Every year around this time the sun starts peeping out from behind the rain clouds, the days get longer and the grass starts growing in Western Washington. This chain of events eventually leads to the dusting off of lawn mowers, weed whackers and garden tools in most yards across the Pacific Northwest. For small engine mechanics this is the busiest time of year and for window and glass companies it means more customers needing replacement units for windows damaged by flying rocks. Since I have already noticed an increase in the number of glass causalities this year I decided to put together a little how to tutorial on measuring glass for replacement units. Sure you can call a glass company to come out and measure up your windows for you. But, if you are handy you should be able to use this guide to help you measure the broken unit so you can install the new unit into your frame and save a bundle of money...which you can spend on getting your lawn mower tuned up or new flowers for the garden. Of course if you get lucky and end up breaking the vent (operable part of an opening window) you are welcome to bring the whole vent into the store so we can measure it for you.
I use a flat head screw driver or putty knife to wedge between the frame and the snap bead. After you get it loose it should pull right out. The snap bead does help keep the glass in place, but your window should also be secured with double stick glazing tape so don't worry about the glass falling out.
The raw edge can be sharp so be careful on this part. Measure the unit from edge to edge and get as exact as possible. Write the measurements down as you go. There is no standard and the measurements have to be pretty exact. When recording the measurements always record width x height.
Every window manufacturer and series have different glass thicknesses so again there are no standards although they usually come in 1/4" increments. To measure the thickness of the unit without breaking the glazing tape seal we slide a business card in between the frame and the unit and mark the card along the edge of the glass. We then measure the distance from the edge of the card to the line to get our overall thickness.
Depending on the age of your window it may or may not have LowE Glass. If your window was manufactured prior to 1990 it is unlikely that it has LowE. However, if your window was manufactured after 1990 then it may have either a hardcoat or softcoat LowE (there are others but these are the two most common). To tell whether a window has LowE you will look for a slight green (softcoat) or purple (hardcoat) tint. If you can't tell, we recommend putting a piece of white paper behind the glass to help make any tint more noticeable If the glass you are replacing stands alone then it isn't as important that the LowE matches the rest in your house. However, if you are only replacing one side of an operable window and the LowE doesn't match one side may look darker/lighter than the other.
If your window shattered when it broke it is probably tempered (safety) glass. If your window broke in large chucks it is probably annealed. However, if your window didn't break and your are replacing the unit for another reason (fog between the panes, ect) then you may not know. All tempered glass should be labeled with a stamp in one of the four corners. Look for the stamp and note if it is tempered or not. There are building codes that require tempered glass in certain applications and it would be shame to have to reorder the same unit later down the road because you missed the tempered label.
If you have any questions on the process please feel free to call us at 425-432-5189 (Maple Valley) or 425-888-5044 (North Bend). If you would like pricing for window units please call us with the above information. To order custom size glass we require a signature to confirm the sizes are correct since the glass can only be cut once. We can accept signatures via email, fax or in person. Good luck and happy mowing! :)