Radiant barrier perforated why

About Us. Contact Us. Search 0 Cart. What is Reflective Insulation. Orders Ship within 1 Business Day. Condensation and Radiant Barriers. Condensation of moisture can be a concern when a radiant barrier is installed on the attic floor directly on top of conventional insulation.

During cold weather, water vapor from the interior of a house may move into the attic. In most cases, this water vapor will not cause any problem because attic ventilation will carry excess vapor away.

During cold weather, a radiant barrier on top of the insulation could cause water vapor to condense on the barrier's underside. Condensation of large amounts of water could lead to the following problems: 1 the existing insulation could become wet and lose some of its insulating value, 2 water spots could appear on the ceiling, and 3 under severe conditions, the ceiling framing could rot.

The perforations in the foil are tiny pinholes that allow water vapor molecules to pass through. In an attic situation this is exactly what you want: moisture moving freely to contribute to an overall dry attic space. Ideally you want full coverage, but a little bit of foil cut out over a large install area is not going to dramatically alter your results or the effectiveness of the product.

So what if you are dealing with a moisture problem that already exists? Well the most important thing is to try to locate the source of the problem. Once you have determined where the moisture is occurring, you should be able to establish what is causing the problem.

The best thing to do would be to remove any and all materials surrounding the source until you have remedied the situation. While moisture has the potential to cause severe problems if untreated, do not let it scare you off from doing home improvements. Understand what you are dealing with, eliminate situations that can cause problems and make sure the space you are working in has adequate airflow and ventilation.

Taking these precautions will allow your radiant barrier foil installation to go smoothly and it will set you up to receive the best-case results from the product. Single Sided House Wrap Foil. Moisture and Radiant Barrier. Myth or Truth? Myth: Using a radiant barrier causes moisture problems that ultimately lead to mold and mildew.

Understanding Condensation Condensation is simply water changing its form. Most Common Trouble Spots What are the sources of moisture? The earth receives all its solar heat through radiation. Dark, rough surfaces will generally absorb radiant heat and become warm, while smooth, shiny surfaces will reflect the radiation. This is why radiant heat transfer can be limited by the use of radiant barriers, which have shiny foil surfaces.

Conventional types of insulation consist of fibers or cells that trap air or contain a gas to primarily retard heat conduction, and, to a lesser extent, convective air flow at various rates. On the other hand, radiant barriers and reflective insulation systems work by reducing radiant heat gain. The R-value indicates the resistance to heat flow. The higher the R-value, then the greater the insulating power.

Radiant barriers reduce only radiant heat transfer though, so the rules as applied to determining R-value of the products relate to not only the thickness of the material but how it is installed. See Section Therefore, due to the way heat is transferred, you still need insulation. The amount of thermal insulation affects the potential radiant barrier energy savings. For example, installing a radiant barrier in an attic that already has high levels of insulation R or above would result in much lower energy savings than in an attic insulated at a low level R or less.

According to the Oak Ridge National Laboratory, your savings on heating and cooling bills will vary depending on a number of factors. These factors include: type of radiant barrier application, size of your house, whether your home is a ranch style or a two story house, amount of insulation in the attic, effectiveness of attic ventilation, color of the roof, thermostat settings, tightness of the building envelope, actual weather conditions, efficiency of the heating and cooling equipment, fuel prices, etc.

The document, Radiant Barrier Fact Sheet , includes a link to the Radiant Barrier Calculator that includes simple calculations on how to approximate the economics of radiant barriers and added ceiling insulation. The calculator is part of the fact sheet but, for convenience, this is the direct link.

A radiant heat barrier must have an air space next to a reflective side to be effective. If you do not allow for this air space, the radiant barrier acts as a conductor and just passes the heat along from a hot surface to a cooler surface. It cannot be sandwiched between two materials, as the air space is critical to its performance.

They should also be installed to prevent dust build-up as dust and dirt will decrease their effectiveness.