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HomeMust ReadShould I Spray Foam My Attic Roof

Should I Spray Foam My Attic Roof

Is Spray Foam That Impermeable

Should the Attic Floor Insulation Be Removed When Doing Spray Foam?

The unvented attic simply would not be effective if the thermal properties of the spray foam were not the highest in the industry. If the spray foam doesnt perform , condensation will occur and now theres no natural ventilation to help circulate air through the space.

Spray foam does perform. Even open cell spray foam has an R-value of 3.7 per inch, which is higher than fiberglass, which is 2.2 per inch. Besides thermal properties, there are other advantages to using open cell spray foam over fiberglass or cellulose, mostly that the foam is less likely to settle over time, wont get damaged by water, isnt attractive to rodents, and is soundproof.

When opting for the sealed attic, its really the closed cell spray foam that is more desirable and nearly mandatory. The closed cells create an air impermeable membrane that serves as a vapor, air, and moisture barrier. Closed cell spray foam has an R-value approaching 6.5 per inch or higher.

Install A Dehumidifier In Your Attic

Still got high humidity? A dehumidifier can remove it.

After from sealing things up and fixing your pressure balance, this is usually the best solution to high humidity in a spray foamed attic. Put a dehumidifier up there, plug it in, set it between 50 and 60% RH, and forget about it. Bye bye, humidity!

Ok, it’s a little more complicated than that. You’ll have to dispose of the water the dehumidifier removes. Since you probably don’t want to go in your attic twice per day to empty a dehumidifier reservoir, you’ll want a unit that drains itself and a dedicated condensate drain just for the dehumidifier. It should drain just like your AC.

Oh, the dehumidifier also does the double duty of moving air around. The next time you’ve got work to do in your attic, it won’t be quite as stuffy up there.

Spray Foam Attic Floor Or Rafters: Which Is Best To Insulate

Are you thinking about re-insulating your attic and wondering if it is better to spray foam the attic floor or rafters?

Either attic spray foam insulation system will work just fine, but the best way to insulate the attic really depends on your situation.

Being a residential spray foam insulation contractor since 2002, weve insulated our fair share of attics with spray foam, sometimes the attic floors and sometimes the attic rafters. Both systems work well, they are just different and have their own pros and cons.

In this article, Ill discuss the reasons why you may want to insulate the attic floor or rafters so you can determine what is the best for your specific situation.

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Maintains The Quality And Integrity Of Liquids Stored Inside The Garage

o It is normal for residents to use the garage as a storage space for things that they feel will be unsafe when stored inside the house. These items may include fuel, chemicals, and paint products. Extreme heat or cold temperature can freeze or cause some of these chemicals to catch fire when exposed to extreme heat. Spray foam insulation will ensure that these items will be exposed to the owners preferred temperature to maintain their quality and integrity over time.

Is It Better To Insulate Attic Ceiling Or Floor

Should I Remove Old Attic Insulation Before I Spray Foam ...

For your home to get the optimal energy efficiency, it needs to be insulated starting at the roof and to the floor. If your attic is unfinished, insulation should be placed between the floor joists and then over the floor joists, using an open-cell with spray foam insulation. If the attic has air distribution, insulate the rafters as well. For a finished attic, insulation should be installed between the wall studs and exterior wall and roof rafters. The exterior walls, including the internal walls attached, unheated garage should be insulated.

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Spray Foam Insulation Is Very Effective For Garages

Picking this type of insulation is highly advised for your garage. With its durable material, your garage insulation will be able to last for decades, unless they are exposed to extreme pressure that may damage or break the material. Also, it is best to hire a spray foam insulation contractor to do the job for you. A contractor will deploy insulation experts that are knowledgeable about the best ways to apply the product. Also, they use the best equipment available to do the job safely and accurately. You may contact Spray Foam Insulation at 880-1927 so that your garage can be evaluated as soon as possible.

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The Importance Of Using Spray Foam To Insulate The Garage

There are various problems that can happen when a garage remains to be improperly insulated or has no insulation installed at all. The garage needs to be treated the same as a house since it is used to store various materials and most of the people use the garage as their workspaces or even as places where they can hold gatherings with their friends and colleagues. Seeing that it is an important asset to your home, you must see to it that it is set up in a way that it can be used at any given time.

