How to Choose an Outdoor Foam

We get lots of questions from customers asking what is the perfect foam 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 outdoor 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 the foam might need to be replaced after several years (depending on your choice of cushion fabric, 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 outdoor foams to help you make an informed decision for your cushion or seating project.

Types of Outdoor Foam

Dry Fast Foam

Dry Fast foam is also known as reticulated foam. This open-cell foam has open pores that promote airflow and excellent water drainage abilities. Water passes right through the foam without being absorbed. This foam dries out quickly and is antimicrobial, making it an excellent choice for outdoor cushions, especially when paired with an equal water draining fabric such as a vinyl mesh.

If the sun gets to the foam through your cushion fabric, then the foam will start to break down. So, although a vinyl mesh cushion cover is great for water drainage, it pays the price for foam longevity. Dry Fast has a maximum density by design, so it can never achieve "high density" classification. This is the reason we label it an "occasional use" foam throughout our website and we don't recommend it for high-traffic, everyday applications.

But if you need quick-drying foam, Dry Fast is the only way to go. Its uses don't end at outdoor cushions. Dry Fast is also used for mattresses and sleeping pads in boat cabins, RVs, tents and camping. The foam's highly breathable nature and superior airflow make it a favorite in the marine, RV and camping markets. If the foam gets dirty, it's easy to hose off and dries in no time. Dry Fast foam has several very useful applications, just take into consideration where you put the foam and how much sunlight it could be exposed to.

Closed Cell Foam

Closed Cell Foam is probably the standard long-term for outdoor boat seating. This foam is designed for flotation purposes and is especially useful for the cockpit cushioning of sailboats and bosun seats. When used for cockpit bearings, they are usually lined with an outdoor canvas fabric. We do not recommend pairing Closed Cell foam with vinyl mesh cushioning material as the foam will be damaged by sun exposure.

The big disadvantage of this foam is that it is the most uncomfortable for the price. it is three times stronger than polyurethane foam and is stiff and unforgiving. However, this can be a huge benefit for cockpit cushions. When getting on and off the boat, you want stiff cushioning to step on so your feet don't roll over or lose your footing. The fact that your pillow can also double as a flotation device is another asset. It shrinks, shrinks and cracks in the sun, but you won't notice it because the foam is always covered with a dense canvas fabric. Closed-Cell Foam serves a purpose, although it is limited. This is not an all-in-one foam option.

High-Density Foam

Until recently, you could not get an antimicrobial version of High Density Polyurethane Foam. We now offer an antimicrobial version, but only in "firm" firmness. High Density polyurethane is the only "frequently used" foam on the market. It is intended for heavy use, everyday seating applications and can last up to 12 years with proper care and maintenance.

It's great for in the boat for salon pillows and mattresses. If using this foam outside, be careful because if it gets wet it will swell like a sponge. There are ways to avoid this, such as to cover the High Density foam with waterproof vinyl. You can also wrap the foam in a layer of Pillow Wrap Silk Film (#103933) for an added level of water protection. You'll also need to pair a silk film with canvas fabric or add air vent grommets to the vinyl cushion to support it out when sitting on the pillow.

Vinyl is a popular choice for motorboat and pontoon seating, especially when using it for applications where the vinyl is clamped to the backing board. With a backer board, there are no seams where air can seep. Again, the biggest risk with polyurethane foam is that it gets wet and doesn't dry out. Then you get mold and mildew, unless you opt for the antimicrobial version.

Because there is a risk of water seeping in and damaging the foam, most powerboaters and pontoon owners are wary of covering them with additional protective coverings. Sailors usually do not cover their cockpits and exterior cushions. They just leave a residue in the element. Therefore, we do not recommend polyurethane foam — High Density or Medium Density — for exterior sailboat cushioning.

Medium Density Foam

Medium Density Polyurethane Antimicrobial Foam is the standard foam choice for the marine industry and for boat interiors. It was the first foam to have antimicrobial properties added. All of the Medium Density foam we sell at Sailrite is antimicrobial. We still consider this an "occasional use" foam since it is not as dense as High Density. It is less expensive but doesn't last as long as High Density polyurethane. Medium Density is what most boat manufacturers use inside boats today.

This foam has the same disadvantages as High Density, given that they are both polyurethane foams. Medium Density polyurethane will soak up water and is not naturally water draining like Dry Fast. If using Medium Density polyurethane outside, you can wrap it in a layer of Cushion Wrap Silk Film to protect the foam from getting wet and use a water-resistant outdoor upholstery fabric.

Ways to Make Your Foam Last Longer

Regardless of which foam you choose for your application, it won't last forever, and that shouldn't be something you expect from foam. 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. 

You have to make a decision based on the information presented and which foam qualities best fit your use. Just know that you might have to replace your foam sooner than you expected depending on where you put it, how often it's used, and the type of fabric covering you choose.

But there is something you can do to extend the life of your foam. Here are our easy tips on how to make your foam last as long as possible:

1. Use protective covers. It can't be said enough that covering outdoor furniture and exterior marine seating will extend both the life of the foam and cushion fabric.

2. Put the cushions away when not in use. If your outdoor seating area is seasonal, bring your cushions inside or out of the elements to extend their life.

3. Protect the foam from the sun and elements as much as possible. So, consider not using vinyl mesh fabric. But keep in mind that mesh is the best way not to sit on wet cushions when paired with Dry Fast foam. This is a dilemma you will have to consider carefully and decide what's best for you — longevity over drainage or drainage over longevity.

4. Use water-resistant and UV-resistant fabric for your cushions. But again, keep in mind that this is a compromise for comfort and possibly foam drainage capabilities if using Dry Fast foam.

Basically, foam life for all of the options listed above has as much to do with care taken and the covering fabric as it does with the foam itself. We have excellent resources to learn even more about foam. On the "How-To" section of our website, click the "Selection Guides" tab. 

You can use outdoor foam as corporate gifts to make your business visibility increase. One marketing strategy to be used that can be effective is if you have business in outdoor furniture or industrial area. 

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