air barrier Archives

August 7, 2020 by Eco Three

Considerations for Spray Foam

Are you thinking about spray foam for your house or building?

When contemplating making your home more energy efficient, there are special considerations for spray foam. Spray foam is a high-performance insulation and air barrier that will help reduce comfort issues and make a home more energy efficient. The preparation and installation needs to be done correctly AND safely. (Read this blog we wrote for BPI to see what can go wrong.) Recently, we have encountered clients who are obtaining multiple quotes for their foam projects. This has given us some good (albeit scary) information about what is and is not being explained to clients for consideration prior to a spray foam project.

These are important things to think about before you have spray foam work done.

Are you able to have all occupants (including pets) out of the house for the installation?
Are you able to have all occupants out of the house for the off-gassing period? (generally 24 hours after installation is complete)
Will the existing attic insulation (for retrofits to existing structures) be extracted/removed? (Read this to see why it matters.)
Are there combustible appliances in the space to be encapsulated? Do they need a fresh air intake/makeup air in order to safely and properly function?
Does the space to be encapsulated (attic) have a duct system in it? Will a supply and return or exhaust be installed…or will there be a louvered door or passage to connect the space to the rest of the conditioned space of the house?
Will soffit, ridge, gable, and/or crawlspace vents be covered prior to spraying?
Does your termite bond restrict what areas are foamed? (especially critical for crawlspaces)

If you are about to go with a company that has not mentioned all these considerations for spray foam, you should think twice…and call Eco Three. We have unfortunately heard too many stories of clients who are unaware of these important factors. We want to help clients stay safe and healthy when getting spray foam – before, during, and after installation.

Eco Three is a trusted, leading-edge home energy authority dedicated to helping homeowners in Alabama through our comprehensive home energy audits and energy-efficient upgrades. Our nationally accredited team of hometown experts uses the latest technology to provide actionable solutions to outrageous energy bills and home comfort issues. We’re an experienced group of people with a unique plan and a sincere interest in making a difference in people’s lives and the environment. We service existing homes as well as new construction.

February 8, 2018 by Eco Three

Spray Foam Gone Wrong

This Blog was originally published on BPI’s (Building Performance Institute) website here.

Also, be sure to check out this video of a spray foam nightmare that we removed and redid for a homeowner via our Eco Three Gulf Coast office.

Spray Foam Gone Wrong: Issues with Air Flow, Chemical Mixing, Thickness and a Single Thermal Boundary

All Photos Courtesy of Eco Three

The popularity of spray foam insulation has steadily increased in recent years. Although it can cost approximately two to three times more than traditional batts or blown/loose-fill insulation, the long-term benefits of foam often outweigh the upfront cost. For those who have had positive experiences with the product, they would recommend spray foam to anyone – even those with sticker shock.

When installed correctly, spray foam acts as an insulator and an air barrier. Depending on the foam type, it can dampen sound and keep moisture out while reinforcing a structure. There are major benefits to using foam; however, there is a lot more to it than just aiming and pulling a trigger. Accurate chemical mixing and proper installation are critical. If either is done incorrectly, several problems can occur.

Potential issues with air flow

For example, when encapsulating an attic by foaming along roof rafters and decking, the entire attic must be sealed to bring the attic inside the thermal boundary. This means that all venting (soffit, ridge, gable or any other venting) must be removed or completely covered. This effect reduces air flow in and out of the attic space to make it “unvented” or “encapsulated.”

Foam reduces airflow in a home, so sometimes fresh air intakes need to be added. An industry standard test called a “Blower Door Test” is the best way to ensure that airflow falls within a target range for the home. If a foamed house is drafty or if the encapsulated attic feels more like the outside temperature, this indicates that exterior air has not been sealed out and is entering through gaps. When an attic is properly sealed and is part of the conditioned space, it should feel about as comfortable as any interior room in the home.

Potential issues with chemical mixing

If the spray foam chemicals are not mixed within the specified temperature range or correct ratio, problems can arise. The product may not adhere to roof decking, attic floors, wall cavities, etc., and/or not expand properly to fill all gaps and cavity surfaces. Improperly mixed applications can also off-gas indefinitely and produce oily residues.

Potential issues with consistent thickness

For spray foam insulation to be effective and maintain a consistent R-Value (resistance to heat), it must be applied in an even thickness. When it is not even, conduction can occur, thus rendering the spray foam ineffective. Using an infrared camera helps identify areas of uneven thickness. Or, one can use a marked stick or skewer to spot check various areas for consistency.

Potential issues with a single thermal boundary

For an attic or crawlspace/basement encapsulation, existing insulation (on the attic floor or crawlspace subflooring) must be extracted so as not to create two thermal boundaries. In such cases, double insulation is not better; it can potentially cause moisture problems.

In conclusion, spray foam insulation – when mixed and applied correctly and evenly – can make a world of a difference in terms of insulating and air sealing a home. Conversely, when it is not done properly by trained professionals, foam can cause big problems. If you find yourself wondering why your spray foam insulated home is not as comfortable as you had anticipated or your bills seem to be high despite this energy efficient product, you may have a problem. Also, if the foam continues to off-gas and produces a smell or an oily residue or seems very uneven, something is not right. Contact a certified and reputable company to examine your home to identify and remedy the issue – either through additional foam or through re-venting and traditional weatherization techniques.

