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Using Expanding Foam: The Essential Guide

expanding foam

Spray foam insulation is slowly taking over as the most popular and commonly used insulation material. In recent years, technological advancements have made spray foam a far superior insulation product to traditional fibreglass and cellulose.

Your home loses heat, which is why you need insulation. But why use spray foam insulation?

In this article, we will break down the benefits of using expanding foam, and explore the best places to install it. Sitting comfortably? Let’s begin…

How Spray Foam Helps With Heat Loss

Our home loses 25% of heat through the roof, 35% through the walls, 15% through the floor, and rest through windows and gaps around the doors.

To build a better thermal envelope, all you need to do is look at the second law of thermodynamics. According to the second law, “heat flows in one direction, from a warm space to a cold one”.

That means that during the Summer, the warm air from outside will flow to the cooler, interior space. And during the long, Winter months, the warm air inside your home will flow to the cooler air outside. Insulation prevents this.

Using Expanding Foam: Key Benefits

The best way to answer why spray foam offers the most salient solution is to look at the benefits it provides. Here is a breakdown of its pleasing range of plus points:

  • Spray foam has the highest R-value among insulation materials, easily outperforming fibreglass
  • Spray foam insulation can reduce the cost of your energy bill by 50%
  • Provides an air tight seal, stopping air leakage and infiltration.
  • Prevents moisture penetration, reducing the potential for mould growth
  • Downsizes HVAC equipment by 30%. Your heating, ventilating, and air conditioning equipment will last longer, as insulation reduces the stress on their workload
  • Improves indoor air quality by reducing mildew, dust, allergens, pollen, and mould from entering your home
  • Reduces outdoor noise, creating perfectly peaceful conditions.
  • Spray foam does not sag, shrink, shift, or degenerate. It will perform for the life of the building.
  • You are getting a healthier and more comfortable living environment
  • An underrated benefit of using spray foam insulation is that the resale value of your home increases.

Fibreglass Compared To Spray Foam

But how does fibreglass compare to this thoroughly modern method? The following list of pointers provides some serious food for thought:

  • Fibreglass does not stop air leakage. Cellulose slows down air leakage, but spray foam insulation stops air leakage altogether.
  • Fibreglass and cellulose are not resistant to moisture and mould.
  • Fibreglass has an R-value of 3.5 per inch, but there is no air seal. Blown in cellulose has R-value between 3 and 4 per inch. Spray foam insulation can have a true R-value of 3.8 to 6.8, depending on the density.
  • Fibreglass sags over time, cellulose settles over time, and leaves sections of the stud cavity uninsulated. Spray foam, on the other hand, completely adheres to the wood studs, and does not sag or shrink.

expanding foam

Using Expanding Foam: The Process

Now that you know why use spray foam insulation, the question is how to insulate with spray foam. The foam is sprayed into the wall cavity in between the wooden studs with special equipment.

Spray foam is made of equal parts of two components, sprayed directly into the wall cavity in question. Once sprayed, the foam will expand up to 100 times its original size in 2 to 10 seconds.

Thanks to the expansive nature, spray foam will fill every nook and cranny, seal all gaps, and permanently adhere to the stud cavity.

One thing you have to consider: Never try to install spray foam insulation on your own. It can be tempting, but spray foam is best installed by professionals. You need to hire a spray-foam contractor who has the appropriate equipment. That includes a truck or trailer to carry the chemicals and spray equipment.

Make sure to hire an experienced contractor. Every insulation is prone to flaws. No insulation is foolproof. Hiring a professional and experienced contractor prevents sloppy foam insulation installation.

You need to know precisely at what moment to spray the foam. Some beginners begin spraying before the chemical components are up to temperature, which affects the overall performance of the foam.

Mixed in the wrong ratio, at the wrong temperature, or poorly mixed in the initial stages, spray foam can shrink away from the rafters or studs. 

Another reason why you need to hire a professional is because spray foam can be messy. During installation, some small, expanding droplets of foam might end up in the air. The droplets end up on your hair, skin, and clothes. Why take the risk?

Open vs. closed spray foam insulation

There are two main types of spray foam. The first one is open cell spray foam insulation, and the latter is closed cell. Let’s take a look at the difference between the two:

–Open cell spray foam is used for residential objects above grade. You can use it for the roofs, attic, floors, walls, and as a soundproof asset.

Open cell spray foam offers R-value between 3.5 and 4 per inch. Open cell is a complete air barrier at 3.5 inches thick, but does not offer moisture vapour barrier. Open cell expands and contracts with building (sponge).

–Closed cell spray foam is best used for commercial, industrial, and metal buildings. You can use it for crawl spaces, basements, and pole barns.

Closed cell spray foam offers R-value of 6.5 to 7 per inch. It is a complete air barrier at 1.5 inches thick, and moisture barrier at 1.5 inches thickness. In terms of consistency, closed cell increases wall strength, and adds to the structural integrity of the building.

Where Can You Use Spray Foam?

Basically, you can use spray foam anywhere in your home. Depending on where you want to install, your contractor will suggest a different type of spray foam insulation. There is no better insulation type, with higher R-value than spray foam. Here are some ideas for where to install spray foam: 

– The basement to seal pipes, plumbing, cracks, framing, and sills. You can use spray foam in the same spirit in the crawl space.

– Use spray foam for your heating, ventilation, and air conditioning, to optimise the performance of the heating and cooling system. Use spray foam around the pipes, floor registers, and condensers.

– Exterior uses for spray foam include electrical and gas penetrations, wall joints in the garage ceiling, around exterior faucets, stone wall repair, water feature fillers, the spot where siding and foundation meet, and many more.

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