No Need for Traditional Insulation
On a non-conditioned building, there really is nothing better than a radiant barrier to control the heat gain. Structures like sheds, carports and barns can all benefit greatly by adding a layer of radiant barrier near the roof line and any sun-catching walls to keep the heat out.
On a non-conditioned building, traditional insulation is not necessary. The goal is NOT to make the structure airtight in order to keep cold (or hot) air inside of it; the building is vented, so it can’t be airtight. Therefore, the most realistic expectations you can have for a building that you are not heating or cooling, is to get it at (or close to), outside air temperature (also known as ambient air temperature). Getting the air temperature lowered is largely relative to the amount of ventilation you have going through the structure. However, keeping the inside of a metal structure at or near ambient temperature is practically impossible if you do not have a radiant barrier. The radiant barrier will work to reduce the surface temperatures, and the ventilation to help bring the air temperatures down.
The main problem with heat gain in a metal building is that it will absorb so much radiant heat that the inside temperatures will far exceed the outside temperatures. The simple solution to this is a radiant barrier; it will essentially act like shade. Reflecting 97% of that radiant heat out of the structure is the key to a comfortable space, even without conditioning it. We have many customers who have used radiant barrier on garages, barns, carports, airplane hangars, work sheds, warehouses etc. with great results in comfort.
How to Install
Ceiling/Roof: It’s important to remind yourself that structures under this category are just that: structures. This means they will not feel or operate like conditioned or living structures; they will be hotter/cooler than a home/office space and they’ll also likely be wetter, and that’s ok. That being said, the goal for these types of buildings is to take the edge of the continual heat gain in the hot months and to help temper the chill in the colder months.
Like most installs of this nature, getting the WareHouseFoil™ closest to the roof line will bring about the best overall results, specifically for hot climates. If you’re doing new construction, the video above will give you some good ideas of how to approach that. If you are retrofitting an existing structure, then you have a couple of options, depending on what the structure is made of.
Simply put – get a layer of foil somewhere below the roof line but above the work space. The foil will will work so that most of the heat that would normally come off the building into the space below the roof line will instead be reflected back out because of the WareHouseFoil™. Remember to leave some gaps or breaks in the install so that airflow can still move around the area as if the foil wasn’t there. More info on proper ventilation here: Basics of Ventilation in Non-Conditioned Buildings.
Walls: If you install the foil on walls catching direct sunlight, it is best to have the foil closest to the outside layer as possible, while still maintaining an air space on one side of the foil. This way it will block the heat at the entry point, rather than letting it travel though all the siding materials. Unfortunately, there are so many different type of construction methods, we cannot cover every type of building type. You might have to get creative on how to install the WarehouseFoil™.
Common Install Questions
Q: Do I need perforated or a solid vapor barrier in my building?
Metal is a vapor barrier; a vapor barrier stops vapor (moisture) from passing through. In a vented barn, shop, airplane hangar, storage facility, etc., the construction is not airtight (remember, this is because they are not being conditioned). For this reason, a perforated product is the best choice to allow any areas of condensation to dry out. Using a solid product would essentially trap moisture behind the foil layer, and trapping moisture is not something you ever want to do intentionally. More info on which to choose here: Perforated vs Solid WareHouseFoil™ – Which One Do I Choose?
Q: Will this stop moisture from forming in my building?
Interior moisture (condensation) is created when relatively warm-moist air hits a cold surface (usually the metal of the building) and one of the biggest issues we hear of with metal buildings are customers seek a solution to “sweating buildings.”
The problem is the building itself may be the SOURCE of the moisture! Livestock, agriculture products, grain etc. all produce high levels of moisture. Because of this, a radiant barrier will probably have limited effect on reducing the sweating in a building. The key is to have more ventilation because this allows the warm-moist air to “flush” out. The best way to protect yourself against moisture accrual is to make sure you have proper/good ventilation in order to prevent moisture from accumulating in the first place. Your second defense against moisture is to use a perforated radiant barrier product so that if moisture does exist, it has a chance to pass through the foil layer and evaporate. Read more about Moisture in Metal Buildings.
How to Install in a Conditioned Barn or Shed
The main thing is to get a piece of WarehouseFoil™ between the walls, ceilings and YOU! We help customers everyday with their particular buildings and applications. Send us pictures, videos etc. We will help you with an install method that will work for your application.
Remember, as long as you can achieve the air gap on at least one side of the foil, it WILL work.
Without having the foil on the outside of the thermal envelope (the area being conditioned), a radiant barrier is not going to offer you a real benefit. It really belongs outside the thermal envelope. So if your construction will be heated and cooled, then you want to get the layer of radiant barrier closest to the outside, and then you can proceed with installing traditional insulation and then drywall/sheet rock to finish it out. Simply put, you layers will be like this:
- Roof deck/Exterior Sheathing
- Air gap (created by foam strips)
- Radiant Barrier Foil
- Batt Insulation
OR like this (if you place the foil closest to the inside for better heat retention):
- Roof Deck/Exterior sheathing
- Insulation (Batt, Cellulose or Foam)
- Radiant Barrier Foil
- Furring Strips (horizontally across studs)
Whichever your situation may be, a conditioned or non-conditioned metal structure, the bottom line is this: adding a radiant barrier is the biggest improvement you can make, for the smallest initial investment. A single layer, installed closest to the outside, is going to result in a more comfortable structure and a more efficient building.