TYPES OF INSULATION
Form	Method of Installation	Where Applicable	Advantages
Blankets: Batts or Rolls Fiber glass Rock wool	Fitted between studs, joists and beams	All unfinished walls, floors and ceilings	Do-it-yourself Suited for standard stud and joist spacing, which is relatively free from obstructions
Loose-fill (blown-in) or Spray-applied Rock wool Fiberglass Cellulose Polyurethane foam	Blown into place or spray applied by special equipment	Enclosed existing wall cavities or open new wall cavities Unfinished attic floors and hard-to-reach places	Commonly used insulation for retrofits (adding insulation to existing finished areas) Good for irregularly shaped areas and around obstructions
Rigid Insulation Extruded polystyrene foam (XPS) Expanded polystyrene foam (EPS or beadboard) Polyurethane foam Polyisocyanurate foam	Interior applications: Must be covered with 1/2"gypsum board or other building-code approved material for fire safety Exterior applications: Must be covered with weather-proof facing	Basement walls Exterior walls under finishing (Some foam boards include a foil facing which will act as a vapor retarder. Please read the discussion about where to place, or not to place, a vapor retarder) Unvented low slope roofs	High insulation value for relatively little thickness Can block thermal short circuits when installed continuously over frames or joists
Reflective Systems Foil-faced paper Foil-faced polyethylene bubbles Foil-faced plastic film Foil-faced cardboard	Foils, films or papers: Fitted between wood-frame studs, joists and beams	Unfinished ceilings, walls, and floors	Do-it-yourself All suitable for framing at standard spacing. Bubble-form suitable if framing is irregular or if obstructions are presentt; effectiveness depends on spacing and heat flow direction

HOW MUCH INSULATION YOU WILL NEED On a new home, find out what the recommended R-value is for the type of heat you are planning to use for the location of your new home. Again, local electric and gas companies can provide this information to you or you can contact the Department of Energy. On an existing home it is a little more complicated, but not hard. First, you need to identify what type of insulation is currently in your home. It may differ by the various locations in your home. In your attic for example, you may find batt or blanket fiber glass over the top of loose-fill cellulose. You may also find multiple layers of batt or blanket insulation. Next, you need to measure the thickness of each of these different types of insulation at the different locations. To help you with this process, take a regular sheet of notebook paper and make four columns. Label the first column "Location," the second column "Type Of Insulation," the third column "Inches Thick" and the fourth column "R-value per Inch." Figure 3 shows you the approximate R-value each inch of the various types of insulating materials provides. Use this chart to fill in the last column of your worksheet. One inch of fiber glass batts or blankets, for example, provides an approximate R-value of 3.2. To find the R-value of 4" of fiberglass, multiply 4 x 3.2 to get an R-value of 12.8. Repeat this process of multiplying the number of inches thick and the R-value per inch of insulation for each area in your home. If you have two different types of insulation together, like our earlier example, find the R-value for each and then add them together. FIG. 3 R-VALUE Insulation Type R-Value per inch of thickness Fiber glass blanket or batt 3.2 High-performance fiber glass blanket or batt 3.8 Loose-fill fiber glass 2.5 Loose-fill rock wool 2.8 Loose-fill cellulose 3.5 Perlite or vermiculite 2.7 Expanded polystyrene board 3.8 Extruded polystyrene board 4.8 Polyisocyanurate board, unfaced 5.8 Polyisocyanurate board, foil-faced 7.0 Spray polyurethane foam 5.9 Let's use an example where we have 6" of cellulose covered by 6" of fiber glass batts in the attic. We take the R-value of cellulose, which is 3.5 and multiply it by 6 to get 21.0. We then take the R-value of fiberglass batts, which is 3.2 and multiply that by 6 to get 19.2. Since the insulation is layered one on top of the other, we add them together 21.0 + 19.2 to get 40.2. If we live in a region where the recommended R-value is 38, we already have 40.2, so we do not need to add insulation. What happens though, if we live in a region that recommends 49–we need to add some insulation, but how much? That's easy too! Take the recommended R-value, which is 49, and subtract what we have already, which is 40.2 (49 - 40.2 to get 8.8). We need to add an R-value of 8.8. The R-value of an inch of fiber glass batts is 3.2. Divide the amount we need to add, 8.8, by the R-value per inch, 3.2, to get 2.75. Batt and blanket insulation comes in several thicknesses. One of these is 3-1/2". So one layer of 3-1/2" fiber glass batt insulation added to what we have will give us a little more than what we need. It is always ok to add more insulation than is recommended. Just remember not to pack it too tightly because packing it can reduce its effectiveness.

