OK, so this house we moved into a year has wooden decks, something I've never had before. I also got a 5 gallon bucket of deck stain with the house. So now what. Does this take a really jumbo roller on a broom stick, or some other application method. BTW, I would search and read, since every thing posted on the internet is 100% accurate......but though I'd ask those I trust first.

short to medium nap lambs wool roller..

apply liberally but no puddles...

I gave up on the currently available deck stains/waterproofing. Everything available is water based. Roll it on- it doesn't dry. After a rain- it's milky looking. The old Thompson's Water Seal was oil based- spray it on with a pressure garden sprayer. Great stuff. Sadly it has gone by the wayside.

 

I went to Sherwin-Williams and got their medium priced deck system. Applied with a roller. Yes, it's basically paint but it is working. Had them put their no-skid (walnut shells) in the cans. 

Rollers as previously described work well. I've also used a pad for staining decking boards with success. The pad doesn't throw the finish like a roller can, especially with thin stains if that's important to you. To get between the deck boards, I use a stain brush. I typically am applying an oil based stain with these tools. The stain I use Is TWP. Could also use a pump sprayer if the viscosity is low enough but need to protect against overspray in areas where you don't want stain. Railings and spindles are always the greater challenge for application. Spray wastes a lot of stain in these instances but brushing is tedious.

Why did none of you suggest that he thoroughly clean and prep (possible sand) the deck first before doing that kind or work.

Please make sure you can out the sides of the boards.  If possible go under the desk and also stain /seal the underside.