Outdoor Cushion Foam 101: What is the best foam to use for outdoor cushions?
When you’re shopping for outdoor cushions and patio furniture cushions, it’s easy to fall in love with the fabric first—color, pattern, and style. But underneath that beautiful fabric is the real workhorse: the foam. The foam inside your patio cushions is what determines how comfortable they feel, how well they support you, and how long they last on your patio.
At Cascadia Outdoor Cushions, we spend a lot of time thinking about what’s inside your outdoor cushions, not just what’s on the outside. This guide pulls back the curtain on foam, how it’s made, and what types work best for patio chair cushions, deep seating, and outdoor living spaces.
What foam really is (and why some foam is denser than others)
All those soft patio furniture cushions start in a very un-romantic place: a chemistry lab.
Most foam used in outdoor cushions is made from petro-chemicals—primarily a blend of polyols and isocyanates. When these ingredients react, they expand into a solid block of polyurethane foam. During manufacturing, the ingredients are mixed, whipped with air, and combined with blowing agents so the foam “rises” like cake batter and sets into big loaves. Those loaves are then sliced into the shapes that become your patio cushions and patio chair cushions.
The key concept here is density:
Foam density measures how much actual material is packed into a cubic foot of foam.
Higher density = more “stuff” inside = heavier, more supportive, longer-lasting foam for your outdoor cushions.
Lower density = lighter, cheaper foam that usually breaks down and flattens faster in patio furniture cushions.
Two foams can feel similar on day one, but the higher-density foam will almost always outlast the bargain foam in real-world use on your outdoor cushions.
Cell structure (open vs. closed) and additives also affect how foam handles water—how it absorbs, drains, and dries—which matters a lot when we’re talking about patio cushions that live outside.
“Outdoor foam” vs. “foam used outdoors” – Foam is foam
You’ll see a lot of marketing language that sounds like there’s a magical category called “outdoor foam.” The truth is simpler:
Foam is foam.
What makes it “outdoor” is how it’s engineered, how it’s covered, and how it’s used in your outdoor cushions and patio furniture cushions.
Some foams are formulated and cut specifically for patio cushions and patio chair cushions, with density, cell structure, and additives that help them perform better in outdoor conditions. But at the end of the day, we’re still talking about polyurethane foam (or specialty foam) that happens to be used outdoors.
That’s why the combination really matters:
The foam type and density
The fabric (Sunbrella, Outdura, etc.)
The design of the outdoor cushion (how water can escape or get trapped)
How you use and store your patio cushions
When we build custom outdoor cushions at Cascadia, we’re not just picking “outdoor foam.” We’re choosing the right foam for your outdoor use.
Types of foam used in outdoor cushions: comparison table
Here’s a high-level comparison of the most common foam and fill types used for outdoor cushions, patio cushions, and patio furniture cushions today.
| Foam / Fill Type | Best For | Comfort & Feel | Water / Drying Behavior | Durability & Lifespan (Typical) | Pros | Cons | Price Level* |
|---|---|---|---|---|---|---|---|
| Standard Polyurethane Foam | Budget outdoor cushions in covered or protected spaces | Medium-firm at first, softens over time | Absorbs water; can stay damp if not allowed to dry fully | ~2–4 years with normal use | Affordable, widely available, can be cut to almost any patio cushion shape | Can absorb moisture, may mildew if repeatedly soaked; loses height and firmness sooner in patio furniture cushions | $ |
| High-Density Outdoor Foam | Everyday patio furniture cushions, deep seating, higher-end patio chair cushions & sofas | Supportive, more “structured” comfort | Absorbs some water but dries faster than cheap foam | ~4–7 years with proper care | Better support and shape retention; more comfortable over time in outdoor cushions | More expensive than standard foam; still needs reasonable protection from standing water on patio cushions | $$–$$$ |
| Reticulated / “Dry Fast” Foam | Outdoor cushions in heavy rain exposure, poolside seating, boats | Firm–medium, very buoyant feel | Open-cell structure lets water pass through and drain quickly | ~5–8+ years with proper care | Drains and dries very quickly; excellent for wet climates or pool areas where patio furniture cushions stay outside | Higher cost; slightly firmer feel (often paired with a fiber wrap for extra softness in patio cushions) | $$$$ |
| Bonded Polyester Fiber (Batting / All-Poly Fill) | Back outdoor cushions, throw pillows, decorative patio cushions | Soft, plush, “pillow-y” comfort | Does not hold water like a solid foam block but can stay damp if packed densely | ~2–5 years depending on density | Great loft and softness, ideal for backs and pillows; resists hard edges in patio chair cushions | Flattens faster under heavy use; not supportive enough alone for most seat patio furniture cushions | $–$$ |
| Shredded Foam / Mixed Fill | Decorative patio cushions, economy options | Mixed feel, can be uneven or lumpy | Varies based on components | Varies widely | Low cost, can use recycled materials in some blends | Inconsistent comfort; can shift and clump; usually not ideal for primary seating outdoor cushions | $ |
| Memory Foam (Not Usually Recommended Outdoors) | Niche use under protective covers in outdoor cushions | Highly contouring, slow-recovery feel | Holds water, slow to dry, not designed for constant outdoor moisture | Can break down quickly outdoors | Very comfortable indoors; molds to body shape | Not designed for outdoor moisture and UV; can trap water and grow mildew; usually a poor choice for patio furniture cushions | $$–$$$ |
*Price levels are relative and meant as a general guide, not exact pricing.
