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Old Windows - Install Plexiglass?

LGreene

Registered User
Joined
Oct 20, 2009
Messages
1,153
Location
San Miguel de Allende, Mexico
A hardware consultant friend of mine lives in a small town in New Hampshire and is active with the town government. The town hall is an older building - 1930's, with the original windows. They are looking to increase energy efficiency and someone suggested installing a sheet of plexiglass on the inside of each of the windows.

The hardware consultant and the fire chief do not think this is a good idea because of emergency egress and firefighting. I don't do windows, so I'm hoping some of you may be able to give us some guidance on this. Your thoughts?
 
In a commercial building the windows wouldn't be a requirement anyway, so the Fire Chief really doesn't have a say in it. Egress and Fire don't have anything to do with it.

I would be concerned about condensation if you add a another layer that isn't factory sealed. But, I could be wrong.
 
I suggest looking into replacing the glass with laminated glass. The laminated glass isn't too thick for the old frames (I assume they are steel windows), and the interlayer of the laminated glass acts like an insulating barrier. Although not as energy efficient as insulated glazing, the laminated glass will have an appearance that is close to the original historic look.
 
Sure it is not a high rise, but how many floors??

Hopefully the exiting is good

Should be able to force open the windows

Tell the chief to sprinkle the building!!!!!
 
I have done interior storm windows such as this before. They should be removable for cleaning as well as emergency egress & firefighting. They should be gasketed to minimize air exfiltration and condensation.

National Park Service Preservation Brief #3 gives methods for improving energy efficiency of older buildings. Storm windows are discussed on pages 8 & 9.

http://www.nps.gov/history/hps/tps/briefs/brief03.pdf
 
I would agree that the windows are not part of the egress scheme, so no jurisdictional intervention should be required.

From a practical standpoint, Lexan, Makroclear, and in particular plexiglass will become scratched and discolored with time and cleaning.
 
Anytime you put in a plastic window in a commercial building, especially if it is burglar or ballestic rated, or ATFP in the military world, the AHJ can determine that you have created a windowless building and the fire sprinkler provisions of Chapter 9 can come into play.
 
the chief wants to send people into that building if it has fire showing???
 
How is the plexiglass to be mounted? With most of the mounting systems I have seen for inside storm windows a solid blow would pop them out and they are readily removable for cleaning the windows behind them. In the event of a fire in the area of the windows they would likely soften and fall out on their own.

Looking at the building, conventional outside storm windows could also be a good choice.
 
Coug Dad said:
Anytime you put in a plastic window in a commercial building, especially if it is burglar or ballestic rated, or ATFP in the military world, the AHJ can determine that you have created a windowless building and the fire sprinkler provisions of Chapter 9 can come into play.
I wonder if the FD classifies buildings in wind-borne regions as windowless.

1609.1.2 Protection of openings.In wind-borne debris regions , glazing in buildings shall be impact resistant or protected with an impact-resistant covering meeting the requirements of an approved impact-resistant standard or ASTM E 1996 and ASTM E 1886 referenced herein as follows:

1. Glazed openings located within 30 feet (9144 mm) of grade shall meet the requirements of the large missile test of ASTM E 1996.

2. Glazed openings located more than 30 feet (9144 mm) above grade shall meet the provisions of the small missile test of ASTM E 1996.
 
I'd getta hold of the "This Old Town Hall" guys, your right up the street from "Baston!"

Is'nt there some Solyndra or government money left for replacing windows with more energy type windows or did that run out?

pc1
 
There are plenty of "historic looking" replacement windows available. Glazing accounts for much of the energy loss in a building - the payoff period isn't usually too long.
 
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