Applying Finishing on a New Deck

Before

This picture was taking immediately after the deck was built.  The top of the deck is made of 2x4 S4S Cedar and I used 2x6 Southern Yellow Pine for the trim.  I think the natural color tone of the cedar is amazing, but since I don't want it to gray out from weathering, a stain and sealant is needed.

Before stain

 After

These two pictures below were taken after I finished coating with the stain/sealant.  

Top shot

Bottom shot

 Process

Pressure Washer

Wood from the lumber yard is not perfect.  Usually wood sits there for some duration and during that period, dirt and even mildew builds up.  So the first thing i did was to use a pressure washer to clean up the top layer of the wood.  I would suggest a 2800 psi pressure wash for this job.  When using one, make sure to have a 20+ degree nozzle fitted.  If you try to use a 0 degree nozzle, the focus on that beam of water will shred your wood if it is bare.  Just constantly move the washer wand not focused on any one spot unless it is really bad.  Some people suggest using a soap additive for decking.  But if it is new wood, you most likely won't need it.  But just know it is available for killing mildew and other growth.  Last thing, check that your garden hose can supply the gallon per minute requirement of your washer, if not, the engine will break.

Blackhawk 2800 psi, 2.3 gpm pressure washer.

Wood Filler

Follow up the preparation with a new deck by filling the knots in the wood planks.  Also identify any knots that are loose and just drill those out and put in the wood filler.  Use ample amount of it and make a mound.  This mound will later be sanded down flush with the board.  I used the Elmer's exterior ProBond wood filler.  My construction friend suggested I use Bondo because it is cheaper.  I ended up going with ProBond because you can stain it.  With Bondo, it comes in a powder mix and you need to add stain while adding water to give it the tint. Depending on the amount of wood filler, you might want to go with Bonder to save on cost.

Sanding

So what's a project involving wood if you don't use your sander?  After you use the wood filler and it has dried, there is most likely excess unless you're doing surgical work on every filling.  Use a hand sander with 100 to 150 grit paper to sand the filler flush with the board.  No need to put pressure on the sander as the vibration will do the work.  Also look for spots on your deck where the grain of the wood has stood up after the pressure wash.  This tends to happen with wood after being exposed to water.  Sand those area down. 

Stain

There are many brands of stain out on the market.  Each brand carry the following 3 types.  

• Transparent
• Semi
• Solid

If you have new decking, you can and should go for the transparent and semi treatment.  With transparent, you can see the natural color of the wood.  Drawback being you need to stain every 1-2 years because the wood is exposed to the sun.  With semi, it adds some coloring to the stain and you can treat anywhere from 4-6 years.  With solid, it's basically painting over the wood and you can get away with treating only every 10 years.

I went with the semi treatment and custom blended to a natural cedar tone look.  I applied the stain with a 5.5 inch wide hand brush.  I went through 2 coats allowing a day to dry in between to let all the gases dry out.