20-Year Warranty

The industry standard now is to only warranty the solid plastic decking for 20 years when it was formerly 50. Why the change?  I think it's because there is no need for the manufacturer to put itself at risk for such a long period when homes change hands on the average of 10 years. It's a lawyer instigated measure based on the potential implications of improper use by a series of unrelated homeowners and not based on the longevity properties of solid polyethylene plastic

You need to understand just why this solid plastic decking came into being. Back in the early 80’s there was a real push by state governments to recycle plastic bags, jars and bottles because polyethylene, from which these containers were made, just wasn't decomposing in the dump landfills. Some of this stuff had been buried in acid soil for over 35 years and had no sign of decomposing. And that's why this material is almost indestructible.

Then the disposal companies became prohibited by the States from burying it. So there were tons of it pilling up alongside every refuse landfill in the country. I saw this for myself every time I would take our wooden deck project's debris over to the landfill. I had no idea how much Coca-Cola Californians consumed until I encountered a mound of nothing but Coca-Cola bottles that was 50 yards long, 40 feet wide and 16 feet high waiting to be crushed. The mounds of segregated plastics were just getting higher and higher every time I went to the dump. 

Decking seemed to be a good application for all this discarded plastic because deck-building consumed so much material compared to other uses and the fact that the resource material was for all practical purposes free. So the States introduced legislation to encourage recycling and sponsored the development of this application to deck planking.

 Although the discarded recycled plastic is cheap, just like any other natural resource, the additives and energy that it takes to make the final product is far from cheap. For instance, we make the doors to our outdoor cabinets and drawers from virgin polyethylene plastic and that costs us 5 times as much as recycled polyethylene plastic. So you are getting the benefit of recycling right in the cost of materials. A deck made from virgin solid plastic would be unaffordable.

The 20-year warranty comes from the manufacturer and guarantees that the boards will not crack, split, get mildew, rot or decay, or suffer damage from insects -- and that's the full extent of the warranty. No insect, bacteria, mold nor chemical can damage this material. Only humans can do that. So it is a no-brainer to warrantee this material for 20 years but no more than that because its not the plastic that can't be trusted, it's humans.

Technical Issues

Color Durability

One of the questions frequently asked of us is: "Does the color of the plastic planking fade from being in the sun over time?" The answer is that there may be some slight fading over its 50 year life-span; nobody really knows for sure, but engineering stress-testing over an 11 year period project this to be no more than 5% during the life of the warranty --  see technical reference # 2 below. There have been sufficient UV inhibitors engineered into the plastic to mitigate fading.

PrimoPlank boards are uniformly colored all-through. This will remain so even if the surface might fade somewhat. So the solution to restoring the color is to remove the superficial layer with a high-pressure washer (3000 psi). This will not damage the solid polyethylene plastic.  Moreover this can be done time and again if the environment calls for it.

This restoration method would not work on PVC planking and would permanently damage composite planking because it would gouge the surface, but not so with 100% solid-plastic PrimoPlank.

I have taken a number of customers out to see three decks that are pictured on my website: The Huss-Thomas project built in Spring 2001, the Mattson project built in the Summer of 2002 and the Taxera project built in the Fall of 2003. I am proud of these projects mainly because they all still look like they were just built yesterday: there is absolutely no fading of the color -- the colors are still bright and the whites have not yellowed one iota. It is way better than my initial expectations.
 

Static Electricity

We have built PrimoPlank decks in all the four seasons and have spent a lot of time walking on our decks when we had auxiliary structures such as patio-covers or masonry borders to construct after the deck was completed. We rarely experienced a static discharge, mostly because we were working on the deck for some time after the plank was laid doing all the detail work. And until recently no customer ever broached the subject with me at all.

However, one of my most recent customers did report experiencing a static discharge after walking across the newly finished deck just after it was opened up to traffic.  After hearing the customer's complaint, I monitored this effect over a period of two months and observed this static subside to the vanishing point.

The deck was built with standard grade planking which has a slight sheen. It was built in Winter on the very top of a Santa Cruz mountain ridge line. It was also built quickly because of the simplicity of the deck itself, so it had a rather reflective sheen on it, more so than all of our other solid-plastic deck projects. But after this initial sheen became flat, the static disappeared. I concluded that this static was generated by a cool dry wind blowing swiftly across a brand new smooth surface, an effect similar to something dragged across a newly laid nylon carpet in Winter. What I have described here is one isolated case; I've had no other complaints. It seems to come from the wind with moisture which strips the electrons off the surface.

My solution: spread powdered cornstarch all over the desk. Then spread it with a push broom. Leave as is for 24 hours and then wash it down with a garden hose the following day. This will replace the electrons back on the surface and at the same time reduce the initial sheen.

The sheen dissipates on all surfaces in a few months regardless of traffic or not. So if any static is experienced, it is surely an initial, temporal phenomenon -- it is a minor inconvenience for a few months when compared with the advantage of never having to strip, sand and stain it over the 40-year life of the deck.

Handling Expansion

A frequently asked question is: "Are there any disadvantages to solid plastic planking?" The answer is yes, only one: polyethylene has an expansion over a 40°F change in temperature of 1/4 inch per 12 lineal feet. Now let me explain why Mr. Deck only offers 2x (1.5 inch) material for planking.

