam does. Two-sided mattresses such as the Monarch and Citation Box Top can be flipped, which spreads the wear over two sleeping surfaces.

What wears a mattress out faster

• Two adults every night rather than one person occasionally. A spare-room bed can last well past ten years; the main bed in a busy house won't.
• Never rotating it. Same shoulder, same hip, same spot, for years. See How often should you rotate your mattress.
• The wrong base. A pocket spring mattress on a slatted base flexes between the slats and wears unevenly. Ours are designed for a firm platform base.
• No protector. Moisture gets into the comfort layers and breaks them down, and it voids the warranty if the mattress is stained.
• Kids using it as a trampoline. Springs don't like it.

Signs it's time for a new mattress

• You wake up stiff and loosen up within half an hour of moving. If the pain goes once you're up, the bed is the likely cause.
• Hammock effect. You roll towards the middle, or towards your partner, without meaning to.
• A visible dip with nobody on it. Strip the bed and look along it from the foot.
• You can feel individual springs through the comfort layers.
• The edges have gone. You slide off when you sit on the side.
• You sleep better in a hotel, a motel or the spare room. This is the one most people ignore.
• Partner disturbance has got worse. As springs tire they stop isolating movement.

If three or more of those sound familiar, it's time, whatever the age.

Body impressions versus sagging

This is the question we get asked most in store. In the first two or three weeks a new mattress forms a shallow impression where you sleep. That's the comfort layers conforming to you, and it's a good thing: it's the mattress doing its job. An impression of up to about 5 cm (2 inches) is normal and isn't a defect.

Sagging is different. It's a dip that stays when there's no weight on the mattress, and if it's deeper than 5 cm it's covered by our warranty, provided the mattress has been on a suitable base and rotated as recommended. The simplest check: strip the bed, lay a broom handle across it, and measure the gap.

Check your warranty before you buy a new one

All Brownie's mattresses come with a 5 or 10 year warranty depending on the model. It covers manufacturing faults in the cover and stitching, and sagging deeper than 5 cm with no weight applied. It doesn't cover normal softening, cosmetic marks, stains or water damage, or damage from an unsuitable base. You'll need your receipt or another proof of purchase. The full terms are on our Returns and Warranty page, and if you're not sure which side of the line you're on, send us a photo and we'll tell you.

Making the next one last

• Rotate it. Every fortnight for the first few months while it settles, then every three to six months. Single-sided mattresses rotate end to end; double-sided ones get flipped as well. It's a warranty condition, not just advice.
• Put a protector on it from day one. The Tencel waterproof protector (from $56) is breathable, machine-washable and keeps the warranty intact.
• Use a firm, flat base. If you're keeping an old slatted base, the Opulence is the model we recommend for it.
• Wash the sheets weekly and air the mattress when you change them.

What's changed since you last bought a bed

If your mattress is ten years old, a few things will be different. Mattresses are deeper now: most of ours are 260 to 340 mm, so check your fitted sheets have a deep enough wall. Pocket springs have come down in price; our entry pocket spring, the Anniversary Pocket, starts at $549 for a Single. And if the people sleeping on it have changed, so might the size: our size chart has the dimensions.

Frequently asked questions

How often should you replace a mattress?
Every 7 to 10 years for most people, sooner if it's sagging or you're waking up sore, later if it's lightly used and well cared for.

What are the main signs you need a new mattress?
Waking stiff, a visible dip, feeling springs, collapsed edges, and sleeping better on other beds.

Can a mattress last longer than ten years?
Yes, especially in a spare room or if it's two-sided and has been flipped and rotated. Judge it on condition, not age.

Does rotating a mattress make it last longer?
Yes. All our mattresses should be rotated, including the zoned pocket spring models. The schedule is above.

Should I replace a mattress that's still comfortable?
No. If you sleep well and there's no visible dip, keep it.

Ready to look?

Lie on a few in store, or use the Bed Selector to shortlist by how you sleep and what you want to spend. Every bed is made to order in our Christchurch factory, and we deliver nationwide.

Related guides: How often should you rotate your mattress · Buying a new bed: the complete guide · Returns and warranty