Deck above a roof with no slope

I have a deck built atop a roof and need help on sloping, I'm using gorilla decking but it won't drain, I have no idea how I can slope it properly
Can anyone help?

 

Is the roof below the deck sloped? Can you post some pics?

 

It above a garage and atop a rubber roof

 

There is no slope on the rubber roof, 2x4s on top off rubber roof

 

Let's see if I'm following this. You had a flat roof over your garage with no slope and apparently no problems. But, it would have been dealing with whatever amount of snow and ice you get. Now you have installed 2x4's with a deck on top of that flat roof and have a drainage problem.

If the new decking is resting on top of 2x4's then they will need to be adjusted to provide your slope. I assume removing the Gorilla Decking is going to be a problem??

Bud

I'm picturing that those 2x4's should have been 2x6's ripped to be 5.5" tapering down to something like 3".

 

I did not put too many boards down, but I'm trying to level 2x4s as easy as possible but have no clue how to

 

Do I shim the planks or the2x4s? What do I use to shim?
How far apart are shims?
Planks are 24" long
2x4s are set already but not sloped at all
The guy who did last job never sloped
I'd hate to rip up 2x4s bc they are drilled in together

 

To advise on specifics we will need some pictures.

Bud

 

pic of the deck unsure if it was able to post

 

That sure looks ugly. I assume that is the flat roof. Being that close to the height of the door I don't see a lot of options. If those boards are currently attached to that roof, any attempt to cut or plane them to obtain your slope would probably create leaks.

No solution comes to mind.

Sorry.
Bud

 

They are screwed together and not attached to roof

 

If I slope the 2x4s would I just need to shim under them? Or is there a better way?
Would I use any special shim?
Is it correct to shim 2x4s?

 

I would first try to cut several notches at the bottom of all the 2x4s and see if that opens a path for the water to drain. If it previously drained off that roof then the notches will allow it to make it's way to the drain point.

 

so u mean take up 2x4s and cut to a slope?
my deck is 24x26
the deck never drained at all, I always had puddles in certain spots

 

Looking at how close they are to that door I don't think you can shim them up.
How thick is the new decking?
If the wood is still solid you could rip them lengthwise to slope away from the house. Is away from the house the direction you need to go?
Being screwed together will make it a little challenging to rip them, but if careful most should be saved.

If they are at all soft I would replace before covering them with a new deck.

Bud

 

about I inch of deck and yes away from house

 

Are you skilled enough and have the tools to rip them with the desired taper?

Bud

 

I gave this a bit more thought. I think your best option here would be to do some type of tile that slightly slopes to a drain. The drain would goto a small manifold under the floor with several small pipes connected to it that are routed to drain off the deck. Another option would be to make the tile slope to one side and have holes in that side were the water could escape.

Either option you need to make a lot of holes to allow for air to flow under the floor.

The key here is to keep the water out of that area and allow enough air flow to prevent moisture build up.

 

I'm thinking of triming last 2x4 to get slope