Can you Plane PT lumber safely

[Greg Cuetara]

I have an exterior deck which is in pretty rough shape. I need to rip the whole thing up to fix the undersides...winter damage. Most of the deck boards are cupped, warped etc. Can I safely plane the boards outside with my lunchbox planer? I assume the deck was built in the early '90's so it is the older PT lumber with bad stuff in it. I don't really care about the boards being perfect so I will not be jointing them first...I was thinking of just pushing them through the planer for a few passes to make them look a bit nicer.

I am currently looking to just replacing the whole thing with new decking but we are looking at trying to sell the house in the next year or two so I really don't want to sink a few grand into decking if I can make what I have look nice.

Maybe there are other options out there I havn't thought of. Any advice would be appreciated.
Thanks,
Greg

[Jim Becker]

You probably would be fine wearing dust protection and disposing of the shavings appropriately, but taking off enough to make them "flat" is going to reduce the thickness in a meaningful way...which affects the load they can carry. Why not just flip them over and re-fasten them down. A "light" cleaning with a pressure washer and/or a safe bleaching agent should be sufficient to make it look a little better and avoid the replacement situation.

[JohnT Fitzgerald]

I agree with Jim - I'd try to leave them the original thickness so they don't lose any strength, and use a pressure washer to 'clean them up'. Flip them, or take them off and let them dry out so they flatten out and then reattach them.

[Lee Schierer]

Bear in mind that planing will also make them thinner and less able to support the weight they did previously. Many people claim great appearance improvemnt by power washing with a good deck wash.

The sawdust will be toxic so don't breath it and dispose of it to the landfill.

[Jim Becker]

Just remember with the power washer that you want a more gentle approach...you want to clean, but not cut the wood...and yes, you can cut right through it with the wrong setting!

[Mike Wilkins]

Neighbor across the street did the flip-over method to refresh his deck. The underside was in fine shape, needing only a coat of deck sealer/stain and the application of new patio furniture and a new grill. Throw in some of those torch thingies that keep bugs away and you are good to go.
This is the method that makes the most sense, since you are going to put the house on the market soon.
Stay safe and watch those fingers.

[Greg Cuetara]

Thanks for the advice. When I do finally get the boards off I will see if I can just flip them over and put a coat of stain down. That seems like the best alternative right now.
Greg

[Jim Becker]

Yea...opague stain is your friend for this job!

[Peter Quinn]

I helped my BIL do the Yankee deck remodel last month (that's what we call flippin the boards here). Be ware that if #2 common was used there may be a lot of wane and open nots hiding on the under side of those boards. All but the highest quality of PT decking really only has to have one "A" face. We wound up replacing about 10% of the total as some just couldn't be flipped.

We flipped the whole deck, refastened, 20 minutes with a belt sander and it looked pretty decent. I'd avoid planing those boards if possible because they are toxic, all that yellow pine will reek havoc on your feed rollers, and you stand a good chance of picking up imbedded rocks or ferrous material from old deck boards that will reduce your surface quality pretty quick even on a skim pass. And forget jointing, you'll wind up at a 1/4" and still not be flat!

[Chris Padilla]

I did some minor work on the bandsaw with a 6x6 PT post recently and that dust had me sneezing and choking. I think the flip method sounds dandy or a good thorough power washing...or both!!

[Wayne Cannon]

Planing pressure-treated boards would remove much of the pressure treated layer, leaving your boards with less protection. I doubt you would plane away half of the trated layer (if color penetration is a valid indication, anyway), but it is an additional consideration.