solid vinyl decking

[nailer8]

i am thinking of taking the marine plywood off of my 28 ft Harris pontoon, and installing "azek" solid vinyl decking . i think it will weigh one pound more per sq ft , about 220 lbs total which will not be a problem. has anyone done this? what other considerations are there ? looking for ideas, thanks

[PAR]

Vinyl decking isn't a structural material, it's a decorative product, though it is tough enough to walk on and accept some static loads, it's not intended for dynamic loads, nor load bearing.

[Jeremy Harris]

Originally Posted by PAR

Vinyl decking isn't a structural material, it's a decorative product, though it is tough enough to walk on and accept some static loads, it's not intended for dynamic loads, nor load bearing.

The stuff being referred to does seem to be structural, in as much as it's intended for use on decking (not the boat sort!): http://www.azek.com/azek-deck/

As this is a pontoon boat, my guess is that this stuff would work OK as long as it's fixed to sound structural supports. A bit unusual, perhaps, but it may give a maintenance free deck for this kind of boat.

[viking north]

Having worked with a similar product but a different brand three important considerations:
#1 Very high longitudional heat /cold expansion/contraction rate. On 20ft. runs from freezing point to say 80 deg. F plus approx. 3/4 in.
#2 Important to fasten as recommended by product instructions.
#3 In warmer temp. it becomes more flexiable so be sure support framing spacing is as recommended or closer.
Other than the weight it seems to perform as advertised.

[PAR]

It is a non-structural material from a engineering point of view. Most pontoon boats have a structural frame assembly, dividing the tubes and supporting the decking, but this support system also relies, fairly heavily, on the dimensional stability, stiffness and strength of the plywood that's fastened to it. Your vinyl decking substitute has none of these necessary qualities. In short, the tubes will act independently of each other, eventually shearing off the welds, from working in a seaway.

[joelsimpson]

Having worked with lots of plywood and with polymer films and solids, I would not typically recommend decking your pontoon boat with vinyl. The strength to weight will be significantly less than plywood. The vinyl will have a much higher thermal expansion than plywood (about 28 x 10 -6 in/in/degF for PVC and 3 x 10 -6 in/in/degF for plywood) as viking north has mentioned. However, if the frame is aluminum, the thermal expansion is about 12 x 10-6 in/in/deg F so the mismatch is about the same factor (3 or 4) just in opposite directions. The other property that is the most detracting in a vinyl which is common to all polymers is that it creeps (stretches under load over time). Get it warm and leave it under load long enough and it will sag between support frames. Hence the suggestion by others to increase the number of frames. It is however, easy to take care of, doesn't need painting and will not rot. If it is attached in planks like decking instead of in sheets like plywood, it will have orders of magnitude less racking strength. You would be advised to replace the racking resistance that was achieved by the plywood with some other structural members. Like everything else, it is a trade.

[nailer8]

I have just joined this forum and I can't believe I have this many responses, this quickly. I want to thank everyone for their help, this is great!! ps. I think I will stick with the plywood

[luckyjr]

http://forums.iboats.com/attachment....0&d=1312513608

I just installed this, it works great.