Some mattresses may have broken or protruding coils; worn springs can sag or squeak, and creaks can also come from a frame, base, floor, or wall. Inspect for protrusions, measure dips, and check slat spacing against your mattress’s support rules. Warranty coverage depends on product terms, and a topper will not fix a sagging or damaged mattress.
Some products may develop visible indentations or coil defects.
Tempur-Pedic lists a visible indentation beyond its warranty threshold as a defect sign, measured with no weight or pressure on the mattress.
Nest Bedding lists broken, collapsed, or protruding coils as possible manufacturing defects, but its warranty excludes normal wear and tear, comfort preference changes, foam softening, and minor indentations.
A straightedge or taut line can help show whether the mattress surface has dropped; do not push the measuring tool into the foam.
Nest Bedding excludes normal wear and tear, foam softening, and minor indentations; it reviews sagging only when caused by a manufacturing defect, not normal wear, improper use, or improper support.
Helix says a sturdy, flat support system helps prevent sagging and extend mattress lifespan.
Bed-base requirements vary by mattress, so check your model’s support rules; inadequate support can damage a mattress or void warranty coverage.
Simmons warns that slats more than 2 inches apart without a solid platform will damage the mattress and void its warranty.
Brooklyn Bedding says its mattresses need a surface with minimal to no flex; slats no more than 4 inches apart work with its mattresses.
Nest Bedding lists slat spacing greater than 4 inches among support systems that do not meet its warranty requirements; queen-size and larger mattresses need rigid center support that reaches and contacts the floor.
When using a slatted frame, Serta recommends slats no more than 2 inches apart; it warns that inadequate support can damage the mattress and void warranty coverage.
Titan accepts a platform bed with slats no more than 5 inches apart as one support option.
Helix recommends thick, wide slats no more than 5.5 inches apart.
Bonnell and offset coils differ in shape and response: Bonnell coils connect and move together, while offset coils flex like a hinge under lighter pressure.
Bonnell coils
Bonnell coils have an hourglass shape, with wider tops and bottoms and a narrower middle.
Look for the wide top and bottom and narrow middle.
Check whether helical wire connects the coils into one moving unit.
Offset coils
Offset coils flex like a hinge under light pressure and give stronger pushback under increased load.
Offset coils may transfer less motion to the rest of the mattress.
Rotating a mattress may temporarily reduce traction on a squeak if the noisy spot is under your usual sleep area. Casper recommends rotating about every 3 months, whether or not the mattress squeaks.
Sleep Foundation says coil mattresses leave room for airflow, sleep cooler than all-foam mattresses, and tend to be responsive and fairly durable. Tom’s Guide says coils transfer movement across the sleep surface, making them unsuitable for bed-sharers, while memory foam provides motion isolation with less bounce than innerspring options.
Nest Bedding lists protruding coils as a possible manufacturing defect, but coverage is limited to qualifying defects under normal residential use; check the specific warranty terms.
A topper cannot repair a failed spring or support core, so address the underlying problem first. A topper can bend into a dip under load, rather than stay level across it. Tom’s Guide lists broken or protruding coils; warranty coverage depends on the brand’s terms.
Does a high coil count prove a mattress is durable?
Coil count is one factor among several in overall coil quality. Check the steel and its treatment, the turns in each coil, and the coil design, since these details also matter to firmness and durability. Tom’s Guide says coil type can influence overall feel and durability.
We read 17 published pages from 11 sites (nestbedding.com, tomsguide.com, Sleep Foundation, allfoam.co.uk and 7 more), checked in October 2026. Every sentence in the answers above cites one of them; the offer card at the end names its own source. This page reports published sources only; we did not test mattresses in person.