Metal roofs are durable and last longer than materials like asphalt shingles. Not only are they durable, but they also look good, causing them to gain more popularity in the US. Despite being sturdy, metal roofs still require insulation to maximize energy efficiency.
Insulation is necessary to control and maintain your home’s internal temperature. However, identifying and getting the ideal insulation can pose a challenge. We can help you overcome that as we will be discussing everything you need to know about insulating your metal roof, including tips on how to do it safely.
Does a Metal Roof Need Insulation?
Your metal roof needs insulation, especially if you want a calm, warm home in cold weather. In fact, almost all roof structures need proper insulation. Many buildings, residential and commercial, employ insulation to minimize noise and maximize the conservation of energy.
Importance of Metal Roof Insulation
Many people may not know this fact that about one-third of heat gain and loss happens through the roof. It is, in fact, a necessary area for heat transfer during insulation. Metal is typically a delicate roofing material, which makes it more challenging to deal with. You know what adding the perfect roof insulation to your home will do for you? It will help you save at least 45% on the costs of heating and cooling. If you intend to convert your attic or have a loft, an insulated roof will help regulate the temperature of the top floors and decrease moisture.
Types of Metal Roof Insulation
There are several options to choose from when you want to insulate your roof, and we will highlight some of the ones in high demand, including their benefits and drawbacks.
Rigid Foam Insulation
Rigid foam insulation is made up of polyurethane or polystyrene. Homeowners mainly use it to help roofs, walls, and foundations resist heat. It is available as panels or sheets and comes in different sizes.
It has prices ranging from $3.95 to $7.20. The more superior the quality, the higher the cost.
Pros
- High heat resistance: Rigid foam insulation offers the highest resistance to heat when the sheets are tightly joined together with the joints sealed or caulked.
- Minimum air leakage: You can install them with more infrequent gaps and joints because they are thinner and heavier than other insulation options. This characteristic helps minimize air leakage.
Cons
- Taping requirement: When you do not fit it tightly, air infiltration occurs. Hence, sealing or taping is necessary to prevent airflow.
- Susceptibility to damage by UV rays: They are prone to damage by sunlight’s UV rays when you do not install them the correct way.
Fiberglass Batts
Fiberglass batts are woven and combined with different materials to make a dense insulating pad. The glass used for this insulation is the same as that used for glassware.
This metal roof insulation has varying prices, which are influenced by the R-value. For instance, an 11 R-value can cost between $0.12 and $0.16 for a square foot. For an R-value of 38, the cost can vary between $0.55 and $0.60 per square foot.
Pros
- Ease of use: Fiberglass batt is one of the easiest and cheapest ways to insulate your metal roof.
- Versatility: You can install it on an existent roof or under your metal roofing panels. Basically, you can tailor fiberglass batt to suit your specific needs.
Cons
- Exposure to harm: Without protection, fragments of the glass can harm your hands or eyes. Even your lungs aren’t safe from it. Hence, wearing protective equipment during the installation of fiberglass batts is vital.
Spray Foam
To use this insulation type, you must first dilute it with water. After dilution, you apply it as a hot liquid using a high-pressure spray machine. The water gets dried when it comes in contact with oxygen in the air, causing the polyurethane foam to expand, toughen, and cure. This reaction happens within minutes and is responsible for the foam’s thickness and rigidity.
Spray foam metal roof insulation is available in two types, namely open-cell and closed-cell spray foam—the open-cell spray foam costs between $0.44 and $0.65 per board foot. Closed-cell foam, on the other hand, typically costs between $1 and $1.50 per board foot.
Pros
- Highly effective: Spray foam is highly effective for metal roofing insulation.
- Protection from rodents and condensation: It prevents the buildup of condensation and insect or rodent invasions effectively.
- Simplicity: It is simple and easy to use. Additionally, you can install it on new or old roofs without affecting or interrupting any process.
- Suitable for irregular-shaped areas: It is ideal for insulating areas with irregular shapes because it is sticky.
Cons
- Requires experience: Installing a spray foam can be tasking, especially when you have yet to gain experience. Hence, we recommend you get a professional to handle the installation.
How to Insulate Your Metal Roof
Rather than get professionals to install their metal roof insulation, some homeowners prefer the DIY (do it yourself) way. If you are one of such homeowners, we advise you to follow the steps below to insulate your roof successfully. For an existing or new roof, here’s how to insulate it:
Existing Roof
Assess the bottom side of your metal roof from within the attic. You will find a sheet of plywood roof decking held up by a frame. The large angle beams are called joists, while the small, horizontal ones are purlins.
Fit fiberglass batts into any space you see between the purlins and the decking. When you pack fiberglass batts very tightly, it tends to be less potent or effective. Hence, it is essential to fit them loosely. Use rigid foam insulation for wider roof decking lengths, cut the sheet to the desired size, and secure it with adhesive or staples.
Place fiberglass batts into any gaps you can find between the sheathing and the purlins. This type of insulation can be less effective if it’s packed too tightly, so try to fit it loosely into the spaces. Cover wider spans of roof sheathing between joists using rigid foam insulation. Cut each sheet to the best size and fasten it in place with staples or sealant.
New Roof
For a new roof, install plywood to serve as structural decking for the roof. Place the wood at a right angle to the roof joists and secure it with nails. Arrange sheets of building paper on the decking.
Install plywood to act as structural roof sheathing. Lay the wood perpendicular to the roof joists and use roofing nails to fasten it.
Place layers of building paper over the sheathing to overlap by at least 6 inches. Use staples or nails to secure it and assist in shielding the products from leaks and moisture.
Now, install rigid foam insulation across the roof’s whole surface and position the sheets so they are close but not too close to overlap. Seal the joints to prevent air leaks or moisture. Install the metal panels over the insulation, following the manufacturer’s instructions.
Conclusion
The perfect insulation for your metal roof depends on your taste or desires. It doesn’t matter what type of metal roof, be it a corrugated or a standing seam.
However, fixing insulation for a metal roof can be knotty. Hence, we highly recommend that you seek the help of professionals if you lack experience working with the types of materials we discussed earlier. They will help you minimize risks and save you the risks involved.
Frequently Asked Questions
How do I stop my metal roof from sweating?
When metal roofs sweat, it results from high humidity, which condenses on the bottom of your roof. The use of underlayment will avert it. In addition, you will have to ensure that the flow of air is not restricted by providing enough ventilation
What is the best way to insulate a metal roof?
Some of the best ways to insulate your roof include using rigid foam, fiberglass batts, and spray foam insulation.
Does a metal roof need insulation?
Yes, a metal roof needs insulation. In fact, experts highly recommend using it for homeowners because of its benefits. The benefits include warming your home in winter and cooling it down in summer.
Is a vapor barrier beneath a metal roof necessary?
It is if you care about your roof sweating. The use of a vapor barrier will prevent condensation under your roof. They also prevent wet air from passing through the insulation.
