When an outdoor cushion goes flat or starts to smell, the cover is often fine and only the foam is worn out. Replacing the foam costs less than a new cushion, but the type of foam matters outdoors: ordinary upholstery foam soaks up water like a sponge, while open-cell dry fast foam lets water drain through.

We compared foam sold for outdoor and marine cushions on foam type, drainage, stated density and firmness, sheet size, and where it is made. If the cover is worn out too, see Best Outdoor Deep Seat Cushions, or browse the Outdoor Cushions category.

Our Top Picks

PickProduct
Best OverallSUNROX DryFast Foam
Best for MadeFoamRush Dry Fast Outdoor Foam
Best for Spec SheetFabric Empire Dry Fast Reticulated Foam
Best for Thick SheetAK Trading Dry Fast Foam
Best ValueFoamma High Density Foam Square
Best for Firm FoamGoTo Foam Firm Upholstery Foam
1
SUNROX sells its DryFast foam as a 3 by 24 by 72 inch sheet made for outdoor and marine seating. It is reticulated open-cell foam, so SUNROX says water drains straight through and air circulates, and the foam can be cleaned with a light hose-down. SUNROX backs it with a 5-year warranty and lists other thicknesses, including 2, 4 and 5 inch sheets.
Pros & Cons

Pros

  • Open cells drain water
  • 5-year warranty
  • Several thicknesses

Cons

  • Density not stated
  • You cut it to size yourself
  • Open-cell foam feels firmer than plush foam
Detailed Review

SUNROX sells its DryFast foam as a 3 by 24 by 72 inch sheet made for outdoor and marine seating. It is reticulated open-cell foam, so SUNROX says water drains straight through and air circulates, and the foam can be cleaned with a light hose-down. SUNROX backs it with a 5-year warranty and lists other thicknesses, including 2, 4 and 5 inch sheets.

Amazon rating: not available in our product data.

2
FoamRush's 4 by 24 by 72 inch sheet is open-cell dry fast foam with a medium-firm feel and a stated density of 1.8 pounds per cubic foot. FoamRush says it is made in the USA, sells it for patio, boat and cabin seating, and offers custom cuts and other sizes on request.
Pros & Cons

Pros

  • Made in the USA
  • Density stated
  • Custom cuts offered

Cons

  • You cut it to size yourself
  • Needs time to air out after unboxing
  • No warranty stated
Detailed Review

FoamRush's 4 by 24 by 72 inch sheet is open-cell dry fast foam with a medium-firm feel and a stated density of 1.8 pounds per cubic foot. FoamRush says it is made in the USA, sells it for patio, boat and cabin seating, and offers custom cuts and other sizes on request.

Amazon rating: not available in our product data.

3
Fabric Empire lists more technical detail than any other seller here: a 2 by 24 by 72 inch reticulated sheet with a density of 1.8 pounds, an air flow figure and tensile and tear ratings. The large open cells are meant to drain and dry quickly, and the sheet ships vacuum sealed.
Pros & Cons

Pros

  • Detailed published specs
  • Good for thinner pads
  • Several widths

Cons

  • Only 2 inches thick in this listing
  • Country of origin not stated
  • Ships compressed
Detailed Review

Fabric Empire lists more technical detail than any other seller here: a 2 by 24 by 72 inch reticulated sheet with a density of 1.8 pounds, an air flow figure and tensile and tear ratings. The large open cells are meant to drain and dry quickly, and the sheet ships vacuum sealed.

Amazon rating: not available in our product data.

4
A 4 inch dry fast sheet that AK Trading says has built-in antimicrobial protection against mold and mildew inside the cushion.
Detailed Review

A 4 inch dry fast sheet that AK Trading says has built-in antimicrobial protection against mold and mildew inside the cushion.

Amazon rating: not available in our product data.

5
A pre-cut 24 inch square in CertiPUR-US certified high-density foam, made in the USA. It is not open-cell, so it suits covered seating or cushions with water-resistant covers.
Detailed Review

A pre-cut 24 inch square in CertiPUR-US certified high-density foam, made in the USA. It is not open-cell, so it suits covered seating or cushions with water-resistant covers.

Amazon rating: not available in our product data.

6
A firm 44 ILD upholstery sheet, CertiPUR-US certified and made in the USA. Like Foamma, it is standard foam rather than dry fast, so keep it dry.
Detailed Review

A firm 44 ILD upholstery sheet, CertiPUR-US certified and made in the USA. Like Foamma, it is standard foam rather than dry fast, so keep it dry.

Amazon rating: not available in our product data.

All Products Compared

ProductBest ForFoam TypeSheet SizeDensityMade In
SUNROX DryFast FoamBest OverallReticulated dry fast3 x 24 x 72 inNot statedNot stated
FoamRush Dry Fast Outdoor FoamBest Made in USAOpen-cell dry fast4 x 24 x 72 in1.8 lbUSA
Fabric Empire Dry Fast Reticulated FoamBest Spec SheetReticulated dry fast2 x 24 x 72 in1.8 lbNot stated
AK Trading Dry Fast FoamBest Thick SheetReticulated dry fast4 x 24 x 72 inNot statedNot stated
Foamma High Density Foam SquareBest Pre-Cut SquareHigh-density polyurethane4 x 24 x 24 in1.8 lbUSA
GoTo Foam Firm Upholstery FoamBest Firm FoamHigh-density polyurethane3 x 24 x 72 in1.8 lbUSA

Top 3 Replacement Foam for Outdoor Cushions Reviewed

#1 SUNROX DryFast Foam: Best Overall

Why We Picked It

SUNROX sells its DryFast foam as a 3 by 24 by 72 inch sheet made for outdoor and marine seating. It is reticulated open-cell foam, so SUNROX says water drains straight through and air circulates, and the foam can be cleaned with a light hose-down. SUNROX backs it with a 5-year warranty and lists other thicknesses, including 2, 4 and 5 inch sheets.