Spray foam insulation is a type of insulation that is made by mixing the chemicals resin and isocyanate. This type of insulation is known for its ability to enter spaces or areas that are hard to reach. This makes it possible to seal even the smallest crack or hole on the walls, doors, and ceiling of a garage. You may refer below to the reasons why the garage must be insulated with spray foam insulation:

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Should I Remove Old Attic Insulation Before I Spray Foam

Well should you? This question has been danced around for quite a few years now. Believe it or not many spray foam contractors either dont know the answer to this question or dont care. Mainly because it can be expensive and make you reconsider doing anything at all. Think of it like this, you called a few companies to come out and give you a quote on spray foaming your attic. The prices vary for the foam and they are doable, but then you notice the additional cost for removal. Wow! Now you are scratching your head thinking, Well do I really need to remove the old insulation, or can it just stay? At this point the guy trying to make a sale no matter what will try to persuade you not to do it just to get the job. But the truth is it takes someone with actual experience and understanding of the process to make a judgement call.

So here are the 3 options with removal.

  • Full Removal
  • Partial Removal
  • No Removal

Now that you know your options Im going to give you 3 reasons why we would do a full removal and then break down why you can get away with partial removal in some cases as well as possibly not having to do removal at all. Remember every home is different for the most part, there is many factors that go into play to make to right call so hiring a company with experience and proper training is crucial.

  • To Prevent Moisture Issues

Removing the old insulation for the attic floor will solve this problem.

  • To Guarantee a Good Seal

  • Improve Air Quality and Reduce Odors

See The Benefits Of Spray Foam Insulation For An Existing Home After Old Attic Insulation Removal

Should I Use Open Cell or Closed Cell Spray Foam in Attic? | Foam University

Now that you have a better understanding why removing old insulation from attic should be done before spray foam insulation can be installed, you may be wondering about the benefits of foam insulation for the rest of your home.

If you live in Michigans lower peninsula or the greater Toledo area and would like to schedule a free estimate to speak with one of our project managers about insulating other areas of your home, give us a call at 866-900-3626 or fill out a free estimate form on our website.

You can also find a ton of great resources in the Learning Center on our website.

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Can You Spray Foam An Attic

dowespray foamatticSpray foamattic

. Correspondingly, how much does it cost to spray foam an attic?

Cost of Spray Foam InsulationSpray foam is available in two types: open-cell spray foam which usually costs $0.44 to $0.65 per board foot and closed-cell spray foam which averages $1 to $1.50 per board foot. The average total cost to have spray foam professionally installed is about $2,366.

Also, can you spray foam the underside of your roof? Open- or closed-cell spray foam is applied to the underside of the roof sheathing, and additional fiberglass or cellulose insulation is blown in as a cost-saving method for meeting high insulation requirements and filling in the cavity space between the rafters to the ceiling deck.

Consequently, should I spray foam my attic?

Spray foam insulation is an incomplete name. It really should be called spray foam insulation and air barrier. A properly done spray foam job not only insulates but also greatly reduces the air leakage of a home. If you leave the existing insulation in the attic, it interferes with the foam installation.

What are the pros and cons of spray foam insulation in the attic?

The pros of installing spray foam insulation

  • air leakage is virtually eliminated.
  • an air-tight seal prevents heat loss.
  • home energy efficiency is assured.
  • seasonal energy bills are lowered.
  • ideal for attics, roofs, walls, floors.
  • higher R-Value than other installs.
  • moisture accumulation is reduced.

Why Remove The Old Fiberglass Or Cellulose When Insulating The Attic Roof Deck

The roof deck should be insulated for several reasons protecting the roof, giving your attic a space that is conditioned, and ensuring there are no drafts in your attic.

When the roof deck is insulated, the air moves into the attic, hits the roof where it cools down, and then falls back down. This means your attic is now a conditioned space, which means you heat and cool that area. You need to have air moving freely in and out of that area.

If there is a layer of fiberglass or cellulose insulation on the attic floor, as the air from your living space heats up and rises, it will want to move into your attic. You want to let that air get into that space without the hindrance of the old insulation.

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Why You Should Rely On Spray Foam Insulation For Your Attic

Insulating your attic with spray foam is a wonderful means to improve the energy-efficient quality of your home. You can even create an unvented attic by applying spray foam to the underside of your roofs deck. Google insulation contractors near me to get hold of an experienced insulation contractor with unmatched expertise in spray foam insulation service.

Smart choice for insulating attic floor

As most homes have vented attics that allow sufficient air flow to control moisture, its important that you ensure that the air is sealed to prevent leak out of conditioned air. Being an air impermeable insulator, spray foam is a good choice to insulate the floor of your attic. It keeps the conditioned air inside the living area while preventing warm or cool air in the attic from entering inside your home. The latter is useful to restrict condensation, mold growth and other problems.

Suitable for unvented attics

Spray foam is a good choice for insulating unvented attics as it acts as a powerful insulator and air-barrier. Here, the applied spray foam helps to control moisture levels, keeping the attic well-ventilated. This insulation when applied to unvented attics reduces energy loss through the attic, keeping homes warmer in winter and cooler in summer. Spray foam also acts as an adhesive to keep the roof deck in position during high winds.

