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Most of the components needed for glazing the broad expanse of a sun-space roof are available as patented systems designed for roofing greenhouses and building long transparent walls. One such system, shown at right, consists of framing hardware—aluminum struts called glazing bars that fit together in Erector-set fashion—and double-skinned acrylic panels that slide into them. Sold by structural-plastics distributors, the interlocking parts must be precut and drilled, then assembled on the roof. The glazing bars come in 25-foot lengths that are cut to size with a circular saw, in a power miter box or with a table saw fitted with an aluminum-cutting blade. The vertical bars that run along the rafters are joined with metal angles to horizontal cross bars, forming a grid that is secured to the roof with wood screws. The grid supports double-walled, /8- inch-thick acrylic glazing panels. Each panel is ribbed, with lengthwise insulating air cavities. The panels are cut to size with a circular saw fitted with an acrylic- cutting blade or fine-toothed plywood blade. To seal the panels against weather or moisture, two types of flexible gaskets—ribbed and wedge shaped—are slipped over flanges on the glazing bars. To drain moisture that condenses in the hollows of the panels, weep holes are drilled through the bottom of the frame. Because the glazing bars are not de signed to house skylights, adapting hard ware is used to construct joints between each skylight and the glazing frame. Aluminum angles sold by metal dealers are screwed to the frame. The skylight flashing is set on the angles, and sealed with wedge gaskets. L-shaped aluminum cap ping angles, attached to the glazing frame with two h-inch sheet-metal screws, cap the ends of the vertical bars. Before the components of the glazing frame are installed, 6-inch-wide aluminum flashing is nailed along the two end rafters and the bottom edge of the roof, lapping over the edges of the wall trim. When the roof is completed, flashing attached to the house wall is lapped over the upper horizontal glazing frame. Assembling a glazing frame. Three types of aluminum bars make up a rooftop glazing frame: End bars form the perimeter of the frame; divider bars support abutting acrylic-panel edges; clamping bars fit on top, sandwiching the pan el edges against the supporting glazing bars. A wedge-shaped gasket, slipped under the clamping bar, forms a weathertight seal on top of the panel. A ribbed gasket, fitted into a slot in the glazing bar, cushions the panel from below (inset, middle). The frame is attached to the roof with 2 No. 12 Phillips-head wood screws through holes drilled along the center line of the glazing bars. Where bars meet at right angles (inset, top), a connecting angle, attached to the vertical bar with 5 No. 8 sheet- metal screws, is inserted into a rectangular slot at the end of the horizontal bar. A piece of aluminum called a terminal section covers the open end of each acrylic panel. Weep holes drilled every foot through the terminal section and the horizontal glazing bars at the bottom of the frame drain condensation from the panels. At each skylight opening, L-shaped filler bars, 3/4 by ¾ by .03 inch, are attached with %-inch sheet-metal screws to the glazing bars that support the flashing for the skylight. The flashing is held down with clamping bars and wedge gaskets. To prepare the framing pieces for installation, first cut all of the vertical glazing and clamping bars to the length of the rafters minus 1 1/4 inches; cut the horizontal glazing bars 45 inches long. (Don’t cut the horizontal clamping bars until after the frame has been installed on the roof.) Drill holes 10 inches apart through the center of each glazing bar for the wood screws that will hold the frame to the roof. Cut filler bars for the skylights and drill them, and the framing pieces that will support them, with screw holes spaced 8 inches apart. Attach connecting angles to the ends of each vertical glazing bar and drill four sets of weep holes into each bottom end bar. Drill the ends of the vertical clamping bars and each of the aluminum capping angles with matching screw holes. Use a knife or scissors to cut gaskets for the glazing bars, trimming the gaskets 2 inches shorter than the vertical bars and 2 inches longer than the horizontal bars. Cut the ends of the ribbed gaskets at a 900 angle, and the ends of the wedge gaskets at a 450 angle. Push the ribbed gaskets into their slots in the bars, working from the ends toward the middle. FILLER; END BARS 74 Fastening the Frame to the Roof 1 Mounting the first glazing bar. Mark a line along the top face of one end rafter 9 inch from its outer edge. Align the outer edge of the glazing bar with the mark, its upper end flush with the upper end of the rafter, and clamp the bar to the rafter. Use a variable-speed drill fitted with a No. 2 Phillips-head bit to drive 2½-inch No. 12 wood screws into the rafter through the predrilled holes. If the screws don’t go in easily, drill pilot holes. Remove the clamps. Cut the acrylic panels 3¼ inches shorter than the vertical bars. Insert the plastic plug strip furnished with each panel into its upper end; cover the lower end with a terminal section. 