While ASAP Roofing is Denver’s number one roofing specialist, we also recognize that when it comes to protecting and preserving the life of your home, roofing is not the only component.
As older homes have less insulation than homes built today, more than likely your energy bills can be reduced by strategically adding home insulation. Even in the case of a new home, additional insulation will pay for itself within a few years.
But before any insulation can be added to any home, it is first necessary to determine the amount, quality and location of your current insulation. When as ASAP ROOFING specialist inspects your home for insulation, he/she will not only give you an energy assessment of your home (based on Government Energy Saving Guidelines), but also identify any areas of your home that are in need of air sealing.
Part of this insulation assessment is determining the R value of your current insulation. An R value measures the thermal resistance of any insulating material and the greater the value, the greater the insulating effectiveness. The type of insulation, the thickness and the density of the insulation all combine to comprise the R value.
An R value also is dependent on the location and way in which the insulation is installed. Insulation will not be as effective when compressed, and the R value can change once it is installed due to thermal bridging — heat flowing through joists and wall studs.
The amount of insulation or R-value you’ll need depends on your climate, type of heating and cooling system, and the part of the house you plan to insulate. ASAP ROOFING also recommends that your house be checked for moisture, as this will effect energy efficiency, as well as the overall air quality of the home.
ASAP ROOFING uses the following types of insulation (as described on energy.gov energy saver website):
BLANKET: BATT AND ROLL INSULATION
Blanket insulation — the most common and widely available type of insulation — comes in the form of batts or rolls. It consists of flexible fibers, most commonly fiberglass. You also can find batts and rolls made from mineral (rock and slag) wool, plastic fibers, and natural fibers, such as cotton and sheep’s wool. Learn more about these insulation materials.
Batts and rolls are available in widths suited to standard spacing of wall studs, attic trusses or rafters, and floor joists. Continuous rolls can be hand-cut and trimmed to fit. They are available with or without facings. Manufacturers often attach a facing (such as kraft paper, foil-kraft paper, or vinyl) to act as a vapor barrier and/or air barrier. Batts with a special flame-resistant facing are available in various widths for basement walls and other places where the insulation will be left exposed. A facing also helps facilitate fastening during installation. However, unfaced batts are a better choice when adding insulation over existing insulation.
Standard fiberglass blankets and batts have a thermal resistance or R-value between R-2.9 and R-3.8 per inch of thickness. High-performance (medium-density and high-density) fiberglass blankets and batts have R-values between R-3.7 and R-4.3 per inch of thickness. See the table below for an overview of these characteristics.
CONCRETE BLOCK INSULATION
Concrete blocks are used to build home foundations and walls, and there are several ways to insulate them. If the cores aren’t filled with steel and concrete for structural reasons, they can be filled with insulation, which raises the average wall R-value. Field studies and computer simulations have shown, however, that core filling of any type offers little fuel savings, because heat is readily conducted through the solid parts of the walls such as block webs and mortar joints.
It is more effective to install insulation over the surface of the blocks either on the exterior or interior of the foundation walls. Placing insulation on the exterior has the added advantage of containing the thermal mass of the blocks within the conditioned space, which can moderate indoor temperatures.
Some manufacturers incorporate polystyrene beads into concrete blocks, and surface-bonded assemblies of these units have wall R-values of R-1 per inch. Other manufacturers make concrete blocks that accommodate rigid foam inserts that increase the unit thermal resistance to about R-2 per inch.
In the United States, two varieties of solid, precast autoclaved concrete masonry units are now available: autoclaved aerated concrete (AAC) and autoclaved cellular concrete (ACC). This material contains about 80% air by volume and has been commonly used in Europe since the late 1940s. Autoclaved concrete has ten times the insulating value of conventional concrete. The R-1.1 per inch blocks are large, light, and easily sawed, nailed, and shaped with ordinary tools. The material absorbs water readily, so it requires protection from moisture. Precast ACC uses fly ash instead of high-silica sand, which distinguishes it from AAC. Fly ash is a waste ash produced from burning coal in electric power plants.
Hollow-core units made with a mix of concrete and wood chips are also available. They are installed by stacking the units without using mortar (dry-stacking) and filling the cores with concrete and structural steel. One potential problem with this type of unit is that the wood is subject to the effects of moisture and insects.
Concrete block walls are typically insulated or built with insulating concrete blocks during new home construction or major renovations. Block walls in existing homes can be insulated from the inside. Go to insulation materials for more information about the products commonly used to insulate concrete block.
FOAM BOARD OR RIGID FOAM
Foam boards — rigid panels of insulation — can be used to insulate almost any part of your home, from the roof down to the foundation. They provide good thermal resistance, and reduce heat conduction through structural elements, like wood and steel studs. The most common types of materials used in making foam board include polystyrene, polyisocyanurate (polyiso), and polyurethane.
INSULATING CONCRETE FORMS
Insulating concrete forms (ICFs) are basically forms for poured concrete walls, which remain as part of the wall assembly. This system creates walls with a high thermal resistance, typically about R-20. Even though ICF homes are constructed using concrete, they look like traditional stick-built homes.
ICF systems consist of interconnected foam boards or interlocking, hollow-core foam insulation blocks. Foam boards are fastened together using plastic ties. Along with the foam boards, steel rods (rebar) can be added for reinforcement before the concrete is poured. When using foam blocks, steel rods are often used inside the hollow cores to strengthen the walls.
The foam webbing around the concrete-filled cores of blocks can provide easy access for insects and groundwater. To help prevent these problems, some manufacturers make insecticide-treated foam blocks and promote methods for waterproofing them. Installing an ICF system requires an experienced contractor, available through theInsulating Concrete Form Association.
LOOSE-FILL AND BLOWN-IN INSULATION
Loose-fill insulation consists of small particles of fiber, foam, or other materials. These small particles form an insulation material that can conform to any space without disturbing structures or finishes. This ability to conform makes loose-fill insulation well suited for retrofits and locations where it would be difficult to install other types of insulation.
The most common types of materials used for loose-fill insulation include cellulose, fiberglass, and mineral (rock or slag) wool. All of these materials are produced using recycled waste materials. Cellulose is primarily made from recycled newsprint. Most fiberglass contains 20% to 30% recycled glass. Mineral wool is usually produced from 75% post-industrial recycled content. The table below compares these three materials.
For more information about ASAP ROOFING’s insulation services, just contact us. We’d be glad to help show you how to improve the energy efficiency of your home.