Sash & case Windows
Sash & Case Windows
in most historic buildings, the window sash, window framing, and the architectural detail surrounding them were all carefully designed to harmonize with the style, scale, and character of the building.
It is important, therefore, to retain the original window configuration, including the size of openings, sills, lintels, decorative wood or masonry moldings, as well as the sashes themselves.
Replacing sashes and frames is often unnecessary, because in many cases existing historic windows can be repaired. If it is necessary to replace or alter any window elements, such changes must be made according to the Commission’s Window Rules.
The historic and architectural character of a building can be seriously damaged by inappropriate window treatments.
The deterioration of historic windows is caused by age, weathering, and inadequate maintenance. Such deterioration makes window operation impossible or inefficient, and diminishes energy performance. Because it is desirable to maintain the original materials in historic buildings, the installation of new window sashes and frames is appropriate only when the windows are in such poor condition that replacement is required.
Deteriorated wood windows can often be restored in a cost-effective manner by treatment with preservatives, wood fillers and epoxies, and by replacement of only severely damaged sections.
Broken, sticky, or loose sashes can be removed from the frames for repair, excess paint can be stripped from the sash and tracks, and weather stripping installed.
Repairing and preserving historic windows rather than replacing them is strongly encouraged, and will save original material while saving money.
Caulking, Puttying & Prevention of Moisture Build Up:
The major causes of water damage to windows are interior condensation and exterior exposure to the elements.
In cold weather, water vapor contained in the warm air inside a building condenses on cold surfaces such as glass panes in windows and doors, or on window and door frames.
Condensation attacks glazing putty and paint, causing loosening, disintegration, blistering, and peeling.
To prevent water damage to exterior components, it is important to seal all places where water might seep into the building.
Windows should be regularly repainted, before old pain cracks and flakes off, exposing the wood.
All horizontal surfaces on windows, such as the sills and the tops of lintels, should be slightly pitched so that water does not collect on them.
Window-glazing putty solves this problem on the actual sash by directing water away from the window muntins.
Priming the wood muntins under the putty helps to protect the wood, should the putty crack and water seep in, and helps to form a better bond between the putty and wood.
In masonry buildings, the joint between window frames and the masonry wall should be caulked to prevent water seepage during driving rains or when ice accumulates.
The caulking compound used should be selected for its color, adhesion, and flexibility.
Most Important of all is..
Repairs & Maintenance
Shrinkage of wood parts often causes window sash to become loose and drafty.
A good way to stop drafts is to install weather stripping. Although weather stripping is one of the least expensive components of a window, it can increase energy performance by as much as 50 percent.
Weather stripping should be installed at the upper, lower, and meeting rails of windows, and around the sash and frame.
Sharp lines around the glass giving a professional finish
A frequent problem with many old windows is that they become difficult to operate, or completely inoperable, due to the accumulations of numerous layers of paint on the sash and frame.
Paint can be best removed by scraping or stripping it off the window components with a chemical paint remover or heat gun
Where sections of wood window sash, frames, or sills have deteriorated but are essentially sound, the deteriorated wood can be consolidated.
The loss of wood is progressive. At first the mass of the wood diminishes but retains its original size and shape.
As decay continues, the wood shrinks and begins to crumble.
Epoxy consolidates can replace the lost mass, restoring strength to the wood. Holes and gaps can be covered with epoxy paste fillers.
Epoxy consolidates are syrupy liquids that permeate porous or decayed woods and are applied to the deteriorated areas to saturate the decayed wood. For consolidates to penetrate deeply and to be effective, all wood must be dry.
Any gaps in the wood are then filled with epoxy paste, which is a consolidate that’s combined with powdery fillers and has the characteristics and flexibility of wood.
Filler can be primed and painted, once it’s cured.
The exterior surfaces of wood windows and window frames should always be painted, rather than varnished. Varnishes and other clear finishes are not durable and historically were very rarely used on windows.
CALL US TODAY FOR ANY SASH AND CASE ENQUIRIES.
The Areas We Cover
- North Berwick
- East Lothian
- West Lothian
- Scottish Borders