RALEIGH - THE BASIC FORMS OF INSULATION
Raleigh, North Carolina. What are the basic forms of insulation? They are: BLANKETS. They come in the form of batts or rolls of flexible products made of mineral fibers. Continuous rolls can be hand-cut and trimmed to fit. They are available with or without vapor retarding facings. Batts with a special flame-resistant facing are available in various widths for basement walls where insulation is left exposed. RIGID INSULATION. It is made from fibrous materials or plastic foams and is pressed or extruded into board-like forms and molded pipe-coverings. They may be faced with a reflective foil that reduces heat flow when next to an air space. BLOWN-IN loose-fill insulation includes loose fibers or fiber pellets that are blown into building cavities or attics. Another form includes fibers that are co-sprayed with an adhesive to make them resistent to settling. The blown-in material can provide additional resistance to air infiltration. FOAMED-IN-PLACE polyurethane foam insulation can be applied by professional applicators using special equipment to gauge mix and spray into the spaces to be insulated. REFLECTIVE INSULATION SYSTEMS. These are fabricated from aluminium foils wtih a variety of backings such as Kraft paper, plastic film, polyethylene bubbles, or cardboard. Reflective systems are often located between floor joists, roof rafters or wall studs. SIPS - Structural Insulated Panels. These are panels made from a thick layer of foam sandwitched between two layers of Oriented Strand Board. SIPs are a widely used alternative construction materila for homes and other buildings. AAC - AUTOCLAVED AERATED CONCRETE. It is an economical solid block that provides thermal and acoustic insulation as well as fire and termite resistance. It is available in a variety of forms, ranging from wall and roof panels to locks and lintels. INSULATING CONCRETE FORMS. These are foam forms filled with reinforced concrete and reinforced bar to create insulated structural walls. They can be used to form various structural configurations, such as a standard wall, post and beam, or grid. THey provide backing for interior and exterior finishes. ICYNENE is the leading soft foam insulation and air barrier system and is becoming the industry standard for providing maximum building envelope performance. Its pour and spray formulations represent a breakthrough in moisture and thermal management. It’s a 100% water-blown foam insulation that minimizes air leakage for increased energy efficiency, creates a healthier indoor environment, reduces airbourne sounds and offers greater design freedom. It doesn’t shrink, sag or settle. It adheres to most construction materials and is a perfect insulation for walls, attics, ceilings and floors.
The following is a listing of the R-Values for various products. Comparisons per inch of thickness are mostly relevant for conductive and convective heat transfer and not radiant heat transfer. Some of the materials listed below are designed to prevent radiant heat transfer. Vacuum insulated panel has the highest R-value at R-45. Aerogel R-10. Isocyanurate and phenolic foam insulations R-8.3 and R-7 respectively. Polyurethane and polystyrene insulation R-6 amd R-5. Loose cellulose, fiberglass both blown and in batts, and rock wool both blown and in batts R-3. Single pane glass window R-1, Double pane glass window R-2, Double pane glass windos with low emisivity coating R-3, Triple pane glass window R-3, Wood panels such as sheathing R-2.5, Vermiculite loose-fill R-2.13 to R-2.4, Rock and slagw wool loose-fill R-2 to R-3.3, Rock and slag wool batts R-3 to R-3.85, Fiberglass loose-fill R-2.2 to R-3.7, Fiberglass rigid panel R.2.5, Fiberglass batts R-2 to R-3.85, High density fiberglass batts R-3.6 to R-5, Cementitious foam R-2 to R-3.9, Cellulose loose-fill R-3 to R-3.8, Icyuene spray R-3.6, Icyuene loose-fill R-4, Urea formaldehyde foam R-4 to R-4.6, Urea formaldehyde panels R-5 to R-6, Ployethylene foam R-3,Phenolic spray foam R-4.8 to R-7, Phenolic rigid panel R-4 to R-5, Molded expanded polystyrene R-3.7 for low-denisty and R-4 for high-density, Extruded expanded polystyrene R-3.6 to R-4.7 for low-density and R-5 to R-5.4 for high-density, Open-cell polyurethane spray foam R-3.6, Closed-cell polyurethane spray foam R-3.6, Polyurethane rigid panel R-6.8 initial, R-5.5 aged (5-10 years), Polyurethane rigid panel R-7 to R-8 initial, R-6.25 aged (5-10 years), Polyisocyanurate spray foam R-4.3 to R-8.3, Foil-based polyisocyanurate rigid panel initial R-6.8, aged R 5.5 (5-10 years), Silica aerogel R-10, Foil-backed bubble pack R-1 to R-2, Vacuum insulated panel as high as R-30? and Cardboard R-3 to R-4. Got that? Natural rock, dirt, sod, adobe and concrete have poor thermal resistance (usually less than 1) but do work well for thermal mass applications because of their high specific heat.
You can use your own assumptions to calculate recommended insulation levels by using the ZIP-Code computer program. It is called ZIP-Code because it includes weather and cost information for local regions defined by the first three digits of each postal service zip code. The type of insulation you use is determined by the part of the country you live in and the nature of the spaces in the house you want to insulate. You should also know that different types of insulation can be used together. You can add batto or roll insulation over loose-fill insulation or visa-versa. Normally, material of higher density should not be placed on top of lower density insulation. It you do you will reduce the thickness of the lower material and thus reduce the R-value. A qualified home energy auditor will check your insulation as part of an energy audit. Your local utility company can direct you to one. This audit will identify the amount of insulation you have and the amount you need.
Tomorrow I will finish this information with a table of basic forms of insulation, how they are installed, where they apply and their relative advantages.
John Fish (919) 696-3474 Email: Marvmax@mindspring.com Website: www.JohnFish.com
