Polycarbonate

I'm wondering if anyone here has worked with twinwall polycarbonate, what your experience was, and how it has held up over time. I'm in the planning stages of a greenhouse/solarium addition that will be framed with mill finish aluminum and sheathed in polycarbonate. There is a lot of good DIY info available from the mfr's like Polygal and Gallina, which includes details and purlin spacings for certain psf loadings. But I'd like to hear less biased opinions on the material from those who have built with it or spec'ed it.

this weekend I am building a 16'x6' skylight in my loft if the weather holds. I have the 16mm triple wall in clear. I'll let you know how it goes.

It will scratch easily. Try to leave the protective plastic on as long as possible.

Pay attention to the markings -- if it's Polygal, one side has the UV protection and is supposed to be the one exposed to the sun.

Make sure you seal the ends of the channels well once it's installed, and do so when it's absoluately dry. You don't want to trap moisture inside, which will lead to mildew and fogging, and you don't want bugs to crawl in there and spin cocoons.

I used one large piece 6' wide by 10' tall for a window in my workshop that bends across 2 walls that are at 120 degrees. I cut it with a plastic blade on a circular saw, and removed material on the inside from one channel in order to bend it. I attached it to studs behind with screws, and used rubber washers with the screws to seal the penetrations. The edges got sealed with clear silicone caulk.

It was difficult to work with such a large piece, but worth it.

I'll see if I have a picture and will post it later if I find one.

-KP

Thanks for the help! I noticed on Polygal's site they note the one side having the UV protection. As for sealing the ends, I saw that Gallina will make pre-cut panels for you with welded ends. Didn't know you could weld plastic. Some of the details and text on Gallina's site seems poorly translated. But I assume it means that the channel is permanently sealed from water and air. That is a major concern for me since the structure will be in a location that floods occasionally. I think trying to get silt stains out of those channels would be impossible. They sell this tape with mesh openings for the bottom of the channels which is supposed to let condensation dry out. sundancesupply.com has some good info. They don't sell H channels because they say they yellow. They have aluminum corner, edge and ridge sections but only in bronze and white.

That window you built sounds cool, kp. I'd like to see it.

You know I have a question about this stuff. A while back in Dwell there was a small house in Cambridge Mass that used (I think) polycarbonate on the backwall of a house--very cool. I was intrigued. Can this hold up? And does it have decent insulation value? I will see if I can dig up a picture if someone else doesn't get to it first.

Deb

Polycarboate will hold up as an exterior material as it is coextruded with a UV protective layer on the outside face. It has OK insulation value (depending on the thickness and when compared to glass) but it isn't as good as a solid insulated wall (obviously) It is also amazingly impact resistant.


I am currently building a backyard studio for some clients that is mostly sheathed in 4X8 sheets of polycarbonate over exposed 2X4 construction.

I'll post some pictures when the polycarbonate goes on which should be in the next week or so.

Mark

Boilerplater,

I'm going to try to show some images of the window on my workshop. Here goes:

-KP

And here's another.

Great looking shop KP! Is that just metal flashing with hardiboard over it? Looks great. What do you figure it will cost per square foot when you are done?

Yes, galvalume flashing (flat strips for the verticals, z-profile for the horizontals) over house wrap over plywood, with pre-painted beveled hardiboard panels. Framing is 3 steel tube columns with bolt-together upside-down-triangle water-jet cut steel roof trusses for the cantilever, with 2x6 infill. Galvalume roof. It's neither insulated nor sheetrocked, but it's plumbed for a sink and a toilet (not yet installed). It's not wired yet, but the conduit is laid... I've been happily using it for all sorts of projects for more than a year now, having sunk about $42/sqft into it. But you are right, it is not yet finished. Wiring is definitely next! Someday I want to enclose the soffit too.

-KP

kp

did you cut the hardiboard panels yourself to get the grid? I've been looking at using hardiboard but the standard size isnt square and Ididnt like the thought of having to cut them all myself.

Yes, cut them myself with a diamond masonry blade on a circular saw. Slightly beveled the edges with an angle grinder. Prepainted them, edges too. It was alot of work, but it sure looks better than the ones the framers installed on my house, which got painted AFTER installation and didn't have the benfit of the beveling.

nice one mate.....might give that serious consideration

cheers

To the person who messaged me asking for installation details on the polycarbonate, please message me with your email and I'll respond. Your first message appears to come from Anonymous User, so replying to it will not work.

Thanks!
-KP

As promised here is the Polygal (actually MacroLux which is the same product/differnt manufacturer) install pics.



You'll notice in this pic that the end of the PolyCarbonate has a "vented" tape applied over the end of the cells. This allows for air and water vapor to get out of the channels reducing condensation build-up. You'll also see that the panels are attached with typical washered roofing screws at the edges and along the center of the panel, at each stud. Over the ends there is a polycarbonate "j" channel to cap the ends. I will be putting massaranduba (tropical hardwood like ipe) trim over the edges to make the install water tight, and to cover the differnt material depths/trim out the windows install.

One note on the install of the screws. The holes must be pre-drilled into the panels 50% larger than the shaft of the screw to allow for the thermal expansion of the material. You NEED to clean up the holes in the polycarbonate exterior face with a razor knife, as when you drill the plastic will burr up and cause the neoprene washers to not sit properly, which will allow a bit of water to get into the interior of the panels. This is probably not too much of an issue when you instal the panels vertically (which they REALLY would prefer that you do), but in this case we chose to install horizontally so we didn't have vertical seams on one facade.

More pics to follow.



A view of the same wall from the interior. The Polycarbonate is simply screwed to the exposed wood framing (in this case stud grade pine that was sanded smooth)



another interior material detail shot showing Hardi-plank slat over studs (with polycarbonate exterior) adjacent to 1/4" birch interior skin.

Mark Meyer

Is there anyplace in the Los Angeles area that a homeowner like me can buy a few sheets of Macrolux or Polygol?

Thanks

Here are links to the cellular Polycarbonate manufacturers that I know of. Most plastics distributors should carry some version of cellular polycarbonate. Let your fingers do the walking through the yellow pages and you should strike paydirt:

SunTuf

PolyGal

MacroLux

I had a really hard time finding 16mm polycarb in 4x8 sheets. there were none locally and some of the online places had minimum orders which I did not meet. I ended up getting mine from http://www.igcusa.com/. the shipping was not cheap, but I really found no other options besides driving to CT to pick up at one of the regional warehouses.

Lucky for us in Austin we have a REGAL Plastics that usually stocks it, and can order other stuff from their sister stores in either Houston, San Antonio, or Dallas, and for small orders they always piggy-back my order onto other larger orders, as long as I can wait a few extra days. I got a 4'X16' sheet of 16mm macrolux, and didn't have to pay for shipping.

Mark

Home Depot sells Suntuf, corrugaged panels 28 wide by 8' and 12' lengths.
And apparently you can special order ridge caps and wall connectors.

Orchard Supply Hardware sells Lexan panels.

GE Polymer Shapes
(Mfg & Distributor of LEXAN)
Santa Fe Springs, CA
562-942-9381