New Home Insulation

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Closed cell spray foam roof insulation on timber frame home in Carrollton, OH

Congratulations! You are building a new home and you are excited but maybe also a little intimidated. There are so many decisions to make that it can make your head spin. Some of these decisions will be for the life of your home while others can easily be modified later; your foundation is there to stay but your bathroom fixtures can always be upgraded. Choosing your new home insulation system is a decision that will have a lasting impact on your quality of life and finances.

With the barrage of images coming at you from every direction, it is easy to be dazzled by the bling but before you settle on that granite countertop, pay attention to the structure of the house: foundation, framing, windows, siding, roof, HVAC, insulation. These are the things that cannot be changed later without great cost so get them right the first time.

This is where working with a team of knowledgeable professionals comes in, people who know that their contribution is one of many system components that must work together; change one thing and it may affect the design of others. At Pure Seal, we understand this process and over the years we have worked with some of the finest architects, builders and craftsmen in our area to help specify and build homes that are beautiful, strong, healthy and comfortable.

For an explanation of the ideas and principles behind our approach, please visit the Resources section of this website.

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What does it take to build a house that is comfortable and efficient? The Ohio building code is confusing; various combinations of R-value, heating duct tightness and air infiltration rates can be used. Bear in mind that the building code is a minimum standard that a house must meet; that is all – a minimum.

Insulation recommendations

At Pure Seal, we believe that the code falls dramatically short in one particular area: air tightness. A house that leaks is a house that is both inefficient and uncomfortable. For that reason we pay great attention to air sealing and we document our results with a blower door test. Our target is a finished house that is at least three times tighter than required by code and we routinely exceed our goal.

Here are our currently recommended specifications, which make up our standard package:

– Under slab insulation: R-10, closed cell spray foam.*
– Foundation walls in crawlspaces and finished basements: R-13, closed cell spray foam.
– Rim joist in crawlspaces and basements: R-20, semi-closed cell foam
– Floors exposed to the outside: R-30, semi-closed cell foam
– Framed wall cavity insulation: R-20, semi-closed cell foam
– Cathedral ceilings and conditioned attic spaces: R-38, semi-closed cell foam
– Unconditioned attic floors: R-60, foam for air sealing and cellulose for additional R-value
– Seal around windows and doors with low expansion window foam
– Caulk wood frame with urethane caulk
– Air leakage target: 2 ACH50 or less**

(*Under slab insulation is not a code requirement but highly recommended. **Air Changes per Hour at 50 Pascal negative indoor pressure, the standard blower door pressure differential.)

Other Design Considerations

These insulation specifications will give you a home that is draft free, comfortable and very economical to operate. The efficiency of the building envelope must be taken into account when designing the Heating, Ventilation and Air Conditioning system (HVAC). It is not only possible but necessary to reduce the size of your air conditioning unit to ensure proper operation and moisture removal in the summer. By reducing the size of your furnace and air conditioner, you will reduce both the installation and operating costs.

Your furnace should be a high efficiency, sealed combustion design. By using such units, you will reduce your operating costs and keep combustion gasses out of your home. If you choose to install less efficient, open combustion units, you must provide a supply of combustion air to avoid the risk of back-drafting, which can be potentially dangerous.

An energy efficient fresh air supply system should be part of your design. Because your new foamed house is going to be very tight, fresh air must be supplied to ensure high indoor air quality. Customers often ask if their house is going to be too tight. The answer is no, a house cannot be too tight but it must be ventilated correctly. Only by making the house tight can we control the indoor climate and air quality appropriately.

We recommend the use of a heat or energy recovery ventilator (HRV or ERV). These systems exhaust stale indoor air and replace it with fresh, filtered outside air. In doing so, they use the energy in the stale air to precondition the incoming air. HRV/ERV systems are very energy efficient. The best of them capture up to 95% of the energy while operating on less electricity than a small old-fashioned light bulb.

If your goal is to build a home that can capture its energy from the sun, the loads must be reduced even further and we have the expertise to help you with that design process as well.


