Polycarbonate windows (Lexan)

[Wao nahele kane]

John - thanks for the heads up on your experience with them. That tips my decision in favor of the polycarbonate option. I also happen to have one 6'X8' window specified above the top split landing. I can fabricate the window frames from basic SS extrusions on-site to make near 90 degree swing awning windows or some modifications thereof. In the end, I should end up with a far stronger product at a fraction of the manufactured cost. Guess it’s time to open up Solid Works and draft up some window frames

E ho'a'o no i pau kuhihewa.

[hotinhawaii]

You may have a hard time getting site built windows to meet the new code requirements as they will not be certified. Here is the new code wrt hurricane resistant construction of windows.
423.5.2 Windborne Debris Missile Impact for Building Enclosure Elements. Exterior glazing and glazed openings, louvers, roof openings and doors shall be provided with windborne debris impact resistance or protection systems conforming to ASTM E1996-05 Level D, i.e., 9 lb. 2 X 4 @ 50 fps (34 mph).
423.5.3 Cyclic Pressure Loading of Impact Resistive Glazing or Windborne Impact Protective Systems. Resistance to the calculated maximum inward and outward pressure shall be designed to conform to ASTM E1996-05.
423.5.4 Windows. All unprotected window assemblies and their anchoring systems shall be designed and installed to meet the wind load and missile impact criteria of this section.
423.5.5 Window Protective Systems. Windows may be provided with permanent or deployable protective systems, provided the protective system is designed and installed to meet the wind load and missile impact criteria and completely covers the window assembly and anchoring system.

More:
“1609.1.2 Protection of openings. In wind-borne debris regions, glazing in building shall be impact-resistant or protected with an impact-resistant covering meeting the requirements of an approved impact-resisting standard or ASTM E 1996 and of ASTM E 1886 referenced therein 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.
Exceptions:
(1) Wood structural panels with a minimum thickness of 7/16 inch (11.1 mm) and a maximum panel span of 8 feet (2438 mm) shall be permitted for opening protection in one- and two-story buildings. Panels shall be precut so that they shall be attached to the framing surrounding the opening containing the product with the glazed opening. Panels shall be secured with the attachment hardware provided.
5-56
UNOFFICIAL ADVANCE SHEET - Contains sec(s). affected since publication of Supp. 13 (1-2012) Official revision to be published in Supp. 14 (7-2012)
BUILDING
§ 5-82
Attachments shall be designed to resist the components and cladding loads determined in accordance with the provisions of ASCE 7. Attachment in accordance with Table 1609.1.2 is permitted for buildings with a mean roof height of 33 feet (10,058 mm) or less where wind speeds do not exceed 130 mph (57.2 m/s).
(2) Glazing in Occupancy Category I buildings as defined in Section 1604.5, including greenhouses that are occupied for growing plants on a production or research basis, without public access shall be permitted to be unprotected.
(3) Glazing in Occupancy Category II, III or IV buildings located over 60 feet (18,288 mm) above the ground and over 30 feet (9,144 mm) above aggregate surface roofs located within 1,500 feet (458 m) of the building shall be permitted to be unprotected.
(4) Glazing in Occupancy Category II and III buildings that can receive positive external pressure in the lower 60 feet (18,288 mm) shall be assumed to be openings unless such glazing is impact-resistant or protected with an impact-resistant system.
Exception: Glazing in Occupancy Category III buildings defined by Table 1604.5 of the following occupancies shall be provided with windborne debris protection:
(a) Covered structures whose primary occupancy is public assembly with an occupant load greater than 300.
(b) Health care facilities with an occupant load of 50 or more resident patients, but not having surgery or emergency treatment facilities.
© Any other public building with an occupant load greater than 5,000.

[Wao nahele kane]

Hotinhawaii... thanks but I’ve been doing this stuff for 35 years now and have been working under the International Code standards for the past 8 years of that 35 years. A 1/4" polycarbonate accompanied by a SS frame as I said earlier exceed the above code requirements. Proof therein is found in the certified testing results of the individual materials used for the windows construction, not in a certified stamp on the window. Same applies to every member within any given structure.
The chances of them not meeting the code requirements are 0. Aside from that… I don’t even need to meet those requirements, though our house was designed to meet them by default as that’s what I’m already used to; my permit was pulled long before the IBC codes went into effect in Hawaii.

Edit to add - Here's an example of one of the materials I'll be using... note the data within the page regarding impact information inclusive of window design applications.
http://www.theplasticshop.co.uk/plastic_..._sheet.pdf

Now ponder this... has the county adopted missile proof walls and if not, why are they adopting these impact windows? A missile may miss a window and penetrate the wall sheathing and kill a person regardless of what the window is rated for.

E ho'a'o no i pau kuhihewa.

[hotinhawaii]

Wao, I wasn't questioning your qualifications or even your design. Sheesh. I was only suggesting that if there is not a certified stamp on the windows that they may not be approved. I also did not know that your permit had already been pulled for this.

I can't tell if the county adopted missile proof wall sheathing or not. It is required for optional safe rooms but I can't tell if it's required for walls.

[Bullwinkle]

interesting - I have always resisted using lexan because I was told it was a hazard in fires - like (old school non release) security bars. Lexan windows could prevent escape in a fire.....

[john the architect]

W,
For a large opening you are best served with a pivoting frame, not one hinged on an edge. Less force, and the pivot could allow it to counter-balance somewhat. But you probably already were thinking that.

John Maloney
310.562.0362
johnmaloney3@me.com
Hawaii Architect AR8082
www.jmagreenbuilding.com