Sheet Polycarbonate for Residential Cladding

Have found at least one product, trade name Lexcel which is of the same composition as Lexan but is corrugated, .25 inch thickness, available in 4' x 8 and 4' x 12' sheets for roughly $1.50 per sq. ft. in translucent opal, UV protected.

Meets ICC flame spread/smoke density requirements per ASTM E 84.

I very well may be off base here, since this type of material is normally used as a glazing, but given that it's impact resistant, water proof, light weight, and color fast over a period of up to ten years in exterior use, why wouldn't it serve very well as both an interior and exterior cladding for Structural Insulated Panels?

I'm convinced I'm onto something here.

If you are anywhere building code compliance requirements are in effect, check with the local agency.

Your insurance carrier may have an opinion, too.

Plexiglas is DuPont's name for acrylic. Lexan is the name for GE polycarbonate.

Polycarbonate is tougher than acrylic, but more expensive. Both scratch more easily than glass.

Thermal properties, expansion, MVTR (moisture vapor transmission rate) UV protection/transmission............................................may influence your decision.

Will do lynlynch.

Have been using the 2006 version of the ICC's International Residential Code as a guide. Acrylic is approved for roofs at slopes of 1/4" in 12" so I may be able to use that as support.

The polycarbonates I've researched all pass ASTM E84 for fire spread and smoke index.

Many thanks.

I used a heavy lexan to glaze my greenhouse when it was first built - it wasn't inexpensive then! Ten years later the gh had to be rebuilt, and we replaced the lexan with double glazed glass and took the lexan down to use for coldframes. There were a few cracks in one or two sheets when it was taken down, but we also had several whole sheets that simply broke during handling. The exposure to sunlight and/or cold had made it brittle.

I've also seen the less expensive polycarbonates used for the walls of freestanding greenhouses. But from limited experience I would say they are even more prone to become brittle and break than the expensive stuff. Depending on the climate that you're in, expect a limited lifespan for the product compared with other choices. Because they are large sheets, you have to replace a whole sheet if it breaks, that would tend to be more expensive than repairs to conventional cladding. Second consideration, you will never get a new sheet to match the old ones, which have weathered and changed colour due to the weather exposure...

Thanks artsmith.

Yes, I'm anticipating replacement of the exterior but am hoping for fifteen years (warranted for ten). I'm told the UV protection that's being used these days is a major improvement and that yellowing is no longer a problem.

Of course, I've been told quite a few things over the years so your warning is well understood and appreciated.

One interesting project was the IBM Traveling Pavilion by Renzo Piano and engineered by Peter Rice. Google that and you can get: http://www.vestaldesign.com/blog/2006/07/renzo-piano-ibm-traveling-pavilion/ http://www.structuremag.org/article.aspx?articleID=476

Isn't that something. Hit it with a sledgehammer to prove it's strength and IBM signed up that day......over two decades ago.

Much appreciated, omw7.

If using acrylic for exterior applcations, then consider coating with UV clearcoat as is used on automotive lamps and such.

DUPONT "LS1" is used extensively for just that purpose. (The "LS1" is a local marking on cans direct from DUPONT Australia to our industry and may be sold as another marking into other markets."

Corrugated polycarb sheeting used for roofing in Australia has issues regarding heat disspiation. The concentration of heat above rafters "chars" the material in around 3 years. There are distinct requirements regarding minimum pitch to enable air flow across the sheets and they require closer spacing of battens to stop "sag" in hot weather.

I suppose, just remember that the material you are considering is a thermoplastic and will bring with it features of the parent material.

Have found an extruded, two wall version of polycarb called Macrolux, 8 mm, UV protected. The opal white opaque version is supposed to reflect a considerable amount of light and therefore heat energy.

The panels will be fully supported by OSB sheathing so sag shouldn't be an issue. The use of a translucent material in such a manner may seem senseless, but the cost numbers versus even vinyl are looking good. Comes with a ten year warranty.

Sold on the siding, wary of the roof. Will pursue further and thanks, Down Under.

You might enjoy a look:

http://cloudtops.com/polycarbonate_macrolux.htm