The Science of Experience



Cathedral Ceilings Need Careful Insulation

Posted by Emillie Lee

Feb 19, 2018 2:03:17 PM



Cathedral ceilings certainly add an element of luxury to a home, but there are some important design considerations to take into account as you begin planning construction of such a ceiling. Many of these concerns are centered around insulation. Making the wrong choice regarding insulation and ventilation can result in rotted wood, reduced durability, and the buildup of mold within the cathedral ceiling.

Using spray-applied insulation is a great choice when building a cathedral ceiling. Not only does spray foam insulation create a tight seal against outdoor air, but it also blocks moisture from entering the ceiling cavity, so mold buildup and rot are no longer concerns. The insulation expands to completely fill the cavity, so there is no air moving through the insulated space and ventilation becomes unneeded.

There are a few important steps to take when planning construction using spray foam insulation for your cathedral ceiling:

  • Extend the roof sheathing so that it meets on both sides of the ridge beam. No spaces should be left.
  • When installing the roof, use an ice and water shield about four feet up from the eave.
  • At the eave on the inside of the roof, use a piece of rigid foam board to fill in the space between the wall and roof sheathing.
  • After applying the spray foam insulation, trim away any excess before hanging the drywall.
  • Make sure that any recessed lights used in the ceiling are airtight and insulated.

NCFI Polyurethane supplies the products and equipment necessary to complete most any spray foam insulation project. Contact us to learn more about our high quality products or to find a spray foam applicator in your area.