Why is reticulated foam more expensive than regular foam?
If you’ve ever compared quotes and wondered, “Why are my outdoor cushions so much more expensive with reticulated foam?”, you’re not imagining it.
Reticulated (or “dry fast”) foam is engineered very differently from a standard foam core used in many patio cushions and patio chair cushions:
It has a highly open, three-dimensional cell structure that lets water pass through almost instantly, instead of soaking in and staying there.
Creating that open network of cells requires more complex manufacturing and higher material costs.
This foam is often used in marine, poolside, and high-exposure applications, so it’s built to perform in harsher conditions than standard foam in basic patio furniture cushions.
All of that shows up in the price. But for certain spaces—like pool decks, uncovered patios, or lake houses where outdoor cushions live in the weather—it’s one of the best investments you can make. Instead of sitting on soggy patio cushions, you get patio furniture cushions that drain quickly and get back to comfortable much sooner after a storm.
What we typically recommend for seat outdoor cushions
Most of our Cascadia customers come to us because they’re tired of patio cushions that go flat or stay soggy after one season. For seat outdoor cushions, we usually recommend:
High-density outdoor foam for:
Everyday patio furniture cushions
Covered porches
Most residential deep seating and patio chair cushions
This gives you a great balance of comfort, support, and longevity while still being budget-conscious for custom outdoor cushions.
Reticulated “dry fast” foam for:
Poolside and dock seating
Uncovered decks and patios
Very rainy or humid climates
Here, the quick drainage and drying are worth the extra cost because your patio furniture cushions are exposed to everything the sky throws at them.
In many designs, we add a polyester fiber wrap around the foam core. This softens the edges, adds a touch of plushness to your outdoor cushions, and gives your patio cushions a more tailored, rounded look—without sacrificing support.
What we like for back outdoor cushions and patio pillows
Back outdoor cushions and decorative patio pillows don’t need the same structure as a seat. Instead, you want them to feel soft, inviting, and supportive just enough.
For backs and pillows, we typically use:
Polyester fiber fill (sometimes channeled or compartmentalized to keep it from shifting inside the outdoor cushion cover)
A softer foam core wrapped in fiber when a little extra support is needed on taller patio furniture cushions
This gives you that “lean back and relax” feel in your patio chair cushions, while your seat outdoor cushions do the heavy lifting in terms of structure and support.
How to choose the right foam for your patio furniture cushions
Here’s a simple way to match foam to your outdoor space:
Mostly covered space, limited rain exposure:
→ Choose high-density outdoor foam for your primary outdoor cushions and patio furniture cushions.Uncovered, wet, or poolside space:
→ Upgrade to reticulated “dry fast” foam to keep your patio cushions draining and drying quickly.Backs and decorative pillows:
→ Go with polyester fiber fill or a softer foam + fiber wrap for plush, comfortable outdoor cushions and patio pillows.
If you’re not sure what’s currently inside your patio cushions, that’s completely normal—most tags don’t tell the whole story.
Need help choosing the right foam for your outdoor cushions?
You don’t have to decode patio cushion foam alone.
At Cascadia Outdoor Cushions, we:
Look at how and where you use your patio furniture cushions
Consider your climate, sun exposure, and rain
Talk through comfort preferences, maintenance, and budget
Recommend a foam and fill combination designed specifically for your outdoor cushions and patio chair cushions
Share a few photos and measurements, and we’ll help you choose the right foam so your patio cushions look beautiful, feel comfortable, and hold up season after season.