So how long Do Wood Decks on utility trailers usually last before needing some decking replaced or all in your experience with them ? They are the cheapest option for new trailers being sold and do wear out eventually.

I am sure if stored indoors it could last indefinitely, but outdoors not as much.. I am sure type of use plays a factor if it has heavy equipment or cars loaded on it day in and out it would go alot faster..

Also Has anyone used a steel decked trailers? I have owned one or two in past and they have drawbacks also besides rust..How about the synthetic wood decking you see at Lowes or HD made out of some "plastic type" material?

 I am just looking to get everyone's experiences so i can recommend what might be the best option to someone else so type of use I or another plan to use it for is undetermined..

OST for more input.

My trailer has a 2x wood deck and will be in need of replacing probably in the next year.  I've owned it since 2006 and it resides outside so it see's all the weather.  
We use it for tasks around the yard (rare) and for hauling stuff to the deer lease (4 wheelers, etc) and camping.  I'd like to know what folks have done as well but I can't see anything that would be as reasonable as wood.  I have seen some folks replace decks with expanded metal but I can see that getting real nasty to maintain and replace when its life is up.

I guess it depends on what you haul with it. My brother-in-law has a landscaping business and his equipment is often muddy, covered with grass clippings, etc. He has found that covering the floor with expanded metal works well. All the mud, snow, water, dirt just runs right out the bottom and the mesh gives great traction even when it's wet. It also never rots.

On the other hand, if you are hauling furniture or something you don't want getting wet, a solid bottom would be better.

Treated wood.

if you ever have to lie on the thing to work on or under a vehicle, you will appreciate the wood. especially in extreme temperatures.

Go with treated wood.  The Trex stuff is 1 inch thick, and 2x treated lumber is 1.5 inches thick.  I have seen Trex bow under the summer sun, so I wouldn't want it on a trailer.  The treated lumber should last you 15-20 years unless it is abused.  We have one flat bed truck with treated wood flooring that is about 20 years old and needs replacing now.  Adding Thompsons Water Seal or some other product should help it along.  
If you need something stronger than yellow pine treated lumber, you might get some rough sawn oak.  The oak is stronger, and rough sawn is a true 2 inches thick.  I put some untreated rough sawn oak on a hay trailer 5 years ago, and only treated it once with Thompsons, and it looks great and no rot yet.  For an even longer lasting wood, you might take that oak and have it treated.  I have heard of others treating oak with a 50/50 mix of used motor oil and diesel.

Treated wood.  Retreat with a 50/50 mix of diesel fuel and used motor oil.  Should last forever.

Apitong

Kinda depends on a lot of things. If there are plenty of supports along the length (to prevent the bowing and sagging), 2X lumber is ok and is pretty easy to replace. Thick plywood is much stronger than the planks. Any wood alone is going to wear and need replacement and can also be extremely slippery when wet. I have one I inherited that has metal grating which is nice for traction but won't let me haul gravel, etc. The one I built myself has 3/4 marine plywood (I'd have never spent the money but I got it free with a few nailholes) with aluminum mesh on top. They type of mesh you see on headache racks and such. That seems to work well for traction and prevents the wood from wearing, while still allowing me to haul gravel and such. Be careful with pressure treated/rot resistant lumber of any kind. At the very least seal or otherwise isolate the parts that are going to come into contact with metals as some of the salt-based anti-rot treatments or other chemicals can corrode metals pretty quickly. Even raw wood will hold road salt and such speeding up metal corrosion.

Dupe. Sorry

Will grip tape stay down being exposed to sun / weather ?

I have not had good luck with stuff you buy at the hardware store.

I've found that treated lumber woks fine for light use trailers but my father and I have put diamond plate sheet metal on top of treated 2x lumber and have had good luck.