Home Insulation Guide: Everything You Need To Know About Home Insulation

November 8th, 2019 BY First American Roofing

What are the benefits of having a properly insulated home?

If your home is properly insulated, you will notice it will stay warmer in the winter, and cooler in the summer. The goal of insulating your house is to make it run more efficiently despite outside weather conditions.

Poor insulation can lead to having higher heating bills in the winter, and A/C expenses in the summer. You could reduce that expense by 10-50% just by improving your home’s insulation. The trick is knowing when your home has insufficient insulation so you can stop wasting energy and start saving money fast!

roll of home insulation

Watch For Signs of Improper Home Insulation

If you are reasonable with your thermostat, and try to keep it at a decent temperature but still notice high energy bills, your home may not be running as efficiently as it should. When your furnace or air conditioner is having to work extra hard to get the house to the proper temperature, it could be poor insulation keeping that from happening. You should be able to run the heat or the A/C for a while, turn it off, and your house maintains that temperature. If that’s not happening, it may be time to examine your home insulation.

Some signs you could have poor insulation in the attic can be anything from feeling cold in the winter months, despite having the heat cranked, and noticing moisture on your ceiling or walls coming from the attic. The imbalance of temperature can create condensation that then leaks down from the attic. It’s important to make sure your home’s attic is both air sealed, and the insulation is at least 6 inches deep, depending on the type of insulation used. Recurring ice dams on your gutters and along the roof every winter is also a sign of poor attic insulation.

Drafty rooms, or rooms that get much warmer than the rest of the house, can mean poor insulation throughout your home, or inefficient heating and cooling overall. A well-insulated home will carry the heat or cold air throughout the home evenly, and maintain that temperature throughout all the rooms. Check your vents, attics, and wall insulation in those rooms in question and add insulation or replace it.

ice dam due to poor home insulation

Find & Seal Air Leaks Around Your Home

A very crucial step to insulating or re-insulating is ensuring proper home air sealing by plugging potential air leaks. This is called air sealing, and without air sealing, before you install insulation, it can be all for nothing. We see homes old and new, especially a lot of homes built around 20 years ago in 2000, that have no air sealing at all, and likely have condensation issues in the attic because of this.

Some areas in your attic where you should air seal are where the electrical wires come up through the attic floor – these connect to your light fixtures, hardwired appliances, and plug-in outlets throughout your home. These holes are 1/2 to an inch in diameter, and if they aren’t sealed under your insulation, that air can be sucked right through the fixtures and outlets and out through your attic. This is stealing precious A/C or heat from your rooms and sending it out through the top of your house. Using spray foam, you can seal around these gaps and holes to guarantee your attic will be fully insulated.

Other areas to seal include the attic entrance, window sills, basement cracks, and your chimney or flue. These all are susceptible to air leakage, which can make your cooling or heating system work extra hard at keeping your house at the right temperature. Air sealing around your home can help alleviate the insulation struggles you’ve had, and before you ever replace or re-insulate your home, you should always air seal these gaps first. Let your insulation work to the very best of its ability – your comfort and energy bill will be worth it.

What Are My Options for Home Insulation?

Fiberglass Insulation

Fiberglass insulation is a fibrous material that is spun from molten glass that has been melted in a high-temperature furnace. The majority of manufacturers also use recycled glass material for this. It may come in rolls or as loose-fill. Because it is made from glass, the very tiny, sharp fibers can make their way into your skin or eyes, causing itching and rashes, so it is imperative to wear safety gloves and glasses when handling fiberglass insulation. The insulation industry has given it the name “filterglass” because it more so filters the heat or air conditioning, rather than stopping it as Cellulose does.

Fiberglass Roof Insulation

Cellulose Insulation

Cellulose insulation is a great green alternative to usual fiberglass insulation. It is made from recyclable materials such as used newspaper or cardboard boxes that have been shredded into small, fibrous particles. Protective chemicals are then added to provide resistance to fire and insects. Manufacturing cellulose loose-fill takes less energy to produce than many other types of insulation. Another benefit of cellulose is its resistance to rodents.

Cellulose insulation

Loose Fill

Loose fill is just as it sounds, and it is either produced as loose materials or broken down into shreds and granules. Loose-fill insulation looks fluffy, almost like cotton candy that you absolutely cannot eat. They are an excellent material to use for going around hard to fill places like around pipes or chimneys up in the attic. They are most commonly sold in bags, and then special equipment blows the material into the building cavities. All types of loose-fill insulation are considered environmentally-friendly because they are produced using recycled waste materials. Loose fill can act differently depending on the type you’ve used. Fiberglass will stay loose after it’s blown in, while cellulose settles. The settled cellulose will compact itself into place and actually create a better R-value, improving its air sealing capability.

home insulation guide - sealing your attic

Blanket Batts and Rolls

Blanket batts and rolls are typically fiberglass, but cotton, wool, and plastic insulation materials have also been manufactured as rolls. This type of insulation is one of the easiest to install, as it’s designed to fit the standard width between wall studs and attic rafters.

