OT house deck coatings

[vpt]

It's time for me to coat my deck again. I had a typical red spray on coating done a few years ago and it is peeling in a lot of places now. The wood is in good shape. I plan to blast most of it off with my pressure washer and scrubbing with a brush.

With that said it is hard to find real world experience and feedback on Deck coatings. Everyone seems to think that there's is the best and most times just sounds like advertising. I am always amazed at the incredible amount of knowledge that is here. I assume some of you have decks and may have some input on what coatings hold up and what coatings don't.

If it was a smaller deck I would just entertain the idea of doing composite. However it is a fairly large deck with three tiers one around a pool a second around a hot tub and the third an eating area underneath a pergola.

Any tips on what would last more than a few years?

A real two-part spray on bed liner like I had done on my car trailer 10 years ago would be awesome, but I couldn't imagine how much that would cost. I also don't know how portable that type of spray system is.

[3illmesmart]

If you have pressure treated wood, nothing is going to last.

[Superbowl]

I never put any treatment on my deck as they all eventually peel and look like crap. I just pressure wash every few years. If I was going to treat it I would used a light thin stain that would not alligator peel so bad later. Thin (non solid) stains just kind of fade away.

[Glug]

Check out the New Zealand Deck Sealant

There is a video.

[Joel]

I have done a few decks and just use the 'top of the line' Behr solid color stain that is made for the purpose. The last one I did was about 5 years ago and still looks pretty dang good. I did a fence a few years before that, and it still looks amazing.

Like with most things, prep is critical. I pressure wash the hell out of everything, and use the deck prep spray if I think it needs it (usually doesn't, but if you have mildew, get that under control first). Maybe some sanding with coarse paper. I am careful to make sure the surface is very clean and dry, and only paint when the weather is going to cooperate (no temperature extremes for several days, no dew that night, no rain for a few days, avoiding the hot sun, etc. - I think this really helps long-term durability). Stay off it and keep chairs, etc. off it for several days until it cures.

I usually spray with an airless, carefully, fairly 'thickly' and of course evenly, one coat. Brushing/rolling works fine for a deck. IIRC, you have painted cars - if so, you already know what you are doing and the same rules pretty much apply.
Anything less than 'solid color' just doesn't last and is pointless IMHO. Yes, it is essentially paint. Transparent coatings seem like a bad joke from my experience.

[J Tiers]

DO NOT use any of those thick coatings. Neighbor did that, and within a couple years the deck rotted out. The coating did not let the wood breathe, and it closed up a lot of the spaces between boards.

The deck was low to the ground, but did have airflow through, side to side. The replacement, on the same framing, same wood type, and with a more normal coating, has lasted several years so far.

[rickyb]

I’m using Cabot deck correct. It’s a solid coating with polycarbonate beads. It fills smaller cracks and is a nonslip textured surface. My brother uses it on hid dock with good success. I’m 5-10 years between coats. I have a sprinkler system for my bonsai that wets the deck every day from may to oct.

[john buck]

I used to fiberglass decks here in Vancouver Canada , that is done here a lot .
First you have to know how to nail down the plywood , have never known a carpenter who knew how to do it .
The fiberglass preperation is just as important . A fiberglassed deck properly done will outlast you .

[I make chips]

You're stuck with the red coating as it comes off in chunks. Substituting anything else after the fact will look like crap.
The problem with us here in cheeseland is the summer humidity then the severe winter cold. Nothing sticks to a deck.

I use a wood preservative (marketing BS) by Cabot from Menards. It's essentially parafin wax in solution and yes it's almost as slippery as ice when it's wet for the first month or two. It's good for two years then pressure wash and re apply it. I have to do my two decks this year. About $140 for a 5 gallon can.

[DennisCA]

DO NOT use any of those thick coatings. Neighbor did that, and within a couple years the deck rotted out. The coating did not let the wood breathe, and it closed up a lot of the spaces between boards.

The deck was low to the ground, but did have airflow through, side to side. The replacement, on the same framing, same wood type, and with a more normal coating, has lasted several years so far.

My parents have painted their deck (also low to the ground) and the wood is untreated and original, been repainted multiple times. Fun fact I asked just how old was it anyway. They said it was as old as the house. Which was built in 1977..

It has a roof so it's protected from direct rain.

[DennisCA]

For our own deck (pressure treated), we apply a mixture of pine tar, linseed oil and red pigments to get a dark red stain.

[J Tiers]

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It has a roof so it's protected from direct rain.

That probably makes a huge difference. It's the damp ground under that causes problems when water gets through the deck.

[Moxiedad2001]

Ah, yes, deck stains, the plague of homeowners! The first thing is to understand that NOTHING will last forever against the effects of sunlight and the expansion/contraction of wood with changes in moisture content. But avoid at all costs the stains that are essentially thin paints. The aftereffects of that poor choice are what you are dealing with now. These "stains" will tend to be heavily pigmented (but not usually so heavily as to cover the grain) and they will contain resin of some sort that dries on the surface by evaporation of the solvent. As I say, that is basically thin paint, and it eventually peals off in flakes leaving a mess. To get beyond this to something better, you will have to remove it all, and that is difficult.

What you want is a deck stain that contains no drying resins but, instead, some sort of oil (tung, linseed, or a modern synthetic) that soaks INTO the wood and polymerizes by the action of oxygen or sunlight. For 20 years I've been using a product in this category called One Time. It's supposed to last for 7 years, but 5 is probably more like it. It gradually breaks down -- or rather disappears -- as the wood naturally weathers, but at least it does not leave a f***king (flaking) mess. Just recoat. This one does, however, need sunlight to cure, though indirect light will eventually do the trick.

[darryl]

I used a Behr solid color stain on my deck and steps, and everything I covered with it rotted out. My dad used Thompsons water seal, and it needs recoat every year. I swear all this stuff is made to cost homeowners- the only thing that I've seen make it for several years is fiberglass. And for some reason, fiberglass seems to like lichen, or the lichen likes it, I don't know. My friend deck has lasted- that's fiberglass with a gel coat. I think part of the solution is making a completely impervious barrier, and the other is having sufficient air flow under it, with no organics growing in the dirt.

I think another part of the problem is that our modern treatment chemicals are not as effective as they used to be. And what's with plywood now? Years ago I salvaged some plywood decking that was still solid as a rock. And I've seen what was called marine plywood come apart in layers after a few years, even though painted with exterior grade paint.

Materials like to degrade. Maybe we should look back at the Skylab experiments to see what materials are actually long-lived.

[Moxiedad2001]

I swear all this stuff is made to cost homeowners- the only thing that I've seen make it for several years is fiberglass. And for some reason, fiberglass seems to like lichen, or the lichen likes it, I don't know. My friend deck has lasted- that's fiberglass with a gel coat.

By fiberglass, I assume you mean epoxy. I don't know what your neighbor's definition is of "lasted," but epoxy breaks down in sunlight. The only way I know to retard (probably not prevent) that is to coat with a spar varnish that has UV filters. Once a little moisture, or even humidity, can get into the wood, it's the beginning of the end for your epoxy -- if it hasn't already started to chalk and break down from UV degradation. And when it becomes too ugly to stand anymore, you are not going to remove what is left with a pressure washer.