Ideally, after you install a radiant barrier the air temperature inside the attic should probably be within 10 to 15 degrees of ambient temperature.
The tests to date have shown that in attics with R-19 insulation, radiant barriers can reduce summer ceiling heat gains by about 16 to 42 percent compared to an attic with the same insulation level and no radiant barrier.
In cold climates, the preferred installation method is laying radiant barrier foil over the insulation on the attic floor to keep heat in during the cold months and to help block heat in hotter months. This type of installation is easier than the conventional staple-up method, but it also has some precautions.
Some studies show that radiant barriers can reduce cooling costs 5% to 10% when used in a warm, sunny climate. The reduced heat gain may even allow for a smaller air conditioning system. In cool climates, however, it's usually more cost-effective to install more thermal insulation than to add a radiant barrier.
Ideally, the attic temperature should be close to the outside temperature, give or take 10 to 20 degrees. If your attic temperature is getting to 130 degrees or hotter, you can expect to see damage to your home. An attic can easily surpass this target in warm climates, getting as high as 160 degrees in the summer.
On a 100-degree day, an attic can reach temperatures of 170 degrees or more due to the radiant heat effect.
A radiant barrier helps homes with HVAC ductwork in the attic by reflecting heat away from the system.
When radiant barriers develop moisture problems, they can impact the efficiency of heat repellency. In addition, unchecked moisture can drop down onto other surfaces in the attic, causing water damage and mold. In order to prevent moisture issues, it's imperative to use perforated radiant barriers.
What is the R-value of your radiant barrier? Radiant barrier on its own has NO R-value; R-value is attributed to materials slowing conductive heat. AtticFoil™ works to block radiant heat (97%) coming in to the attic by stapling it to the rafters, but it has no R-value.
This is because an air gap provides an additional layer of insulation that helps to prevent heat from passing through the barrier and into the living space. If you are installing a radiant barrier, it's recommended to leave an air gap of at least 25mm (1 inch) between the barrier and the surface it's installed on.
Certified attic specialists recommend installing a radiant barrier. A radiant barrier reflects the sun's rays away from your home, preventing your insulation from becoming another heat source. It keeps your house cool and your cooling costs at bay.
With Wi-Fi signals, unless the radiant barrier is between you and the router, there is unlikely to be any impact.
As long as homeowners or certified attic specialists install them appropriately, radiant barriers last anywhere from 80 to 100 years.
This type of insulation is most effective in warmer climates, but can also be used for comfort and energy savings in cold weather. The radiant-barrier insulation is attached to roof rafters, floor joists, and wall studs to reduce radiant heat flow, mostly from the outside in, but also from the inside out.
Install electric ventilators and attic fans, which remove hot air from an attic. They have thermostats that turn the fan on at a recommended preset temperature of 100-110 degrees. Alternatively, install passive vents such as gable, soffit and ridge vents, which are openings in the roof that allow hot air to escape.
Installing a radiant barrier costs $1,700 on average, but often ranges between $710 and $2,840 depending on whether your pro uses a foil or spray on type.
Ideally, after you install a radiant barrier the air temperature inside the attic should probably be within 10 to 15 degrees of ambient temperature.
This is probably the easiest method to install Radiant Barrier AtticFoil™: lay the foil out over the existing insulation on the attic floor.
A radiant barrier installed in the attic effectively blocks most radiant heat transfer. LP® TechShield® Radiant Barrier helps block up to 97% of the radiant heat transfer from within the panel, cooling attic temperatures up to 30 degrees.
Radiant barriers may be installed in attics in several configurations. The simplest is to lay the radiant barrier directly on top of existing attic insulation, with the reflective side up.
Aluminum covered radiant barrier products (like Original AtticFoil™) are pretty difficult to start burning, but once they flash (catch fire) the polyethylene scrim inside will continue to burn at a relatively slow rate.
This might surprise you, but radiant barrier foil on its own has virtually no R-Value!
Moisture problems, air leaks, inadequate attic ventilation, dust accumulation, compatibility issues with existing insulation, and condensation are some of the common challenges associated with radiant barriers.
Generally speaking, vapor barriers are considered an essential moisture-blocking tool for climates that experience significant levels of humidity. For that reason, building codes in more humid locations will often require them, in which case you might not have much say about whether to install one or not.
You can also install the foil over insulation that is already inside your attic ceiling, between the roof rafters. This method is usually used in colder climates because it maximizes the heat retention of the attic space while helping during the colder months as well, even in places like Southern California.