Frequently Asked Questions (FAQ)

 What is spray foam insulation?

Spray foam insulation is formed by the mixing of two chemicals and is applied with a spray gun to residential, commercial and industrial building structures for a multitude of purposes. Once the liquid is sprayed on the surface, it will expand from 30 to 100 times its original volume depending upon the foam product and the needs of each application. During the expansion process, the spray foam will chemically bond to the surface it is applied to and harden in less than ten seconds to form a solid plastic barrier. 

How is Spray Foam insulation installed?

The Spray Foam insulation is sprayed into place onto a studded wall, attic roof deck or other structure that is clean and free from debris.  The foam insulation can be sprayed after electrical and plumbing services are in place. It then expands 30 to 100 times its initial volume in seconds, permanently adhering to the surfaces of the surrounding building materials and sealing all cracks and gaps.

Is spray foam insulation a safe product for my home?

Pentoir Spray Foam is an EPA approved product that safe for you and your family.  Spray foam will harden after sprayed and emit no harmful gases making it completely safe for your home or business. 

How does SPF reduce energy use in buildings? 

  • SPF provides a continuous air barrier.
  • SPF prevents moisture infiltration through air leakage.
  • SPF minimizes dew point problems and condensation.
  • SPF avoids thermal bridging.
  • SPF resists heat movement in all directions.
  • SPF provides reliable performance under varying conditions.

How does Spray Foam Insulation control indoor air quality and comfort? 

Spray Foam Insulation provides a sealed thermal envelope. When the spray foam expands, it conforms and fills each cavity and void completely.  This will reduce air infiltration and dust while eliminating harmful household mold and mildew. Spray Foam Insulation provides a healthier living environment with no harmful emissions that can cause allergic reactions.

What is the difference between open and closed cell spray foam? Which one is best for me?

Both open and closed cell spray foam are superior to fiberglass and cellulose. They provide better insulation, restrict air infiltration and increase moisture blocking. Closed cell spray foam costs more than open cell; however, it provides greater insulation and has the ability to add structural strength. To choose between closed and open cell you must look at several factors:  
  • do you need complete moisture and vapor barrier?
  • How much of an energy savings are you wanting to achieve?
  • If you live in an area with violent storms, you may want to add structural strength to your walls and attic.

How long does spray foam insulation last?

Indefinitely!   Spray foam is an inert, long lasting polymer and its physical properties change very little over time. The application process is the most essential factor in this process. Always use trained technicians with the proper equipment to insure you receive the highest quality results.

Will spray foam insulation save me money?

Spray foam insulation will save you money. The initial cost to install spray foam insulation is more than conventional insulation; however, your energy saving potential is increased by up to 50%. This cost will quickly pay for itself while adding value to your home or business. In some cases, you are able to reduce the size of your central air conditioning equipment during new construction or remolding. This is an immediate impact on cost.  

How will spray foam affect my roof warranty? 

Spray foam insulation installed to the underside of a roof deck should not affect its warranty.  In fact, your roof’s structural strength will increase. Sheathing and shingles are unaffected by this application. In all cases, we do recommend that you speak with your roof warranty company.  We will assist you with any concerns.  

How long has spray foam been around?

Although spray foam insulation as we know it today truly emerged in the 1980s, spray foam actually has its roots several decades further in the past, beginning with the development of polyurethane foam in the 1940s by Otto Bayer. The first applications were for industrial projects and commercial cold storage facilities. Later, spray foam applications were developed for roofing systems. Early on, this technology was primarily developed due to its ability to add structure strength and not for its energy saving benefits.

Can I install spray foam myself?  

There are kits on the market that could allow you to complete a small project. However, due to the complexity of the insulation process, the need for specific training, special equipment and knowledge of safety precautions, we do not recommend allowing just anyone to install spray foam. Spray foam installation requires a skilled technician to insure chemicals are mixed at the correct ratios and temperatures. Also, during application, it is important to use proper techniques when applying spray foam.  Pentoir Spray Foam will provide the necessary equipment and trained technicians to insure your insulation project meets the highest standards. 

Can spray foam insulation be applied in crawl spaces under my house, below my wood floors?

Yes. This is a great place for spray foam insulation. Applying foam insulation under the wood floors or under subflooring will create an air seal and insulates the floor. It also seals all the cracks and holes preventing the intrusion of rodents, insects, and spiders. The spray foam insulation creates a tighter and stronger floor with less creaking noise form walking. The foam will protect your wood floors from ground moisture which can slowly rot your wood. Installing fiberglass batts under your floors is a huge mistake--they tend to settle, creating an air gap where moisture can penetrate and damage the wood.

When is the best time to install spray foam?

For new construction or renovations, it is the last installation to take place before drywall installation. The technician will install the insulation after the windows, doors and roof systems are in, the electrical, framing and plumbing inspections are complete, and after any other electrical or mechanical system located behind the drywall is installed. With existing homes, the spray foam insulation can be installed to the attic, roof line, basement and sub-flooring to seal in the house.

Do you need to remove wiring before installing spray foam? 

No. Spray foam insulation can be applied directly to properly sized electrical wiring. Certain electrical fixtures, such as lights, may require the use of a box type barrier for cooling and air circulation.

