How do I measure an outdoor daybed mattress for a custom cover?

Measure the foam core itself, not the old cover. Record the length and width seam-to-seam, then the thickness at the side edge. Round to the nearest quarter inch and double-check each number before ordering — we sew to exactly what you enter.

Does the custom outdoor mattress cover come with a foam insert?

No. This is a replacement cover only — it zips over the foam core you already have. If your foam itself has broken down, our sister brand ZIPCushions makes custom outdoor foam and complete cushions, and their team can match your daybed dimensions.

Which fabric is better for a poolside daybed — Sunbrella Horizon vinyl or Sunbrella Canvas?

Poolside, choose Horizon. It's a marine-grade waterproof vinyl, so splashes, wet swimsuits, and sunscreen wipe straight off without soaking in. Canvas is the better pick for covered porches and shaded patios where you want a softer, woven feel and breathability matters more than waterproofing.

Will a waterproof mattress cover trap moisture inside the foam?

No — as long as the foam goes in dry. Horizon vinyl blocks water in both directions, so a dry core stays dry. If your foam is already damp, let it dry fully before zipping the cover on, or choose breathable Sunbrella Canvas so air keeps moving through the fabric.

How do I get a thick outdoor mattress into a fitted cover?

The zipper runs the full long edge of the cover, so it opens wide like a clamshell. Fold the mattress slightly along its length, slide it in zipper-side first, then let it expand into the corners before closing the zip. A 6-inch core goes in far easier than with the short zippers on store-bought covers.

Can you make covers for porch swing beds and trundle daybeds?

Yes. We sew to the measurements you enter — swing beds, trundles, window-bench mattresses, and camper pads are all fair game. Non-rectangular shape? Measure at the widest and longest points and note the details at checkout.

Custom Waterproof Outdoor Mattress Covers

Name: Custom Outdoor Mattress Cover
Brand: ZIPCovers
SKU: custom-outdoor-mattress-cover
Price: 21.3 USD
Availability: InStock

Description

An outdoor mattress is the biggest cushion on your patio — and the hardest one to find a replacement cover for. Store shelves stop at standard sizes, and a 75 x 31 x 6 daybed pad is nobody's standard. A custom outdoor mattress cover fixes that. You measure the foam and pick the fabric. We sew a replacement outdoor mattress cover to those exact numbers. No bunching at the corners. No zipper strained across a too-tight seam.

That fit matters more on a mattress than on any other cushion. Daybed and porch-bed pads live outside for entire seasons, soaking up sun, rain, pollen, and humidity. A waterproof outdoor mattress cover in Sunbrella Horizon keeps the rain out of the foam entirely — water beads and runs off instead of sinking in. And because the cover comes off in one zip, you can rinse it, wipe it down, and put it back without wrestling the whole mattress into a machine.

Foam cores fail when their covers fail. It's that simple. Replace the cover before the foam soaks, mildews, or breaks down, and the mattress you already own keeps working season after season. That is the whole point of a replacement cover — protect the part that is expensive by renewing the part that isn't.

Ready to fit yours? Enter your measurements above, or explore the full outdoor cushion covers collection.

Why Choose Our Custom Outdoor Mattress Covers?

Custom-Tailored

Sewn to your exact length, width, and thickness — not rounded to the nearest stock size. Boxed corners match your foam's true depth, so the cover sits square on the daybed frame instead of ballooning at the edges. Twin-size porch bed pad or short trundle cushion — we cut the fit for that one mattress.

Breathable Design

Sunbrella Canvas is a woven acrylic that lets air move through the fabric, so foam dries out between uses instead of staying damp underneath. If you choose the waterproof Horizon vinyl instead, moisture never reaches the foam in the first place — surface water wipes away in seconds. Either way, the mattress underneath stays drier than it would in a cheap boxed-store slipcover.

All-Weather Performance

Both fabrics live outside full-time: UV-stable through long summer sun, mold- and mildew-resistant through humid weeks, tear- and abrasion-resistant against daily use. Horizon adds full waterproofing and cold-crack resistance for mattresses that stay out through rain and temperature swings. This is fitted protection for the way a daybed actually lives — outside.

Effortless Maintenance with Functional Features

Horizon vinyl wipes clean with mild soap and water — sunscreen streaks, pool splash, and dust come off in one pass. Canvas spot-cleans with a soft brush and mild soap, and a hose rinse handles routine care. The full-length YKK zipper means you never fight the cover on or off, and the zipper flap keeps grit out of the teeth.

Long-Term Durability

The warranties above aren't decoration — Sunbrella stands behind both fabrics for five years, and the double-stitched seams and corrosion-resistant hardware are built for years of zip-on, zip-off use. One well-made cover outlasts several bargain slipcovers — and keeps your foam alive the whole time.

Step-by-Step Measuring Guide

• Pull off the old cover and measure the bare foam core — never the old fabric, which has already stretched or shrunk.

• Measure the length seam-to-seam at the longest point.

• Measure the width seam-to-seam at the widest point.

• Measure the thickness at the side, from bottom seam to top seam.

• Cross-check every number twice before ordering. We sew to the measurements you enter.

Fabric Information

Pick the fabric that matches how exposed your mattress is. Sunbrella Horizon is a marine-grade vinyl — fully waterproof, with a knit backing and four-directional stretch that pulls smoothly over thick foam. It shrugs off spills and stains, resists cold cracking, and meets Cal. TB 117-2013 flame-resistance standards, and wipes clean with a damp cloth. Horizon carries a 5-year limited warranty against strength and color loss, plus a 3-year warranty against microbial pinking.

If your daybed sits under a covered porch or gets pulled in between uses, Sunbrella Canvas is the softer route: a 100% solution-dyed acrylic that is water-repellent, breathable, and UV-stable, with the same 5-year limited fabric warranty.

Construction doesn't change between fabrics: double-stitched seams, boxed corners cut to your stated thickness, and a heavy-duty YKK zipper along the full length of the cover. The zipper is corrosion-resistant and sits under a fabric flap, so rain and sprinkler spray don't find their way to the metal.