Protecting stained glass windows

We also offer a variety of glazing material options to best fit your individual needs. Call today to speak with us: See our case studies. Call today to speak with us: 1. Without protecting your stained glass windows, it is nearly impossible to prevent damage from the elements, vandalism, or loss of heat and air conditioning.

This sophisticated process involves the contouring of the aluminum framing to closely match the existing architectural millwork allowing the existing architecture to remain dominant. Our craftsman have mobile bending devices so the new framing can be fully customized on-site. Protective glazing greatly extends the life of stained glass windows in certain situations. It is critical, however, that protective glazing be adequately vented to allow air circulation and that it be easily removable for future cleaning or restoration.

Shoddy workmanship can cause more damage to the glass than it would have acquired without glazing. She recommends taking the following into account when considering glazing:. The lifespan of lead depends on the surrounding environment, but eventually it will have to be replaced. Unfortunately, complete re-leading is one of the most expensive restoration projects. Phifer advises caution before committing to a complete re-leading of the window.

Once the panel can be evaluated in a studio, sometimes only a small part of the window needs re-leading. This conclusion was reached in a study of 'Protective Glazing' that was commissioned by the National Center for Technology and Training conducted by Inspired Partnerships Inc.

Chicago, Illinois. This study examined data from churches in the Chicago area and found that the energy saving benefit derived from the installation of exterior glazing was minimal for intermittently heated buildings. It cannot be disputed that cold air will draft through and around a stained glass window in addition to an increase in humidity from condensation and leaks as a result of wind driven rain; all these are inherent in any single glazed system.

Heating and cooling cycles promote expansion and contraction of the stained glass window and this movement will loosen the glazing cement that is packed between the flanges of the lead came and the stained glass, eventually producing leakage see cementing page The traditional method to handle this condensation and leakage was to install collection pans at the bottom of the stained glass windows. Medieval gothic cathedrals with stone frames had these water collection troughs carved directly into the stone sash.

Some frames even had these water collection gutters slope in from both sides to the middle with a weep hole cut through the frame to channel the collected water to the exterior of the building, in some cases out through a gargoyle's mouth. A properly designed and installed exterior glazing system will create an effective barrier to prevent cold air drafts and rain leakage.

In addition it will reduce the consequence of vandalism and storm damage. It is imperative to specify a protective glazing system that is a proven and effective barrier to ensure the precious stained glass heritage is preserved for future generations. Unfortunately follow up studies, conducted to measure the effectiveness of protective glazing installed in the US, indicate that these windows have suffered more damage to the stained glass and their frames from improperly designed protective glazing systems than from damage caused by storms, fires and vandalism combined.

How could this happen? The primary cause is the condensation that naturally forms on the interior side of the exterior glazing. In a single glazed system the stained window is the exterior glazing and this condensation moisture is collected at the bottom of the window and allowed to evaporate into the interior of the building see previous paragraph.

However, in an unvented double glazed system, as is the case with a stained glass window and a protective glazing, the condensation moisture is trapped within the closed airspace. A continuously damp space such as this, is conducive to the growth of microorganisms that secrete organic acids that attack the stained glass, oxidize the lead and metal frames and rot wooden frames.

Additionally this unvented space is also a serious heat trap. It is widely accepted that expansion and contraction cycles deteriorate most building materials, including stained glass windows, causing reinforcing systems to fail, premature metal fatigue and deterioration of both the frame and the lead in a stained glass window. The super heated air also creates pressure on the stained glass window and protective glazing, contributing to the deflection of the stained glass window.

Stuff like that happens, though. Protective glazing, though, is one line of defense against breakage. The glazing helps protect windows from rocks, baseballs, hailstones and more. Vented protective glazing offers numerous advantages. For instance, water is the enemy of stained glass windows.

It can etch and pit glass, corrode metals, rot wooden frames and remove fired paint. Moisture will get trapped against the window causing all sorts of trouble. Venting needs to be at both the top and bottom of each independent panel, which allows for air to be fully exchanged several times daily. Oh, and proper ventilation is important, too.