3 Tips for Installing Metal Roof Insulation

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Metal roof insulation has a lot of benefits but installing this insulation is a little bit different than the other options you could choose because it usually requires a few more steps. There are some tips for installing metal roof insulation that can make this project easier.

Many office buildings and homes use metal roof insulation as a way to cut down noise pollution and help with energy conservation. Using tips for installing metal roof insulation makes it a lot easier and more affordable to insulate the building and take advantage of having this feature in place, because it will save you money in the long term.

How It Works

Metal roofs have been a very popular building option for some time, but people have just started using insulation within the roofing system more recently as a means to block out sound and keep heat in.

One big benefit is that insulation muffles the sound of rain on the roof. This noise is a somewhat unpopular feature of traditional metal roofs with no insulation.

If you’ve ever heard the sound of rain on an uninsulated metal roof, you know how unpleasant this can be. Insulation greatly reduces this sound.

The insulation softens not just the sound of rain and weather. It decreases the noises from the outside world in general and muffles the sounds from within the building, too, as compared to an uninsulated metal roof that tends to echo and amplify sound.

The insulation also provides temperature regulation, keeping the building cooler in summer and warmer in winter. This is more energy-efficient, as it means HVAC systems can do less work to keep the building comfortable.

You end up spending less on your energy bill thanks to this insulation, which means the cost of insulating the metal roof will pay for itself in time.

There is yet another benefit to having insulation. The insulation helps keep the space dry, which prevents the growth of mold and mildew.

This is no small feature, as mold and mildew are dangerous to your health and they can be a real pain to remove once they have started to grow.

Once you know you need insulation for your metal roof, you have to decide which insulation you’d like to use.

Types of Metal Roof Insulation

Wondering how to insulate a metal roof? First, you will have to make some choices about the type of insulation you want to use.

Choose the roof insulation you want to have based on cost, ease of installation, and the qualities you're looking for. Remember also that you need to choose a type of installation you can actually install based on your own ability and the amount of help you have to put in the insulation, as one option is easier to do alone or with two people than the other.

Foam Batting

Foam batting is affordable and easy to install. It is soft padding that comes in big rolls and it’s an extremely popular roof insulation material that is used for all kinds of roofs, not just those made with metal.

Foam roof insulation is made with fiberglass, so wear eye protection and a face mask during installation. Breathing in fiberglass particles is very harmful to your lungs, so leave this protection in place the entire time your working with the insulation.

Install foam batting with staples. The staples can go through the batting directly into the roof paper and sheathing behind it.

Add staples all around the seams to secure it in place. Leave a small gap between panels of insulation, about 1/8 of an inch, and staple foam pads to the sheathing and not to each other.

Fiberglass insulation under metal roof buildings is a pretty easy, quick insulation, particularly when compared to your other options.

Rigid Board

Rigid board insulation provides good insulation for metal roofs. This insulation is made with polyurethane or polystyrene.

The sheets are rigid and stiff, as the name implies, and they are tightly fit together on the inside of the roof.

Cover the backside of the rigid board panels with glue and place them against the inside of the roof. Panels are sealed together at the seams with caulk.

This tight seal between panels creates good thermal insulation. Make the seal even tighter by placing duct tape over all the seams after the panels are all installed.

Leave a small gap, about 1/8 of an inch, between every few panels you install. This is called an air gap and it is necessary to promote airflow.

Learning how to attach foam board insulation to metal roof buildings is fairly easy. It’s actually getting the panels in place and securing them that is the difficult part, as you will likely need another set or hands or two in order to get this done.

Rigid board insulation is made with closed-cell foam. It is often called Styrofoam insulation.

Tips for Installing Metal Roof Insulation

Insulating a roof is a big project in any circumstance. It's going to take several hours and it's not going to be easy but the end result is worth it because this project will pay off in time.

Use roof insulation tips to get a better finished result and make the entire project a little easier. You will end up doing more work if you follow these tips, but you will end up with insulation that is effectively and more professionally installed.

Install Sheathing

You need roof sheathing, which will give the insulation for metal roofs something to connect to. Install your own sheathing by placing plywood panels between the roof joists.

Attach the plywood to the joists using roofing nails. This creates a secure backing for the insulation so that it is easy to staple or nail the insulation material to the underside of the roof.

It is much easier to nail or staple into plywood than it is into metal, after all.

Place a vapor barrier over the plywood once all the sheathing is installed. This prevents humidity inside the space.

Paper Lining

Before placing any insulation, place building paper on the roof sheathing. Each paper sheet should overlap by six inches.

Secure the paper to the sheathing with small roofing nails or staples. The staples will go in more quickly than nails.

