Facings as Vapor Barriers

The main function of facings is to act as a vapor barrier. While a vapor barrier may not necessarily be able to stop the flow of water vapor, it does an excellent job of minimizing the rate and volume of the flow. This prevents moisture from accumulating within the insulation blanket and the structure, which translates into consistent thermal values and lower heating and cooling costs.

Facings intended to serve as vapor barriers should be installed on the inner, heated surface of the insulation, where vapor pressure is the highest. This helps in preventing vapor from reaching the cooler air and condensing.

VAPOR BARRIERS PREVENT VAPOR FROM REACHING COOLER AIR AND CONDENSING.

Recommended Installation Methods of Insulation

Roof insulation rolls are cut to lengths that will cover the distance from eave to eave, leaving a one-foot overhang on each side of the building.

1) Start at the end of the building and temporarily secure one end of the roll by attaching the insulation to the eave strut with double-faced tape.

2) Pull the insulation across the purlins with the vapor barrier toward the building interior. Double-faced tape attached to the opposite end of the insulation will keep tension on the roof roll while the metal panels are being attached over the insulation.

3) Install the next roll in the same manner, making sure the rolls are stretched tight, aligned properly and closely butted.

4) Fasten tabs using one of the methods described on the following page. Any rips or tears must be covered with matching facing tape to ensure a tight vapor seal.

5) Trim excess insulation flush to prevent it from acting as a wick and moving water into the building.

Foundations

Do I need a foundation for my metal building? - Some people choose to pour a full slab foundation, however if you're planning on leaving the floor in a dirt or gravel condition, concrete piers will do the job just fine. Please contact a customer service representative if you don't plan to pour a full slab foundation.

Can you provide an engineer stamped foundation layout? - Yes, but in some cases your soil conditions play a major role in the type of foundation you can use. Contact our special sales department for more information. If using a local engineer, we will provide anchor bolt plans to aid your engineer in designing the foundation.

Do you supply the hardware to attach the frame to foundation? - No, the anchor bolts are usually supplied by a concrete contractor and placed when the foundation is poured.

Installation and Selection of Insulation

We provide the highest quality products available. However, proper installation and selection is imperative for maximum effectiveness. Please refer to installation instructions to ensure correct procedures are used. Facings that have been torn or punctured are no longer capable of blocking water vapor and may eventually do more harm than good. Be sure to quickly patch any holes in the vapor barrier.

When selecting a facing, special consideration should be given to its reflective quality. A facing with high reflectivity reduces the need for high light levels in work areas. This results in reduced energy costs and increased productivity.

Although the fiberglass insulation itself is not affected by cold weather, the facing is. Colder temperatures can cause cold crack, a situation where the facing becomes brittle and if handled can crack. Bay Insulation recommends that vinyl faced fiberglass products never be installed in temperatures below 40 degrees.

Proper Ventilation of a Building

Proper ventilation in a building can be an effective measure for condensation control. The end use of the building must be the controlling ventilation design parameter, especially above drop ceiling areas. Ventilation system design should be done at the initial building design stage. Use of a design professional is strongly recommended to assure the best possible system.

CONDENSATION CAN BE MINIMIZED THROUGH CONSIDERATION OF CLIMATE, RELATIVE HUMIDITY AND THICKNESS OF INSULATION.