I’ve had a discussion twice today with customers on this subject, so I thought I’d post an analysis and my thoughts on the subject. There are a lot of things to consider…although pre-grooved boards are more expensive ($.35-$.40/LF milling upcharge) you will use less screws. However stainess steel screws in quantity are less expensive than the clip/screw combo. However you will have more labor cost because you pre-drill two holes per joist instead of one.
Let’s assume for argument that you are purchasing 500 square feet of 5/4 x 6 Ipe decking. That’s approx. 1090 lineal feet, and your joists are 16″ on center:
Pre-Grooved – $3.85/LF @ 1090 LF = $4,196.00 875 hidden fasteners (5 boxes) @ $99.00/box = $495.00 GRAND TOTAL = $4,691.50
Non-Grooved – $3.50/LF @ 1090 LF = $3,815.00 1750 SS screws (5 boxes) @ $38.00/box = $190.00 Grand Total = $4,005.00
Even if you add the cost of plugs ($263 for this job), you would still be $400 cheaper if you face screw it. Now the intangible – the cost of labor. How much longer is it going to take to drill twice as many holes and counter-sink those screws? The time and cost will vary based on the installer. So in my humble opinion, the cost is really a WASH. It will come down to your personal aesthetic preference and how comfortable you are with the manufacture’s stated performance level of a hidden fastener.
One last thing to consider is any future repairs that may need to be made. My feeling is that if you are going to use hidden fasteners, whether it be EB-TY, Ipe Clip, Tiger Claw, or whatever you should choose to use, go with the 5/4 material. It’s going to be more stable than your 4/4 thickness if it tries to move or cup. Cupping is a bad thing with hidden fasteners, because you are only imbedding the screw from one side. You are relying on the clip to hold the other side in place. To me, this increases the risk of failure. Also, if you do have failure on a board, then you must undo the boards from the leading edge, you can’t just pull out the troubled spot like you can if you face screw. You have to face screw your edge boards anyway, so my thought is just do the whole thing that way…but these are just my thoughts…you be your own judge. Feel free to call or email us with any questions, and also feel free to post your thoughts or experiences here, I’d like to hear yours.