Best Way To Insulate A House For Winter

Living in south central PA, you have a lot of things to “winterize” each year. You might put snow tires on your vehicle. If you have a spigot, you have to drain the attached hose. You make sure you have the appropriate winter clothes and shoes to stay warm on a snowy day. One area of your life that should definitely be “winterized” is your home, and you do that through appropriate insulation.

South Central Services has insulated hundreds of homes around Greencastle, Mechanicsburg, and York, PA. We are passionate about functional insulation. Whenever the weather turns cold, whether or not your insulation is functional becomes very apparent.

By the end of this article, you’ll understand the best way to insulate your home for winter to stay warmer and save on your energy bills.

The Stack Effect Is Why Your House Is Cold.

The stack effect explains how air exchanges through a building in the cold. As the air in your home warms up, it causes convection. Warm air rises and finds its way to the “lid” or top ceiling of your home. Eventually, that warm air finds its way out of the home through any penetrations upstairs.

As warmer air exits through the roof, that air is replaced by colder air pulled in from underground. A basement or a crawl space often has gaps or porous masonry walls, allowing the replacement air for the exchange to come inside. If new air wasn’t drawn inside, the warm air escaping would create a vacuum effect in your home.

Since warmer air is replaced by colder air, the home gets colder and colder. You are more uncomfortable, so you turn up the heat. This cycle continues, leaving you chilly and with higher energy costs.

The stack effect is an expected phenomenon. What can you do to limit its impact on your home?

Start With An Airtight Seal In Your Attic.

Since the cycle begins with the majority of warm air exiting through your roof, your first step is to block any cracks or crevices in your attic. If the conditioned air in your living space can’t get to the roof, it can’t escape. This air-seal significantly reduces the concern of cold air being pulled inside.

You need an airtight seal upstairs. Depending on your budget, you have two options.

On A Tighter Budget? Install Blown-In Insulation On The Attic Floor.

The more affordable option with the most performance is blown-in insulation paired with an airtight seal. Neither blown-in cellulose or blown-in fiberglass can create an air-seal.

Blown-in insulation functions by creating layers of small particles made of a material with a higher R-value. These layers stop conductive heat transfer. However, when it comes to heat moving through the air, the best blown-in insulation could do is slow down convection or radiant heat.

Since your attic needs both insulation and an airtight seal, install an air-sealing product on the attic floor before adding blown-in. These products, such as can foam, can eliminate air leakage points like can light, plumbing penetrations, or gaps in the construction.

Have More To Spend? Opt For Spray Foam Insulation.

The best performance for your attic is spray foam insulation. Spray foam is a premium product with a matching price tag. You don’t have to invest in a separate air-sealing product when you use spray foam. Spray foam insulation air-seals and insulates simultaneously.

Spray foam insulation is an incredibly versatile insulation option. Not only can spray foam be used in other areas of the home, but it can also encapsulate your attic.

This insulation is spray-applied to surfaces, so the underside of your roof can be insulated instead of the floor.

While attic encapsulation is more expensive than floor insulation, it comes with numerous benefits. The most significant difference between these two options is the environment upstairs.

By insulating the attic floor, you stop your thermal envelope before your attic. The attic doesn’t have to be conditioned.

By encapsulating, your thermal envelope stops at your roof. You can control the temperature upstairs. If you have any HVAC ductwork running through your attic, you’ll want to opt for attic encapsulation. HVAC equipment performs best when it exists in a conditioned environment.

You Can Also Insulate Your Basement Or Crawl Space.

By insulating your attic, you’ll eliminate most of the problems associated with the stack effect. However, air will still escape your home. When that happens, replacement air will be sucked in from below the ground.

To keep your home warmer, you can insulate the problem areas downstairs.

Your Basement Band Boards Need Closed Cell Spray Foam.

Any home with a basement should have basement band boards (also known as rim joists). The band boards are where your masonry walls meet with the wood construction upstairs. There are gaps in this area where the wall meets the ceiling.

Since your basement walls are porous, cold air can easily pass through them. The band boards are a key area where cold air is sucked inside.

If you insulate your rim joists with closed cell spray foam, you can insulate and air-seal.

If You Have A Crawl Space, It Should Be Encapsulated With Spray Foam.

Not every home has a basement. Some are equipped with musty crawl spaces. A crawl space is usually the stuff of nightmares: mildew smells, insects, rodents, dampness, and claustrophobia.

However, your crawl space doesn’t have to stay a nightmare. Encapsulation will leave your crawl space clean, dry, and accessible.

When it comes to combatting the stack effect, encapsulation also prevents dirty, cold air from being pulled into your living space. An encapsulated crawl space has closed cell spray foam installed in its rim joists, and the crawl space becomes part of your conditioned space.

While you’ll never want to make a home in your crawl space, the air that freely exchanges between that space and your living space will be the same temperature and quality.

Your Below-Grade Upgrades Can Wait A Year If They’re Out Of Budget.

Spray foam insulation is expensive, and it would be reasonable if you cannot afford to upgrade both upstairs and downstairs in the same season. If both are within budget, you can absolutely have both taken care of at the same time.

If not, we recommend starting with your attic and saving your below-grade upgrade for next year. This method will also allow you to file for a federal tax credit multiple times. Spacing out your energy efficiency upgrades will save even more money.

Don’t Add Insulation Just To Insulate.

It is very tempting to think of insulation and its performance as an input and output. If you add insulation, your house will be warmer, right?

In reality, every insulation offers different features and performance. Most budget-friendly insulations do not air-seal, which limits their effectiveness in the home. We recommend pairing budget insulations with an airtight seal to maximize their performance.

Even so, a maximized blown-in or batt will not compare to the performance of spray foam insulation. Spray foam is a permanent and versatile insulation solution with a built-in air-seal.

The answer is not to just add insulation, but to add the right insulation according to your budget and goals. Anything else would be a waste of your time and money. And perhaps worst of all, your home won’t be more comfortable or affordable to live in for insulation’s sake.

The right insulation solution will keep you warmer in the winter and make heating your home less expensive.

The Bottom Line About Insulating Your Home For Winter

Homes are cold in the winter due to the stack effect. Without effective air-sealing, air exchanges uncontrollably, leaving occupants defenseless against the cold. To properly insulate a home for winter, start with your attic. Be sure to get an airtight seal upstairs to prevent the stack effect cycle. If it is within budget, you can then insulate and air-seal your below-grade spaces like the basement and crawl space.

Now that you know how to insulate your home for winter, your next step is to:

• Estimate the cost of spray foam for your attic
• Estimate the cost of blown-in insulation upstairs
• Estimate the cost of encapsulating your crawl space