Commission seminar offers insight into windows
March 27, 2014
Few things convey individuality in a structure as much as its windows. The location, size, spacing, material and design of windows tell the structure's age and style, and offer its inhabitants light, heat, egress, and fresh air. Windows have been incorporated in our structures since we moved from caves. Today, technical advancements allow modern buildings to have vast expanses of glass that are energy efficient and safe instead of the small panes present in most mid-19th Century and earlier homes.
The Mount Vernon Historic Preservation Commission will be sponsoring a historic windows seminar from 9 a.m. to noon on Saturday, March 29, at Mount Vernon City Hall. David Wadsworth, an expert on historic windows from Decorah, will be the presenter. There is no charge for Mount Vernon residents; the cost is $5 for non-residents.
Wood was the traditional material for window frames and sashes and still forms the base of most modern residential windows. Exterior cladding materials such as aluminum and vinyl add durability and reduce maintenance, but they also reduce your options for color and present a different appearance, in particular how they are trimmed. Wood is still exposed on most window interiors. There is a growing trend toward vinyl and glass composite windows, but wood still dominates.
If you live in one of Mount Vernon's late 19th Century homes, you have probably had to deal with aging wood windows. Most are double hung (bottom sash slides up, and the top sash slides down), single glazed, and many have dividing muntin bars. They typically used a rope or chain with a counterweight hidden in the jamb for ease of operation, and they rattled when the wind blew. They were trimmed with wide wood boards to place emphasis on the window, inside and out. Wood storm windows came along in later years to improve energy efficiency but can be cumbersome to install and remove, in particular if you have a two-story house. Like the window itself, they require maintenance. The combination storm window improved energy efficient with regard to air infiltration and added functionality, but they presented further challenges to design and color when attempting to restore an older home.
The first tenet in historic preservation is first, preserve or restore existing materials. Just because the windows are old and rattle doesn't mean they should be replaced. Older windows require maintenance - painting, caulking where the frame abuts the siding, and occasionally reglazing. None of these items is cause for replacement. The chain or rope counterweight system for many of these windows is missing or broken (the rope often rotted). These can be repaired by removing the interior trim and replacing or repairing the attachment. If you don't want to do that, you can fill the void (a big energy loser) and replace the mechanism with a friction or spring loaded device to assist in raising and lowering the window.
The two areas most in need of repair in windows are the sills and the lower exposed end grain of the window sash. Sills can be replaced if they are deteriorated beyond repair, or they can be repaired with an epoxy compound. Decayed window sashes are a more serious issue. A carpenter with experience in repairing windows should be consulted if the sash deterioration is advanced. Note the reference to experience in this type of work. The first choice of many contractors is to replace the window with a vinyl replacement or insert. If they must be replaced, you should have them replaced with sashes that resemble the original in material, size and design as closely as possible. If the thickness of sash and jamb permit, you should consider a sash with insulated glass. Replacement with a totally new window, while an attractive option, should be the last option, in particular if you are thinking of a non-wood option. Any replacement (including siding) should replicate the design of the original wood trim on the exterior. Removing or covering the trim, leaving only the exposed window trim of a new window (typically 1 to 1-1/2") dramatically alters the appearance of a structure - for the worse - from a historic perspective.
If you are contemplating a window change or upgrade, feel free to contact the Mount Vernon Historic Preservation Commission for ideas, tips and sources of materials and windows. The March 29 seminar is also an opportunity to learn more. If you have any questions about the seminar, contact Leah Rogers at 319-895-8330 or LDRog215@aol.com.