Réemploi et reconfiguration thermique des fenêtres bois en ... - Prebat

PUCA - Réemploi et reconfiguration thermique des fenêtres en fin de viePARTIE 1amount of energy to make, deliver and install new windows and transport the old windows to thelandfill. In addition, new windows also have many more constituent parts that are likely to failresulting in operation that deteriorates with age. It also becomes increasingly difficult to findreplacement parts as the windows age, but glass, glazing, and sash cord; the basic necessities forrehabilitating historic wooden windows will always be available. Finally, the old-growth heartwoodthat historic windows were manufactured with has a far greater lasting capacity than new secondgrowth timber due to a number of reasons including density and resin content.As mentioned earlier, there are a number of options available for increasing energy efficiency, andwhen applied simultaneously, these methods can increase the overall efficiency of historic woodenwindows dramatically. For example, much of the heat loss and air leakage involving historic woodenwindows results from the hollow, un-insulated space created for the window weights on either sideof the window sashes. However, replacing the window weights with spring-loaded window tapebalances will eliminate the need for the weights thus allowing for the installation of insulatingmaterial in the now vacant sash boxes.It is also possible to rout grooves in the meeting rails of the sashes and install RST Corporation’sWS87 offset plastic leaf seal as well as routing the lower sash rail and installing a piece of WS10plastic tube seal where the sash meets the sill. Grooves can also be routed on the outer edges of thesash stiles and WS84 plastic seal installed there as well.All of these materials and methods are recommended as NPS “best practices,” and when installedproperly are unobtrusive. Other companies make similar products.Although storm windows can result in condensation and potential rot if used incorrectly, wheninstalled properly and with an eye toward taste, they can be an attractive addition to the building. Afine example of this approach was employed by window specialists from Allegheny Restoration andcan be seen at the Monroe County, West Virginia courthouse.If storm windows are not desirable, something as simple as insulated window treatments with nomore than a quarter inch gap at the sides of the window opening can reduce heat loss by as much as27%.If the wooden windows are retained, they should be removed, prepared, primed, painted, and thenre-glazed. Old caulking should be removed from around the exterior window frames and sills andthen re-caulked. This will stop a great deal of cold air infiltration. After the sashes are re-roped andre-installed, two sash locks set a distance apart can then be used to keep the windows tightly shut.The following paragraph was taken from the conclusion of National Park Service Preservation Brief #9and reflects the opinion of Technical Preservation Services who recommend the retention and repairof original windows whenever possible. “We believe that the repair and weatherization of existingwooden windows is more practical than most people realize, and that many windows areunfortunately replaced because of a lack of awareness of techniques for evaluation, repair, andweatherization. Wooden windows which are repaired and properly maintained will have greatlyextended service lives while contributing to the historic character of the building. Thus, an importantelement of a building's significance will have been preserved for the future.” As a preservationhistorian and past contractor I agree.[1.58]Juin 2012Les Bâtisseurs d’Emmaüs160