2 Squaring the frame. Slide two horizontal end bars onto the connecting angles of the bar in stalled in Step 1. Place a divider bar on the adjacent rafter, inserting its connecting angles into the free ends of the horizontal bars to form a four-sided frame. While a helper holds one corner of the frame at a right angle with a carpenter’s square, screw the end of the divider bar to the rafter. Similarly, square and secure the other end of the bar, then drive wood screws through the remaining holes in the bar. Drill two holes 1¼ inches apart through each end of the horizontal bars into the connecting angles. Screw the bars to the angles with %-inch sheet-metal screws. Then screw the horizontal bars to the roof. 75 3 Installing the skylight. Install the glazing bars fitted with filler bars on the roof. Set the curb of the skylight in the framed opening so that the skylight flashing rests on the filler bars. Trim the flashing as necessary with tin snips so that it overlaps the filler bars % inch on all four sides. Working from in side the sun space, use 2-inch wood screws to at tach the skylight curb to the sides of the rafters and the wood blocking. Continue adding to the glazing frame until you reach the last vertical end bar. To prevent water infiltration, run a bead of silicone caulk around the perimeter of the glazing frame where it meets the roof framing. 4 Glazing the roof. Peel back the protective masking from the edges of a glazing panel and position the panel within the first frame of glazing bars. Place a clamping bar on top of the vertical end bar and rap the clamping bar with a rubber mallet to engage the hooks on its under side with the center flanges on the bar. Similarly, install the remaining panels, reaching up from between rafters and through the opened skylights to secure the vertical clamping bars. • When the glazing panels are in place, carefully measure between the vertical clamping bars along each horizontal glazing bar. Cut horizontal clamping bars exactly to these measurements and install them on the horizontal glazing bars. 5 Completing the roof. Squeeze a wedge gasket under each vertical clamping bar, leaving 1- inch loops of gasket 3 inches from both ends. Compress the loops under the clamping bars—the extra length allows for shrinkage. To reach the top of the roof, hang a ladder fitted with ladder hooks from the skylight frame or roof peak. As you install the gaskets, clean their ends and the joints in the aluminum frame with naphtha, and seal them with silicone caulk. Screw the predrilled capping angles to the vertical clamping bars. Flash the peak of the roof with a strip of aluminum wide enough to lap over the top horizontal clamping pars, and long enough to extend past the roof six inches at each end. Bend the excess down. Glaze the triangular section of the side wall with acrylic panels, to overlap the frame 3/4 inch on each side. Install the panels as you did the south wall glazing. Then strip the protective masking from all the acrylic panels. 76 Emplacing the Sliding Door 1 Positioning the door frame. Trim the corner posts at the rough opening in the side wall with face boards, bringing their surfaces flush with the surface of the horizontal batten across the top. Assemble the sliding-door frame ac cording to the manufacturer’s instructions and insert it into the opening, pressing its attached exterior trim flush against the rough framing. (Sliding doors vary in height, and you may need to nail a 1-by-6 to the rough opening sill plate or the header to reduce the height of the rough opening.) Level the door- frame sill, shimming it as necessary, and fasten it with the screws provided by the manufacturer. Plumb and level the sides and top of the frame, shimming if necessary, and screw them to the rough opening. 2 Installing the glass panels. Seat the stationary panel in its upper and lower channels and push it against the side channel of the door- frame until it locks in place. Then fasten the panel with the hardware provided by the manufacturer. Attach rollers to the bottom of the sliding panel if they are not already in stalled and insert the panel into its upper and lower channels. Install the door lock and caulk the joints between the door frame and rough opening with butyl caulk. 77 . |