There are three types of insulation: fiber, foam and reflective. However, rigid foam insulation, which contains hundreds of millions of densely packed air cells, is the most effective. The concept of air being the most effective insulator, rigid foam insulation has sheer volume of compressed trapped air which gives it great thermal performance. All insulations use air to decrease the insulation’s conductivity to prevent convective heat loss. This occurs often when the flow of gas occurs; making it important to keep gas as still as possible.
It is also “hydrophobic,” which makes it impossible to be penetrated by moisture. This penetration could cause permanent loss of R-value and can make the insulation ultimately useless after a period of time. By using this insulation, it can make achieving energy efficiency in a building more possible. Rigid foam works to slow the flow of heat through building and seals this building envelope by preventing outside drafts and air leakage. This maintains indoor air quality at a impressive rate. This insulation saves money by reducing one’s heating and cooling loads as well as achieving both comfortable living and working spaces for users. However, the effectiveness of any insulation is highly dependent on its proper installation.
Foam insulation comes in either rigid sheets or spray. They can be used to insulate almost any part of one’s home from the roof down to the foundation. Great thermal resistance and structural strength are two benefits to using this type of insulation. This insulation type also has a higher R-value per inch than fiber insulation because it uses HCFCs instead of air to create pockets in the foam sheet. This adds values from R (3.6) to R 7.7. The cost of this type is more costly than that of fiber. One purchases it per inch. When using spray foam, it may be used in both open or closed spaces as well as ducts or pipes that pass through building envelopes. Low-density urethane spray can achieve up to R-11 per inch, almost most of these foams are rated much lower. These sprays are effective at sealing out drafts.
There are several types of foam board. Most are used with polystyrene, polyisocyanurate or polyiso and polyurethane. Molded Expanded Polystyrene Foam board (MEPS) is a closed-cell board that can be molded into everyday items such as coffee cups and shipping materials. This insulation is commonly known as beadboard. To make this loose, unexpended polystyrene beads contain liquid pentane and are mixed with a blowing agent and poured within an enclosed container. This mixture is then heated to expand the beads many times the original size. The beads are then injected into a mold. Under more heat and pressure, they are expanded to foam blocks and are shaped as needed after the heat settles.
MEPS’ physical properties vary with the type of bead used because it is manufactured at various densities. If it is used for roofing materials, it has to be dense enough to be walked on without damage. However, wall insulation boards can be several times less dense. MEPS is also available with a variety of facings. Spaces between foams beads can absorb water, thus a vapor diffusion retarder is important so that water transmission through one’s insulation does not occur. This foam board can be used as the insulation for structural insulated panels and insulating concrete forms as well.
Next, is extruded expanded polystyrene foam board, a closed-cell insulation that is similar to MEPS. It is created by polystyrene pellets that are mixed with chemicals that liquefy them. Then, a blowing agent is injected within the mixture, which forms gas bubbles. This thick, foam liquid is forced through a die. After it cools, this panel is cut. This type is more expensive than MEPS. It’s much more consistent in density and also has a higher compression strength than MEPS. This makes it more effective for roofs and wall panels. It also has great resistance to moisture absorption.
Polysiocyanurate and Polyurethane Foam Board, both are similar closed-cell insulation materials. Both of these materials offer high R values, one can use a thinner foam board to have the required thermal resistance one desires. This can be extremely helpful if there are space limitations involved. Polysio insulation is available in a variety of compression strengths. This strength involved the ability of the foam to resist deformation and the ability to main its shape when forced or loaded down. Polyiso also can handles a wide temperature range, which makes it effective as a roof insulation. When combined with laminated aluminum foil facing, it is also an effective moisture and vapor barrier.
Great care should be taken in selecting foam insulation because insect problems can occur. Carpenter ants and termites will sometimes tunnel through polystyrene and polyisocynaurate foams to nest in cavities or create protected passages to wood within a building’s foundation. To err this problem, one specific company has added boric acid insect repellatant to its insulation. Tests have been done to ensure that this is effective at keeping insects away from one’s insulation.
Rigid foam insulation was tested effectively by one Northwest builder who has been working with insulation for nearly 25 years. He commented that it has made great positive effects on his customers’ utility bills and has been energy efficient. For example, in his five-year-old neighborhood, most homes average 2,600 square feet. One ranch-style home uses just 900 gallons of oil a year. When in all reality, it should use at least 1,200 gallons to effectively health it. But because of its great insulation job, the customers are saving nearly 1/4 of their yearly bill, almost $500 a year and $40 a month.
