Open-Cell Vs Closed-Cell Spray Foam Insulation

Open-Cell Vs Closed-Cell Spray Foam

Open-cell and closed-cell are two types of spray foam insulation which offer benefits for both new construction and renovation projects. Spray foam does more than block heat flow. It also blocks airflow. This makes your home more comfortable and reduces your energy costs.

Here, we will analyze open-cell foam spray foam vs closed-cell foam to help you make a wise, informed choice regarding which insulation to use for your specific application.

What is spray foam insulation?

Let’s begin by explaining what spray foam insulation is. Spray foam insulation is a chemical-based insulation. It’s mixed at the jobsite by insulation contractors and then applied with a sprayer to the desired location.

Spray foam is used to insulate ceiling cavities, walls, and floors. Foam insulation is a great choice for insulation your home because of its unique structure. It doesn’t shrink, sag or settle over time. Spray foam, both open-cell and closed cell, can last extremely long.

Benefits of spray foam insulation 

Spray foam insulation is not only energy-saving, its application is relatively easy, even in challenging areas. And it can offer cost savings.

It can be utilized in both residential and commercial buildings, in agricultural facilities, in wood or steel framed structures. It can even be used to insulate storage tanks.

The versatility of spray foam insulation is much appreciated by both home and business owners and construction professionals. Spray foam insulation is a great idea to look into if you see signs your home is not well insulated.

Spray foam insulation is efficient. It doesn’t sag or settle over time like fiberglass insulation can if not correctly installed. Spray foam insulation adds structure and sturdiness to buildings. Spray foam insulation’s ability to expand into every crack and crevice prevents entry by rodents and insects. It lasts longer than alternatives, so uses up less materials, resulting in a reduced carbon footprint.

open cell vs closed cell r-value

What’s the difference between closed-cell and open-cell spray foam insulation?

There are two types of spray foam insulation: open cell spray foam and closed cell spray foam. Each type has its strengths and weaknesses and neither is better than the other. It all comes down to choosing the right type for you and your needs.

Let’s examin the differences between open-cell spray foam insulation vs closed-cell spray foam insulation.

Open-cell vs closed-cell Spray Foam Composition

Open cell foam insulation, on the other hand, is light, flexible, and easy to use. Closed cell foam insulation, however, is very rigid and dense.

Open cell spray foam, for example, is much more flexible than regular foam and will make it easier to install new wiring. To get the foam where you want it, all you have to do is to use fish tape.

Closed cell wiring is not possible, but the foam’s durability is excellent when left exposed. Because of its rigid structure and durability, closed cell is ideal for exposed walls. It won’t get damaged by machinery or tools.

Open-cell vs closed-cell density

Closed cell foam has a higher density than open cell foam. Open cell foam averages about.5 lbs per cubic foot. Closed cell foam may have a density up to three times higher, at 1.75 pounds per square foot.

Open-cell vs closed-cell sound dampening qualities

It is important to know what sound dampening actually means before answering this question.

Soundproofing and sound dampening are two different things. A room that is soundproof means it is impervious to sound. Sound dampening is a way to reduce sound transmission.

Open cells have a thicker, more flexible material that reduces sound waves better than closed cells.

You will need to soundproof your entire room or structure with special sound panels, noise isolation foams, sound barrier material, and noise absorbers.

Open-Cell versus Closed Cell Insulation

Open-cell vs closed-cell moisture permeability

The one spray foam allows water to pass through, while the other blocks it completely.

Open cell foam is naturally moisture permeable. This means that water can flow through it. There are variations in the ability to absorb free-standing water depending on which spray foam brand you choose.

A good spray foam might only retain 5 percent of its weight in water. Open cell spray foam brands may retain up to 75 percent of their weight in water.

Closed cell spray foam is, however, 100 percent moisture impermeable. This means that water cannot move through it. Although the moisture impermeable option sounds better, open cell spray foam can still be useful on roof decks in attics.

