What Is Metal Roof Insulation? | Metal Roof Insulation Options

What Is Metal Roof Insulation

Ever wondered what, in colder areas, provides insulation to the entire house? This question may strike your fancy, primarily if you reside in a relatively hotter place.

Metal roofing is a long-lasting, low maintenance alternative to traditional asphalt shingles. While asphalt shingles may have lower upfront costs, they are vulnerable to shrinking, eroding, and cracking, especially in regions of the country where they’re exposed to extreme weather conditions.

Insulation Materials: 1. Fiberglass, 2. Mineral wool, 3. Cellulose, 4. Natural fibers, 5. Polystyrene,6. Polyisocyanurate,7. Polyurethane,8. Perlite.

Thermal insulation is the reduction of heat transfer between objects in thermal contact or in range of radiative influence. The slate roofing system is the most durable and longest-lasting roofing material, with a life expectancy of more than 150 years. The next most durable material is clay, which has a lifespan of about 100 years

If it does, continue reading this article until the end, as we will lay down different details relating to metal roof insulation, how it can be installed, why you need it, the pros and cons, and others.

What Is Metal Roof Insulation?

Metal roof insulation, in simple terms, stands for providing insulation to the metal roofs to improve energy efficiency, acoustics, comfort, and in some cases, even living standards in modern and commercial buildings both.

In buildings that aren’t insulated yet, in them, the majority of thermal transmission takes place through the roof, which puts insulation high on the agenda.

The question that is probably biting your head off will now be dealt with in the paragraph hereunder.

Why Do We Need Metal Roof Insulation?

This metal roof insulation is needed for plenty of reasons, the most important being its energy enhancement attribute. With the rise of heat, most of the energy gets lost through the roof of any structure or building.

In such scenarios, metal roof insulation comes into the picture with its energy enhancement feature, which also helps lower your electricity bill.

There are different options to go for when choosing metal roof insulation, and if you happen to vote for stone wool products, they will yield a number of benefits.

Stone wool products fill the bill between two metal sheets, thus reducing heat transmitting through the roof and simultaneously clamping down on the rain noise from swamping the building envelope. You can choose the density which fits the requirements of your buildings.

Even if you go for any other option, it would act as a barrier and protect the buildings from rain, hail, and overheating when the temperature increases slightly.

Going for stone wool insulation also brings to the table the benefit of excellent acoustics for metal roofs- the benefits have already been delved into in the paragraph above this one.

Rigid Foam Insulation Under Metal Roof

A rigid foam board is one of the options of many available to homeowners. Rigid foam board is considered to be more expensive than its competitor batt insulation, and understandably so.

The R-values of foam board are placed at a higher level than that of Batt insulation. And we might as well remind you this is an exterior roofing insulation option and not an interior one. Again, this is also beneficial to block out any sound coming from your neighbors’ place.

The downside of this option would be more or less the same as the batt insulation one, it is rigid, so it won’t be as easy to move around congested and tight areas.

Again, the homeowners won’t be as affected, for this straight-up comes over the insulation, so this problem doesn’t really come into play.

The thing that you must bear in mind while going for this sort is that moisture control is critical. Your roof must allow for air to pass through in and out. Installing a vapor barrier is easily done.

Metal Roof Insulation Options:

There are different metal roofs with insulation options to choose from, and those are:

1. Fiberglass Batts:

Fiberglass Batts

This metal roof with insulation type is one of the most popular types, as it is relatively inexpensive and available in a variety of properties with different R-values.

These come in similar variations, and if you are not well acquainted with what this R-value means, it basically determines the thermal resistance. Therefore, the higher the R-value, the more insulation it provides to any roof.

This is necessary because different areas with different temperatures require different layers of insulation. Now the question arises whether you should insulate your metal roof with fiberglass batts or not.

If its budget is limited then one can compromise on this option as it offers insulation at a bargain-basement price. Again, just because an item is of low cost does not mean that it is of standard quality.

On the flip side of the Betts, this comes with a number of negatives. First of all, it cannot be flexibly moved and shaped around the corners, rafters, and wires in your roof.

And secondly, they do not effectively remove moisture from the roots. However, this does not seem to be a major concern until the surface becomes moist and the moisture disappears immediately, and if the surface remains moist, the insulator will lose its R-value.

Professional installation can reduce this type of risk, as they can install moisture barriers based on their own experience and allow moisture to be removed.

They will take care of moisture barriers and ensure that airflow is needed to disperse the moisture. However, if we consider this from the point of view of the majority, these are no longer sufficient forms of insulation for metal roofs.

If one settles on this type, one must certify whether one can breathe in small pieces of glass. And if not, get the right PPE or play safe, and don’t take matters into your own hands. Call a professional installer and ask them to install it.

2. Rigid Foam Board:

Rigid Foam Board

This type of insulation has already been probed deeply. To encapsulate it, these tend to fall on the expensive side of the cost scale because it offers more insulation to the metal roof. Again, this is most suitable for exterior applications and not interior ones.

Hardened foam boards are more expensive than batt insulation, but the R-value of foam boards is much higher than that of bats.

This can be used as an external roofing insulation option. In addition, this material is good at soundproofing.

There’s a common demerit that is shared by both batts and rigid foam insulation, and that is, their insufficiency to adapt to tight areas and rigid corners. Though, this does not really put the monkey wrench in the works.

Also, if you are going for this type, be sure to build a moisture control layer along with it; otherwise, you will have to incur costs to make repairs.

3. Spray Foam Insulation:

Spray Foam Insulation

Next up, we have spray foam insulation. This, again, is expensive when pitted against fiberglass batts. Another thing to worry about is that it does not have a high R-value per inch in contrast to rigid foam insulation.

