b"Universal Replacementof Old Finned Windows New Construction finned windows have been usedextensively, and over the last 20 years the majorityhave been uPVC. Bargain builder windows havebegun to fail and are in need of replacement.There are considerations with the replacement, and most of them are due to differences in framedepth, and existing interior and exterior trim.The common technique, chosen solely for economicreasons, has been touse a reciprocal saw tocut out the old windowand leave the old finbehind the existing sid-ing and trim. This isnot the best approach Regardless of whatbecause it destroys the style old windowwater management, was used in a home,does not reconstruct it, and covers over the debris in if it was mountedthe opening cavity which then is difficult towith a fin, the finproperly seal. It will be only a matter of time beforewas covered withit will fail and leak. Similarly, prying the old window - flashing and thenfin and all - out of the opening leaves a similareither siding or trimwas used to coverbroken water management condition behind thethe flashed fin.old siding and trim, which is again covered over and difficult to properly seal.The preferred technique is to cut or remove the exterior trim/siding to expose the old windows finand flashing. The flashing is removed and the old window is removed, and a new finned window isinstalled in its place and reflashed and re-trimmed.This approach yelds the best long term result. The new box-frameThe new window, however, needs to be the perfectreplacement window size - similar fin dimension, and similar depth, etc. can be mountedfor a quality and weathertight finish. It often requires against the new exterior trim usinga more expensive window than the typical replace- pocket Install ment product, and offers fewer style options. techniques. There is a method that will yield a proper result, using a box-frame product. This universal approach NOTE: It is important to repair the flashing in theto replacing a finned window simply has the exterior opening, around the jambs and header, and create atrim removed to expose the old fin, and new exterior drainage accommodation (effective sill pan or drainagetrim reinstalled over the repaired flashing before mat) on the sill. Also, placing 1/16 - 1/8 shims oninstalling the new window. This new trim is 3/8 the sill, over a tapered piece of siding slanted towardswider than the old molding. This allows it to extend the outside and covered with flashing, will raise theinto the opening forming a blindstop to which the new window properly to allow drainage to the outside.new box frame window is installed in a familiarTwo cap nails, installed on the sill overlap flashingpocket install. will complete the weep system. The Contractor's Guide to installing Vinyl Windows 43 2020 AWDI, LLC Do not reproduce without permission"