Wear appropriate personal protective equipment
■ To minimize upper respiratory tract irritation, measures should be taken to control the exposure. Such measures will be dictated by the work environment and may include appropriate respiratory protective equipment. See OSHAs respiratory protection standard.
■ When appropriate, eye protection should be worn whenever SVF products are being handled.
■ Personal protective equipment should be fitted properly and worn when required.
2. Removal of fibers from the skin and eyes.
■ If fibers accumulate on the skin, do not rub or scratch. Never remove fibers from the skin by blowing with compressed air.
■ If fibers are seen penetrating the skin, they may be removed by applying and then removing adhesive tape so that the fibers adhere to the tape and are pulled out of the skin.
■ SVFs may be deposited in the eye. If this should happen, do not rub the eyes. Flush them with water or eyewash solution (if available). Consult a physician if the irritation persists.
Before starting, verify that the machine is set in accordance with the instructions on the bag. The machine settings were developed by manufacturers using machines in good working order and proper application techniques. Always keep the hose level, and install with a minimum of hand deflection. It is also important to always blow parallel with, and not across, the joists. To verify that proper amounts are being applied, it is wise to section the attic into quadrants and make sure one-quarter of the specified number of bags is used in each section to achieve the desired R-value.
Applying insulation in unfloored attics. NAIMA recommends that the installer keep the hose parallel to the floor, with the insulation falling
10 to 12 ft in front of the hose. It is best to back away from the work while blowing, to prevent packing. The installer can blow three or four joist spaces from one position by moving the hose to the right or to the left. Where working space is tight, the installer should prevent the insulation from packing by allowing it to blow off his or her hand.
Special construction conditions will require extra attention during installation. For example, the insulation is to be installed on both sides of obstructions such as solid cross-bracing, wiring, and masonry chimneys. If a batt or baffle is not used to block off the ends of joists, the insulation is to be applied to the outer edge of the plate. When roof construction does not allow full depth to the ends of the joists, the insulation can be “bounced” off the underside of the roof to increase density in that area, but be sure not to block the eave vents15 (Fig. 7.12).
Clearance needs to be maintained around heat-producing devices, fossil-fuel appliances, and light fixtures, or as specified in the local building code. For example, the insulation is not to be placed in airspaces surrounding metal chimneys or fireplaces. Unfaced fiberglass insulation can be used between wood framing and masonry chimneys.
The installer should even out any high or low spots to verify that the minimum thickness has been achieved. Some areas will not be covered by design. Access panels, stair wells, and fan covers will need a piece of batt insulation on top of areas where loose-fill insulation has not been applied.
If the attic space is already floored, the installer should attempt to blow no more than 4 to 6 ft under flooring. This will require the
removal of floorboards (or plywood sheathing) approximately every 8 to 12 ft to guarantee adequate blowing coverage. When blowing below a floor, the installer should insert the hose approximately 4 to 6 ft under the floor and gradually pull it out as the space fills with insulation. Twist and turn the hose as it is removed to ensure complete coverage of the area under the floor. In finished attic knee walls and slopes, it is possible to use retainers and blow knee walls, but it is easier to use batts (Fig. 7.13).
Applying insulation in sidewalls. Regardless of the outside finish, all existing house sidewalls are insulated in a similar manner. [As opposed to the Blow-In Blanket System (BIBS), which is installed while the home is under construction. See Chap. 9.] The only variable is the method required to remove the exterior finish in order to access the stud cavity. There can be many variations of the procedures for the removal and replacement of different types of side – wall materials. Any method that gives sufficient access to the sidewall area can be used, but an experienced carpenter, framer, or mason should be used to guarantee that the existing exterior finish material will be returned to its original condition.
Generically speaking, the first step is to have isolated portions of the outside finish removed. Openings are then made in the sheath-
ing so that the loose-fill fiberglass can be blown into the empty stud spaces. The “double blow” method, with two openings (top and bottom), is commonly used for sidewalls. Different applicators have different methods of filling sidewalls, but it is generally recommended that the lower holes be filled first to ensure that the lower parts of stud cavities are filled. Some stud sections may require three or more openings because of construction features, such as firestops, blocking, junction boxes, electrical cables, and bracing (Fig. 7.14).
NAIMA’s guidelines state that openings should be made into the stud area for each 4 to 5 ft in wall height. Since blowing is limited to no more than 4 ft down or 12" up a space, this is the only way to ensure the stud space will be filled properly. Blowing through a single opening in an 8-ft wall could leave some of the stud space with voids or no insulation. One way to check the actual stud cavity depth is to drop a plumb bob into the wall. Areas above and below windows and below firestops and bracing also must be opened to determine the exact location of obstructions and ensure that the cavity is filled completely.15