shinobu, we live in south lake tahoe, just completed a deck around 2 sides of our house. we replaced a redwood deck and then some, tore down substructure and started from the ground up. we researched all the usual suspects. we decided against trex for several reasons. several friends used trex, and within a couple of years had to replace decking, got involved in warrante issues, but trex eventually offered to replace material only. redwood was considered briefly,but decided against because existing was redwood and was only 15 years old. we decided to go with ipe, bought it in sacramento at berco redwood, paid 2.20 lf. they delivered. I built it myself, finished in october,berco replaced several sticks, probably my fault because wood sat outside for a while.I am waiting for warm weather to sand and seal,but it came out beautiful.we surface screwed, cleaned the snow off all winter. we plan to use tps 116 and see how much work it will be to maintain, if too much we will let it go to silver.part of the back deck is about a foot off the ground, good drainage underneath, runoff from the roof when snow melts not a problem. no mold, no cupping. bottom line epi a good choice. If your in the area, your welcome to come take a look at it. A bit of a learning curve, but it worked out well. one thing though, I originally got some bids from local contractors, most never heard of ipe, and the ones that did charged double the price to install.

A couple years ago I was looing for something that I could put over my old deck to restore the beauty of it. I found a product that was tropical hardwood strips mounted in squares on a special backing. The wood was called Curupay I believe. Anyway, I bookmarked the site because I couldn't afford it at the time. It is: http://www.ecoarbordesigns.com/curupaydouble.html. It was shown on a This Old House show so you can see how it goes up. It is a darker (not blackish) shade.

You can buy composite material from any local lumber yard. As the deck goes I wouldn't break it up into a 2 tier deck especially that size unless you have 2 exit points from the house on 2 different levels and a step-down is a must. Do you have a picture of the house where the deck is going? That would be helpful.

Some composites can be slippery, but one of the most common complaints I hear about them is that they get too hot to walk on in bare feet. I'd recommend a tropical hardwood over composite or pressure-treated wood. A species like Cumaru, Tigerwood, Massaranduba, Garapa, or Ipe. These woods are dense enough to avoid splinters, and have some natural anti-slip properties. They're also strong enough to last for decades with hardly any maintenance, as long as you don't mind the deck turning gray. https://www.advantagelumber.com/wood-decking.htm Ipe: Garapa: Grayed Out: Massaranduba: