With its debut in the ’60s, ICF construction has evolved and its recent growth brings change and improvement to ICF construction. The forms have evolved to offer improved indoor air quality, durability and strength, as well as extreme energy efficiency. However, regardless of construction method, heat will ultimately escape through the roof unless insulated properly-a common occurrence as most ICF homes and commercial structures feature conventional wood frames and trusses, making it difficult to provide an effective air barrier.
So what is the proper way to put a “lid” on your ICF constructed structure? Spray polyurethane foam insulation is one method to create an air barrier. SPFs seal the envelope of the structure, decreasing air transfers and creating a thermal barrier that reduces dust and noise.
There is a common misconception among builders and contractors that spray foam is too expensive and too difficult a process to complete without subcontracting the work.
This is understandable considering the most frequently used option in the industry is a monstrous high-pressure spray foam system which is both complex and expensive.
There is a more cost-effective way for ICF builders and contractors to spray foam without subcontracting the work and without making a large investment in high-pressure spray foam equipment.
Some of the newer low-pressure systems available keep the foam at a consistent temperature, which is absolutely key. If foam travels through a long, unheated hose, the composition of the foam could fundamentally change by the time it is actually dispersed depending on external temperature conditions. Some products, such as Fomo’s Magnum Heated System, are refillable, two-component systems that include a hot box for easy transportation, and a specialized gun attached to a heated hose pack with up to 200 feet of hose for nearly any application. When compared to high-pressure systems, this alternative option offers contractors lower entry cost, minimal set up and tear down time and ease of use. In addition, category suppliers are going a step further, utilizing refillable cylinders, making systems some of the greenest, most convenient, cost-effective spray foam options on the market. Disposable two-component spray foam kits are not generally recyclable and are not ideal for large jobs, and high-pressure systems require 55-gallon drums that are used once and disposed of in a landfill. With some systems, tanks are refillable and used over and over again.
Heated refillable low-pressure systems are really the missing link between disposable spray foam kits and costly, complex spray foam rigs. These systems offer a way for ICF builders and contractors to spray big foam jobs without high entry costs, maintenance costs and complexity of high-pressure foam systems.
Above is a comparison chart representing the various ways foam can be dispensed-including disposable kits, heated refillable systems and high-pressure systems.
There are four key elements to consider once you have decided to work with foam:
What type of foam do you need? Low density or high density?
High-density, closed-cell polyurethane spray foam is among the most efficient way to insulate a residential or commercial property, ICF or otherwise. Typically the R-value is around 6.0 per inch, and the closed-cell nature of this foam has a greater resistance to air leakage, low moisture vapor permeability and excellent water resistance.
Low-density, open-cell foam is another option ideal for topping off an ICF structure. One of the advantages lower density foam provides is a more economical yield, since foam density is directly related to yield (lower density equals higher yield). Although the R-value of open-cell foam is slightly more than half that of closed-cell foams, usually around 3.5 per inch, these products can still provide excellent thermal insulating and air barrier properties. Open cell foam is more permeable to moisture vapor but is incredibly effective as a sound barrier, having approximately twice the sound resistance in normal frequency ranges as closed-cell foam. Other characteristics of open-cell polyurethane foam usually include a softer, “spongier” appearance, as well as lower strength and rigidity than closed-cell foams.
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What type of system will work best for you?
A low-pressure heated hose system produces the same type of two-component foam as a high-pressure system (i.e closed-cell Class 1 insulation spray foam), so the composition of the foam is not a factor. However, high-pressure systems take a great deal of time to setup and tear down compared to refillable heated systems, and that is important to note in terms of efficiency. Also, when using a high-pressure system, other workers like electrical contractors, plumbing contractors, etc. on the construction site have to vacate the area when a high-pressure system is in use and for up to 24 hours thereafter, whereas with a low-pressure heated hose system, there is no need to wait. Considering time is money, using a low-pressure system is the obvious choice.
Something else to consider is that some foam fulfillment facilities have a wait-period based on the type of foam you order, so don’t be afraid to question your supplier’s tracking system and wait time. Even the weather can be a factor when dealing with foam. Depending on the climate you commonly work in, you will likely need a heated hose that allows for application in nearly any situation-outdoors, indoors and in both cold and warm weather conditions. Consider everything from timing to climate when deciding on a system.
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What makes the most sense financially?
Consider the number of foam jobs you’ll be doing over the course of the next six months. High-pressure systems work well if your main service is spraying foam, while low-pressure systems serve as a great addition to your business. The expense of set-up and maintenance in a high-pressure system may be more than you’re willing to endure, depending on your commitment to spraying foam.
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How much foam is enough?
Spray foam is more expensive than fiberglass or cellulose insulation; however the energy efficiency outweighs the expense. As a result, many ICF builders are opting for about two-thirds inch of foam with a cellulose insulation combination. This hybrid-type system offers all of the benefits of foam while providing the remaining necessary R-value. W&C
