Frequently Asked Questions 

Can I keep the existing insulation in my attic?

The answer depends entirely on the spray foam application you are choosing.   When the attic is unvented, the answer would be no.  An unvented or closed attic assembly is one of the most popular applications for spray foam.  When your mechanical system or ductwork is in the attic this application yields the greatest amount of energy savings.  For this application foam is sprayed to the attic ceiling or roof deck, making the area semi-conditioned space.  It is crucial that all existing insulation is removed from the attic floor prior to the retrofit application using spray polyurethane foam insulation in the unvented attic assembly.  The thermal envelope is being moved from the attic floor to the roof deck and in order for the attic assembly to perform correctly, there must not be any vapor or thermal insulation barrier between the occupied area and the attic. Existing insulation removal is required by Code.  The removal of the insulation is required to ensure an airtight seal is created with the foam along the top plate of the exterior walls.  The existing insulation can provide a safety risk since it is located directly on top of the sheetrock ceiling and does not allow the applicator to achieve a proper footing in the attic when installing the SPF Insulation.  The existing insulation has the ability to leach the odor created during the install of the SPF Insulation.  This leaching action can cause the SPF install odor to linger indefinitely.   The attic floor must be vacuumed prior to the spraying operation.  Unfortunately rodents and other pests may sometimes inhabit attic spaces.  If the excrement, filth, and remains of these pests are not removed from the attic floor, the odors associated with them will have no place to go except into the inhabited space of the residence.  While this is an unpleasant topic, keep in mind that with the sealed attic that results from the retrofit application, your customer should not have to contend with these odors in the future. Sometimes pests and rodents hide very well in the building structures; therefore it is advisable to use pest control foggers to help eradicate these creatures from the attic. If such creatures are not eliminated from the building prior to the spraying, their exit path could possibly be blocked. This may lead to the death and decay of the rodents inside the closed attic.

What about DIY, can I do it myself?

Demilec does not support anyone installing spray foam insulation other than an Authorized Contractor.  There are several reasons why installing spray polyurethane foam is not a project for even the most seasoned do it yourself veteran or an untrained contractor.  The possible pitfalls of doing this range from multiple safety issues to performance problems and lower yields causing the project to cost much more than a professional job.

All persons spraying polyurethane foam need to wear the proper personal protective equipment.

While it is entirely possible to buy spray foam packs or kits, because of their low yields, they can often cost more per board foot than a professional would charge to do the project correctly.  Professional spray foam contractors have mobile factories that are designed to heat and process the chemicals to produce their maximum yield.  These mobile factories can cost more than $100,000 and require highly trained individuals to operate them.

Buildings are complex operating systems with all major components contributing to their overall performance.  Any change to even one component will impact the other components, which will affect the performance, indoor air quality, moisture, and energy consumption of the structure.  All of these factors should be addressed by a professional prior to and after the installation.

Making sure the home is sealed properly and testing the project is essential.  A professional will be familiar with all of the challenges in sealing the home properly.  They will also have all of the tools necessary, such as a blower door, to verify the performance of the structure.

What can we expect when having Demilec spray foam installed in our home?

The first step to having a great spray foam installation experience is finding the right Authorized Contractor.  Be sure to read our page on “What to Look for in a Retrofit Installer”. Your contractor should review the entire project with you from start to finish.  Their review should include safety measures taken on the job such as:

  • Protecting finished surfaces or other areas from over spray
  • Isolating the work area
  • Informing you of their plan for ventilation of interior applications
  • Extinguishing all sources of ignition during the process including pilot lights to gas stoves, water heaters, dryers, furnaces, etc.
  • Ensuring that there are no pets, children or other occupants in the structure during the installation or ventilation process.

As a homeowner, you will need to

  • Prepare the home by moving your furniture to give the Authorized Contractor a path large enough to access all of the areas they need to get to, including removing pictures from hallways they will be moving around in and clearing out the attic.
  • Have a plan for where your family will be staying during the installation and ventilation period.
  • Ensure that friends, relatives and neighbors are aware of the project and when the crews will be working at your home.
  • Give your Authorized Contractor full access to the property including parking at the closest access to the structure.

Now that my attic is so nice, can I store my things in it?

In accordance with the International Residential and Building Codes, an attic sprayed with an SPF material may only be used for the servicing of utility and mechanical systems.   No storage is allowed in these areas.  Code compliant storage can be created by providing an approved thermal barrier or, depending on the product, an interior finish system or intumescent coating can be applied.

Should there be an odor after the install?

If you have concerns about odors that you believe may be related to the spray foam insulation, contact your contractor to ensure proper installation procedures were followed and a thorough clean-up was completed. If your concerns are not resolved, please contact us at 817-640-4900.