fire rated glass?

[waggie]

I'm about to pour footing on an attached workshop, so I'm still a ways away from framing. The common wall currently have two 6'x4' windows, the plan is to just close them off since residential requirements dictate one hour fire rating and it's cheaper to just dry-wall it all off. However, I'm entertaining the idea of being able to look into my workshop/garage from the house. I realize fire rated window is probably out of my budget. But I don't need to be able to open window to the shop, just be able to see into/out of it.

my contractor has just begun to look into this as well. Presently, he was quoted $25 per square foot not including the frame.

has anyone worked with fire rated glass that can offer any pointers? thanks in advance.

 

[waggie]

here's a pic

 

[dirtybiker]

Glass blocks are the first thing that came to my mind. I think the Hr. rating of those depends on what they are being put into. Eg( brick or wood)http://www.glassblockdesigns.com/fire.php

 

[christopizza]

I used refactory glass in one of my wood fired pizza ovens to allow me to light the interior. We had big scary fires in there and it held up - I mean hot enough to melt and flatten wine bottles.

I seem to recall it was silica glass....

 

[Pinhook]

If it's a one hour wall the glass only has to be rated for 20 mins or 45 mins to get assembly listing.
Call a commercial glass installer or subcontractor and inquire about pyro stop or fire stop glass.

 

[Architorture]

6x4 is probably pushing the maximum area allowed by most fire rated glazing systems...and it would require a steel frame in all likelihood.

Although I'm not sure that window openings are allowed into a garage regardless of their rating as a window.... It may have to be considered a wall assembly which might be more restrictive

 

[Sureshot]

You can also get fire rated covers that roll down in the event of a fire. Not sure of the source but we had to have them at an old employers new shop between the office and shop area.

 

[Wingnut65]

Pinhook and Architorture have good info on rated glazing. Sureshot is referring to a fusible link roll down shutter that may be acceptable in this condition.

The size of glazing allowed is not by the overall window size, but of the exposed glazing area. Your 4'x6' window is 3,456 square inches, which could work with Pyrostop glass, but nothing else. The solution would be to put in a mullion down the middle and make two window panels that would be around 1,700 s.i., which can be achieved with a wider variety of glazing options and budget prices.

And, Yes, you will need to have a fire rated frame to install it in. The most cost effective would be a rated hollow metal frame.

Check out TGP Fire Rated Glazing or Safti First for more info on glazing options.

Another idea if you really want to have a window, determine what you want to spend on a rated frame and fire rated glazing and have your builder block in the 4x6 opening to reduce the size for the window to meet your budget. Nothing says the window has to be 4x6.

 

[waggie]

thanks all for the great information.

I will take this information to my contractor.


Serious question: doesn't putting 20 or 45 minute glass into an one hour wall defeat the purpose? building codes are weird.

I haven't thought of dividing the opening in halfe or quarters, that's a good one.

i was aware that it will have to be some sort of metal frame (since wood and fire proof doesn't really make sense)... but what does this mean? more $$?

4x6' is the current size of window opening. I dont mind if it were blocked to make it smaller (due to budget)... just wanted to know if it's possible to do the full size.

 

[nehog]

Personally I'd put a wall in, and if I wanted security I'd put in some video cameras. Windows to an interior place always seem to be out of place to me, too...