Building Roof Insulation: Different Types and Uses
Building insulation refers broadly to any object in a building used as insulation. While the majority of insulation in buildings is for thermal purposes, the term also applies to roof insulation, acoustic insulation, fire insulation, and impact insulation (e.g. for vibrations caused by industrial applications). Often an insulation material will be chosen for its ability to perform several of these functions at once.
Choose Your Insulation
How you insulate your attic depends on whether you want a “cold” or “warm” roof space. A cold roof requires insulation at joist level to stop heat escaping through the unused roof space. A warm roof is insulated between and under the rafters of the roof itself. The recommended depth for insulation has been increased recently, so you may have to increase the depths of the joists or rafters if you want to create usable platforms of storage space.
Insulation that is recycled is a green and non-itch alternative to conventional blanket insulation. The techniques for laying this are the same, but non-itch insulation makes it a more comfortable process. Check the instructions on the product to ensure that you install it to the right depth requirement.
One of the most widely used forms of attic-insulation, blanket insulation is simple to work with – although you should always wear protective clothing, as it can be uncomfortable to handle. Before starting, ensure that you have measured the surface area of your attic accurately and that you bear in mind the recommended depth requirements and order accordingly (manufacturers supply blanket insulation in many different depths, so you must remember to order to the correct depth as well as to the necessary surface area). Always consider the recycled and natural alternatives to conventional blanket insulation.
A variety of rigid insulation types is available to managers, including wood fiber, perlite, polyisocyanurate, expanded or extruded polystyrene, cellular glass, and gypsum board.
Wood fiber is an organic insulation board composed of wood, cane, or vegetable fibers mixed with fillers and binders. The insulation can be asphalt or asphalt coated to enhance moisture resistance. Managers should consider uncoated insulation in applications where the selected roof covering is incompatible with asphalt-based coatings.
Perlite insulation board is composed of inorganic, expanded siliceous volcanic glass – perlite -combined with organic fibers and binders. The top surface of the insulation board features an asphalt coating or a proprietary coating formulated to limit adhesive – asphalt – absorption into the insulation during the roof membrane application.
Polyisocyanurate is a closed-cell foam plastic insulating core sandwiched between organic or inorganic felt facers, glass-fiber mat facers, or glass-fiber-reinforced aluminum foil facers. A chlorine-free blowing agent expands the foam material, creating the closed-cell structure that gives the insulation its high thermal resistance. Air diffusion into the insulation cell structure results in a slight reduction of thermal resistance, but its insulating efficiency remains higher than other rigid insulation.
The maximum thermal performance or R-value of insulation is very dependent on proper installation. Homeowners can install some types of insulation — notably blankets and materials that can be poured in place. Other types require professional installation.
When hiring a professional certified installer:
- Obtain written cost estimates from several contractors for the R-value you need, and don’t be surprised if quoted prices for a given R-value installation vary by more than a factor of two.
- Ask contractors about their air-sealing services and costs as well, because it’s a good idea to seal air leaks before installing insulation.
Roof insulation material has many advantages and some of them are stopping radiant heat, preserving energy and providing more comfort with less utility cost.
Roof insulation can be helpful in many conditions. It helps lowering down the total energy consumption cost with providing greater comfort levels for the occupants and help to reduce the HVAC equipment requirements.
Roof Insulation as a Barrier
Roof insulation is an ideal way to prevent unwanted heat penetration from the outside. Roof insulation foil will reduce the amount of the sun’s radiant heat that penetrates in summer by up to 97% and also render better thermal protection in the colder situation in winter. Effective temperature insulation material preserves the convective heat inside in the winter and creates the warmer atmosphere. Applying the perfect type of insulation diminish the amount of energy required for the heating and cooling inside the building and thus permit to run heating and cooling device less and making them last longer with reducing energy cost. It also helps to get a smaller size of HVAC equipment for a larger size of buildings.
Properly installed roof insulation material also decreases the chances of thermal and moisture condensation creating problems like mold, mildew, rot and dripping. Applying roof flood insulation with enough ventilation below the roof surface will help moisture to escape and stop the ice buildup and damage caused by it.
Know the Different Types of Roof Insulation Material
Roof insulation materials are of two different types; reflective insulation material and bulk insulation material in the form of blankets, blown in cellulose, sprayed foam and rigid boards. Most of the home, commercial building, and metal structure combine materials in the form of foil and bulk insulation to create complete insulation system. However, in hotter and colder climates, insulation roof with reflective insulation material is quite enough to get better control from unwanted temperature gain or loss and moisture penetration.
Basics of Reflective Roof Insulation Material
Reflective roof insulation material is made from the two different layers of aluminum foils sandwiched with the inner layer of foam, plastic bubble sheet or fiberglass. This structure is perfect for pole barn roof insulation. It reflects around 97% of radiant heat from the roof surface and prevents energy and higher temperature penetrating inside.
What is Bulk Roof Insulation?
Blankets or Batts – most of this insulation material is made up of fiberglass, cotton, sheep’s wool or mineral wool. It works well against the enlarging and rising flow of warm air and thereby trapping heat from penetrating inside or outside.
Rigid Foam – this material has little advantage over the blanket insulation as it does not compress or absorb the moisture and have higher insulation characteristic with longer life. It is ideal for roofing insulation where space is confined
Sprayed Polyurethane Foam – Sprayed foam is ideal for insulating metal walls and roofs to seal it from air and moisture leaks. It controls condensation as well. However, this is not easy to apply and requires technical support while insulating.
What is Heat Barrier Roof Insulation?
The best way to insulate against the temperature during summer is to get reflective insulation material. It has a higher tendency of reflecting the sun’s radiant heat and creates a heat barrier under or over the roof. Studies done by the Florida Solar Energy Center shows that such a material is effective because of the use of aluminum. In retrofit applications, applying a heat barrier below the attic surface can lower the cooling cost. However, such a heat barrier is the most effective in a situation where there is long and harsh summer.
How Does a Heat Barrier Roof Insulation Work as a Temperature Barrier?
Radiant heat barrier materials mostly block the inflow of heat from the roof surface and stop it from entering the house. The majority of the material made from the aluminum prevents 97% of radiant heat and reflect it back to the outer atmosphere instead of permitting it to heat the attic. It results in increased indoor comfort and less energy consumption in a warmer climate.
Know the Metal Roof Insulation Materials
The ideal insulation material for metal building is reflective insulation. It can be laid under the metal roof decking. In addition, it may be associated with spray foam from the underneath once the roof decking is in place. In a cooler atmosphere, a combination of Batt insulation and reflective foil insulation can work best. Applying the reflective insulation on a warmer side will double as a vapor barrier and stop moisture from getting inside. However, any of these types will help reduce the noise levels both inside and from the outside as well. Condensation is one of the major problems faced in the metal structure. Water and moisture in contact with metal surface create corrosion and can reduce the service life of the structure. Accumulation of water on the roof surface can directly result in dripping, staining, mold, mildew, and odors. Additionally, it is important to remember that water or ice collection in fiberglass, blanket or paper wool can seriously degrade the thermal and insulation performance of the material.
All of these problems can be overcome by properly installing a vapor barrier system under the roof. Even in only moderately humid conditions, moisture condensation can stimulate serious problems for unprotected metal structure. Fiberglass insulation isn’t that effective in moist climates. Using reflective insulation can be better. It will not get wet and has a longer life compared to wooden, paper, and fiberglass. It acts as vapor retarder by limiting the passage of water vapor and moisture thereby preventing condensation problems.