Add Supports

If you're working with foam batting, it's a good idea to install supports on top of it to keep it in place. You can use almost anything to serve as a support network, from nylon straps to chicken wire.

You can use 12 gauge wire placed crosswise between supports to hold the batting in place. Each piece of wire will be about 15 1/2 inches long and go right between the rafter studs.

Chicken wire and mesh netting can also be used and this material may be more affordable. Place this material between roof joists to hold the insulation in place and you have a more secure final result.

Rigid insulation boards are nailed into place and need no extra support.

Installing Metal Roof Insulation

Insulating a metal roof will add temperature regulation to reduce energy bills, prevent moisture, and help to reduce noise. It's not difficult to install insulation as a DIY task, though it does take a lot of time and a lot of steps.

Once you know the process, you can add insulation to any metal roof you encounter.

Metal Roof Insulation FAQs

What is the best insulation to put under a metal roof?

Foam batting is the most popular choice when it comes to roof insulation because it is affordable and relatively easy to install, compared to other options.

The best insulation for metal roof buildings is the one that’s most practical for you to install, as all insulation types pretty much serve the same purpose of protecting the building from moisture, muffling noise inside and out, and providing better temperature control for the interior space under the roof.

How much air gap between metal roof and insulation?

Do you need an air gap for your metal roof insulation? What even is an air gap?

An air gap is the space between the roof and the insulation, or sometimes it refers to the space between panels of insulation.

Airflow is necessary for metal roofs. According to research, this little bit of airflow actually improves energy efficiency because the pockets of air act as a type of insulation, too.

Leave a 1/8-inch gap between insulation panels and leave about two inches of space between the metal roof and the insulation. This allows the roof to "breathe."

How do you install roll insulation on a metal roof?

Learning how to insulate metal roof buildings with foam is not so hard. You basically unroll it and secure it using pretty standard tools and materials.

The hardest part is working with the mask on the entire time. Be sure to take frequent breaks and go outside for fresh air while you work.

When installing foam insulation from a roll, cover the roof with sheets of insulation by placing them next to each other. Do not let the insulation panels overlap.

Use double-sided tape to secure the foam insulation to the sheathing and then go back and secure the insulation all around each seam using staples. A staple gun will make this go rather quickly.

Metal roof insulation rolls are available in different sizes, so you can choose what you want to work with depending on how large your roof is.

Don't forget to leave small gaps between each panel, about 1/8 of an inch.

Does roof insulation go shiny side up or down?

Some insulation may have a shiny side, an effect that is achieved with foil. This is not done for looks but to reflect heat.

It works as a type of heat insulation for metal roof buildings.

This is a radiant barrier that deflects the heat of the sun, so it needs to be facing up toward the sun. The pretty shiny side will be completely hidden and facing toward the roof, not down and into the room.

How do you insulate a metal roof from the inside?

Figuring out how to install insulation under metal roofing comes only after you choose which type of insulation you want to use. Start with this and then, learn the process for installing the particular type of metal roof insulation you want to use.

Metal roofs can be insulated with foam batting or rigid foam boards. Spray foam is another option, but you will need to have that professionally installed.

What kind of insulation do you put under a metal roof?

Different types of foam are used to insulate metal roof buildings. Soft, cushioning foam batting, stiff foam boards, and spray foam are all used to insulate these types of roofs.

What is the cheapest way to insulate a metal shed roof?

Foam batting is the most affordable option when it comes to metal roof insulation. This is not just the most affordable, it's also easier to install as a DIY option.

Can you use spray foam to insulate a metal roof?

Spray foam can be used to insulate a metal roof but spray foam is difficult to apply and must be done by a professional. Spray foam insulation for metal roof buildings is not an option for the DIYer, so if you're looking to do this yourself you want to stick to foam batting or rigid foam boards.

Can you install insulated metal panels?

If you are installing a new metal roof, consider using insulated metal panels rather than adding the insulation later. Insulated metal roof panels actually have the insulation included, so you install both the roof and the insulation all at once.

Metal insulated panels cut out some of the work but they cost more than standard metal roof panels. Insulated metal panels cost about twice as much as standard metal roof panels.

Further Reading

5 Energy Efficient Roofing Materials To Use

5 Ways Metal Roofing Increases Home Value

12 Things to Know If You're Considering a Metal Roof

Building a Garage - Roof Framing

Everything You Need to Understand About Insulation

How and Why to Insulate Your Attic

How to Install Insulation Sheathing

How to Install Metal Roofing

How Much Metal Roof Material Do You Need?

How to Insulate a Shed Roof

How to Save Money With Insulation