Because it is mostly hot and very humid outside the building, the vapor barrier should be installed on the exterior of the insulation. This is recommended to keep the outside moisture from getting into the less humid, cooler interiors and damaging the building’s structure.
When should you not use a vapor barrier?
In many colder North American climates, vapour barriers are a required part of building construction. You may find that vapour barriers are often not required in warmer climates. And, if installed in the wrong climate or on the wrong side of building materials, a vapour barrier can cause more harm than good.
What happens if you don’t install a vapor barrier?
If water vapor diffuses or infiltrates into the wall cavity and finds the cool surface, moisture problems can occur. Of course, you can have moisture problems here even without the exterior vapor barrier because of what Bill Rose calls the rule of material wetting.
Where should vapour barrier be installed?
Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions: the inner surface in colder climates and the outer surface in hot, humid climates.
Do you need vapour barrier on interior walls?
Normally interior walls do not require a vapor barrier, but there are some situations where it is highly recommended. Interior bathroom and kitchen walls, for example, are areas where there is great benefit to installing a vapor barrier. Bathrooms and kitchens produce an enormous amount of water vapor daily.
Should I put a vapor barrier on my ceiling?
It is essential to have a vapor barrier installed with your ceiling insulation. It’s not uncommon for moisture and dew to form on a ceiling because of the temperature differences; moisture can cause mold and rot if left unchecked.
Do you need vapor barrier in garage?
The primary function of a vapor barrier is moisture control. In the garage, like other spaces in the home, condensation results from moisture in the air. Excess condensation and humidity levels in your garage can damage your garage’s foundation and cause tools, vehicles, and cabinets to rust faster.
Do vapor barriers cause mold?
The Problem With Vapor Barriers
This can lead to significant moisture problems and mold; problems occur when walls get wet during construction or more often throughout the home’s life.
Should I put a vapor barrier on my basement walls?
Steve Bliss, of BuildingAdvisor.com, writes: The short answer is: Don’t use a vapor barrier in a finished basement. This is asking for trouble, especially with a full bathroom, which generates a lot of humid air. Rigid foam board on the interior, like you have, is the ideal insulation.
Does a bathroom need a vapor barrier?
Protection From Moisture or Vapor
A bathroom is generally a very warm place. This is because whenever warm air meets colder air, the formation of moisture is therefore guaranteed. The vapor barrier is vital as it screens the place where the moisture could definitely form.
Should you put vapor barrier behind Cementboard?
If it’s a cement board, you need a vapor barrier, because cement retains moisture, which means the wood next to it is always damp.
Does drywall act as a vapor barrier?
The permeance of unpainted drywall is very high, generally between 20 and 90, so it’s not a vapor retarder at all. Meanwhile, air leakage through a 1 square inch hole in a sheet of drywall allows 30 quarts of water vapor to pass through the drywall under the same conditions.
