having looked at both plastics(I use the term as generic and not in any sense derogatory) and composites, I rejected both for my deck. The following issues came up: plastic only: Boards are soft-especially in hot weather. Need rafters closely spaced. No more than 12" apart even with boards perpendicular to beams. I had a diagonal board layout with 16" spacing making this impractical. If a deck does not use diagonal boards, use extra cross bracing to protect it from twisting motions in strong winds(newer building codes). Plastics have a high degree of expansion with temperature and so will expand and contract more than the underlying frame. This may affect the esthetics and is something you should be aware of. This is why vinyl siding gets wavy. Use of lighter color surface best to minimize color fading issues. Composites: Much stronger than straight plastics. These contain essentially a mix of fine cardboard particles and plastics. Newer ones wrap solid plastic around outer surface for longer life. This is because mildew and fungi love to eat out the cardboard. Trex has had to settle numerous lawsuits from people whose decks disintegrated as the deck was transformed into a spongy plastic with all the cardboard particles eaten out. While these decks are strong and low maintenance, it is critical that they be thoroughly cleaned at least annually to keep mildew from getting established. How well the cardboard is protected is the key concern in a composite deck. In pressure treated wood, copper in the pressure treatment kills mildew. My old deck was cedar(untreated wood) and rotted through completely from mildew and fungal damage within 20 years. I could press my thumb through the tops of 4x4 rail posts. Deck boards disintegrated to the point of failure. As an aside, the cardboard outer layer in modern drywall is why houses can have mold problems. Old plaster walls were far more resistant.

Hello! Thanks for considering AZEK decks! We offer free samples on the site here: https://azek.com/store/catalog-and-samples and you can learn more about our decks here: https://azek.com/products/decking  We stand by our decks with 30-year & lifetime warranties, an feel that our moisture resistant capping will keep your deck looking beautiful for as long as you own your home!

"... the floor level isn't too far from the house." In my case, that would settle it. It would be a hard surface patio. "... we are also tossing up either using an umbrella or pergola so we can use it all year round." Most pergolas are open to the sky. What makes it usable year round ... protection from rain, sun or both? "... I dont have the skills to choose colours, plants, screens and so on so it looks like a good job." Where you need to start is with a LANDSCAPE DESIGNER ... not a contractor, unless he is also a designer, or is capable of doing good design. The range of talent varies widely. You have to examine their past work to see if they have good problem solving skills. If there is not a good local designer in your area, it is possible to find someone who will work by remote, but this demands much more out of you, as the provider of all information.

I have done quite a few decks, with differant products. Some good, some I have found out to be crap. Whatever you go with, make sure its a good company, that they have been in the composite business many years so they have already gone through the issues. For the happiest results, stay away from the cheap lines. Every manufacturer has a cheap line so they can get sales at all price points. Personally I would shy away from cheap stuff from China. If you go Trex, do the transcends line. Most of the main competitors carry a good, better, best line. Make sure you are sticking with the higher quality lines when comparing. All composites get hotter than wod in the sun. In hot weather and diect sun, some are unbearable to walk on. I am currently doing a 27x20 deck (my own), and I am using miosture shield-vision line. They have some colours in that line that have what they call cool tech technology. They say it is suposed to be cooler by up to 35%. I do not know about that, but last summer I did my own testing on a bunch of composites (trex transcends included). The moistureshield cool tech was definatley cooler tomthe touch by far, also the infra red thermometer measured it the coolest by far as well. I wrote the results down and even did a very ameturish video (would have to find it). The better composites now are called capstock, that means they are capped (3 or 4 sides) in a heavier pvc style capping whichnis supposed to be better than non capped. Some scratch easier, some fade more. Some resist moisture damage more. Some are much more slippery than others, especially when wet. For me, moisture shield visions line checked the most boxes, and have been around probably the longest or close to it. Apparently they are even approved to be in water and in dirt.....most composites will fold in hat scenario. Bottom line, don't shop by price first. Shop for: Company track record and longevity, quality product (dont get the lower end line) Most importantly install it 100% directly to manufactures instructions (not necessarily to what the store or sales guy says). If there ever is a claim, if it is not installed properly...your basically done. Good luck with your project.