As a building professional, nothing is as frustrating as a delay in your construction project due to choosing the wrong materials and worst case scenario, your client experiences a problem after the project is complete. Whether or not a 6 mil vapor barrier plastic is thick enough for a crawl space is circumstantial to the conditions of the crawl space, the planned usage of the crawl space, and the project budget.
The plastic sheeting experts at Americover can help you find the right vapor barrier for your crawl space project. Our team members have experience and knowledge. “Vapor barriers have been a primary focus of Americover Inc. for decades,” says Daniel Mergens, Account Manager. “It is important to pick a material that has been tested to meet building safety standards”
The first step to choosing the right vapor barrier is to choose the right thickness. Below are the requirements for plastic sheeting to qualify as a vapor barrier.
Is 6 Mil Vapor Barrier Plastic Thick Enough for a Crawl Space?
Yes. 6 mils is the minimum thickness for vapor barriers. Most vapor barriers may range from 6 to 20 mils in thickness. Although 6 mil is the minimum standard, the crawl space environment may require a thicker material to effectively block moisture and gases.
Not every plastic sheeting that is 6 to 20 mils thick behaves as a vapor barrier. The term “vapor barrier” describes plastic sheeting with a specific set of properties that make it suitable to be installed in a crawl space or anywhere else on your construction project. Although it may be tempting to buy the cheapest 6 mil plastic sheeting you can find, plastic sheeting meant for installation as a vapor barrier should meet the recommended requirements.
What Makes Plastic Sheeting a Vapor Barrier?
Plastic sheeting must meet certain thickness, permeance, and permeability requirements to be considered a vapor barrier.
As stated above, a vapor barrier has to be a minimum of 6 mils, but available in thicknesses between 6 to 20 mils thick. We typically recommend a thicker material that can withstand the handling and installation process without ripping and tearing, but is light enough for to install in a tight space.
This is the moisture transmission rate of plastic sheeting. The lower the transmission rate, the more effective the sheeting is against moisture migration. The permeance of plastic sheeting is measured in perms – one perm is equal to one grain of water vapor per hour, per square foot of material. According to the regulatory code ASTM E96, plastic must have a perm rate of 0.1 or less to be qualified as a Class I vapor barrier, making them the most suitable for building applications.
Permeance and permeability may mistakenly be used interchangeably, but they are different. Permeability is calculated by multiplying permeance by thickness and measures the tensile strength and puncture resistance of a material. Most regulations require Class A plastic sheeting to be used as vapor barriers, which have a minimum 45 lb per inch tensile strength, and 2200 grams puncture resistance.
Top Vapor Barrier Plastic Sheeting Recommendations for Your Construction Applications
Selecting a crawl space vapor barrier depends on the complexity of your application. Below we share our top recommendation for vapor barrier plastic sheeting installation in walls and flooring.
For crawl space projecs that require a vapor barrier installed within walls, builders commonly use a thinner plastic sheeting option such as 6 mil, but for the best durability in the crawl space, our vapor barrier experts instead recommend choosing 8 mil plastic sheeting.
In contract, to the crawl space walls, For the floors, we recommend a thicker plastic sheeting option such as 10 mil – 20 mil. This higher thickness is built to resist puncturing and tearing in high foot traffic areas. Here are some of our top selling products.
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Americover is the smart source for plastic and polyethylene sheeting. Trusted by contractors and distributors across the construction and agriculture industries, our American-made products combine reliability with quality and innovation.
As an Americover customer, you will receive the personalized support of a dedicated account manager to simplify the ordering process and ensure the best solution for every one of your projects. Our friendly, knowledgeable staff is here to answer your questions and fulfill orders Monday-Friday from 7 a.m. to 4:30 p.m. Pacific Standard Time. If you would like to speak with a representative, call us at 760-388-6294 or get in touch by filling out our contact form.