Can I Seal a Deck?

[MossRoad]

Carpet over decking will quickly conform to the ridges of the board spaces and look strange AND it will hold moisture on the boards, which you do not want.
The spaces between the boards are there to let water through AND to allow for the boards to expand and contract.
If you seal up those spaces, your deck will rot quickly, and maybe the joists underneath them, too.
The key to making a deck last long is to keep good air circulation around it and standing water off of it.

As others have mentioned, you could put a sloped ceiling under it with corrugated metal so it drains forward. Just be sure that it allows for good air circulation or you may get mold and/or fungus under the deck if it stays dark and damp.

 

[pacerron]

Carpet over decking will quickly conform to the ridges of the board spaces and look strange AND it will hold moisture on the boards, which you do not want.
The spaces between the boards are there to let water through AND to allow for the boards to expand and contract.
If you seal up those spaces, your deck will rot quickly, and maybe the joists underneath them, too.
The key to making a deck last long is to keep good air circulation around it and standing water off of it.

As others have mentioned, you could put a sloped ceiling under it with corrugated metal so it drains forward. Just be sure that it allows for good air circulation or you may get mold and/or fungus under the deck if it stays dark and damp.

I agree with MossRoad.

If you don't like the barn tin look you might also look into Vinyl panels that are made to finish the underside of porch ceilings.
I have a cape cod style house with a roof over it that has those panels. They span over 8 feet from the house out to the front column beam and the porch is 50 feet long. The profile of the panels and the locking of the edge ridges makes them completely self supporting over the 8 foot length. They are just supported on the ends by an aluminum molding made for the purpose. 20 years and no sagging.
Of course I don't have rain water on top of the panels either. You might have to screw them into a support running down the middle for a water load above them. I have a vented overhanging soffit beyond the beam so there is air circulation.

 

[lakngulf]

If the answer is to fix something underneath the deck porch, the looks will not matter....It is underneath my house, behind the concrete footing wall. I looked at something like that for the rain water diversion, but a simple ditch and exit pipe took care of that. Putting tin underneath will be a chore as there is little working space underneath, and I am not sure that would divert the cold wind. But that may be my only answer.

The expensive answer is to take up the existing deck boards, and replace with those interlocking deck boards that send the water away from the house. The new interlocked boards will have to run perpendicular to the wall. Thought about putting these on top of existing, but that creates a step up at the door.

 

[PILOON]

10 years ago we decided that the under deck area would make a nice summer room.

I suspended metal roofing under my deck with a reasonably generous slope to drain rain away from the house.
I then installed windows all around and we now enjoy a nice bug free area.
Snow loads are not a problem as it is the deck that supports it and only water gets to see the metal roofing.
I ordered the metal white on the reverse side as that was we'd be looking up at.
Floor is carpeted over concrete and upholstered furniture lives out there year round.
A big surprise bonus was how cool that area is as sun never hits the tin and also wind breezes thru causing a cooling effect, to add it gets to the 80's and 90's around here and that 'tin room' is where we go to cool off.
LOL, often thought of adding dripping water on the roof (er ceiling) for a real cooling. My guess is even a soaker hose would make me a poor mans air cooler.

 

[jinman]

Milton, I'm not sure I understand the problem or the area in which you have to work. Your deck looks raised well above ground level behind your stairs. Unless there are things I cannot see there, I'm really confused. Are your deck joists not supported by a ledger board up against your house? I'd love to see a picture of the problem area.

 

[Sawdustsmb]

Sounds likw you need to take a section of blocks out of your current wall, pour a new footer and lay up a new block wall at the back and side perimeter of your deck

 

[lakngulf]

Sounds likw you need to take a section of blocks out of your current wall, pour a new footer and lay up a new block wall at the back and side perimeter of your deck

I see that as an option. In essence, create a new barrier wall the follows the line of the deck. Will need to put some thought to that.

 

[lakngulf]

View attachment 306899

Milton, I'm not sure I understand the problem or the area in which you have to work. Your deck looks raised well above ground level behind your stairs. Unless there are things I cannot see there, I'm really confused. Are your deck joists not supported by a ledger board up against your house? I'd love to see a picture of the problem area.

I realize that I have not presented a clear picture of the problem area. I will try to draw it out, and will get better pictures. Indeed the outer portion of the porch is high off the ground, but the lot slopes steadily and the actual area under the house is close to the ground. There is partial standing space that narrows to just crawl space.

EDIT: I have tried to add a crude drawing, showing the area giving me the problem. Most of the deck is outside the house.

 

[MarkV]

It is hard to visualize and I think some of us are misunderstanding the setting. As I get it, the additions were set on a footing with a short block wall that created a crawl space. The covered recessed/raised area of the deck is over that crawl space. That allows some water and a good bit of air flow to come through the lower level of the house. Am I on track here Lakngulr???

MarkV

 

[lakngulf]

It is hard to visualize and I think some of us are misunderstanding the setting. As I get it, the additions were set on a footing with a short block wall that created a crawl space. The covered recessed/raised area of the deck is over that crawl space. That allows some water and a good bit of air flow to come through the lower level of the house. Am I on track here Lakngulr???

MarkV

Yes, Mark, you are spot on. Perhaps this picture with my grandson Jack will help a bit. The area under him and to the right of the swing is the problem area, the deck to the left of the swing is ok. The concrete footing wall is probably right under his bottom.