The cost of foam insulation is typically two to three times the cost of fiberglass but good insulation pays for itself in energy savings. Those savings will more than cover any increase in your mortgage payment so you will save money every month. On top of that, your home will be more valuable and easier to sell should you later decide to move.

Before we undertake a job, we provide you with a written proposal, which clearly states the work to be done and what the price will be. We urge you to carefully examine competing proposals and compare apples to apples. Material choices and installed R-values can significantly impact cost.

Under-slab insulation
If you are installing radiant heat in your slab, insulation is a must. Even if you are not, R-10 foam insulation will be a great comfort boost in a finished basement. (Chardon, OH)
Exterior foundation insulation
Closed cell polyurethane spray foam can be applied with ground contact and provides a continuous layer of insulation (Chagrin Falls, OH)
Polyurethane foam being applied
Notice how quickly the foam expands to fill the cavity.
Sprayfoam finds and seals all gaps
Sheathing must be installed with gaps to allow for seasonal movement. This leaves a hole that air can move through. Sprayfoam solves that problem
Foam seals around pipe
Notice how the spray foam completely seals the gap around this pipe, which prevents unwanted air infiltration (Bainbridge, OH)
R-20 with 4 inches of spray foam.
Our 1 pound density polyurethane spray foam has an R-value of almost 5 per inch. This means that we get R-20 in a 2x6 wall with little waste of material . The foam is air impermeable so it doesn't matter that the cavity is not filled; the foam defines the boundary, not the drywall (Novelty, OH)
Exterior walls in timberframe home
Sprayfoam automatically conforms to any cavity size or shape (Hiram, OH)
Detailed air sealing
We use low expansion window foam to seal between the window and the house framing. Gaps between the framing members are sealed with urethane caulk (Avon, OH)
Spray foam used to air seal an attic floor
It is critical that all gaps between the living area and the attic be sealed. Notice the boxes in the background. They are boxed and foamed can lights. Once sealed, the attic floor is covered in a thick layer of cellulose (Westlake, OH)
An unconditioned attic
This attic floor was insulated with cellulose to R-60. We foamed for the skylight.
An all-foam attic floor system
For the ultimate in cleanliness and durability, some clients prefer spray foam over cellulose on the attic floor (Kirtland, OH)
A conditioned attic
A conditioned space is the best choice if there is duct work in the attic. Spray foam insulation in the roof keeps the summer heat out and losses from the ducts are eliminated (Novelty, OH)
Circular roof
This circular roof is 30' in diameter and 40' high at it's peak. The irregular cavities are a perfect application for spray polyurethane foam (Chesterland, OH)
Blower door test
We use our blower door to test for air tightness during the insulation process and again after the house is completed (Kirtland, OH)

Pure Seal Testimonial:

In 2013 as I was designing my home, I was very interested in employing environmentally conscious initiatives. I had educated myself on the long-term benefits of using geothermal versus conventional furnaces. I also knew how my consumption would be less if I had better quality insulation and thicker walls. A friend who had built their home a few years earlier had used Pure Seal instead of conventional fiberglass insulation. When I asked him about his 4 year utility averages on an 8000 square foot home in Chagrin Falls Ohio, I was certainly intrigued. Torsten met with me and my LEED certified designer to explain to us the benefits of foam insulation compared to the builder’s standard of blown in cellulose. Within the week he prepared an estimate and a fluid plan to maximize the benefits of all elements in my structure, HVAC etc. In January of 2015, his team followed the original plan and integrated well with my chosen builder to insulate the home. I was really impressed with how small the utility bills were throughout that year of construction. During the finish, there were some minor adjustments that required him to come on site for some modifications. I could always count on him to be there within 24 hours with a site visit and a quick implementation of a solution.

From inception to the finish, I found that Torsten and Pure Seal have delivered both in product and service. Though there is some financial investment compared to minimal, conventional materials, there is no question that I feel my decision to insulate this way was well-placed.

Najia Usman D.D.S.