exterior sheet material

[frogwood]

I have a request from someone to make some large decorative porch brackets at approx 26 x 26. I make smaller sizes in wood but concerned that this size is large enough to potentially have some problems. I could use .75 pvc sheets. Anyone have issues with this material? expansion a problem?

I have never used Extira. Would this hold up outside with various cutouts exposing a lot of edge surface?

Anyone have any other material ideas? Duraply would probably do. Again
a lot of edge and painting.

Also anyone have a good source for the pvc sheets. Looks like in my area it is about $140 a 4 x 8 sheet.

Thanks ahead of time guys for your opinions.

Allen

[steve_g]

Allen

I could use .75 pvc sheets. Anyone have issues with this material?

Are you referring to the foamed PVC products like Sintra? If so... unsupported it will creep and sag.

Steve

[frogwood]

Steve thanks, I am not familiar with brand names but I think that is the material. The outside is pretty hard but the interior is softer and you can
dent it with you fingernail. I looked up Sintra and perhaps Azek is another brand of similar if not the same material.

So it droops, sags? If I have a bracket that is basically 2' x 2' triangle with
cutouts in it will sag? Creep do you mean expansion with heat?

Allen

[steve_g]

Allen

By creep I guess I mean the same as sag, but over time... It also will move a lot with temperature changes... If fastened at the vertex and a point, it will buckle in between. The colors aren't UV stable and must be painted. I have successfully used foamed PVC for letters only when they are 100% bonded to a substrate.

Steve

[CNYDWW]

I have a fair amount of experience with the EPVC Foam. Kleer is my favorite brand. What you have to watch out for is warping and sagging specially with heat. For corner brackets i wouldn't go much larger then 12x12. I would use MDO heavily primed for something that large. If you can, get it thicker then 3/4" or laminate two pieces.

Regards
Randy

[letterman7]

If they aren't structural, HDU sheet is ideal for this. Comes in thicknesses up to 4" if you can stomach the price..