Which Foam Should Be Inside Your Outdoor Cushions in Canada?

Quick answer: If your outdoor cushions stay out in the rain, they need Dryfast foam, an open-cell foam that lets water drain straight through. If they live under a roof or come inside when it rains, HD36-R (medium) or Lux-R (firm) gives a more upholstered feel. Never use Super Soft foam for seats. Whatever the foam, bring cushions in, dry, before freeze-up.

When outdoor cushions disappoint, most people blame the fabric. Usually the real culprit is hidden inside. A cushion that stays soggy for days after a thunderstorm, smells musty by August or feels flat by its second summer almost always has the wrong foam for the way it is used.

Canada makes foam choice matter more than most places. Spring brings weeks of rain and snow melt. Summer storms roll across the lake and soak everything in minutes. In the fall, cushions left out a little too long meet frost. Here is how to pick the right foam for your deck, dock or porch.

Why ordinary foam struggles outside

Standard furniture foam is made for living rooms. It is comfortable and supportive, but when it gets soaked it acts like a sponge. Water works into the foam and stays there, sometimes for days. While it is wet, the cushion is cold and clammy to sit on, and it is an ideal place for mildew to start.

In a Canadian climate, trapped water causes another problem. A cushion that is still damp inside when the temperature drops below zero overnight goes through freeze-thaw cycles, just like a driveway. It is not something a good cushion should ever have to face, and it is the main reason we always recommend storing cushions indoors for the winter.

Your four foam options

Dryfast: for cushions that live in the weather

Dryfast is an open-cell foam with a very open structure, so water passes straight through instead of being held. After a downpour, it drains and dries far faster than standard foam. It is the foam to choose for:

• Open decks and patios with no roof
• Docks and boathouses, where spray and dew are part of every day
• Boats and pontoons
• Chaise lounges and sectionals that are too heavy to bring in every time it rains

Dryfast has a slightly firmer, springier feel than indoor foam. It carries a 5-year foam warranty. Read more about using it at the lake in our guide to cottage and dock cushions.

HD36-R (High Density): for covered outdoor seating

HD36-R is a medium foam with a comfortable, supportive feel. It is the right choice for a covered porch, a screened-in room, a sunroom or a deck under a solid roof, where cushions rarely get rained on. It is also a good fit if you happily bring cushions in whenever rain is forecast. It carries a 7-year foam warranty.

Lux-R (Luxury): for a firmer seat under cover

Lux-R is our firm foam. Choose it under cover when you like to sit up rather than sink in, or for seats that get heavy daily use. It carries a 7-year foam warranty.

Super Soft: back cushions only

Super Soft gives a relaxed, sink-in feel to back cushions. It is never right for a seat, indoors or out: it compresses too far and flattens quickly. It carries a 3-year foam warranty.

All our foam is CertiPUR-US certified.

A simple way to decide

• Does the cushion get rained on where it sits? Choose Dryfast.
• Is it under a roof, or do you bring it in when rain is coming? Choose HD36-R for medium or Lux-R for firm.
• Is it a back cushion and you want it soft? Super Soft is an option, under cover.

If you are on the fence, think about your real habits, not your best intentions. Most cottage cushions end up staying out longer than planned. That is where Dryfast pays off.

How thick should outdoor cushions be?

Thickness matters as much as foam type. Too thin, and you feel the frame through the cushion. As a general guide:

• Dining chairs and occasional chairs: 2″ to 3″
• Muskoka chairs: 2″ to 3″, so you are not tipped forward off the slope. See our Muskoka chair cushion guide.
• Lounge chairs and sofa seats: 4″ to 5″
• Deep seat back cushions: about 4″

If a seat feels too firm, go thicker rather than softer. Our cushion thickness and foam guide and our article on deep seat outdoor cushions go into more detail.

Foam and fabric work together

Dryfast foam drains well, but the cover has to let water out too. Sunbrella fabric pairs well with Dryfast because water that gets in can drain and the fabric dries quickly. Most Sunbrella is water-repellent rather than waterproof. If you choose a waterproof fabric, such as Sunbrella's marine or Rain ranges, it keeps rain out of the foam in the first place. Our guide What is Sunbrella fabric, and is it worth it in Canada? explains the difference.

Protecting foam through the Canadian year

Spring

Spring is wet. Hold off putting cushions out until the deck has dried and the snow melt has finished. Even Dryfast cushions are happier on edge during a long rainy spell than lying flat in standing water.

Summer

After a storm, stand cushions on edge so water drains out of the bottom. Unzip covers on standard-foam cushions if they ever get soaked and let them dry in the sun.

Fall

Clean the covers, then dry the cushions completely, inside and out, before they go into storage. Press the centre of each cushion. If it feels cool or damp, it needs more time. Pick a dry run of weather in September or early October, before the nights get cold.

Winter

Store cushions indoors, somewhere dry and above freezing, standing on edge or loosely stacked. Use breathable bags rather than sealed plastic, which traps moisture. Our full guide to storing outdoor cushions over a Canadian winter covers it step by step.

Replacing foam only

If your covers still look good but the foam is soggy, crumbly or flat, you do not need to replace the whole cushion. Measure the inside of the cover, seam to seam, and order custom cut Dryfast foam to that size. Every builder offers foam only, cover only or complete cushions, with no minimum order. Foam is cut within ±0.5″ of your size, and standard shapes are made in 2–3 weeks. Canadian orders ship with duties and GST/HST paid. See ordering custom cushions to Canada.

Frequently asked questions

What is the best foam for outdoor cushions left in the rain?

Dryfast foam. Its open-cell structure lets water drain straight through, so the cushion dries quickly instead of staying soggy.

Can outdoor foam freeze?

Foam that is wet inside can freeze when temperatures drop. That is why cushions should be dried completely and stored indoors before winter.

Can I use Super Soft foam for outdoor seats?

No. Super Soft is for back cushions only. On a seat it compresses too far and flattens quickly.

Can I order foam without a cover?

Yes. Measure the inside of your cover seam to seam and order foam only, cut to that size.

Is your foam certified?

Yes. Our foam is CertiPUR-US certified.