Hello,

We are located in southern new jersey about 3 miles inland from the coast. We are in the middle of having a IPE Deck built and need some advice. I was feeling pretty good about the deck until I stumbled across some of the threads of this forum. Admittedly, I am now a bit worried.

First let me give a few particulars about the deck. It is about 820 sf and the deck is about 5 ft off of the ground. The framing is made from pressure treated lumber. The joists are 16" apart center to center. The decking material is 5/4 x 6 (actual measurements 1" X 5 1/2"). The Deckmaster coated hidden fastening system is being used to hold down the decking. The fastening system is where my concerns now lie.

When in the design phase we told the contractor that we would like to avoid seeing the screws in the deck. He recommended the Deckmaster hidden fastening system. He said on short deck 1' or 2' trying to fasten underneath is just not possible (though Deckmasters says it is). But my contractor said since my deck is 5' off of the ground made it a great candidate for this type of fastening system.

We are now in at the point where about 25% of the decking is now installed. After reading how badly the underneath mounting systems have been trashed I started to worry. I have looked over the IPE boards that have been put down so far and the contractor is using the prerequiste 2 screws per joist per IPE 5/4 X 6.

I did see that some people have had success with the Deckmaster system, which gives me some hope. But I was considering some changes from our original installation plan. We originally felt we would not seal our deck at all and just let it turn that silver patina color all over. Also we weren't thinking of putting any skirting around the edges of the deck (lots of free air flow underneath the deck especially being 5' ft off the ground).

The changes we were considering made me think that we might increase the chances of the boards cupping. Which in turn started to make me worry about the holding power of the Deckmaster system versus top screwing the boards (as per many of the threads in this forum).

The first change, we thought about having the deck sealed to preserve the pretty brownish color. Many of the threads argue seal one side, seal all sides, and back and forth with no definitive answers. One post talked about sealing one side allows moisture to seep in underneath and expand the bottom thereby promoting cupping (I thought IPE was so dense it didn't absorb water?). Since none of the IPE decking boards laid down have been sealed underneath or on the sides if we have someone come in later to seal the deck I can't imagine they will crawl underneath to seal the bottom and forget about the sides of the decking. How do you seal the side thru an 1/8" or so gap? This is where the fastening system if strong enough will keep it from cupping I imagine (or am I incorrect in this assumption).

The second change we are considering is having a solid IPE vertical skirt all around the sides of the deck, very pretty but cuts down on free air flow and increase humidity underneath the deck adding to the potential cupping problems and putting more pressure on the Deckmaster system. Also, the samples I showed the contrator of vertical skirting showed 8x8 air vents for air flow underneath. and the verical skirt boards had no gaps. He said those small vents did not allow enough air flow and that he would space his vertical skirt boards 3/8" apart thoughout the installation. He said these gaps would allow plenty of air flow under the deck. Is this enough air flow???

Questions:

1) Would asking the contractor to use more the 2 screws per IPE 5/4 X 6 IPE deck board add holding power? There are plenty of holes and you could easily put 3 maybe 4 screws per board. Would this add enough strength to prevent a potential disaster?

2)Should I just eat the boatload of cash I paid for the deckmaster system and pay for a top screw and plug solution right out of the gate to prevent future cupping if I seal and skirt the deck?

3)Or am I better off not skirting the deck (or maybe just skirting it with some type of wide open lattice with lots of air flow) and avoiding sealing and just live with the silver patina color to keep the cupping pressure on the Deckmaster system to the bare minimum.

Any help, insights, thought, or comments you may have will be greatly appreciated!!!!

Thanks George