Under deck waterproofing options

[TheCabinetmaker]

I enjoy watching this channel. This may be what you are looking for: https://www.youtube.com/watch?v=nMpTcKIQXfs In this video they are replacing wooden decking with a fake wood decking material that will drain the water away. They were doing what you want to do.

[arthropod98]

I enjoy watching this channel. This may be what you are looking for: https://www.youtube.com/watch?v=nMpTcKIQXfs In this video they are replacing wooden decking with a fake wood decking material that will drain the water away. They were doing what you want to do.

holy crap . . . that's so wild . . . i just watched this last night and was gonna post it.  


this is the stuff, which is pretty cool:  DuxxBak Dekk | Composite Deck | No-Drip-Through Deck (duxxbakdecking.com)

[Willyou]

holy crap . . . that's so wild . . . i just watched this last night and was gonna post it.  


this is the stuff, which is pretty cool:  DuxxBak Dekk | Composite Deck | No-Drip-Through Deck (duxxbakdecking.com)

I've seen this as well. Very cool product.

[OneStaple]

That DuxxBak Dekk looks very intriguing, and certainly seems like a fairly straightforward installation. You'd really want to be careful that the slope of the joists/framing is away from the house though. I wonder how much slope is needed for it to be effective (you wouldn't want standing water!).

For my application, I'm not sure it's the best choice, in part because I'm planning to keep the existing decking that is already painted to match the rest of the deck (there's another level to the deck closer to ground level that I won't be doing waterproofing on). From some searching online, it seems like the DuxxBak is in the neighborhood of $13-$15/sq ft. That probably makes it competitive (when accounting for waterproofing) when you're putting a new composite deck on. But if I'm only addressing waterproofing, it would roughly double my costs.

From what I can tell, Dek Drain or Trex RainExcape is in the $6-8/sq ft range. Or roughly half of that if you DIY with EPDM rubber. I will likely pay a bit of a premium for one of the ready-to-go systems just because my time will be a premium while we're moving houses and I have 100 new projects to tackle.

Tyler

[Willyou]

...I wonder how much slope is needed for it to be effective (you wouldn't want standing water!).



Tyler

I don't know what the company recommends, but I wouldn't install it with less than 1/4" per foot (2%) continuous slope (no humps or dips). I would be curious to know what the slope of the one installed in the video was. It looked very flat, but I know it is hard to see without a reference plane.

[Snipe Hunter]

I don't know what the company recommends, but I wouldn't install it with less than 1/4" per foot (2%) continuous slope (no humps or dips). I would be curious to know what the slope of the one installed in the video was. It looked very flat, but I know it is hard to see without a reference plane.

Yea, that is pretty much a solid rule of thumb for drainage

[arthropod98]

I don't know what the company recommends, but I wouldn't install it with less than 1/4" per foot (2%) continuous slope (no humps or dips). I would be curious to know what the slope of the one installed in the video was. It looked very flat, but I know it is hard to see without a reference plane.

if you mean the perkins video . . . i THINK the guy guesstimated it was about 3/8" per foot.

[joe1086]

Drifting off topic...

Many years ago I built a 12x20 second floor deck and wanted a dry patio beneath it. I sloped it at 1/4" per foot, so over the 12' span the deck was 3" lower from the futhest point from the house. Most people didn't notice the drop, but I sure did. It always bothered me.