Red iron steel buildings have a lot going for them in terms of strength and longevity, so red iron is an excellent choice in many cases for prefabricated steel buildings. What steel alone is not good at is retaining heat when you want that and repelling it if you want to keep the place cool. Just as with other building materials, insulation is required to take care of this.
The term that is used to measure a building’s ability to resist temperature change is r-value, where the r stands for resistance, specifically thermal resistance. The higher the r-value, the more constant the temperature can be, as regulated by your heating or a/c.
R-value is a measure of the performance of the insulation, not just the material the building is made of. Anyone who has sat in a beautiful but freezing stone building will know that it is not just metal that suffers from this. Similarly, a cute but relatively flimsy wooden structure can be stuffy in the summer but chilly and draughty when the wind is howling during the cold season. All materials need insulation.
There is a common misconception that prefabricated steel buildings are particularly susceptible to temperature changes because steel conducts heat and cold easily. Technically, steel is a “good” conductor of temperature, but it is only good if that is what you want. If you are pumping heat into a red iron steel building and the framework and skin are allowing it to pass through and disappear into the air outside, that is not good at all. It’s exactly the same if you’re using air conditioning to keep the building cool, but the walls and roof are soaking up the sun and acting as radiators, warming the interior.
But this is not really a problem, because your red iron steel building just needs some help in the insulation department, and that can be done quite easily through spray foam or fiberglass. The question is, which one?
How Fiberglass Insulation Works
To get right down to basics, fiberglass is a material made of extremely thin glass fibers, woven or spun together, with millions of tiny pockets of air between the fibers. Perhaps surprisingly, air is a relatively poor conductor of heat because of the way its molecules are spaced.
We have a perception of air as being good for warming and cooling us in different ways. When it has been heated and we get a waft or a blast of it, it warms us up. When we get the same blast of cold or cool air, it removes the warm layer of air next to our skin.
So, air itself is not a good conductor and therefore it slows heat transfer within fiberglass. Which is the object of the exercise.
How Spray Foam Insulation Does It
Spray foam works in a different way, primarily by eliminating drafts. The fact that it is sprayed in the form of a foam doesn’t mean it stays a liquid. It is a combination of chemicals that expands and hardens, so it gets into seams and cracks, blocking them and keeping the air out. What you get, then, is cold air on one side and warm air on the other – and never the two shall meet.
Which is Better for a Red Iron Steel Building, Fiberglass or Foam?
This decision comes down to ease of application versus aesthetics. Fiberglass works best in a cavity, so you will need a layer of something on the inside of the building, with a gap to the exterior skin which you can fill snugly with fiberglass insulation – and it must be a snug fit to do the job properly.
With spray foam the surface of the foam can be the interior face of the wall, so you must be happy with the way that looks and confident it is not going to be damaged by activity in the building. Furniture gets pushed against walls, pictures are hung there and so on.
Moisture is another potential issue. Fiberglass insulation is porous, which means fluids can move through it. It may be necessary, then, to use a vapor retarder in the form of a sheet of some material that does not permit moisture transfer. Spray foam insulation does not have this issue, because it is a waterproof barrier.
The choice between spray foam and fiberglass insulation for a red iron steel building is, therefore, not really to do with the red iron itself, but what the building is used for and the amount of moisture that is going to be involved, generated either by the weather or what is happening in the building.
The Comparative Disadvantages of Fiberglass and Spray Foam Insulation
The disadvantages of fiberglass insulation include the issue of moisture and therefore potential damp and mold, plus its tendency to settle over time, which can result in gaps appearing and the loss of efficiency. There are also health and safety concerns due to the irritating qualities of glass fibers, which can affect skin and even the lungs if inhaled.
Most of the potential dangers in this respect will apply to whoever is installing the fiberglass, and only really affects the occupier of the building if they are installing it themselves. A good professional insulation company will ensure its staff are properly protected and also that the finished job is clean and the cavities are sealed so that there are no stray fibers floating around.
Spray foam insulation also comes with certain potential health issues for installers, but because of the need for specialized equipment, installation is carried out by professionals who are properly clothed and protected from the gases involved.
Post-insulation issues can include ventilation problems, with the foam being a victim of its own success, and masking pest issues.
The choice of insulation for red iron steel buildings is very dependent on individual circumstances and should be made in consultation with the building’s constructors.