Number one choice for new and existing construction

Improves energy-efficiency

To Prevent Moisture Problems


Think about temperature. Think about dew point. If you leave the insulation in the attic floor after insulating the roofline, the attic will be cooler in winter than if you remove the insulation.

But a common reason to put spray foam on the roofline is to avoid having to air-seal the attic floor. Thus, the air in the attic is connected with the air in the house. That means its more humid than outdoor air and more humid than vented attic air. Cold air is dry air, you know.

But now the attic isnt vented to outdoors. The attic is much warmer than outdoors in winter but significantly cooler than the living space if you leave the old insulation in the attic floor. That makes the surface of the spray foam cooler, possibly even below the dew point.

Removing the attic floor insulation will solve this problem. It is not, however, the first solution. As Dr. Joe Lstiburek says, we shouldnt be calling these things sealed attics or unvented attics. We need to think of them as conditioned attics. Once you deal with the air up there, this problem goes away, with or without the insulation in the attic floor.

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Problems With Spray Foam Insulation In Attics

The use of spray foam attic can present many potential problems, especially when it comes to the improper installation of this material within this area of your home. Spray foam installers may miss some of the air leakage sites in the attic, which can lead to problems in the insulation of the attic. When there are air leaks that occur in an attic it can lead to energy efficiency problem within the environment which can mean higher energy bills. Additionally, the application of too much or too little spray foam can also become a major issue in attic insulation. When there is too much spray foam that is added to a specific area in an attic, the expanding foam can envelop the boundaries between conditioned and unconditioned space. Whereas too little spray foam insulation can leave for thermal bypass because of the complete lack of insulation in the attic.

Moisture is also another huge issue when it comes to spray foam insulation in an attic. It has been said that insulating with spray foam insulation at the roofline will lead to moisture problems with the roof sheathing. One of the most common reasons to put spray foam on the roofline is to avoid having to air-seal the attic floor, because the attic is connected with the air in the house and indoor air is more humid than outdoor air which can cause moisture problems.

Spray Foam Insulation Mold Problems

To Get A Better Air Seal

Spray foam insulation is an incomplete name. It really should be called spray foam insulation and air barrier. A properly done spray foam job not only insulates but also greatly reduces the air leakage of a home.

But that only works if the installer can get it into the places where most of the air leakage happens. In an attic, the eaves are one of the most critical places to get good coverage with the foam.

If you leave the existing insulation in the attic, it interferes with the foam installation. Yeah, if you do a really good job raking the insulation back, you can still do a good job with the foam. But its harder and the chances of success are lower. I know. Ive done blower door tests on homes where they left the old insulation and the leaks were at the those transitions where the old insulation got in the way. The photo below is one of the homes I tested where the installer didnt get it sealed up.

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What Is Spray Foam Insulation

Spray foam is a liquid mixture of isocyanate and polyol resin that is forced together under pressure. When sprayed onto a surface it adheres and then expands to up to 60 times its original size. The result is a waterproof and airtight barrier to both water entering and loss of warm air from your home.

Spray foam can be used in many applications around the home, but is most commonly used as an insulation product either on the rafters of your roof or inside your interior and exterior walls.

There are two main types of spray foam insulation: closed cell and open cell. The former is a dense material that is perfect for sound insulation, while the latter has larger air pockets, and works well as an insulation material. However open cell does allow more air to pass through, enabling more effective ventilation.

When using spray foam insulation, you can achieve an entirely waterproof and airtight solution, but this can mean that warm air can become trapped in the space.

Other Reasons To Remove The Old Attic Insulation

DIY Spray Foam Insulation – What You Need to know Before You Start

Another reason you will want to remove the insulation on the attic floor is that if the airflow is hindered, there will be a difference in temperature from the attic to the rest of the house.

For example, in the summer, if it is 85 degrees outside, it is around 100 degrees in the attic, and the house is about 70 degrees. That is about a 30-degree difference between your living space and your attic.

Any time there is a temperature difference, there is a potential for condensation the higher the temperature difference, the higher the probability of condensation because you have a bigger window for a dew point to fall into. This also has to do with the humidity in your home.

The old insulation on the floor of the attic will almost always be cellulose or fiberglass, which are both fibrous materials that are both proven to retain and hold moisture and foster and invites condensation along with those moisture issues.

This condensation can then move into the drywall of your ceiling and the trusses inside the attic floor. The big issue is this creates the perfect condition for mold to grow not only in the insulation, but in your ceiling and other areas of your attic.

The bottom line is the old insulation needs to be removed because it hinders the airflow into the attic, it can promote mold growth, and it is dirty. The old insulation on the floor has been exposed to air from the outside because the attic is vented.

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