A few things to keep in mind is never trying to compress a roll to fit. You will have to cut it to the proper length with a utility knife and always wear protective gloves and goggles due to the fiberglass material being an irritant. Fiberglass batts are quite ineffective in walls or vaulted ceilings and you’ll be better off dense packing cellulose or using spray foam insulation.

Rigid Foam

Rigid foam, or insulation board, is a lot thicker and sturdier than the roll or blanket foam, as you can tell by the name. This insulation is available in sheets of different materials and thicknesses. The main types of rigid foam insulation sheets include expanded polystyrene, extruded polystyrene, and polyisocyanurate. It is also stronger, permeable to water vapor, and water-resistant. Typically, rigid foam is only used in certain applications like basement walls, vaulted ceilings, and attics.

Sprayed Foam

Sprayed foam allows you to cover more surface areas, and hard to reach areas than other forms of insulation, sealing leaks and gaps in existing walls. We commonly install this in basement sill boxes, vaulted ceilings, and attic knee walls.

It works by spraying liquid polyurethane into the wall cavity, where it expands and hardens into a solid foam. It can work on larger areas as well, using a pressure sprayed option. Spray foam comes in either open-cell or closed-cell foam, which is denser, materials. Contractors will often recommend open cell due to it being cheaper, and turning a higher profit for them, but steer clear of that. Closed cell is much denser, with a higher R-value, and it’s more expensive but worth it. Again, always call a professional for insulation needs, especially with more complicated versions like sprayed foam, where precision is vital.

spray foam home insulation

Understanding R-Value

R-value is a number given to the insulation to determine its conductivity, and ultimately it’s effectiveness at insulating your home. The “R” in R-value stands for resistance to heat flow (through conduction). R-value only measures conduction heat, which is how heat travels through the fibers in the insulation to warm your home. The higher the R-value, the greater the resistant to heat flow, and the greater the insulating effectiveness. The R-value per inch will determine how thick you need to make the insulation. So, the R-values for the insulation types we’ve displayed above would be as follows:

Loose-fill (fiberglass): R 2.2-2.7

Loose-fill (cellulose): R 3.2-3.8

Spray foam (open-cell): R 3.7

Spray foam (closed-cell): R 6.5

Blanket Batt (fiberglass): R 2.9-3.8

Rigid foam (polyisocyanurate): R 6.5-6.8

Rigid foam (extruded polystyrene): R 5

Rigid foam (expanded polystyrene): R 3.8

As you can see, rigid foam, or foam board, has some of the highest R-values per inch of all the insulation, but this just means you need fewer layers to insulate to the standard for your home. So depending on the recommended R-value for your climate, you will multiply your amount of insulation inches to reach that number.

How Do I Know Which Insulation is Right for My Home?

A professional should always help you determine which insulation is right for which parts of your home. Energy Star does list some recommendations for what R-value your insulation should be, based on your climate, which is divided into the zones below.

home insulation guide: location based insulation

Based on these zones, you can generally determine the recommended insulation for your walls, floors, and attic. Note, this is a recommendation for insulating wood-framed homes.

home insulation chart

As you can see, the higher the zones, the higher the R-value. This is due to much colder conditions in general, but also reasonably humid summers – so the insulation needs to withstand large fluctuations in temperature. The lower zones don’t need as much attic floor insulation as they are in warmer and drier climates. You will also notice there isn’t much concern for humidity and condensation accruing in the attic in these lower zones.

How Much Money Can I Save Reinsulating My Home?

It depends on many factors how much money you can truly save on energy bills by reinsulating your home. Older homes benefit most from evaluating and reinsulating, mainly those built before 1970-1980, before energy efficiency was truly implemented into new home builds. You can expect to save between 10% and 50% in energy costs, and depending on the size of your home, it could be hundreds of dollars in savings a year!

As one of the few trade allies for Focus on Energy in our area, First American Roofing can offer homeowners a lot of benefits when insulating their homes. We can get them rebates that can get them up to $1,760 off their project, and sometimes even more! We adhere to strict installation standards, using only the best materials, and can assure you it’s being installed correctly. We know insulation, and we understand how it affects your overall home performance. Contact us at (608) 291-3129 to talk home performance, and schedule your home performance test. From there, we can determine a course of action that works best for you, and can get you the greatest return. Protect your investment with First American Roofing.