Expanding foams are a really useful part of any builder’s arsenal. These incredibly versatile products have a range of potential uses, from soundproofing and insulation to adhesives and clean finishes to walls.
Due to the increasing number of uses expanding foam has, there are increasingly more variations on the product available on the market. Many expanding foams have overlapping uses but certain features suit particular jobs.
Here, we’re going to walk through some of the most common uses for expanding foam and some of the key things to look out for in the various foams that are available.
Common Uses for Expanding Foam
Because expanding foams are relatively cheap, easy to use and effective, they’ve earned a lot of uses across the building industry in the last few years. The vast majority of them can be placed into the following categories.
Filling Gaps
Many installation and construction jobs will result in a gap being made somewhere, particularly if pipes or wires are installed through walls. These gaps will need to be filled, both for insulation and aesthetic purposes – people want to see a clean finish.
Expanding foams are aptly suited to this job as they can be squeezed into tight, oddly shaped spaces before expanding. Many expanding foams can also be sanded and painted once they’ve been cured.
Sealing Doors and Windows
Internal-external passages, such as doors and windows, are the number one culprits for heat loss in any building. It’s not just about the installations themselves, though. Any small gaps around newly fitted doors and windows can let the heat out.
As mentioned above, expanding foam is a great way to seal small gaps around doors and windows. Most expanding foams come with thermal properties to improve insulation and can be used internally and externally.
Bonding Insulation Boards
While expanding foam doesn’t have the strength to be used for structural purposes, it can work as an adhesive when adding things like insulation boards and panels.
Alongside expanding foam’s insulation properties, it can also help offer soundproofing, making it a popular tool for internal jobs like basements.
Types of Expanding Foam & When to Use Them
As mentioned at the beginning, the vast majority of expanding foams are versatile enough to be used in multiple applications, both internally and externally.
However, some expanding foams have slightly different qualities that make them particularly suited to specific jobs. Beyond universal qualities such as curing times, here are some of those qualities you should look out for when purchasing expanding foam.
Fire Resistance
Perhaps the most important consideration for builders is fire resistance.
Not all expanding foams are fire-resistant. If your project requires fire resistance – when sealing doors, for example – then ensure you get a fire-rated expanding foam, such as the Soudal FR Fire Stop B1 Foam.
Internal or External Use Foams
After fire rating, the next most important thing is to consider whether your foam can be used externally or not.
Often, whether a foam can be used for external gaps comes down to its rigidness and moisture protection. Most external-use foams will be closed-cell, which makes them set harder and stop the passage of moisture.
The vast majority of expanding foams, including our Soudal Standard Self-Expanding Filler Foam, are suitable for external and internal use. Softer open-cell foams, sometimes called adhesive foams, are only recommended for internal uses.
Open or Closed-Cell Foams
The biggest difference between types of expanding foams is often whether they are open or closed cells.
To put it simply, closed-cell expanding foam sets as a hard surface, offering little give. Closed-cell foams are also watertight when set.
On the other hand, opened-cell expanding foams set more softly and don’t offer complete moisture resistance. These differences influence when each form is most suited.
Closed-cell expanding foams are more suited to filling gaps and external uses due to their hard setting and moisture control.
On the other hand, open-cell foams are better soundproofers and can avoid issues with trapping moisture, making them suited to internal uses.
If you’re looking for an insulation board expanding foam for internal use, our Fixing Foam Panel Adhesive might be just what you need.
We’re confident that you’ll find whatever expanding foam you need here in our range, alongside accessories like expanding foam guns for clean application. Take a look at our range today.
