Vapor Barrier


Vapor Barrier

Vapor Barrier Raleigh, NC

The proper placement of a vapor barrier is a key component to consider when planning a building’s wall design, as well as crawl space design. The purpose of vapor barrier systems are to control the amount of water vapor that diffuses through a wall or floor. Searching for how to install vapor barrier in crawl space? Many commercial building codes in Raleigh and throughout the Triangle area require encapsulation of structures with a vapor barrier. When condensation permeates walls and floors, it can lead to the deterioration of components, mold, and ultimately leads to expensive repairs. Repairs that could have been avoided with proper waterproofing services early on.

What is a Vapor Barrier?

There are several types of crawl space vapor barrier material available for both residential and commercial structures. Some of the most common types of materials include aluminum foil, polyethylene, polyurethane coatings, and rubber membranes. Simply defined, a vapor barrier is any type of material that prevents moisture from penetrating through ceilings, floors, and wall. The two most commonly used types of materials are plastic sheeting and also paper-faced insulation.

Correct Installation

In order to stop condensation from forming, you should install a vapor barrier on the warm side of the wall, floor, or ceiling. This prevents warm air from condensing on cold surfaces inside your walls. In colder climates such as Maine, vapor barrier installation is usually on the inside of the wall assembly over the insulation. For warmer areas such as Raleigh, most professional vapor barrier system contractors installing a vapor barrier on the exterior side of the insulation before installing the sheathing.

Contractors install vapor barrier first, prior to interior gypsum drywall and exterior sheathing like DensGlass. A standard barrier may include four-millimeter-thick sheets or rolls of plastic. This heavy weight plastic allows for encapsulation of the entire wall. This advance preparation then impedes wet air intrusion into the insulation. Thus, preventing condensation from forming within structure walls.

Improper Installation Of Vapor Barriers

The incorrect installation of barriers can lead to a host of moisture-related problems. The purpose of vapor barriers is to stop commercial and residential walls, floors, and ceilings from experiencing water intrusion that begins in the form of condensation. More simply put, the material of a vapor barrier completely prevents moisture from passing through. This goes both ways though. If a wall has moisture within it prior to the placement of the vapor barrier, it can also stop the wall from being able to dry. When installation occurs in walls where the climate is typically very warm, this can become a problem. Air-conditioned spaces will prevent the walls from drying inward. Therefore, in warmer climates, it works best if the installation of the vapor barrier is on the exterior side of the wall.

It can also cause a major condensation problem if it’s installed on both sides of the wall. If you seal off both sides of the wall, it traps the air with no place for it to exit. Also, if installation takes place over the top of building paper where exterior brick walls are. This can result in condensation and mold. As well for these types of applications, it’s better to install it on the interior side of the walls.

Why Do You Need a Sealed Crawl Space?

Preventing moisture from entering into crawl space air is a huge benefit that vapor barriers can accomplish. A sealed and encapsulated crawl space is a huge plus when it comes to preventative home maintenance. A crawl space left unsealed can result in seemingly innumerable hidden issues. For instance, moisture can cause mold to form on insulation and framing members of the structure. For new constructions, installing a moisture barrier on the ground prior to the foundation is key to stopping moisture. As concrete floors age, they often settle and crack, which allows moisture from the ground to rise to the surface. This can cause standing water on your floor and yard drainage problems as well as a variety of mold issues.

One method often deployed for older concrete floors with gaps in the floor is a process known as a crack injection. The process utilizes a variety of materials including epoxy, liquid cement, asphalt, and polyurethane grout injections. Seal foundation cracks immediately, it can prevent moisture from the ground from entering into your structure. Attic crawl spaces and areas behind kneel walls should also be taking into consideration for effective moisture control.

There are many reasons why vapor barrier installation should occur in all crawl spaces. Such as:

  • Reduces Wood Rot
    • Lumber that is subject to moisture will eventually rot and decay. Rotting wood creates the perfect environment for mold to grow. The structural integrity of your home will also be compromised with rotting framing members.


  • Eliminates Remediation Expenses
    • Once moisture and mold have formed on wood and insulation? You will need to hire a professional mold and mildew remediation company to safely remove it. Once the remediation process is complete, the expenses can grow with the replacement of insulation and damaged wood.


  • Protects Infrastructure Components
    • Your home’s electrical wires are a key component to running your house. But what if moisture gets to into them? It can lead to rusted wires, electrical shorts, and electrical fires. The plumbing in a structure is also very important and can ultimately experience issues that stem from moisture problems. As well, boiler systems, HVAC system components, and even water heaters within structure’s crawl spaces can become damaged. Therefore, prepare ahead of time and take steps to prevent a wide array of catastrophic damage that can occur because of moisture. It is paramount to invest in professional vapor barrier installation for your home or business.


  • Maintain Your Property’s Value
    • Prevent problems associated with damp, humid, and moist stagnant environments that harbor mold and mildew growth. Take steps ahead of time. Strive to prevent moisture related issues below your property as well as within its walls.
  • Keep Your Family Safe
    • According to many credible sources, including the National Center for Biotechnology, innumerable studies point to many negative health effects associated with living in damp indoor environments. Mostly because warm, moist environments provide the perfect home and breeding ground for many types of fungi and bacteria to prosper.

To name only a few health problems, researchers continue to find evidence of the correlation with:

  • respiratory problems
  • sinus issues, such as frequently recurring sinus infections
  • headaches
  • skin problems like eczema
  • microbial infections of the skin such as, tinea pedis (athlete’s foot)
  • asthma

Researchers have even found solid evidence of certain types of cancers that are ultimately linked to residing in damp indoor environments for periods of time. The list goes on and on. Avoid all the nasty health complications as best you can by investing in a professionally installed vapor barrier for your home or business.

Call a local, skilled, qualified, and insured company with a well-known name you can trust to properly install your new vapor barrier system Call Raleigh Waterproofing Today (919) 877-9969