Sunday, February 02, 2014

Why we don't use deck clips anymore


  Sometimes a better idea isn't; Ford's Pinto, Chev's Vega, AMC's Pacer, Honda's Del Sol...  In this spirit of failure, wouldn't it be good to fasten decking from the side or from beneath, so that all the fasteners are hidden?

  Alas, another tragic error. 10 years later it seems to cause rot. It works fine in the middle of the boards, however, at the ends the excessive fastening have caused the boards to rot, and the deck to be condemned prematurely.


Speaking as someone that has had a piece of decking snap under me, and had my leg slide into a space 5.5" in width, the feeling of your skin being peeled off is not just alarming--its downright disconcerting. This is a nasty thing to go through and not recommended for entertainment.  (I doubt the guys from JackAss would even try it).

As you know, decking soaks up moisture from the ends of the boards, and when you put 5 fasteners through the end of the board and one is a pointed part of a clip, which cracks the board width wise, it amounts to pulverization. Cracks draw moisture in, and as this select pressure treated decking in this case dries out, the cracks grew larger. Untreated grains are exposed and rot is accelerated.

People suggest securing from beneath using strip type products that screw to the joists and the underside of the decking, which works fine--until you refinish. Then when the painters sand the old finish off, they sand the tips of the screws off causing black stains in the pattern of the screws on the top surface most notable on red cedar decking. Hidden fasteners of any kind are often a bad idea. I expect that the tops of the joists will deteriorate due to screws being driven in along the same grain. Cracks are likely.

Keep in mind, when you hide the fasteners where stain doesn't get into the wound, and where the sun doesn't reach to dry the wood, moisture will fester, and rot will occur. 

Solutions?

Pre-finish the decking so that it doesn't expand and contract. Seal the end grains as you build and use a waterproof epoxy to heal the wounds. Touch up...voila, no fasteners, no premature rot. We do this all the time. Since the decking is stable, not absorbing moisture with every rain, and shrinking as it dries, you can use nails for this method.

Alternatively, if you are in love with screws, (as I am not), you can countersink the screws prior to installing, then use a tapered plug cutter and plug all the holes after installation using waterproof epoxy.  Again, no premature rot.

*  If you reside in Canada, import high VOC finish from the USA. Canadian stain manufacturers have been prohibited from producing high VOC finishes and we have not found a coating that offers durability produced in Canada. ONLY high VOC finishes will be durable long term. Speak to your local paint store to learn more.


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