Can I Seal a Deck?

[lakngulf]

Maybe this will help. The area to the left of the black line is the problem area. The black line is on the concrete block wall below.

 

[pacerron]

You can see by looking at your original picture from down in the yard describing the problem that no one could see that your deck
was bi-level. We were seeing your description as water flooding the area under the main deck.View attachment 306956

 

[Western]

Another option may be to remove the deck (problem area) and install a super light weight 2" concrete slab, similar to what you see at Hotels and large apartment building's for stairs and upper walkways, that would seal it off and you could finish it in many ways, stain or stamp.

Just trying to throw out something else.

 

[wawajake]

I have had a very similar circumsyance but without the "heating issue of cold draft" ....but I have tried various solutions . I first did the outdoor carpet on the 12 x 24 area , it actually even held water and it would run off or could be broomed for the first year , but then as wear occurred iby next summer t would leak thru to area below (and in winter thaws this would freeze on concrete below and entrance there (see pic)...so then I did the steel roofing screwed underneath deck on furring strips that are spaced thicker every 24 inches so that steel is sloped away from house with a one inch drop over 12 feet. (12 ft sheets are a pain to install but it worked) I even rigged a eavestrough system for area over walkway. I have not completed steel under all of it yet, but I am also considering covering the 2x6 deck boards from the top with Pressure treated 5/8 plywood and then doing carpet again. But it should be noted others are correct that the carpet caused accelerated rotting of wood , some of my 2 x6 boards will need replacing even though they were PT wood , but they are 15 years old and only one coat of stain on them when carpet went down on them three years ago.
In all honesty the best solution would be the vinyl floor system suggested above in other post by someone else, but it is expensive . Perhaps you could use the blue rigid styrofoam from underneath between joists for draft and insulation value and then use steel over that to direct water away if need be.

 

[jinman]

Okay! The light just came on brightly in my brain. The problem is on the inset behind the concrete wall. You've created a "bathtub" there that rain fills up for you. I believe you could put thin Hardie Backer or some other waterproof subfloor over the deck and then put vinyl or tile down to catch water and seal the edges off so water will run off the front toward the stairs instead of standing and leaking around the door and walls. If the thickness of 1/2" plus the tile or vinyl is too much for your door sill, you may have to remove the 2x6 deck boards and replace them with the thinner 1x6 boards or just use plywood subflooring with the Hardie Backer. I think the deck coming up and doing a replacement is the only thing that will you the results you want. The real kicker is that you need the area to be at least 1/2" higher than the deck so it drains and water does not pool there. Trying to do this and not get it higher than your door sill may be a challenge. If it's higher, the water will just run into the house. This would create another huge problem.

 

[lakngulf]

You can see by looking at your original picture from down in the yard describing the problem that no one could see that your deck
was bi-level. We were seeing your description as water flooding the area under the main deck.View attachment 306956

Yes, sorry about that. Glad I could get a better picture this morning.

 

[pacerron]

Okay! The light just came on brightly in my brain. The problem is on the inset behind the concrete wall. You've created a "bathtub" there that rain fills up for you. I believe you could put thin Hardie Backer or some other waterproof subfloor over the deck and then put vinyl or tile down to catch water and seal the edges off so water will run off the front toward the stairs instead of standing and leaking around the door and walls. If the thickness of 1/2" plus the tile or vinyl is too much for your door sill, you may have to remove the 2x6 deck boards and replace them with the thinner 1x6 boards or just use plywood subflooring with the Hardie Backer. I think the deck coming up and doing a replacement is the only thing that will you the results you want. The real kicker is that you need the area to be at least 1/2" higher than the deck so it drains and water does not pool there. Trying to do this and not get it higher than your door sill may be a challenge. If it's higher, the water will just run into the house. This would create another huge problem.

Jim,
Looks like from his end view pic the deck boards are already 1 x ...
Need to see what is acting as joist support under the raised section of deck and how they are attached.
If he doesn't know now he needs to unscrew a few boards and take some measurements. Also find if there is any slope now and how much.

 

[jinman]

Jim,
Looks like from his end view pic the deck boards are already 1 x ...
Need to see what is acting as joist support under the raised section of deck and how they are attached.
If he doesn't know now he needs to unscrew a few boards and take some measurements. Also find if there is any slope now and how much.

Yep, I think he probably needs to remove all that deck and put sub-flooring, Hardie board, and tile or vinyl for a waterproof surface. He might be able to put the Hardie Board right on top of his deck if thickness is not an issue with the 1x6 boards. It should extend out to the 1st step dropoff for the best water shedding. That whole area needs to be a waterproof floor with sealed edges around the structure. There may be better solutions than the sub-floor and Hardie board. With a 3/4" sub-floor treated plywood and the 1/4" Hardie Board, it should be about the same thickness as the 1" thick boards. With the HardieBoard premium product, it will be about 1-1/4" thick. Additionally, there would be the thickness of the ceramic tile or sheet vinyl. The dimensions add up in a hurry.

The Hardie Board is an interior product, but should hold up fine in this area because it is used as a backer in showers. It is mold inhibiting and will not spread fire or burn. I know Milton wants to do this as inexpensively as possible, but if it is done right, he can do it once and forget about it. I'm learning some of the same lessons on my decks. You can do it right once or re-do it often.

EDIT: DUROCK is another product that is similar to Hardie and may be cheaper.

 

[pacerron]

Yep, I think he probably needs to remove all that deck and put sub-flooring, Hardie board, and tile or vinyl for a waterproof surface. He might be able to put the Hardie Board right on top of his deck if thickness is not an issue with the 1x6 boards. It should extend out to the 1st step dropoff for the best water shedding. That whole area needs to be a waterproof floor with sealed edges around the structure. There may be better solutions than the sub-floor and Hardie board. With a 3/4" sub-floor treated plywood and the 1/4" Hardie Board, it should be about the same thickness as the 1" thick boards. With the HardieBoard premium product, it will be about 1-1/4" thick. Additionally, there would be the thickness of the ceramic tile or sheet vinyl. The dimensions add up in a hurry.

The Hardie Board is an interior product, but should hold up fine in this area because it is used as a backer in showers. It is mold inhibiting and will not spread fire or burn. I know Milton wants to do this as inexpensively as possible, but if it is done right, he can do it once and forget about it. I'm learning some of the same lessons on my decks. You can do it right once or re-do it often.

EDIT: DUROCK is another product that is similar to Hardie and may be cheaper.

The troublesome part is the description of the wind under the house making the other rooms cold.
That needs to be addresses prior to any new decking.
He said:
"Several years ago I had a builder add some rooms onto the front of my cabin--two bedrooms and a large sun room. I lay out the design and made a slight error. I wanted a porch that was covered a bit, so I could sit out while it was raining. The porch was covered with deck boards. Problem is, the concrete blocks and footing ran along the rectangle of the addition, while the porch was inset from that. I know that is confusing, but the issue is the deck boards of the porch allow wind and rain to get underneath my house. I took care of what rain gets in by ditching and creating an exit for the water."

 

[3v0]

I expect you dismissed the following suggestion but it should be investigated. Maybe you are thinking it will cost too much or that you will need more support to hold it. You won't really know till you get a quote.

Another option may be to remove the deck (problem area) and install a super light weight 2" concrete slab, similar to what you see at Hotels and large apartment building's for stairs and upper walkways, that would seal it off and you could finish it in many ways, stain or stamp.

Just trying to throw out something else.