When new teak decks are really nice. They are grippy when wet and look great. For me, though, they are a real deal buster. They are a lot of maintenance. About once a month I would carefully clean the decks with a product that washed and conditioned the teak. This was rubbed in with a 3M pad on a block so it did not eat out the grain. Twice a year I would go around and spend half a day replacing plugs that had gotten loose. I found that ever other year I had to rake out a large number of seams and recaulk. Sooner or later teake decks will start to leak and when they do they will rot out the substrate which in the case of Cheoy Lee was generally plywood. This is one of those big jobs that suddenly sneak up on you after the boat is 20 or so years old. (It happens slower up north where the boats are out of commission and covered for the winter,but sooner in the south where the exposure to near tropical sun can really take sits toll)
I also do not like having that much weight up high where it increases roll angle and reduces stability.
ronjon, there is a forty someting cheoy lee right next to me where I am on the hard. This guy is redoing his teak deck ,what he does is rip it all up (fiberglass not wood underneath)fill in all the holes and puts the teak back down with exopy .If you want I will get his email and he can explain the process further.
One point that I want to clarify, Cheoy Lee glassed over the plywood before laying the teak decks. The deck fastening carry water into the plywood once the deck starts to leak. If you get it early the plywood could be intact. Generally before you find out that you have a problem the deck core is has a fair amount of rot.
Almost all boat builders core their decks with one of a number of materials. Probabaly the most common is end grain balsa. Balsa has a lot going for it. It is inexpensive, and has very good adhesion to the resin. It is very and good sheer and compression qualities. It conforms to fairly complex cruves and Balsa properly installed is quite durable. Of course there is the rub. Proper installation means complete bonding to the glass/resin laminates, sealing of all penetrations, and replacing high stress areas with non-compressible materials, typically marine plywood.
Another material used for coring is high density closed cell foams. High density foams are more expensive, harder to work with, not quite as sheer resistant as balsa, but will not rot even if allowed to get wet. It is really the best choice but because of expense it is pretty rarely used.
Lastly, there is plywood coring. Plywood coring is usually a misnomer. For the most part boats with plywood decks are actually built like a wooden boat except that the plywood is glassed over. In places were labor is cheap, this is the most inexpensive way to build a deck. It also provides a very sturdy substrate to fasten teak decks to. The problem with that is that each of the screws that fasten the deck enter the core and when the deck leaks moisture and air are present and so rot is just a matter of time.