Warning: Chemicals used during spray foam installation are flammable and improper installation could cause a fire.

July 28, 2017 by Eco Three

Case Study on Air Sealing

Attic Culprits

There were several large, open chase ways exposing the backs of interior walls with no insulation. These allow hot (or cold) attic air to radiate through the walls and into the conditioned living space. We also found plumbing and electrical penetrations that were unsealed and allowing unconditioned air to enter the conditioned space. Light fixtures, especially can lights, often leak air from the attic into conditioned space causing excess heat (or coldness).

We completed our audit and prepared our report with the prioritized and customized scope to improve the comfort of their home. Our top two priorities were sealing the duct work and AIR SEALING. Insulation was a close third, but due to budget constraints, the clients decided to have us do the duct sealing and the attic air sealing. And guess what?! They could immediately feel a huge difference in the evenness of the cooling throughout the home – even in the front room.

Balloon Framing

This home is not unique in terms of air flow and leaking ducts. It was built with balloon framing, which means wall cavities run from the unconditioned crawlspace, past the conditioned spaces, all the way up to the unconditioned attic. This was a popular way of building before the introduction of central heating and cooling because balloon framing causes stack effect and air flow for drafts and natural ventilation. Since the introduction of central heating and cooling, we work to stop this venting so that the HVAC system works more efficiently and the walls do not radiate hot or cold air from outside.

If you are unsure if your home is properly air sealed and performing at its best and most efficient state, call us to investigate (Birmingham area: 205-314-3500 or Gulf Coast area: 251-615-1330).

August 9, 2016 by Eco Three

Importance of Air Sealing

The Importance of Air Sealing

air leakage - open top plate allowing hot air to enter — Open Top Plate Allows Hot Attic Air to Enter Conditioned Space

Insulation is an extremely important aspect of home energy efficiency and home performance. However, air sealing is an equally important component that is often overlooked. When we talk about an air barrier, we are referring to the “building envelope” – a boundary between conditioned space and unconditioned spaces. The tighter the envelope, the less air is leaking in and out of your home. Generally, the air barriers in a home are the exterior walls, the attic floor, and the ceiling of the basement/crawlspace. All of these locations contain plumbing and electrical penetrations, unsealed recessed/can lights, open chase ways, and open bottom and top plates that all provide pathways for air infiltration and exfiltration.

air leakage - can light open to hot attic — Unsealed Recessed Light Allows Hot Attic Air to Enter Conditioned Space

Think about it this way…have you ever been out in cool weather with a little wind and put on a sweater or fleece jacket? You may have felt warmer but still felt the wind blowing through. If you couple your sweater or fleece with a wind breaker or shell, you would feel even cozier. Well, think of your house the same way. The insulation is like your sweater, and a properly sealed envelope (or air barrier) is like your wind breaker. When your HVAC system (heating or cooling) turns on, it pulls air into the central return from wherever it can (along paths of least resistance), and heats or cools and dehumidifies the air before it forces it out via the registers into each room. Oftentimes the systems will pull air from your hot (or cold, depending on the season) attic or basement and then work to cool or heat it. Wouldn’t it be less work and take less energy for your HVAC system to heat or cool air that is NOT coming from the outdoors?! Definitely. A tighter home holds more conditioned air, so that your HVAC system has less work to do. Therefore, with proper air sealing and sufficient insulation, you spend less money on your power bill and stay more comfortable.

Case Study:

Open Top Plate with plumbing and electrical penetrations — Unsealed Plumbing and Electrical Penetrations in an Attic Provide Pathways for Unconditioned Air to Enter Conditioned Space

We performed an energy audit on a historic home in the Forest Park neighborhood of Birmingham in the summer of 2015. The clients were having trouble keeping the home cool enough to be comfortable, and there was a front room with lots of windows that never got cool enough to be in. Their AC system seemed to run constantly and was not able to keep the house at the desired temperature. However, the basement/crawlspace was very comfortable…because that is where the duct work was located, and it was leaking very badly. We completed our audit and prepared our report with the prioritized and customized scope to improve the comfort of their home. Our top two priorities were sealing the duct work and AIR SEALING. Insulation was a close third, but due to budget constraints, the clients decided to have us do the duct sealing and the attic air sealing. And guess what?! They could immediately feel a huge difference in the evenness of the cooling throughout the home – even in the front room. This home is not unique in terms of air flow and leaking ducts. It was built with balloon framing, which means wall cavities run from the unconditioned crawlspace, past the conditioned spaces, all the way up to the unconditioned attic. This was a popular way of building before the introduction of central heating and cooling because balloon framing causes stack effect and air flow for drafts and natural ventilation. Since the introduction of central heating and cooling, we work to stop this venting so that the HVAC system works more efficiently and the walls do not radiate hot or cold air from outside.

If you are unsure if your home is properly air sealed and performing at its best and most efficient state, call us to investigate (Birmingham area: 205-314-3500 or Gulf Coast area: 251-615-1330).