What Is Window Glazing and Why Should You Care?

gla·zier

/ˈɡlāZHər/

noun

1. a person whose profession is fitting glass into windows and doors.

glaz·ing

/ˈɡlāziNG/

noun: glazing

1. the action of installing windows.
   • glass windows.
     “sealed protective glazing”

glaze

/ɡlāz/

verb: glaze; 3rd person present: glazes; past tense: glazed; past participle: glazed; gerund or present participle: glazing

1. fit panes of glass into (a window or doorframe or similar structure).
   “windows can be glazed using laminated glass”
   • enclose or cover with glass.
     “the verandas were glazed in“

noun

noun: glaze; plural noun: glazes

1. 1.
   a vitreous substance fused on to the surface of pottery to form an impervious decorative coating.

Confused? It gets “out there” in a hurry! Commonly, “glaze” or “glazing” refers to the putty that forms a wedge between the wood ribs (we stay away from a lot of technical jargon here) and the glass. Properly applied, it is invisible from the inside and looks like a machine put it on. Improperly applied, it looks like a first grade play-doh project gone very wrong.

So what’s the deal? In our minds, we install or replace glass, and then we glaze the window! We use glazing putty to do so (very good stuff, $50 a gallon Sarco putty). When we see what a lot of people think is rotted wood, it is actually failed “glaze putty”, so we “re-glaze” the windows!

According to Webster, we are WRONG in our terminology, we would like to think we are simply being practical as opposed to trying to win a grammar contest however…

Now that we have that out of the way, what exactly is glaze putty and why does it matter?

Historically, whiting powder and linseed oil are combined in various ways to make up a soft “putty” that is then applied to a window as described above. Once exposed to air, it solidifies, some variants become concrete-like and some retain some resiliency. It firmly affixes the glass to the wood as the linseed oil chemically bonds with the wood, we use linseed oil to break down stubborn old glazing also (it can be tough to remove). When paint is applied in the right way, water has no chance of getting to the wood, and glazing can last many many years, depending on exposure to sunlight and the elements.

The good news for homeowners is that “re-glazing” windows is not too difficult. Getting old glaze out can be tough, but putting new glazing on is something that can be done efficiently on site and make a huge difference in the looks of your windows!