Proper insulation makes a huge difference in both your comfort and your wallet. And without a doubt the most effective insulation is spray foam. You can pay a contractor thousands of dollars to do it for you, but if you are to it you can save a ton of cash doing it yourself.

There are some excellent DIY spray foam insulation kits on the market, but how do you know what you need to get your job done right? Do you need open or closed-cell spray foam? How much should you order? Besides the kits, what else do you need? What about safety?

We are going to cover all these topics and more in this article. When you are through with this you should have a clear understanding of the different types of polyurethane SPF, their applications, what you need to do it yourself, and how to make sure you do the job right.

What is Spray Foam Insulation?

Spray Foam is a polyurethane plastic insulation. DIY kits are comprised of 2 components and come in 2 tanks, typically called “A” and “B” components, one a isocyanate and the other is a polyol resin. When the 2 liquids mix it creates an expanding foam that hardens. It is great to fill all the nooks and crannies that more traditional forms of insulation can’t even touch.

Why Spray Foam?

Up to 40% of energy is lost through less effective insulation. Air escapes through the gaps that fiberglass or other traditional insulation can’t block.

Polyurethane spray foam is the most effective insulation on the market because it goes on as a liquid, and then expands to fill the space,so it fills all the gaps that traditional insulation does not.

Although it’s more expensive than other insulation, SPF does a better job keeping a living space comfortable with greatly reduced loss due to air infiltration. The savings more than outweighs the cost in the long run.

Closed cell spray foam can improve the strength and durability of a building. The rigid foam completely fills cavities making them stronger as well as insulating.

And it’s easier and faster to apply SPF than to install traditional fiberglass insulation.

Open Cell vs. Closed Cell Spray Foam Insulation

First of all, what’s a cell? Well in this case a cell is referring to the bubbles that make up the foam.

As the name says, closed cell spray foam has closed cells which makes for a more dense impermeable barrier. Open cell foam has open cells, which makes for a more permeable, softer and more flexible foam.

Closed Cell SPF Features and Uses

  • High R-value – 6 -7 per inch.
  • Dense – as high as 1.75 pounds per cubic foot. Provides maximum rigidity.
  • Completely blocks air movement.
  • Expands to about 1” when sprayed.
  • Acts as a vapor barrier.
  • Available in e-84 fire-rated versions for maximum safety.

Closed cell is great for strong insulating in a tighter spaces. It provides maximum insulation so it’s best for harsher weather conditions. It’s rigidity and acts as a vapor barrier. You can get the fire rated E-84 kits for maximum safety. 

Open Cell SPF Features and Uses

  • R-value is about 3.5 per inch.
  • Not as dense – typically about .5 pounds per inch. This makes it softer and more flexible.
  • More fragile, easier to damage.
  • Expands to about 3” when sprayed.
  • Is not a vapor barrier.

Open cell is great for soundproofing and to insulate areas that may be more convoluted or difficult to reach. It’s also better for a ventilated area. Because it’s softer and it expands more it’s easier to get in those hard to reach areas.

What you choose to use depends upon how the foam is to be used. Take a look at the following video which does a great job explaining this:

How to Calculate How Much Spray Foam Insulation You Need

To figure out exactly how much you need you need to gather a bit of information and do a little simple math. You need to know:

  • Square footage of area that the SPF will be applied.
  • The R-value required.

What is R-Value?

SImply put, R-Value is the measure of thermal resistance. The higher the R-value of insulation the greater the resistance to the flow of heat.

The US Department of Energy has put together a map that shows recommended R values based on climate conditions as well as energy costs in various parts of the country.

Recommended Home Insulation R-values

Click Image to See the full table (opens in new tab).

Spray foam has a higher R-value than other kinds of insulation, which means you need less of it to achieve quality results. Here’s how it stacks up:

Fiberglass batts: R-3.1 to R-4.3 per inch
Loose-fill cellulose: R-3.1 to R-3.8 per inch
Open cell spray foam: R-3.6 to R-7 per inch
Closed cell spray foam: R-5 to R-6.8 per inch

What is a board foot?

SPF yield is measured in board feet. 1 board foot is 12” square and 1” deep.

You’ll notice that most of the DIY spray foam kits have a number in the product model name. For example 605, 620 etc. That number refers to the theoretical yield of that particular kit in board feet.

A Simple Calculation

To calculate how much you need just figure out how many board feet you require.

