Windows

Table of Contents


1. Refurbished window.

Description

There are eight windows in the original schoohouse as built in 1879. Six, like the one pictured, are double hung sash (3x2 top and bottom), while two at the "rear" are double hung sash (3x1 top, 3x2 bottom). All components including the frame and trim are made from Australian Red Cedar (Toona Ciliata).

They were originally lacquered and so would have displayed their beautiful deep red colour and grain.

Many of the original glass panes are still intact with their manufacturing defects adding character, and are all 2mm thick. Any panes that I've replaced are also 2mm so as to maintain the same overall sash weight, which is generally 16lbs top and bottom for the full height windows. A few of the individual counter weights (two per sash) are 9lbs, not 8lbs.

Most/all glaziers will not sell 2mm glass for windows anymore so I specify picture frame glass. The minimum thickness today for window glass is 3mm, which will usually be used in much larger pane sizes than I have here.

Trim

Architraves

Several windows will need new trim to replace sections that are either damaged or that no longer fit for various reasons. It's unfortunate because the original trim throughout the schoolhouse was all Australian Red Cedar (Toona Ciliata) and is very rare today, but any replaced pieces will not be discarded. They'll become stock to be used to repair other components that need it.

Ideally I'd like to match the original profile. However, although similar, none that I've found match in size (usually smaller) or in the eligance of the curvature. I may yet choose to have a custom router bit made and then mold my own architraves. The same bit could also be used on the new skirting and, although that skirting profile would depart from the original, it would be an acceptable upgrade.



2. Original architrave cross-section

3. Custom router bit profile traced from a cross section of the original architrave.

Otherwise, the nearest profile I can find is the Carbitool TFM32 B 1/2, which appears to have been used on architraves in newer parts of the building, such as the main entrance hall and bathroom areas. It is 6.3mm shorter in profile length (the B dimension below) and the transition from the concave to convex radii of the ogee section is straighter. It currently costs about AU$120.

Thermal treatment

The question of insulation comes up often. For the old schoolhouse summer is not a problem as it requires very little to no cooling. Heat retention during cold months is the aim.

Possible treatments are:

  • double-glazing: requires complete replacement of sash because of the additional thickness and weight.

  • storm windows: the primary requirement is the retain heat in cold weather, therefore internal rather than external additions would most likely be used. These need to be removable and storable, therefore they need to be robust as well as effective. Low-E glass or optical grade acrylic would be preferred to minimise visual disturbance but very cheap alternatives are possible, perhaps as a temporary trial, and if the frames are well made then could be reused. Help with drafty windows. Generally detract from window aesthetic.

  • internal shutters: not all that effective unless they are particularly tight sealing.

  • low-E blinds/shades: cellular shades are the most effective and best when tight fitting

  • low-E on-glass films: any that are effective for cold climates are expensive but not compared to other treatments. They are minimally invasive aesthetically but do not fix drafty windows. Here is a comparison.