1/2"x4'x8' PVC panel expansion and contraction


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Old 11-26-19, 09:52 PM
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1/2"x4'x8' PVC panel expansion and contraction

I'm thinking of using multiple 1/2"x4'x8' PVC panels (made by Veranda sold at Home Depot) in an outdoor multi panel privacy screen, framed in wood, (either IPE or Cedar) but am worried about possible PVC expansion and contraction causing issues. The manufacturer states that the maximum expansion is 1/8", but that appears to be optimistic, based on what I've read about other PVC products....I've read that an 1/8" expansion is possible per foot.......so it may be that the manufacturer's estimate is based on having the the panel fastened down every foot......Anyone have any experience with these or similar PVC panels and their behavior outdoors in high sun exposure, and wide swings in temperature areas? The screen will be in the Atlanta area.
 
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Old 11-27-19, 04:12 AM
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add a link!

wood is usually set with 1/8" gaps and viny does expand a lot more!
 
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Old 11-27-19, 04:27 AM
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Yes, vinyl expands a lot. Here is a product info link I found for a expanded PVC sheet, hopefully similar to what you are considering. Thermal expansion is covered in section 2-2. Basically they say it expands .00004" per inch per degree Fahrenheit. So, an 8' long panel may change about 3/8" from a zero degree winter's night to a hot summer day in the sun. Much less than 1/8" per foot but still enough that you need to account for it.
 
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Old 11-27-19, 07:13 AM
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Additionally, the color it is painted or the (color of items you fasten to it) will affect the temperature and amount it expands. It's why Azek, for example, requires paints used on Azek pvc to have a light reflective value (LRV) of 55 or higher.

When pvc is fastened to a house, the house doesnt move nearly as much as the pvc does. Typically fasteners aren't going to move 3/8". But that movement can wallow out a fastener (nails or staples) and eventually weaken it's hold. So usually about half the movement will show up at the panel edge, the other half will show up as waving between fasteners. More waving if screws are used and less actual movement since screws typically hold better than nails do.

Don't know what your plan is so it's hard to comment more than that.
 
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Old 11-27-19, 10:26 AM
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Thanks for the replies. There are two links below which somewhat show what I have in mind for the outdoor privacy screen. The screen would be framed in wood, with panels cut out of PVC......I thought I could screw in from the frame into the side of the PVC to fasten the PVC......the size of the PVC cutouts might be approximately 2' x 2' at the smallest to 4' x 4', the largest, depending on the design. Maybe 5 panels connected by piano hinges for a total size of 8' tall x 12' wide. The links just give a general idea of possible ideas/designs. With the expansion/contraction of the PVC, it seems attaching to the frame from the side may not work......maybe caulking with flexible caulk....I was told that caulk or adhesive doesn't work well with IPE......it doesn't adhere.

https://secure.img1-fg.wfcdn.com/im/...om-divider.jpg

https://www.1stdibs.com/furniture/bu.../id-f_2336642/
 
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Old 11-27-19, 11:13 AM
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The second picture is an aluminum frame. The first may also use a metal frame but it is hard to tell.

You could router a channel in your supports and cross pieces and the just place your panels into the channel leaving enough slop for any expansion.

 
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Old 11-27-19, 12:41 PM
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I agree that mounting your panels in a slot is probably the best option. Smaller pieces can be screwed or otherwise securely fastened but with big 4 x 8 sheets I would let them float so they can find their happy place depending on the season. Make the slots nice and deep so the PVC is well engaged. On a windy day it could do a bit of flexing and you don't want it to pop out of the frame.
 
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Old 11-27-19, 01:30 PM
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I wouldn't cut the sheet up into small pieces. Your frame perimeter could have the dado, and allow a little wiggle room on the 4x8 panel. Then if you want to divide it up to make it more decorative, apply wood to either side of the panel to make it "look" like it's divided.
 
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Old 11-28-19, 10:38 AM
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How small a size would be o.k. to screw into the side of the PVC? I guess the smaller the PVC piece, the less it expands and contracts, so a smaller piece could be screwed in. The channel idea sounds good for bigger pieces that span the panel....24" or so. I'm wondering how much can be routed out for a channel....I was planning on using 2" x 2" IPE (or maybe cedar) for the posts, (actual dimensions 1.5"x1.5")....will a 1/2" wide and 1/8" deep (or 1/4") channel be too much for the 1.5" x 1.5" IPE 8' post? I have some IPE samples of 2x2" and the stuff is like concrete.....
 
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Old 11-28-19, 11:44 AM
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I have no idea what you are envisioning, as far as fastening the 1/2" sheet of PVC. We are probably imagining two different things.

It would be practically impossible to fasten through the side of your IPE frame and hit the edge of the 1/2" material without coming out the edge of it or splitting it.

I would not try to fasten the edge what way. I'd make a frame from your 2x2... (2x3 or even 2x4 might be better) Dado the boards before you assemble the frame... make the dado at least 3/4" deep to accept the 4x8 sheet of PVC. You could then fasten the frame onto the sheet by fastening through each side of the dado- through the front of the frame, catching the edge of the PVC sheet, and partway into the rear side of the frame. (This way you are catching the face of the sheet, not trying to nail into the end of the sheet.)

Once you assemble the frame around the sheet of PVC, you could apply more trim (1x2 or whatever) onto each side of the panel to divide it up into any shape or design you want to make it decorative. Then fasten those to each side of the PVC. IMO, that's why a 2x3 frame would be better... if the frame perimeter had more depth you could apply a thicker trim onto each side. Side view of 2x3 frame: 1" decorative trim... 1/2" PVC in a 3/4" deep dado... 1" decorative trim. Use the trim to create your panel look.

If you used 2x4's you wouldn't even have to fasten the PVC Sheet to the frame because you could use the decorative trim (which could be 2x2s fastenened on either side of the PVC sheet) to fasten the sides of the frame together.

But not telling you how to do it, its your project. Just a suggestion.
 

Last edited by XSleeper; 11-28-19 at 12:02 PM.
 

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