No matter what style of roof you have, ceiling insulation is vital. One of the most difficult ceilings to insulate may be vaulted or cathedral ceilings. The problem in correcting cathedral ceilings is expense. Most homes have a finished cathedral ceiling and most homeowners are not thrilled about removing and replacing the finished materials.
Mold growing on cathedral ceilings is an indication of poor ventilation or a roof leak. Tackling this project is messy but vital to your home's health and comfort. Be sure to repair the roof prior to tackling the mold.
"The cathedral ceilings of the 1970s and 1980s were thermal disasters. In most cases, these ceilings leaked air, leaked heat, created monumental ice dams, and encouraged condensation and rot. In many cases, roofers tried to solve these problems by improving ventilation openings in the soffits and at the ridge; these “improvements” often made every symptom worse." Read more
Should I Vent My Cathedral Ceiling?
Cathedral ceiling venting can be a controversial topic. The best answer is, "Well, it depends."
Building codes have required venting cathedral ceilings. The problem with that is some contractors will use flimsy foam board baffles that cannot stand up to the pressure of the batt insulation.
When venting an area, cardboard baffles or plastic baffles seem to work better. Also, you may decide not to vent at all if you go with a two component polyurethane spray foam. Then you get into the controversy of open cell or closed cell spray foam. Again, it depends on your home.
How do you plan on insulating your cathedral ceilings? You can go through the roof if you have roof problems that warrant removing the roof but no one wants to tear there roof off to insulate there ceiling if it is not necessary.
The interior option could be just as demanding. Vaulted ceilings 20 feet off the ground with tongue and groove wood may be as costly and difficult as a roof tear off and certainly less messy on the inside of your home.
Many times an incorrectly insulated ceiling can lead to humidity and mold issues and cannot be ignored.
Mold on the Ceiling
The presence of mold on your ceiling usually means one of two things, you have a humidity problem or a roof leak. Both are huge problems and require quite different solutions.
We are seeing a rise in humid attics over the last few years requiring the installation of a dehumidifier. This could be caused from the way the attic was designed along with the type of insulation used and whether ventilation was done correctly if needed at all.
Stucco homes seem to be better insulated and may actually trap moisture especially during a plumbing issue.