FIG. 4 - Loose-fill insulation material is spread easily with a plywood rake cut to the correct size and depth. FIG. 5 - Cut a piece of plywood and make a rake for applying any type of loose-fill materials

SPREADING LOOSE-FILL INSULATING MATERIALS Loose-fill insulating materials of rock wool, fiber glass or cellulose are commonly used for insulating attics. Vermiculite is not currently used for homes, but it may be found in older homes. It is best to install these materials with a plywood rake attached to a rake handle, making spreading much easier. To make this type of rake, cut a scrap piece of plywood to the length of the space between the joists plus 4" (Fig. 5). The extra 4" allows for an overhang on the joists. Next decide how deep you plan to install the loose-fill material. For example, suppose you are planning to lay the loose-fill material to a depth of 3" between the attic joists (Fig. 4). Measure the depth in the space you plan to fill then saw the plywood rake as illustrated in Fig. 5. The rake should ride on the joist on either side and level the material off evenly to a depth of 3". Attach a handle, making a handy tool that will save you hours of backbreaking labor and enable you to rake the material easily and evenly into otherwise unreachable corners (Fig. 5).

FIG. 6 - When using blanket insulation, always place the vapor barrier toward the heat source and insulation outside of any pipes. FIG. 7 - Staple blanket insulation from below. FIG. 8 - Always allow for adequate air circulation in the attic, especially around vents. FIG. 9 - Allow air to flow in and around the eave vents and out through a roof, ridge or gable vents. FIG. 10 - Blanket insulation without a vapor barrier can be wedged between ceiling joists. FIG. 11 - In some cases, you may want to apply the insulation between the rafters. FIG. 12 - Always double back the roll of insulation at the end for maximum efficiency.

APPLYING INSULATION IN BLANKET FORM Always apply blanket-type insulation with the vapor barrier facing the interior of your home. The vapor barrier should always be toward the source of heat in the winter (Fig. 6). Never place a vapor barrier between two layers of insulation. This can lead to a condensation problem and reduce the effectiveness of the insulation. Lay the blanket as close to the joists and floor as possible. Fill any gaps with loose-fill insulation or place another layer of blanket insulation across the previous layer. Always place insulation on the outside of pipes or ducts (Fig. 6). This means the insulation should be between the outside wall and the pipes. When using blanket insulation, always place the vapor barrier toward the heat source and insulation outside of any pipes. Staple blanket insulation when laid between joists in the attic (Fig. 7). Most rolls of blanket insulation materials have flanges that can be stapled or tacked to the ceiling joists, as illustrated. Always keep the blanket as close to the joists and floor area as possible–fill any gaps with strips of insulation or loose-fill insulation. Never allow blanket-type insulation to cut off the flow of air and stop proper ventilation in an attic (Fig. 8). Blanket insulation should never block the air movement from the eave vents into the attic. Proper ventilation in the attic is very important in any insulation job. Make provision for air to flow in and around the eave vents and to flow out through a ridge vent roof ventilator or through a ventilator on the end of the house (Fig 9). Blanket insulation without a vapor barrier can be wedged between existing ceiling joists (Fig. 10). Make sure the insulation comes to the top of the plate to avoid heat loss from the penetration of wind under the insulation. Failure to pay close attention to this detail can lead to a frost line forming on cold, windy days. It will form on the inside wall where the ceiling and walls come together. There are special formed inserts made of foam or plastic designed to go up next to the roof between the rafters. They help with both the airflow and the frost line. Many of them are designed to be installed during new construction. But they can be installed in an existing roof with very little extra effort. In some cases, it may be easier to apply the blanket between the rafters on the roof (Fig. 11). In this case, staple the blanket insulation directly to the rafters. Repair any major tears or rips in the vapor barrier and insulation by adding additional vapor barrier and insulation to build up to the level on the normal insulation run. Whether you apply the insulation to the attic roof or the floor, always double it back at the end for maximum efficiency (Fig. 12). Illustration A shows how the blanket of insulation material can be rolled at the end between the attic joists. Illustration B shows how the same material can be doubled back between the rafters of the roof.

FIG. 13 - Use scraps of insulation material to insulate around openings.

INSULATING WALLS If possible, lay blanket-type insulating material between the studs in the wall. If you're using insulation blankets without a vapor barrier, they should be forced into the area between the studs. Then, place a polyethylene vapor barrier on the inside face of the wall. Staple the vapor barrier into place. When building a new structure, insulate the full wall, including around the openings for doors and windows. Use drywall with a foil back as a vapor barrier instead of polyethylene if it is more practical. Blanket insulation material with a vapor barrier attached can be stapled into position. When the blanket has a vapor barrier, take the time to staple or tack all sides, bottoms and tops. This increases the efficiency of the insulation. Use scraps of insulation material to insulate all the cracks and crevices around doors and windows (Fig. 13). Then use scraps of vapor barrier to seal these areas. Staple the barrier in place.