The foam will discolor if there is a leak. This will let you know where it is and allow you to repair it quickly.

Closed cell spray foam can conceal the leak until it builds up elsewhere, causing much greater problems and headaches.

Open-cell vs closed-cell air seal

Spray foams in both open and closed cells provide an air seal to prevent drafts, heat loss and moisture from entering your home.

This air seal is only possible with a minimum thickness of 2 inches for closed cells and 3 inches for open cells. These are the minimum recommended amounts. However, the recommended amounts can vary.

Spray foam thickness will vary depending on the application and the purpose of the spray foam.

Open cell spray foam should be 6-10 inches on the roof deck or ceiling, depending on where you live, and 3 in the walls. Closed cell foam insulation should not exceed 4- to 5-inches above the ceiling, and 2- to 3-inches within the walls.

It might surprise you, but this spray foam is sufficient to provide the best value for money with the thermal resistance and air seal required for certain areas.

Many people believe that more foam means higher R-Value. However, that is not true. Although R-Value is important, thermal resistance is what R–Value measures. The most important thing is an air seal. Once you have reached a threshold such as the amount of foam required to make an air seal, it’s not worth adding more foam.

Open-cell vs closed-cell r-value

Spray foam insulation’s R-Value can vary depending upon the product and manufacturer.

The R-Value of open cell foam is usually in the range R-3.6 to R-3.9 per inch.

R-6 to R-7 is the common range for closed cell foam R-Value.

Spray foam R-Value is affected by many factors, including its type, age, and resistance to moisture.

Open-cell vs closed-cell spray foam cost

cost of spray foam insulation

Spray foam insulation cost will vary depending on the area being insulated, how difficult the job is, the thickness and type of foam used.

Let’s compare the costs of open-cell and closed-cell spray foam.

Let’s say you have a 1,000-square foot attic and you want spray foaming. A 7-inch open cell would cost $5,250, which includes the removal of any old insulation. If you wanted to install closed cell in the same attic, at the same depth as the open cell, it would run upwards of $10,000. Closed cell spray foam is recommended at a thickness of 5 inches. This would cost around $8,350.

Another open cell spray foam cost comparison is made using crawl spaces.

An average 800-square-foot crawlspace with a 3-inch wall would require open cell spray foam. The cost to install it at $3,350 would be. Closed cell spray foam costs $3,700 for the same crawl space. We recommend 2 inches of the material, which would cost around $2,900.

Open cell spray foam installation is easier. The foam is also less expensive to make, so it is more affordable.

Closed cell spray foam is more costly to make. It must be applied in thin coats. This can lead to increased installation time and costs.

Review of open-cell vs closed-cell comparison

Neither open-cell or closed-cell spray foam insulation is superior to the other, overall. The decision of which to choose depends upon the intended use. Here is a summary of features for comparison:

Closed-cell spray foam insulation

  • Has a greater R-value
  • Is more rigid
  • Offers a more solid vapor, moisture and water barrier
  • Is great for crawl spaces 

Open-cell spray foam insulation

  • Expands more extensively –  to fill nooks and crannies
  • Offers a higher level of soundproofing
  • Lets water pass, allowing leaks to be located – preventing damage
  • Is more affordable
  • Is optimal for walls and attics in many areas

Open-cell vs closed-cell spray foam – which to choose?

open-cell vs closed-cell

The good news is you don’t have to use exclusively open or closed-cell spray foam insulation for an entire residence or commercial building. Not only each project, but each area within a structure may require a different choice. Following are a few more thoughts.

Both open-cell and closed-cell spray foam insulation are great products offering a wealth of benefits. But they are made up of chemicals and must be handled with care during application.

It’s best to hire a professional to ensure safe and proper installation. Sunlight Contractors serves New Orleans and the entire region of southeastern Louisiana. We can assist you in determining the best ways to utilize closed-cell or open-cell spray foam insulation for your construction or renovation project.

Scroll to Top