Replacing a Window | Workbench Magazine |
There are only two solutions to this problem, he tells me - never start remodeling, or never stop. Now that I've renovated some of the Workbench house, I know just what he means. Thankfully, I like the work and the results, so I'll keep going. My latest adventure involved putting in a replacement window. It was surprisingly easy, in part because I didn't have to disturb my new siding or the interior wall. Ease of installation is one of the key virtues of a replacement window. The old framing, jambs, and casing stay intact while the "performance" parts - the sash, seals, and glazing - get replaced by newer and more efficient components. The window I needed to replace was a double-hung wood window in a small bathroom. Double-hung windows feature an upper and a lower sash, both of which travel vertically in a wood or metal track. They're the best candidates for this type of replacement. The new window is a Precision Fit Replacement Window from Pella Corp., one of a handful of large manufacturers that offer wood replacement windows. Most companies offer sash companies offer sash replacement kits, but Pella designed this series with "single-unit construction." This means the sash are fitted into a sub-frame that's ready to install as one unit, rather than individual components that you have to put together. I like this approach because it keeps the installation very simple and allows a tilting sash feature for easier cleaning, but the average cost (about $350)is higher than most sash kits. Replacement windows are custom-fitted items, either made to order or offered in sizes to match most existing windows. If you're doing the installation, check the manufacturer's guidelines for measuring your old windows correctly. The measuring procedure for the old window may vary with different replacement systems, but the basic dimensions you'll need are the width between the two side jamb faces, and the height between the sill and the head jamb. When installation day arrives, carefully unpack the window, check the dimensions against what you ordered, and read through the manufacturer’s instructions before you begin. Out With the Old For some people, demolition work involves just two tools - a hammer, and a bigger hammer - but a little more finesse is needed here. Remember, you'll need to keep some of the old materials to reuse, so don't ruin them. The inside stop molding is part of the track for the power sash, and it has to come off first. Use a utility knife to score the paint where the stop meets the jamb, then use a small flat bar to pry the molding loose. Removing the inside stop will free the lower sash unit, but you'll also have to snip the sash cords or springs used to keep it open. Older windows will have cotton cords with iron weights suspended behind the jambs. Some newer models will have a flat steel spring that provides the lift tension. In either case, the lower sash will come free when you cut stop those connections. The jambs on older allwood windows have wooden center strips called parting stops, so named because they separate the upper and lower sash. Pry these out before you try to remove the upper sash. If your window has a metal sash track like mine, use a pair of putty knives as wedges to help pop the upper sash out. Then remove and discard the metal track. With both sash out, remove any sash balance or pulley hardware that's in your way, and tuck some fiberglass insulation through the holes, filling in behind the jambs. The blind stop, the outermost molding of the sash track, stays intact. It will provide support and a sealing surface for the frame of the replacement window. Scrape any paint ridges or debris from the blind stop, then do a test fit with the new window. Set the bottom of the window on the existing sill and tilt it up into place. Once you're sure you've got a square fit with a little clearance at the top and sides, remove the window and caulk the inside faces of the blind stop. In with the New As you start the installation, have some tapered wood shims and a little more fiberglass insulation on hand. Some of the insulation belongs on the underside of the new sill, so you'll have to turn the window upside down and press fit the material in place.
Finally, nail the inside stop molding back in place Here's a tip for reusing the old stop: If any of the finish nails came off with the old molding, use pliers to pull them through the wood. Trying to back them out usually pops bigger holes from the molding's face. And in case you're nervous about swinging a hammer next to your new glass, cut some cardboard from the packing box and use it to shield the window. This simple precaution is worth its weight in peace of mind, even if you've got a good hammer arm. Some putty for the nail holes and a little touch-up paint will wrap up the work on the inside. To ensure a weathertight installation, go outside and run a bead of exterior caulk along the perimeter of the new window. Reprinted with permission from Workbench August 1997 |