In this part of the country we get cold weather and we get wind. Spray foam stops the wind and stops moisture movement and adds 2.5x-3x more structural rigidity to a building than fiberglass or cellulose. Fiberglass allows wind and moisture to move through it. Cellulose does better but depending how it is installed is prone to settling which leaves voids at the top of the walls. We have had many people comment that they wished they had used foam instead of cellulose or fiberglass.

Yes, there are 2 different types of spray foam, open-cell and closed-cell foam.

• Open cell foam is a softer foam that has an R-value of roughly half that of closed cell foam. It stops air infiltration and most of the vapor transmission but requires a vapor barrier in North Dakota’s extreme cold climate.
• Closed-cell foam is more rigid than open-cell foam, has an R-Value of roughly twice that of open-cell foam and does not need a vapor barrier.

Open cell spray foam has an R-Value of roughly 3.5/inch depending on manufacturer.

Closed Cell spray foam has an R-Value of roughly 7/inch depending on manufacturer.

It is not uncommon for applicators to use both but we only spray the closed cell foam for 3 reasons:

• moisture control
• twice the R-Value
• resistance to damage

Moisture can penetrate open cell spray foam if there is no vapor barrier. As the vapor drives into the open-cell foam it will eventually come in contact with the exterior of the building which will be wood or metal. This moisture has the potential to rot or rust a building from the inside out. It does take high humidity but it can happen in a cold climates. The closed cell foam under normal humidity levels (less than 60%) does not allow for moisture transfer and can endure submersion under water for brief periods of time without its performance being compromised.

Twice the R-value per inch is another reason we use closed cell foam. Sometimes you need to get a lot of R-value in a space where there is only a few inches. With the closed cell foam we can pack a lot of insulation into a small area which will lead to greater comfort and energy savings.

When it comes to damage the closed cell foam is much more resistant to tearing, punctures and animal damage. In the ideal situation the insulation would be covered up but there are many cases where the foam is left either fully or partially exposed. In these cases there will be less chance of damage with closed cell spray foam dues to its density being 4x that of open cell foam.

There are 2 answers to this question: What works and what is needed to meet IBC code.

Shops typically get 3″ in the walls and 3″ on the ceiling. If they will be used as cool storage (around 35 degrees) then 2″ works fine. If it has to be code compliant then 3″ in the walls and 5″-6″ in the ceiling or 15″ to 19″ blown loose fill.

A house is typically 3″ in the walls and 5″-6″ in a non-vented ceiling or 15″-19″ blown loose fill if it has a vented attic.

Both shops and houses only get spray foam in the ceiling if a conventional vented attic is not used. A standard vented attic in a house or shop can have an R40 to R50 installed of blown cellulose or blown fiberglass and is much cheaper than the foam and has a performance comparable to foam. In areas that are difficult to insulate with the cheaper fiberglass or cellulose then we use spray foam. This can be in a vaulted area or a low pitch roof that will have the heating and ventilating ductwork ran.

To be IBC code compliant yes. Polyurethane spray foam is considered a plastic product and the code requires it to be covered with a thermal barrier. A thermal barrier can be 1/2″ drywall or intumescent coating that offers protection to the spray foam in case of fire. The thermal barrier typically adds a minimum of 15 minutes of fire resistance before a fire can penetrate into the foam. 

Does a building always get a thermal barrier, no. It is the responsibility of the owner to make sure their building is compliant. Many times the owner does not want to pay for the extra cost of sheeting or the thermal barrier coating. Most customers are more concerned with insurance than compliance and many insurance companies will insure your building regardless of compliance.

As a responsible insulation contractor we will always communicate code and offer services that will make a building compliant. That being said its always the call of the owner.

Spray foam is installed after the rough-in plumbing and after the rough-in electrical. It is easier for us to spray around plumbing and electrical wires and boxes than it is for other sub contractors to dig foam out. It is code compliant that electrical and plumbing can be encapsulated in foam so we usually install spray foam right before you drywall or sheet you walls.

Closed cell spray can take water for quite some time and not be adversely affected. We have actually had a basement that we spray foamed with 3″ of closed cell foam get completely flooded for over 3 weeks. When the water receded we did a absorption test and adhesion test. The foam was still dry and when we dug through it to the concrete substrate it was still fully adhered. The home owner cleaned out the house and we sprayed the remaining portions of the basement.

It is possible for closed cell spray foam to take water on in the case of abnormal high humidity for extended periods of time, like months. In cases where high humidity is an issue we recommend an HRV or heat recover ventilator commonly know as an air to air exchanger. How they work is they remove the stale humid air from inside a building replacing it with fresh drier air from the outside. The heat recovery unit heats the incoming air with the outgoing air in the winter without mixing the two so the building get fresh dry air with minimal energy loss. We recommended a humidity level range of 35% to 45%. If the foam does take on water it is an easy fix. Just get the building to normal humidity levels and the water will perm out of the foam over time.

Great question. Ideally spray foam sticks best when it is warm and dry. For wood we recommend 35+ degrees substrate temperature and for steel we recommend 40+ degrees substrate temperatures. We do insulate wood projects all year round but we have to heat the building with heaters that do not put moisture into the air. Both diesel and propane (especially propane) bullet heaters exhaust moisture into the air. Moisture in the air likes to condensate on cool surfaces like exterior walls which reduces adhesion. Better safe than sorry. We do on occation if the situation warrants will spray when conditions are not ideal but we refuse to warranty the work. We would rather spray when we can guarantee adhesion but will spray whatever…whenever a customer wants.