Do Not Nail Down T&G decking exposed to the weather. J.

How should I secure the T&G to the decking? Screws? Glue? Both porches are covered and roofs above have gutters. Water from gutters goes into buried pipes and exits far in the back yard, so very little moisture under porches. Only about 18" of the decking at the edges of the porches get wet when it rains. Are you concerned that the T&G will buckle over time?

Its not just water,exposure to weather exchange ya know like hot and cold,dry and humid wind blown rain well you get the idea.

Do not treat this deck like it was a floor inside your house or build it that way. T&G decking drains the same way face fastened decking does thru the gap.

I fasten T&G S American decking thru the G with ss square drive trim screws after a predrill not going thru the pt frame only the decking, cut a 1/2'' slot in the T every 3' or so, snug fit not jamed up tight installed with consttrustion adhesive on the joists. Done corectley the slot and the screw will not show.

If your price for " mahogany " is less than ipe,the odds are you are not using real mahogany. J.

Does it make any difference that my boards are running parallel with the slope instead of perpendicular to it? What do you use the cut the T in the groove? Is the T to help with drainage? Yeah, this is the asian mahogany for sure, but the honest mennonite I'm buying it from has sold it for 25 years and insists it lasts at least that long.

It would be better for the decking to run in the direction of the fall. I cut the slot with a jig saw,yes it adds a little extra drain area.

If the man has been selling it for 25 years..he will know what it does exposed to the weather. J.

Thanks John. What about the sealer? Any advice there? Prior to installation, I was going to buy a 14' roof gutter, cap the ends and fill it an inch or so with penofin for hardwoods, soak each board for 30 seconds, then let them dry in the shade on the framing of the porch or on saw horses. I'll probably repeat this process a second time to ensure a good seal. I was going to let the boards dry with the groove facing down to avoid any strange patterns, although I had wet areas of oil on other pieces of wood where I've used penofin and the oil absorbed without leaving any residual marks. I don't want to have to use a brush or a cloth on 200 boards unless I absolutely have to. After the deck has been installed, I expect a pad or rag would be much easier for future maintenance coats.

Pre finish will have very little effect and could work in reverse. J.

I clarified the wood species and it's Cambara from South America, so it's actually not from asia. I'm getting a price of $1.10 per linear foot which I believe is 3" face tongue and groove (although I need to double check the dimensions). So, you're recommending that I leave the bottom of the boards unsealed and only seal the tops after installation? Is that to to let the boards breath better?

Exactley. J.

I asked the same question of the board supplier and they confirmed what you are suggesting; that most installers do not seal all sides of the boards. Aside from being a pain in the butt and added a lot to the cost, he explained it like this. The top side is the side where the sealer is going to fail first due to use. When that happens, water will start to penetrate the wood. If the water cannot exit the boards, you now have pretty good conditions for rot.

I suppose if someone applied a new sealer coat on top every six months, this might not happen, but why bother taking the risk and going through the additional work / expense me wonders? I'm going with sealer on the top only and will report back after a few years.

Dave, please contact me regarding this if it isn't too late. If you already sealed, please contact me still.

Never stop selling. J.