Deck Prep: Sanding > Powerwashing

jellydonut

I think sanding your deck, instead of stripper and powerwash is much more efficient and looks better. By the time you apply the stripper and powerwash it seems to be equal to the time of just using a finishing sander to sand the whole dam thing! The only downside is that it's really hard to do rails because of the awkward and tight layout. Anybody have any suggestions to get awkward spots?

poppameth

Sanding is better but not really any more efficient IMO. You still need to treat it to kill mold/mildew spores as well just in case.

slickshift

Whichever way, mechanical or chemical, you need to kill the m/m

Each has it's advantages
Some coatings have a suggested preference

The biggest disadvantage to sanding is you need to set every last one of the nails or screws below the line to which you are removing material (or else it's chew up your sander pretty quickly)

jellydonut

slickshift, wow - you know your stuff.
I used this makita finishing sander i bought at home cheapo and man those nails ruined the day. Anyways, The alleged solid stain on the deck looks like its rusted on the deck. I was using 60 grit sandpaper and it got rid of some but there was still alot left. I'm gonna get the nails flush, but I would really appreciate any suggestions on a specific sander that would be good - I'm gonna buy it tmrw.

poppameth

You could try a product like Flood's Powerlift deck stripper. It's designed to loosed those tough coatings so they can be power washed off. Do that first to remove the majority of the stain and sanding will be a lot less labor intensive after.

mjdonovan

I just finished powerwashing and resealing my mahogany deck. I'd never do it again. Sand it. I found it impossible, even with a high powered powerwasher to remove all of the old deck sealant. I sealed over it anyways. Two weeks later I still have a sticky deck in places.

If I were to do it again, I would sand it first, then powerwash it with a product that would be sure to kill any mold spores.

For me the future is composite decking material. Zero maiintenance and a consistent look.

poppameth

Don't count on that. I've done a decent business selling solid stains to people who have composite decking. Fact is, there is still a wood component to it and it can be stained, even by something as simple as a potted plant leaking dirt on it.

jellydonut

I'm gonna go with the powerwash first and then sand to get out anything that doesn't come out.

@mjdonovan: what kind of sander did you use?

slickshift

That is correct
A powerwasher is not meant to remove old deck sealant

That is incorrect
Composites still need regular maintenance, washing/cleaning, and mildecides, just as much as a wood deck (in the same circumstances) would
The "finish" is more consistent than a transparent or semi-transparent stain, but not more than a solid stain which they are attempting to emulate
they do, however, fade even more than solid stains, and can fade unevenly depending on traffic and sun

Not that it's not a great choice for you, but they are not "zero maintenance" by any stretch

slickshift

That would be my usual MO