A few manufacturers are offering 5/4x (it's actually only 1 inch thick) solid-plastic boards for use as planking and are calling it their most "popular" product. The reason for its popularity is that this is what the manufacturers are promoting because:

(1) It lets them produce more product in a given time because there is less material to process and
(2) its cost is less than the 2x-material and that helps the sale of their product in the market place.

What we found in the actual performance of this 5/4 planking was that if it were applied in cool weather, it warbled later in hot weather between the points of fastening: up between one pair of joists and down between the next and so on, especially pronounced in the direct sunlight. This doesn't occur with the 2x thickness.

Even with 2x6 planking, this expansion characteristic still needs to be addressed: For large or long decks, it is best handled by running the plank either diagonally or perpendicular to the house wall. In situations where long runs of planks are necessary, planks need to be spliced. Splices are made with 45° beveled ends so one board can slide up over or down under the next in line when it expands. The top bevel should also be chamfered too to keep the top plank from rising noticeably above the deck level when fully expanded. In long-run situations, the plank length should be kept to 12 feet or less.

For decks built in confined areas, the planks are kept at a 1/2-inch distance from any walls. This is accomplished by setting the ledger joists on both sides of the enclosed area out 1½ inches from the building’s wall by placing 10-inch long 2x spacer-blocks between the wall and the ledger-joists when framing. These should be centered no farther apart than 3-feet. The ledger-joists are then fastened to the wall with ½ x 7 lag-bolts with washers, through the center of the blocks behind them. The planking is pre-cut short by 1 inch and the ends are fastened to the protruding ledger joists on both sides, leaving a ½-inch expansion gap on each end between the wall and the ends of the planks. A trim strip may be used on top of the planking to hide this gap if the planks aren’t already hidden by protruding siding.

Fasteners

Nails
We have nailed solid-plastic planks using both a hammer and a nail-gun and found it difficult to get the nails through the plastic without bending. This is because of what we call "the Skin Effect". The plank's outer surface is denser than its interior. So when the nail gets down inside the plank and begins to penetrate the bottom skin layer there is too much resistance and the nail kinks upon further force being applied to it. Furthermore, when the head of the nail did finally reach the plank's surface, the plank resisted the head’s being counter-sunk flush with the surface. So we avoid nailing altogether.

Screws
We mostly lay this 2x solid plastic planking with 3-inch Dacronite (coated steel alloy) or stainless steel (expensive) flared-head screws and pre-drill holes with a counter-sink bit. This is the safest method for avoiding the possibility that any future expansion would force the plank to lift off the joist and pop the fastener.

However, only half the screws are needed for holding solid-plastic planks fast because these planks don't warp like wood does and only one screw per joist is adequate.  The screws are placed near just one of the plank's edges and staggered from one edge, then the other, along each course, one per joist. Then if the pattern is reversed on the next course, no line of fasteners will be noticeable on the finished deck.

There is another advantage in using screws: if the deck is basically symmetric, these planks can be unscrewed at a time far into the future and turned over and refastened -- giving a brand new surface. You can't do that with any planking other than PrimoPlank, even solid plastic planking, because most manufacturers distinguish the top from the bottom with surface features. PrimoPlank is identical on either face (unless specially ordered with a textured surface).

Hidden Fasteners
The hard-plastic biscuit called Eb-Ty will work beautifully with the polyethylene plastic. PrimoPlank 1½ thick standard grade can be ordered with a pre-routered ¼-inch groove along each edge, called G&G, short for "groove and groove". For other grades of PrimoPlank, the builder will need a powered biscuit-cutter tool to cut the groove into the side of the plank every other joist.

This fastening method not only looks clean but handles the expansion and contraction of long-length planks beautifully. Click on picture to go to Eb-Ty's product page.

Invisible Screws
We have come across a new steel-alloy deck-screw that is designed to snap-off just below the head when the screw's head reaches the surface. It's 3½ inches long and was engineered specifically for solid-plastic decking. It has two separate, threaded sections along its shank, one to fasten into the frame and one to fasten into the plank. So these fasteners essentially get sunk into the plank and disappear from view. They leave only a very small pin-hole which closes up within 24 hours! That's the good part. However there are some disadvantages:

One disadvantage is that the screws can never be removed. But a big disadvantage is: every now and then, a screw brakes off during insertion prematurely. It seems to happen when these snap-screws hit a knot in the joist below. Sometimes it could be backed out with a vise-grip pliers and sometimes it couldn't. We handled that by pounding in the remainder of screw's protruding shank of about ⅛-inch. But later the broken shank rusted and was visible.  It happened enough times that I don't recommend this way of fastening.

Joist Spacing

The recommended spacing of joists is 16 inches on-center for the 2x thick plank. It's 12 inches for anything of lesser thickness. This applies even when the planking is laid diagonally, up to 45° incidence with the ledger. Any angle greater for the 2x thickness will require 12-inch spacing of the joists.

Cleaning

As a matter of course, the deck owner should get himself an inexpensive ($100) low-pressure pressure-washer (1400 psi) and occasionally clean the deck from bird, berry and tree sap droppings and routine soiling.

 Kaarcher makes a very nice low-pressure washer which we have used on all of our plastic deck projects. It comes with a spinner-spray nozzle which adds a real punch to the revolving jet-spray -- cleans off just about anything.

See it work here.