The Best Outdoor Foam: Pros & Cons of Marine & Patio Cushions
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Lots of customers ask us what the perfect foam is for their outdoor application that will last for years in the sun, rain, saltwater and more. The truth is, there is no perfect foam. Every foam type has its pros and cons. The best you can do is choose a foam that meets most of your criteria, with the understanding that it might need to be replaced after several years (depending on your cushion fabric choice, your climate, and whether you cover your cushions or bring them out of the elements).
We're going to discuss the qualities of each of our Sailrite® CushionRite® outdoor foams to help you make an informed decision for your cushion or seating project.
Types of Outdoor Foam
1. CushionRite® Dry Fast Antimicrobial Foam
Best For: Quick-drying and high-airflow.
Dry Fast foam is also known as reticulated foam. This open-cell foam has large, open pores that promote airflow and excellent water drainage abilities. Water passes right through the foam without being absorbed. This foam dries quickly and is antimicrobial, making it an excellent choice for outdoor cushions, especially when paired with a similarly water-draining fabric, such as vinyl mesh.
If the sun reaches the foam through your cushion fabric, the foam will start to break down. So, although a vinyl mesh cushion cover is great for water drainage, it comes at the price of foam longevity.
While Dry Fast foam's density technically meets our high-density classification, its open-cell structure is designed for maximum airflow rather than durability. This is why we label it an "occasional use" foam (1-3 year lifespan) and don't recommend it for high-traffic, everyday applications where longevity is the primary goal.
But if you need quick-drying foam, Dry Fast is the only way to go. It's also used for mattresses in boat cabins, RVs and tents where superior airflow is needed. If the foam gets dirty, it's easy to hose off and dries in no time.
Shop CushionRite Dry Fast Foam
2. CushionRite® Antimicrobial Cushion Foam
Best For: Mold/mildew resistance in standard cushions.
This is our go-to high-density (1.8 PCF) polyurethane foam for outdoor and marine applications. Its unique antimicrobial formula actively inhibits mold and mildew growth, a major concern in moisture-prone environments. It's also formulated to be "antipinking," preventing the common pink staining that can plague marine vinyl.
This foam has the same disadvantages as any polyurethane foam: it will soak up water like a sponge and is not naturally water-draining like Dry Fast. If using this foam outside, you must protect it. We recommend wrapping it in a layer of Cushion Wrap Silk Film and using a water-resistant outdoor upholstery fabric. This foam is the standard for many boat interiors and exteriors due to its mold-inhibiting properties and 3-5 year lifespan.
Shop CushionRite® Antimicrobial Cushion Foam
3. CushionRite® Flotation Antimicrobial Foam
Best For: Flotation, safety, and very firm seating.
Flotation foam, also known as closed-cell foam, is the long-term standard for specific outdoor boat seating. This foam is designed for flotation purposes and is especially useful for sailboat cockpit cushions, life jackets, and bosun's chairs. When used for cockpit cushions, it is typically covered with an outdoor canvas fabric, such as Sattler® or Sunbrella® Marine Grade.
The big downfall of this foam is that it's the most uncomfortable to sit on. This PVN foam is extremely firm ("Firmest" 61+ IFD) and stiff. However, this can be a huge benefit for cockpit cushions. When climbing in and out of a boat, you want a stiff cushion to step on so that you do not roll an ankle or lose your footing. The fact that your cushions can also double as flotation devices is another asset.
We do not recommend pairing Flotation foam with vinyl mesh cushion material, as the foam will start to break down with sun exposure.
Shop CushionRite Flotation Foam
4. CushionRite® Premium & High Resilience Foams (With Modifications)
Best For: Adapting high-end indoor foams for protected outdoor use.
CushionRite® Premium Upholstery Foam and CushionRite® High Resilience (HR) Upholstery Foam are our top-tier, high-density polyurethane foams. They are our "frequent use" foams intended for heavy-use, everyday indoor seating.
Premium Foam is our densest option (2.8 PCF) with a lifespan of 10-12 years.
High Resilience (HR) Foam (2.3 density) offers a luxurious, spring-back feel and an even longer lifespan of 12-20 years.
These are not outdoor foams. Neither is antimicrobial, and both will swell up like a sponge if they get wet.
However, they can be adapted for outdoor use if they are fully protected. This is a popular choice for high-end powerboat and pontoon seating, where the foam is covered with waterproof marine vinyl and stapled to a backer board. With a backer board, there are no sewn seams where water can seep in. If there are seams, wrap the foam in a layer of Cushion Wrap Silk Film (#103933) to add water protection.
The biggest risk is the foam becoming wet and not drying out, which can lead to mold and mildew. We do not recommend these foams for exterior sailboat cushions, which are typically left out in the elements.
Shop CushionRite Premium and High Resilience Foam
How to Extend the Life of Your Outdoor Foam
Foam won't last forever regardless of which type you choose. None of the foams mentioned above are "perfect" for outdoor cushions because, as you've learned, there is no such thing as a perfect foam.
Regardless of which foam you choose, proper care can significantly extend its lifespan:
- Use protective covers. Covering outdoor furniture and exterior marine seating will extend the life of both the foam and cushion fabric.
- Put the cushions away. If your outdoor seating area is seasonal, bring your cushions inside or out of the elements.
- Protect the foam from the sun. Consider not using vinyl mesh fabric, unless water drainage is your absolute highest priority.
- Use water-resistant and UV-resistant fabric.
Final Thoughts
No foam is perfect for every outdoor application, but by weighing the pros and cons of each, you can make an informed decision. Need more guidance? Visit the Sailrite website and search "foam" to explore selection guides, blogs and expert tips for your next DIY upholstery project.
Ready to upgrade your outdoor cushions? Browse our full range of CushionRite® foams today!