Thanks for replying! The choice I face is just letting the deck continue to crumble slowly (I think it will be some years before replacement) or trying to slow its deterioration with some sealing product. Unfortunately I'm striking out on finding that product. I'd still appreciate any suggestions.

Never heard of anything made that would stop composite that is bad from turning the rest of the way into garbage unfortunately.

Any money you would spend slowing the failure would be better spent replacing it so much sooner.

Let's say you bought a good quality epoxy resin, it is about $100/gal. Resin does not cover like paint, so 100 sq ft per gallon coverage. Then a high-quality porch floor paint to protect the resin from UV, that's $58/gal but at least it covers about 300 to 400 sq ft, but you need two coats. For a 16x20 deck this comes to $420.

treated wood decking is about $1.15 sq ft, and a composite is abut $5 (and up). You could replace today with wood for less that an epoxy treatment.

Casey

What composite decking do you reccommend?

I have been using lowes choicedek. My upper deck is almost 7 years old, color is driftwood (light beige) which is no longer available, no problems, I am in a dry climate. My lower deck is choicedek foundations, the reddish color, and it fades to pink, but I'm ok with that. I just installed that last summer. It was less than $20 for a 12 foot plank, on sale.

I am not as picky as a lot of people are, though. You should look at reviews for the decking you are considering. Different climates/applications get different results sometimes.