So for example, say you have an area of 100 square feet, and you need an R-value of 6. Closed cell spf R-value about 6 – 7, so you would need 100 board ft.

It’s always a good idea to get about 10% more than you think you need. Yields are theoretical, you may end up wasting some, and you do not want to run out before the job is done.

Where to Buy DIY Spray Foam Insulation Kits

Unfortunately the big hardware stores like Lowes and Home Depot usually don’t keep SPF kits it stock, or they only keep the smallest kits. So if you are just doing a small project you can head over to one of these stores but you should call first to avoid a wasted trip. You can have them ship larger kits to your store. This can take a couple weeks, so if you are going to go this route make sure to plan ahead.

There are several companies that sell SPF online, and they also sell the same products on Amazon. Spray foam is a hazardous material, and heavy, so shipping costs are something to consider. The websites advertise a lower price, but shipping is not included.

On Amazon they all play the game of advertising free shipping, but the price is marked up. Looking closely at this we found that it pretty much works out to be the same.

Although there are others available, we like the following, all of which are available on Amazon:

Larry’s Top Choice:

Dow Froth Pak Closed Cell Spray Foam Insulation Kit

Dow Froth Pak 650, Best Spray Foam Insulation Kit

Our top choice, is the Dow Froth Pak Closed Cell Spray Foam Insulation Kit.

We have found these kits to be the the best overall quality, and no wonder given that Dow has a long history of producing excellent products.

Aside from the quality of the SPF and the hose and spray mechanism, the Froth Pak is available in a wide variety of sizes. The smallest kit they offer is only 12 board feet, which is great if you are just doing a small job. The largest single kit is 650 board ft, which is the highest yield of any single kit on the market.

And if you are doing a large project you can get multiple kits on Amazon at great prices with free shipping.

Click the buttons below to get the prices on Amazon for the kits you need.

Best Closed Cell Kit Bargain:

Foam It Green Closed Cell Spray Foam Insulation Kit

Dow Froth Pak 650, Best Spray Foam Insulation Kit
The Foam It Green Closed Cell Spray Foam Insulation Kits have one really nice thing going for them: they come with almost everything you need to get the job done, including spray tips, tyvek suit and more; everything but the respirator.

Another nice thing about Foam It Green SPF is that the foam turns green when the mix is right, so you always know whether or not the spray is working properly.

Foam It Green does not offer as many size options as Dow, but their product is very good.

Tiger Foam 600 Closed Cell Spray Foam Kit

Dow Froth Pak 650, Best Spray Foam Insulation Kit
Our 3rd choice is the Tiger Foam 600 Kit. This is a fine kit. The reason it is our 3rd choice is that it is only 600 bd. ft. for the same price as comparable kits that contain more product.

Still their Amazon rating is very high, and as already mentioned, it is a great product.

Personal Protection Equipment

It goes without saying that when spraying the foam safety must come first. You need to protect your lungs, your eyes, and your skin, so you will need a NIOSH approved respirator to protect your lungs, a Tyvek suit, nitrile gloves, and safety glasses or goggles to make sure that you are safe when doing the job.

NIOSH Approved Respirators

Professionals who do this on a daily basis have very high quality respirators that are quite expensive. If you are doing the job yourself, especially if it is just a small job, you may not want to spend so much for this piece of equipment. Fortunately there are some less expensive options on the market, and many of these are available on Amazon.

Our First recommendation is the UOPASD Organic Vapor Respirator Full Face Gas Mask. Unlike most respirators, this one includes a filter. It’s a quality product at a reasonable price.

Another good choice is the North Safety 770030L 7700 Series Silicone Half Mask Respirator along with the North 75SCP100 Combination Gas and Vapor Cartridge.

Protect Your Eyes

If you are using a half mask like the North Safety Respirator mentioned above you will also need protective goggles or glasses.

The Dewalt DPG82 Anti-Fog Dual Mold Safety Goggle fits the bill nicely at a reasonable cost.

Protective Clothing

Available in many sizes, the Dupont Tyvek 400 is just the right thing for a DIY spray foam insulation project.

Dupont Tyvek Suit

DIY Spray Foam Insulation – A Great Way to Save $$

The effectiveness of SPF is undeniable. You can save up to 40% on your heating and cooling bills, so in the long run it will pay for itself. Doing it yourself you can save even more. Just be sure that you do your research, take proper precautions, and do the job right. When its all done you’ll be glad you did.