This energy saving aspect has become very important. According to the U.S. Department of Housing & Urban Development, energy costs for an average family has increased 25% since 1998, and home heating and cooling bills are the highest monthly payments for families after their mortgage one. It’s no matter homeowners are looking to more efficient ways to insulate their homes, what’s next would be windows and doors. The real question is why aren’t more homeowners using this insulation; the answer – they don’t know about it. This insulation won’t sag, settle or mildew. It has been used in over two millions home including the White House and the Taj Mahal. They create great value for one’s insulation dollar. The best performance of foam board insulation depends on its proper installation. It is often best to hire a certified insulation installer to do the job. When working with a installer, be sure to obtain written cost estimates from several contractors.
Also, it is important to ask about air-sealing services and the costs for those as well. If one decide to do it on your own, one should be aware that it weighs considerably less than plywood, which makes it easier and faster to install. It also has built-in rigidity which helps it to be scored and cut with common tools fairly easy. Neither sagging nor settling is ever a problem. Be sure to obtain the instructions and safety precautions from the manufacturer of the particular foam board. Also, check your local building and fire codes for any other instructions.
Another thing to avoid is direct sunlight damage to the foam board. Over a period of time, the sun’s ultraviolet rays can damage the insulation. If you are installing a roof insulation, apply a coat such as tar, acrylic, silicone or rubberized pain. One can also cover the foam with a rubber or plastic membrane or asphalt and roofing felt. It is important you are using compatible products. Certain solvents in coatings can dissolve certain plastics. One should take time to ensure fire protection as well when installing. Foam insulation is relatively hard to ignite, but when it is it burns quickly and emits a dense smoke full of toxic gases. Because of these combustion characteristics, foams are used for construction as a covering for a fire barrier.
It is also important to avoid potential moisture problems. In colder weather, certain warm inside air that contains water vapor can sneak past wall finish and insulation, creating condensation in the colder wall cavity. In hot climates the same situation can occur as well, just in the reverse direction. If enough of this happens and water cannot space then wood, rot, mold and other moisture problems can occur. Foam board insulation is often installed between the exterior finish and the studs of exterior walls. By placing insulation boards tight together and sealing seams with tape or caulk, air infiltration can be prevented. Studies have shown, that condensation rarely occurs in these area unless there is a significant problem with the wall assembly.
Be sure to wear adequate clothing that will protect your skin from contact with these materials, it may cause irritation. Read the label and follow all instructions. Do not ever cover or hand-pack insulation around stove pipes, electrical fixtures, motors or any heat-producing equipment. Electrical fire-safety codes prohibit this type of installation within three inches of a recessed fixture enclosure, wiring compartment or ballast.
If you are working in an old home, you may wish to hae an electrician check to see if electrical insulation is degraded in any spots or if the wires are overloaded. These may be hazardous situations in which to add thermal insulation within this closed cavity around wires. Also if a home was wired used knob and tube wiring, National Electric Code forbids the installation of lose, rolled or foam-in-place insulation. Proper ventilation (especially in attics or crawl spaces) must be maintained to avoid overheating in the summer and moisture buildup all year long.
One should consider installing batts and rolls within attics, the process is easy, but doing it correct is the important part. In unfinished attic floors, one should begin work from the perimeter toward the door. If this is a newer construction, vapor retarded should be installed so that the facing is placed down towards the ceiling board, except if in constant hot humid climates where unfaced batts should be used. If there is no insulation in the attic, fit the insulation between the joists.
On walls, one should begin work at the top and work down. Place the vapor retarder towards the lived-in side except if the home is located in a hot climate all year long. Fit the insulation through the wood frame studs and then cut off excess where necessary.
Next, secure the insulation by stapling the flanges of the vapor retarded according to manufacturer’s directions. Cut the flanges carefully to fit around obstructions with no gaps. Do not compress the insulation to fit around with no gaps.
In conclusion, there are three types of insulation one may be used. However, rigid foam insulation remains the most effective by saving customers several hundreds of dollars yearly by creating a more compact sealed in foundations. One’s heating and cooling systems are more secure and effective with this type of insulation. When installing this insulation, all proper instructions should be followed. Great consideration should be made in creating a proper installation – – because it directly affected the effectiveness of the material