Do you need a vapor retarder or a vapor barrier with SPF insulation? 

It depends of the use of the building, the climate and the materials of construction. In normal occupancies and moderate climates, SPF insulation typically does not require a vapor retarder. Extremes of climate and building use may require vapor retarders/barriers. Check with your design professional for specific recommendations and refer to SPFA technical document, AY 118, Moisture Vapor Transmission for further information. 

Is SPF a good soundproofing material? 

Yes. Both low and medium (2lb/cubic/ft) density SPF effectively reduce noise from outside sources by sealing cracks and gaps that allow sound to travel through the walls, floors and ceilings into the building. They are less effective against noise caused by vibration. 

Can we add or remove wiring after spray foam is installed? 

Yes. We recommend always using an electrician. He will be able to pull wire and make any necessary upgrades with the spray foam already installed. For some applications, such as theater rooms, we recommend the use of conduit with in the wall structure prior to spray foam installation. 

Do building codes allow for spray foam?

Even though spray foam is still considered new technology, building codes do allow for this application. In most cases, you may even be eligible for tax benefits. Some states, such as Florida, have mandated lower rates on homeowners insurance due to the benefits with storm damage prevention. 

Since spray foam insulation is so much better than fiberglass and cellulose, why isn’t everyone using it?

[When spray foam was first introduced in the early 70s, there were some concerns with toxin levels from large amounts of formaldehyde in its chemical makeup. Today’s spray foam insulation does not contain formaldehyde. The cost of electrical power was also a fraction of what it is today. Since then, energy costs have sky rocketed and are predicted to continue to increase as the demand also increases. With the movement to “go green” and the greater long term financial value of spray foam as compared to fiberglass or cellulose insulation, the commercial and residential demand has also increased.]

Does spray foam insulation contain formaldehyde?


Do you need a contractor’s license to install spray foam??

No, you do not. Keep in mind--this is an investment in lower energy costs, mold prevention, noise reduction, and better air quality. Due to the complex nature of the equipment, safety precautions with chemicals, and understanding of how temperature affects application, we strongly recommend using professionals only.

Will spray foam insulation absorb or trap moisture?

Closed cell spray foam will not allow moisture, air movement or condensation. Open cell spray foam insulation can absorb moisture; however, it will dissipate the moisture within a relatively short period of time. Spray foam insulation will expand sealing all gaps so these moisture sources are virtually eliminated. Cellulose and fiberglass are porous and will allow moisture to soak and ruin the insulation. [Spray foam insulation is ideal for areas with significant temperature changes between summer and winter. ]

If I use closed cell spray foam insulation under the roof deck, do I need to ventilate the attic?

With closed cell spray foam you should seal your attic as tight as possible from the outside by eliminating vents. We do advise a form of air exchange between the attic and the living space to allow air circulation while creating a true thermal envelope. 

What is the difference between a vented and unvented attic? 

[Unvented (conditioned) attics use air-impermeable insulation as a barrier to prevent moisture condensation on the underside of roof decks. Vented attics minimize condensation by allowing the escape of moisture to the exterior by air flow. ]

If I have spray foam insulation on the underside of the roof deck, will a roof leak root my roof?

No--spray foam installed to the underside of a roof deck will not root your roof. When spray foam insulation is installed to the underside of a roof deck, a chemical bond forms allowing no gaps for any water leak to become trapped.  Spray foam insulation will help protect your home or business by preventing water from leaking through your roof material.

How do you install drywall over spray foam? 

After spray foam is applied, fully expanded and hardened, the technician will use a special cutting tool to create a smooth surface for the drywall installer. This technique will ensure the drywall will lay flat without bowing.

 How does spray-foam compare with fiberglass batts and blow-in cellulose?

1. Fiberglass batts will not stop air leakage. Blown-in cellulose will slow down air leakage. Spray-foam will stop air leakage dead. Spray-foam is also mold and moisture resistant unlike fiberglass and cellulose.
2. Fiberglass batts can sag over time; blown-in cellulose can settle over time: both situations will reduce R-value an increase energy cost. Spray-foam completely adheres to wood and sheathing; the result is a permanent barrier to heat loss and air intrusion.
3. Spray-foam can add strength and rigidity to your house. Fiberglass batts and blown-in cellulose will not.
4. Spray foam will not provide a home for moisture and mildew. Fiberglass batts and blown-in cellulose can provide a home for mold growth due to moisture.
Closed cell foam insulation….R 6.7 per inch
92% Efficiency Rating
3 ½ inches in a 2x4 wall with a 92% ER is equivalent to R63.7
2 inches in a 2x4 wall with a 92% ER is equivalent to R40.18
1 inch in a 2x4 wall with a 92% ER is equivalent to R20.09
Does not collect moisture
Open cell foam insulation……….R 4.21 per inch
44% Efficiency Rating
3 ½ inches in a 2x4 wall with a 44% ER is equivalent to R13.72
Collects moisture
Cellulose insulation………R 3.5 per inch
36% Efficiency Rating
3 ½ inches in a 2x4 wall with a 36% ER is equivalent to R12.74
Collects moisture
Fiberglass insulation…….R 3.2 per inch
32% Efficiency Rating
3 ½ inches in a 2x4 wall with a 32% ER is equivalent to R11.2
Collects moisture