Insulated Glass Replacement

DEAR TIM: The insulated glass sidelights next to my front door will not come clean. Upon closer inspection I can see that the seal has probably broken. The dirt and film is on the inside of the panes of glass.

Is it possible to install new glass or am I forced to buy a complete new front door unit? Where in the world do you get insulated glass? Georganne G., Hoffman Estates, IL

DEAR GEORGANNE: I wonder if we have the same front door? The same thing happened to me recently. If you do have a similar door design, you are in luck. It is often possible to re-glaze glass doors, sidelights, and windows that have insulated glass. The job is typically not hard but it can be slightly tedious.

The new insulated glass panel is leaning against the green door trim. It was made by a reputable local glass company.

The first thing you need to determine is how the glass was installed in the first place. The wood sidelight frame was undoubtedly milled with a built-in rabbet profile. This milling process creates a recessed area in the frame where the glass rests. Once the glass is in place, small wood trim strips are added on the exterior side of the sidelight. These decorative strips of wood hold the glass in place so that it will not fall out of the frame.

Inspect the exterior of your sidelights and see if you note a small uniform hairline crack about one half inch from the edge of the glass. This may be the edge of the small piece of wood trim. Use a sharp flexible putty knife with a fairly thin blade and try to lightly hammer it into this crack. Once the blade is past any paint or dirt, you may find it plunges into the sidelight frame about three quarters of an inch. This is a good thing as the putty knife is telling you that it has glided past the wood trim and the insulated glass.

The wood strip that holds the glass in place often has a factory-applied water and wind sealant on the side that touches the glass. This sealant can harden over time. If you try to pry the wood strip off too fast, you can crack the trim strip. Gently try to tap the edge of the putty knife blade between the glass and the wood strip. Keep the putty knife blade at a low angle so it is nearly parallel with the surface of the glass. Take your time with this step as it is important to salvage the wood strip in its entirety.

Once the wood strips have been removed you may see some staples or nails that once held the wood strip in place. Use a needle nose pliers to pull these fasteners out of the frame. At this point, you may need some assistance. The only thing holding the glass in place may be friction, some interior glazing compound and possibly paint that has lapped over the inside of the glass panel. In other words, the glass may fall out of the frame without warning. Put on a pair of light leather gloves and ask a helper to gently push against the top of the glass from the inside. If all goes well, the glass will start to tilt out of the frame. The gloves will protect your hands from being cut by a sharp edge on the insulated glass panel.

The replacement glass panel needs to match your existing one in width, height and overall thickness. The glass panel should not fit tightly into the rabbeted frame. There usually is a one eighth inch space between the glass and the wood frame on all four sides of the insulated glass panel. Glass panels that fit too tightly can break if the wood frame expands or contracts from changes in the weather or stress that occurs from house settlement.

The new glass can be ordered from a local glass shop. Building codes dictate that sidelight glass, door glass and other types of windows must have tempered safety glass. Be sure the glass panel you order meets all current building codes. The glass shop will undoubtedly have to order the replacement panels from a special glass company that makes custom tempered glass to size. In my case, I only had to wait one week to get perfect replacement panels. I also ordered my glass with argon gas. This gas helps to deaden noise and it also is more energy efficient.

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