SuperDeck is stain, which does not require a primer like paint does. It is also what I would use.

 

I would stain it. Paint is a constant maintenance headache. There are solid color stains that look like paint. Sherwin Willamns makes to SuperDeck formulas (actually three). Solid and transparent stains which is what you want. They also make SuperDeck Dock and Boat. That is intended for old previously stained decks that may akso have checks and splits on the surface. You DO NOT WANT that for a new deck, I use it on my 35 year old deck and it hides a lot of aging issues .

 

Your contractor is right you need an oil base primer first if you intend to paint but I wouldn't recommend paint on decking and would also opt for a deck stain. Stain won't last quite as long but doesn't require as much prep when it's time to recoat.

I like to use either a transparent/toner stain or semi-transparent when staining new wood, IMO it looks better .......... but you can use solid stain if you wish.

 

Both have pros and cons. ....... Most like to stain, I don't. Stain is an easier prep, but unless you are disciplined to re-stain every two years. you will degrade your deck sooner. If your stain looks like it needs to be redone, it is already way past due, and moisture has been allowed to penetrate the wood. The film build of stain is just too thin for me. ...... Were I forced to use it, I would lay down 3 coats at the start just to equal one coat of paint.

Neither would I use a 'primer'. ........ Yes, I grew up with the 'oil primer' on wood story. Even used to tell it when in the business, before I decided it was marketing BS. ....... I have never used (which I have on my shelf) an oil base primer on wood in over 20 years. ....... Top shelf exterior house paint, done. (Satin minimum sheen)

My only exception would be IF you had 'ponding water' on wood. In that case I doubt I would even use primer, but instead do two coats with an exterior alkyd.

 

The trick is to use a pigmented stain for longer life. The clear type do not hold up well to UV damage. Pigmented stain will penetrate the wood and hold up much better to foot traffic. Good idea to sand the wood with 80 grit sandpaper to open up the grain for the stain with exterior decking.

 

Either option can work, it all depends on the outcome you are wanting for the long-run. Super Deck is a water-based stain that comes in either semi-transparent or solid body. It's not a bad product, but since it is water-based it will end up needing to be touched up probably every year - especially if it is a high traffic area. The oil-based primer and then painting option is not a bad choice if you want this to last for some time without having to touch-up as often as you will with the superdeck... The oil-based primer recommendation is for holding back the tannins or whatever in the wood so that it doesn't end up bleeding through and showing through the paint later on. I have tons of first hand experience with all of these products and also the SW products too, and personally I would go with the oil-based primer and then top-coating with a latex paint instead of using the super-deck. If you are set on using a stain, use the Armstrong Clark exterior wood stain instead of superdeck.... it will last 3 times as long.