Roof Insulation - Radiant Heat Prevention

Among the many parts of the house that need insulation, the roof is one of the more important places. Roof insulation has many other uses on top of stopping radiant heat from the sun. It can preserve the energy and amend the more comfort with less overall costs on utilities.

This insulation also renders better thermal protection in colder situation in winter. (The insulation preserves the convection heat inside.) With proper installation, it also decrease the chances for thermal moisture condensation that can create problems like molds, mildew, rot and dripping.

Types

There are two different types of insulation materials for the roof. There is the reflective insulation material and bulk insulation material in forms like blankets, blown-in cellulose, sprayed foam and rigid boards.

Most in homes, commercial buildings, and metal structure unite both of materials in the form of foil and bulk insulation. This is to create insulation system. In hotter and colder condition insulation roof using reflective insulation materials is good for better control of unwanted temperature gain or loss, including moisture penetration.

Reflective insulation

The materials for reflective insulating system are made from two different layers of aluminum foils sandwiched with the inner layer of foam, plastic bubble sheet or fiberglass. It reflects about 97% of radiant heat from the roof surface and prevents the heat from coming inside.

The basic idea is actually reflecting back the heat into the outer atmosphere instead of permitting it to get the attic heated.

This system is best in summer when it reflects back the heat from the sun. This is because of the use of aluminum. In retrofit conditions, having a radiant barrier below the attic surface can lower the cooling costs, especially in long and hot summers. 

Bulk insulation

This is composed of blankets or batts insulation materials made of from fiber glass, cotton, sheep’s wool or mineral wool. This works well against the rising flow of warm air, thereby trapping heat from penetrating inside or outside.

The rigid foam has little advantage over the blankets because it does not compress or absorb the moisture. It also has higher insulation characteristic with longer life. The sprayed polyurethane foam is ideal for insulating metal walls and roofs to seal the air and moisture leaks, and controlling condensation as well.

Wood-frame home roofing

Making a total insulation system using reflective and bulk insulation materials is also ideal for most homes in any condition. In attics that are unheated, bulk insulation materials can be used on the floor while the reflective under the roof to reflect inside heat.

In heated attics, the same insulation can be applied over the roof surface to get the relief from radiant heat. Most of home roofs has enough room between the rafters to allow two inches of airspace for air circulation under the roof. 

The space allows the moisture and vapor to penetrate direct inside the house. The reflective insulation will act as a vapor barrier as well here. Roof insulation can be helpful in many conditions. Not only does it lower the energy consumption, it provides greater comfort levels.