How To Install Roll Insulation [The Complete Guide]

Insulating your house can be one of the best cost-cutting decisions you can ever make. Not only will having your house insulated result in a significant decrease in utility bills, but you’ll also find it to be a fine home improvement investment. Now that you’ve decided to have your place insulated, you probably did a thorough investigation on which type of insulation best suits your needs. Although there are several types out there, the most commonly preferred insulation is fiberglass that typically comes in the form of batts, rolls/sheets. The difference between batts and rolls is that batts come already cut in equal pieces while rolls come in large pieces that can be cut as needed.

Roll insulation

How Much Roll Insulation Will Be Needed?

Before buying insulation rolls, you’ll need to first find out how much of it will be needed. All you have to do is measure the length and width of the surface you want insulated and multiply both values to get the measurement in square ft. Note down the calculation and show it to the supplier where you’re getting the rolls from. For a precise calculation, you can have a professional come by and measure the area. Also, consult your supplier about the recommended R-value of the insulation according to your region’s climate. The R-value determines how much insulation material will be needed in getting the job done. Furthermore, don’t forget to comply with your local building code’s insulation requirements.

For your convenience, I created a roll insulation calculator to easily calculate how many square feet of insulation you need.

Whether you go for batts or rolls, keep in mind that installing batts is less time-consuming as they are already cut according to the standard size of 8 ft walls. As for rolls, you’ll have to cut them into equal pieces individually. Unlike other types such as loose-fill, rolls can be installed without assistance from a professional. However, there are a couple of things you need to look out for. Even if you’re a DIY expert, the chances of messing up roll insulation are not slim for anyone. Before we continue with our guide on putting up those sheets, we believe it’s important for you to understand why proper installation is necessary.

The Importance of Installing Rolls the Right Way

Here’s the thing: the core purpose of insulation is to block airflow as much as possible and keep the internal area protected from the harms of external temperature. Take the example of a cold breeze making its way into your house from a small opening. Although that opening is puny, it can change the temperature of the house to a great extent, right? Such is the case with installing rolls. Your goal is to not leave a single ounce of space from where air might sneak from outside. Now we know that covering every centimeter is impossible due to uneven surfaces but our point remains clarified. Try covering every single opening and pay special attention to gaps on the corners and sides during installation.

Things You’ll Need

As mentioned previously, the installation of rolls is the easiest as compared to installing other sorts of insulative materials. Before we move towards the main procedure, here are a few things you’ll need to have by your side.

  1. A sharp cutter or knife
  2. Measuring tape
  3. Face mask
  4. Glasses
  5. Safety gloves
  6. Staples OR Wires

Safety Precautions

Now that you’ve got the material, let us proceed towards some precautions. Safety comes first, especially when it comes to installing insulation rolls. Fiberglass, specifically, can be harmful as the fibers it contains may cause respiratory issues along with skin irritation. Therefore, it is necessary to adhere to safety precautions and wear a safety mask, glasses, and gloves to minimize exposure to the fibers. Note that fiberglass will not affect your health negatively in the long run but it may cause minor harm upon exposure so it’s advised to keep your mouth, nose, eyes, and hands covered at all times during the installation, especially at the time of cutting rolls.

Installing Insulation Rolls

If you’ve decided to go for rolls, you’ll have to first measure the area between the studs in the wall you want to be insulated. Go ahead and use that measuring tape to get an accurate idea of how much material would be required. After you’ve noted that, take out the insulation roll and make cuts according to the size you measured. Standard stud width does not range more than around 12-15 inches. When it comes to cutting, proceed with the cutting process after placing the insulation material on a wood board. You can extend the measuring tape along with the roll or mark your measurements on it. Now, slowly cut through the roll with the sharp blade in a straight line. For a tight fit, add half an inch extra to your measurement.

After you’re done cutting the pieces, position them between the studs and slightly push to make the fit perfect. Remember, the moisture-resistant side should be facing you while the fluffy material faces the wall. Also, you don’t want to make it too tightly compressed against the wall. Pushing too much would negatively impact the material’s insulative properties. After you’ve made the material sit properly, it’s time to ensure the rolls stay in their place. There are two ways of doing so:

1. Wire Support

You can easily come across insulation supporting wires that come in different stud sizes. These wires can be pushed between the studs and hold the insulation roll in its place. This way it won’t keep pushing out from time to time.

2. Staples

Another common way of making your roll insulation stay in place is through staples. Simply grab a staple gun and fasten staples around the roll. It’s best to keep at least a foot of space between two staples. This way your rolls won’t be compressed too much.

Unlike installing insulation on walls, attics generally require two layers of insulation on the floor for optimal results. The first layer goes in line with your attic’s studs while the second one is spread in the opposite direction. Think of it as two lines intersecting each other on a cross. As for the attic’s walls, the above-mentioned method would be sufficient.

Tips to Remember

  1. For a straight cut during slicing rolls, gently press your knee against one side while you run the blade across. This will help maintain a straight line and keep the roll in place.
  2. Since insulation rolls are dense in material, a dull short blade won’t do you any good. Ensure the blade you’re using is long enough to reach the bottom and sharp enough to get the job done with minimal effort.
  3. It’s always better to cut the rolls in a slightly bigger size than the actual measurement. if you fall short, you’ll face trouble filling the cavities, but if you cut slightly more material, you can trim the excess off later easily.
  4. You must look for any damaged pipelines around the surface you’re insulating. Even minor leakages can make your insulation go to waste within a month or two. So, it’s best to get some repairs done before you continue.
  5. Small openings around pipelines or connection boxes can be covered by spray foam if you want to secure your insulation to the highest level. Just grab a can of foam and spray it around the gaps.

Re-Installing Insulation

If you already had your building insulated but it got compressed or caught mold, it’s best to get rid of the old material instead of adding a new layer on top. Otherwise, mold would eventually make its way to the second layer and ruin it. Therefore, it’s necessary to not just eliminate the remains of your old insulation material but also get fixes done if needed. For example, look for spots where plumbing work might be needed. Check if all the pipelines around the place are in good condition. No cracks should be visible anywhere near the surface. Examining these little details can save you a fortune as they are the factors that contribute to your new insulation’s long life.

Why Choose Roll Insulation?

Roll insulation brings a plethora of benefits. Firstly, it’s simple to install and takes no more than a couple of hours at most to get the job done. You don’t have to pay for professional installation. Also, rolls are easier to manage and measure, unlike loose-fill insulation. Not to mention the affordability of the material that makes rolls the most widely preferred insulation option. As for the effectiveness, yes, rolls might not be as effective as loose-fill. However, if you abide by the instructions and ensure to cover small openings, then there’s no doubt you’ll find rolls to be greatly effective.


Just a couple of tools, some insulation rolls, and a few hours are all that you need to have a successful installation procedure. Remember to keep our tips in mind and keep an eye out for repairs before putting those rolls up. We hope our guide helps you have an enjoyable and trouble-free installation process!

Charles John

Experienced HVAC technician with 8 years of experience in the industry. Capable of handling all sorts of heating and cooling equipment as well as proficient in operational management, construction-related techniques such as preventative maintenance, electrical troubleshooting and AutoCAD

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