Hurricane Impact Windows on Cantilevered Balcony 1

[A M K]

I’m looking for help or advice on determining whether replacing a screen or single pane widows enclosed balcony with hurricane impact widows creates any structural problem. These condos were built in the 1970s in South Florida and most have a 6’ x20’ balcony concrete floor construction and side walls with the 6’ cantilever. Floor to ceiling height is 8’. Over the last several years some impact windows have been installed with no noticeable problem, but concerns on how to determine allowed weight of windows have been raised.

 

[phamENG]

Generally I would say no. I've never met anyone who takes the weight of a window into consideration in design, unless it's a really unique situation. We just design for the weight of the wall all around. A design that takes locations of fenestration into account is entirely too tight; not to mention the fact that it's all but impossible to predict locations (or replacements) throughout the life of the structure.

Typical exterior wall weight will vary between about 10psf (light frame wood with vinyl siding)80+psf (reinforced CMU with brick veneer). For comparison, a 1" thick pain of glass weights about 13psf. Even in multi pane, laminated glass you're not likely exceeding the weight of the wall.

If it is a genuine concern, then you should have a structural engineer look into it and do an analysis of the supporting balcony.