Most instructions show measurements taken within the tracks from one side to the other, and from top to bottom. These measurements are sufficient for box frame or pocket replacement - i.e., “Frame-In” replacement. However, win- dows are installed initially against the rough framing (the rough opening), before the interior wall board and exterior siding is installed and trimmed out. If the old wood window has weights, there is a weight pocket behind the jambs. The outer surface of the sloped sill of old wood windows is considerably above the rough sill; and depending on the thickness of the window sill itself, it becomes difficult to estimate the real rough opening dimensions unless the old window was totally removed. And, certainly you don’t want to be remov- ing the old window and then measuring in order to properly size the new window. Perhaps worse is receiving the new windows on the job, removing the old windows and finding there is a mis-measure (really a mis-estimate) requiring fill-in or larger gaps that invite water and air infiltration. Experienced installers may be able to “eyeball” the real dimension, but the safest way is to get the real dimensions and supply them to the factory with the order. The drawings show the actual relationship between the rough opening and the interior surfaces of wood and finned window. Using a small drill bit, it is possi- ble to make a small hole into which the drill bit can be inserted, and using your fingers, you can identify the additional space that will be exposed when the old window is totally removed. These techniques can be used when you want to determine the space that will be left after the full frame is removed for Metal Windows and others where mounting parts are“buried” inside the wall. Professional measurement sheets have extensive dimension call-outs. Too much information back at the factory is better than too little. Use your best judgement. Measuring for Full Frame Removal EXTRA SPACE IN WEIGHT POCKET Using a small drill bit, create a hole in the frame or wall board to insert. Using your fingers, as shown, push the drill bit until it rests on the rough opening framing. Remove the drill bit and measure from the tip of your fingers to the drill bit tip and add that to the measurement between the inside surfaces of the old window. Window Fitters Guide to Window Installation 24 ©2022 AWDI, LLC Do not reproduce without permission Sash Weights SAMPLE MANUAL
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