Key Specifications

  • Amazon rating: not available in our product data
  • Foam type: reticulated open-cell (DryFast)
  • Size: 3 x 24 x 72 inches
  • Care: hose down (maker)
  • Warranty: 5 years (maker)
  • Other thicknesses: 2, 4 and 5 inch listings
ProsCons
Open cells drain waterDensity not stated
5-year warrantyYou cut it to size yourself
Several thicknessesOpen-cell foam feels firmer than plush foam

Best For

Uncovered patio seating that gets rained on.

Who Should Skip It

Shoppers who want pre-cut squares with no trimming.

Verdict

The most complete outdoor foam listing here, with a long warranty.

SUNROX DryFast Foam

#2 FoamRush Dry Fast Outdoor Foam: Best Made in USA

Why We Picked It

FoamRush's 4 by 24 by 72 inch sheet is open-cell dry fast foam with a medium-firm feel and a stated density of 1.8 pounds per cubic foot. FoamRush says it is made in the USA, sells it for patio, boat and cabin seating, and offers custom cuts and other sizes on request.

Key Specifications

  • Amazon rating: not available in our product data
  • Foam type: open-cell reticulated (Dry Fast)
  • Size: 4 x 24 x 72 inches
  • Density: 1.8 lb (maker)
  • Feel: medium firm (maker)
  • Made in: USA (maker)
ProsCons
Made in the USAYou cut it to size yourself
Density statedNeeds time to air out after unboxing
Custom cuts offeredNo warranty stated

Best For

Deep seat cushions that need a thick, drainable core.

Who Should Skip It

Thin chair pads under 2 inches.

Verdict

A thick US-made dry fast sheet with a published density.

FoamRush Dry Fast Outdoor Foam

#3 Fabric Empire Dry Fast Reticulated Foam: Best Spec Sheet

Why We Picked It

Fabric Empire lists more technical detail than any other seller here: a 2 by 24 by 72 inch reticulated sheet with a density of 1.8 pounds, an air flow figure and tensile and tear ratings. The large open cells are meant to drain and dry quickly, and the sheet ships vacuum sealed.

Key Specifications

  • Amazon rating: not available in our product data
  • Foam type: reticulated open-cell
  • Size: 2 x 24 x 72 inches
  • Density: 1.8 lb (maker)
  • Packaging: vacuum sealed
  • Other sizes: 1/2 inch and 40 inch wide sheets listed
ProsCons
Detailed published specsOnly 2 inches thick in this listing
Good for thinner padsCountry of origin not stated
Several widthsShips compressed

Best For

Thin chair and bench pads, or layering under a thicker core.

Who Should Skip It

Deep seat cushions that need 4 inches or more.

Verdict

The best choice if you want to compare foam specs before buying.

Fabric Empire Dry Fast Reticulated Foam

Also on Our List

  • AK Trading Dry Fast Foam (Best Thick Sheet): A 4 inch dry fast sheet that AK Trading says has built-in antimicrobial protection against mold and mildew inside the cushion.
  • Foamma High Density Foam Square (Best Pre-Cut Square): A pre-cut 24 inch square in CertiPUR-US certified high-density foam, made in the USA. It is not open-cell, so it suits covered seating or cushions with water-resistant covers.
  • GoTo Foam Firm Upholstery Foam (Best Firm Foam): A firm 44 ILD upholstery sheet, CertiPUR-US certified and made in the USA. Like Foamma, it is standard foam rather than dry fast, so keep it dry.

How to Choose Replacement Foam for Outdoor Cushions

Dry Fast or Standard Foam

Dry fast (reticulated) foam has large open cells, so water runs through instead of soaking in. It is the better choice for cushions that get rained on. Standard high-density foam is softer and often cheaper, but it holds water, so use it on covered porches or inside covers that resist water.

Thickness and Size

Measure the old cover, not the old foam, because foam compresses as it wears. Match the thickness the cushion had when new, which is often on the original listing or tag. Foam cut very slightly larger than the cover fills the corners better than foam cut to the exact size.

Cutting

Full-length sheets need cutting. An electric carving knife gives the cleanest edge. Pre-cut squares save the work if your cushions are a standard size.

How We Evaluate Replacement Foam for Outdoor Cushions

For this guide we compared foam sold for outdoor and marine cushions on foam type, drainage, stated density and firmness, sheet size, warranty and country of manufacture. We read each maker's specifications and left out foam sold only for indoor use. Most listings had no rating data in our product feed, so ratings did not decide the order. We did not handle or measure this foam ourselves, every figure comes from the maker's listing, and we never repeat a durability claim as our own.

Variants of one listing count as a single product, and we would rather list a few strong picks than pad the list. Our full process is on the How We Review page.

FAQ

What is the best foam for outdoor cushions?

For cushions that get wet, open-cell dry fast foam, because it drains instead of holding water. For covered seating, high-density foam is softer and works well.

Can I use regular foam in outdoor cushions?

Yes, under cover, but it soaks up water. Keep the cushion dry and store it in wet weather.

Does dry fast foam need a waterproof cover?

No. It is made to let water through, so pair it with a breathable outdoor fabric that drains too.

Final Verdict

SUNROX DryFast is our top pick for its open-cell foam, size options and 5-year warranty. FoamRush makes a thick US-made dry fast sheet, and Fabric Empire publishes the most detailed specs.

AK Trading adds antimicrobial treatment, and Foamma and GoTo Foam are firm, US-made options for covered seating.