The Historic District

Why is the glazing putty side always on the exterior ? Is this about aesthetics or function ?

While we are waiting for the experts to respond, I'll submit that the outside of the window is where the rain hits and putty is meant to be watertight whereas wood muntins are not.

maybe because the putty is unattractive so it is further from the eye?
I once locked myself out of the house I was staying in. I took out my pocket knife and picked the old putty out, removed the pane and got in without causing too much damage. later we re-did the putty. It was my brothers house and he was happy I managed to get myself out of the situation without really doing any damage. also made us realize they aren't very secure. I wonder if that makes it not a break and enter?

Manalto wrote:While we are waiting for the experts to respond, I'll submit that the outside of the window is where the rain hits and putty is meant to be watertight whereas wood muntins are not.

Ding Ding Ding! Correct answer - if you put a sash in the other way around it would rot out in no time.
tbhe putty sheds water away from the wood

Mick_VT wrote:

Manalto wrote:While we are waiting for the experts to respond, I'll submit that the outside of the window is where the rain hits and putty is meant to be watertight whereas wood muntins are not.

Ding Ding Ding! Correct answer - if you put a sash in the other way around it would rot out in no time.
tbhe putty sheds water away from the wood

Okay, that settles it. I pondered this as to why the putty was exposed as it will disintegrate with weather exposure, but had not cosidered the watertight aspect. The putty on my windows was starting to crumble after 120 years - I guess that is a reasonable period of time before a product deteriorates.

It really should last 130 years but you've got that fierce Canadian weather.

I've wondered this too!
I need to redo the putty on mine too. It's a daunting task because we have (what feels like) a hundred windows on this place!
Better add that to my to do list.