Nonetheless, one can wholeheartedly opt for this if they are looking for a complete insulation, as this option seems the best out of all the three.

Talking about its adaptability, we just went over the inability of rigid foam to be installed around tough areas and tight corners/wires.

Spray foam, on the other hand, can be effectively sprayed wherever you want, for it is an interior insulator. So, if there are any tight areas, rigid corners, and wires, you can go ahead and install this one.

The mechanism behind spray foam insulation is that when you spray it, it spawns across, filling every crevice, nook, and cranny. This mitigates your stress of the roof’s R-value decreasing in case you missed any spot.

This one is preferred amongst homeowners or construction agents, especially because it eases out on stress of renovations.

The disadvantages have already been thoroughly harped on, they are extortionate in price, and you cannot probably find a way out of DIYing this spray foam.

Speaking of these forms, spray foam insulation comes in two forms, namely: closed-cell and open-cell. The latter one will cost you much less, though not sufficient when it comes to providing a higher R-value.

This type is suitable for houses built in moderate areas and where the weather is not chilling. On the other hand, closed-cell is costlier, but one can trust them with better insulation.

Regardless of whether you go for the former or the latter, both of them are inherently moisture resistant, which means they allow for moisture to pass through them without damaging the insulation in any way.

However, before pitching on spray foam, always check in advance with the manufacturer to ensure whether the foam and roofing material are in communion with each other or not.

How to Install Metal Roof Insulation?

Installation of metal roof insulation isn’t a difficult process whatsoever; pay heed to the following points.

1. Using Foam Batting: The first and foremost point worth noting is the best material after considering all the sides.

These are paper-covered fiberglass and can be side on wherever the owner wants to get it installed. This is a much better alternative to spray or rolled-up ones, for they lay flat.

This type of material can be easily installed with metal roof insulation. It is in the form of foam batting for metal roof insulation.

This is usually a different design from roll-up type insulation as it comes in panels instead of fiberglass. This metal roof insulation can be used on the outside or inside of the casing.

2. Laying insulation on paper liner: The most common mistake committed by any homeowner is that they don’t bother spreading/laying anything underneath the sheathing. Consider this, especially in the places where molds are likely to build their small homes.

This paper wrap holds significance, owing to its efficacy in stopping water from building up in the space between the metal roof and sheathing. Consider this, especially in the places where molds are likely to build their small homes.

3. Install with Staples: This will help the owners to get the installation work over with quick 1½-inch staples. Just go through a few sheets of insulation, and you’d know they are reliable and secure.

One of the proven benefits of using staples is that they don’t result in large holes when penetrating into the sheathing. Also, the removal process is easy too when fixing repairs.

4. Cutting of panels on the roof:- Before you set about the journey of metal roof insulation, bring it up on the roof.

This would avoid unnecessary up-and-down movement for tools and other gadgets needed for the installation process. Cut foam panels on the roof for precise cuts and easy placement.

5. Necessary to leave gaps between gaps:- One point is that when there are holes or small rifts between the insulation pieces.

There’s an easy and quick outflow and inflow of air, provided the gaps are within ⅛ inch. They are important for the health of the whole and the insulation sheets.

6. The use and placing of purlins:- The most popular method of placing metal roof insulation on any roof is to lay out purlins across the shingles that the cross may already have.

However, you could just lay down the insulation between these purlins. Bear in mind the thickness of the insulation you have pitched on should be the same size so that the metal roof hugs it better.

Pros and Cons of Metal Roof Insulation

Pros and Cons of Metal Roof Insulation

The pros and cons of insulation are contingent upon the type of insulation you are going for. If the owner happens to go for batts, they are inexpensive, but they provide lower thermal resistance values.

Conversely, if someone plumps for a rigid foam insulation alternative, they would be charged more, the reason being its high thermal resistance values.

The last option, i.e., spray foam, could be immoderate with low R-values. The only merit of this is they are easily moved around small and limited corners, whereas the former ones prove to be relatively inefficient.

Pros of Metal Roof Insulation:

The Pros of Metal Roof Insulation:

The pros of metal roof insulation are as follows:-

  1. Metal roof insulation lasts for a longer time.
  2. It is lightweight.
  3. The installation of roof insulation is very fast and easy.
  4. It does not catch fire.
  5. It is environmentally friendly.
  6. Metal roofs are energy efficient.

Cons of Metal Roof Insulation:

The cons of metal roof insulation are as follows:-

  1. The Initial cost required is high.
  2. There may be chances of expansion and contraction.
  3. Metal roofs can be dented.

Also Read: What Is Modified Bitumen Roof? | How to Install Modified Bitumen Roofing?

Metal Roof Insulation Cost:

Metal Roof Insulation Cost

The cost entirely depends on the material you are opting for. The installation process can cost you anywhere from $4 to $6.50 per square foot; these are the cost of the panels you are choosing.

The entire insulation material and installment process will set your wallets back by $10,000 to $17,000 in total.

There could be cheaper alternatives as well, and there is also an option to completely get away with installing it. But in the long run, it won’t be beneficial whether you plan on staying in the house or selling it.

This method packs a punch by acting as acoustic insulation, keeps moisture and water at bay, and also adds curb appeal to those who are planning on buying your property.


The aforementioned article deals with the metal roof insulation process. This article has everything you may be looking for, including different insulation options available to any homeowner, the cost of getting these metal roof insulation installed, pros & cons of having such insulation built onto your roof.

For those of you who are not well familiar with metal roofs, insulation can run your eyes through the section where we discussed its definition at length.

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Frequently Asked Questions

What Is the Best Way to Insulate a Metal Roof?

The best material for use with metal roof insulation is in the form of foam batting. This is different from the normal roll-up type of insulation as it comes in panels rather than paper covered fiberglass.


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