Old Composite Decking Sealing - Experience?

[budget76]

May be a longshot, but has anyone had experience trying to bring some life into older, tired composite decking? Replacing it all is not in the cards $$ wise. Would love to make it repel water better & resist mold more than it does now.

We have what I assume to be early-2000's TREX that has become porous and absorbs, not repels water. Gray colored. It has almost a 120 or 240-grit feel to the surface, definitely not smooth like new stuff.

I see two options out there: DEFY and Rustoleum. Anyone have experience with either? Would prefer Rustoleum since I can get it local, and test on some scrap pieces/hidden spots before buying 4-6 gallons.

https://www.homedepot.com/p/Rust-Oleum-RockSolid-1-Gal-Gray-Composite-Deck-Coating-350007/308854826

https://www.defywoodstain.com/product/defy-composite-deck-waterproofing-sealer/

not my deck, but looks similar

 

[budget76]

well, either the wrong area to post or everyone has more $$ and just replaced it

probably going to try the Rustoleum product since I can get it locally. Will try to make sure I post up before/after results

 

[benwah]

I mean, I recoat Trex systems all the time but not to a smooth finish.

What I do is grind it with 16/20 grit metal Bond Diamond bits in my floor grinder. Then I apply epoxy at about 15-20 mils, broadcast quartz to rejection, then top coat with a polyaspartic.

If you wanted a smooth floor you could skip the broadcast. But, you need a somewhat aggressive profile on there since the composite material is not porous at all.

 

[benwah]

3 pics I found. 1st is after the grind. 2nd is after the broadcast. 3rd is during the poly top coat.

 

[budget76]

wow! looks like the "best" way to go for sure, but a bigger project than I want to tackle after all the others we've done on this house.

If I can make it water repellent again I'm happy

 

[budget76]

I picked up 2 gallons of the Rustoleum product. Brushed some on a scrap piece I found in the yard and let it dry. It may not pretty it up perfect, but it sure as hell sealed it up and made the water runoff again. That will be a win in my book.

Hoping to get at least some of the deck done before the weather starts to turn. I'll post up some before/afters if it happens.

https://www.rustoleum.com/product-c...xceptional water,cleans up quickly with water.

 

[gshockw]

So the deck has to be grind for the new coating? I have a new deck and it shows all kind of dirt. Foot traffic and dirt on it. Want to fix that.

 

[budget76]

So the deck has to be grind for the new coating? I have a new deck and it shows all kind of dirt. Foot traffic and dirt on it. Want to fix that.

not the one i'm using. just clean it then seal like a clearcoat/stain type application. looks like benwah's solution is a much more high-end/permanent solution than I have the time/$$ for in this case

 

[Shiftless]

(Deleted)

 

[Shiftless]

I mean, I recoat Trex systems all the time but not to a smooth finish.

What I do is grind it with 16/20 grit metal Bond Diamond bits in my floor grinder. Then I apply epoxy at about 15-20 mils, broadcast quartz to rejection, then top coat with a polyaspartic.

If you wanted a smooth floor you could skip the broadcast. But, you need a somewhat aggressive profile on there since the composite material is not porous at all.

How does the cost of that process compare with replacing the boards?

 

[benwah]

Much cheaper and so much less labor IMO.

A 400 sq ft deck for example would require:

5 gallons of epoxy @ ~$80/gallon
100LB silica sand ~$20
2 gallons of Polyurea + pigment @~$200/gallon
1 gallon Denatured alcohol or acetone $25
1 gallon Xylene $25
Grinder Rental (I have no idea how much this is)
18" roller frame and 2 rollers ~$60
Chip Brushes, cut pots, 5g mixing buckets ~$40

400 sq ft Trex I believe is around 3k.

 

[Shiftless]

Your numbers top $1000

The top grade Trex at Home Depot costs about $5 / sq. ft. for a total of $2000
If the framing is all OK, it seems to me that the labor to just remove and screw down new lengths of Trex would be no worse than all the sanding and finishing.

There are many other options besides top grade Trex at lower cost. I see prices for Trex between 3 and 7 dollars/ sq. ft.

 

[budget76]

following up on this old thread. no pics handy at the moment, i'll try to get some and upload

in general - the Rustoleum Composite Deck product - i would rate it a 4/10.

It's VERY watery and cans seem inconsistent in pigment/consistency from can to can. I have gone through 5 cans some seem more gray others more brown. Thankfully most dry "close" to the same. Did not mix all in a big bucket like i could have. it DOES waterproof and bead water after drying, but longevity doesn't seem very good.

Did a small part of my deck last year. Initially repelled water very well (right next to the pool). this year, it's already starting to absorb again. Color is better than the untreated tired decking, but it's fading again. it needs to be re-coated

Overall, it was the only option I could find. I will not use it again, I'll either bite the bullet and re-deck, or maybe try something like a rubberized coating. I'm committed now and had to order another 5 cans to finish. Home Depot no longer stocks it in-store, and online only 1 color is available. Luckily Menards stocked it for shipping, only place I could find more. Dunno if HD/Rustoleum got too many complaints and is discontinuing, or if its just supply shortage.

 

[CombatNinja]

So many people think composite decking is going to last "forever'. I look at it like a 10 year solution in which, granted, you don't have to do a thing to it. But don't fool yourselves, it will wear out.

 

[PatriciaM]

following up on this old thread. no pics handy at the moment, i'll try to get some and upload

in general - the Rustoleum Composite Deck product - i would rate it a 4/10.

It's VERY watery and cans seem inconsistent in pigment/consistency from can to can. I have gone through 5 cans some seem more gray others more brown. Thankfully most dry "close" to the same. Did not mix all in a big bucket like i could have. it DOES waterproof and bead water after drying, but longevity doesn't seem very good.

Did a small part of my deck last year. Initially repelled water very well (right next to the pool). this year, it's already starting to absorb again. Color is better than the untreated tired decking, but it's fading again. it needs to be re-coated

Overall, it was the only option I could find. I will not use it again, I'll either bite the bullet and re-deck, or maybe try something like a rubberized coating. I'm committed now and had to order another 5 cans to finish. Home Depot no longer stocks it in-store, and online only 1 color is available. Luckily Menards stocked it for shipping, only place I could find more. Dunno if HD/Rustoleum got too many complaints and is discontinuing, or if its just supply shortage.

Thank you for updating your advice. I might have bought the Rustoleum product if you hadn't changed your recommendation.