[plazaman]

I need to attach Trex over this metal deck , any suggestions ? ( that ikea junk will be removed )
The Trex will literally lay on top the deck , I just need something that will hold it in place from under .

 

[Calidecks]

Is there room under the doors or door for a sleeper system?

 

[plazaman]

There's room and it's accessible

 

[Calidecks]

You could put PT 2x flat at 16 o.c.. If it's visible from below this might be an eyesore though. You might have to float the sleepers, doesn't look like you can tie them to anything. However you might be able to incorporate some hardware to take out any bounce it might have. You may be able to tie the hardware from the grate to the joists every so often, or whatever that is.

 

[Calidecks]

Or tear out that metal grate system and use real joists. Don't know how practical that is.

 

[CarpenterSFO]

Mike: Just so I understand what you're asking about room under the doors: are you asking if there's room to put down sleepers on top of the grate and still get out of the door that the photographer is standing in? or something else?

 

[Calidecks]

Yes exactly, so he can put sleepers with decking he will need a minimum of 2.5" of clearance. I could be on the wrong track here, but it's something to consider.

 

[CarpenterSFO]

Yes exactly, so he can put sleepers with decking he will need a minimum of 2.5" of clearance. I could be on the wrong track here, but it's something to consider.

O.P. could put matching or perpendicular flat PTs under the grate, and bolt the sleepers and those things hard together. Short carriage bolts from the top, nuts on the bottom. Once a year you tighten up the nuts (assuming it's really accessible underneath) to take the rattle out.

Edit: Might not be that pretty underneath.

Edit again: Or skip the boards underneath and just put hard rubber washers, flat metal washers, and nuts, attached to the same carriage bolts from the sleepers above. Commercial job in NYC; cost is of no concern, so all hardware is gold-plated stainless.

 

[plazaman]

Ripping out the grid is not an option. I gotta bolt some sleepers up there

 

[CarpenterSFO]

Ripping out the grid is not an option. I gotta bolt some sleepers up there

How pretty does it have to be underneath? If you use square plate washers beneath it might be strong and fairly presentable.

 

[plazaman]

Notched 2x6 PT sitting on the inside of the beam, decking screwed on top of it through the grids. 2x6 are floating, not attached.

 

[CarpenterSFO]

What I imagine that you mean is that you have 2x6 joists running left to right (in the picture in your first post). The ends are notched into the web of the beam that we see in the middle, with the other ends attached somehow out of the left and right sides of the picture. The decking runs top to bottom, screwed down to the joists. Maybe you have blocking stiffening it all.

And this is because, referring to Mike's post #4, there in fact is NOT room to lay 2x sleepers on top of the grid. Is that the case?

If so, I'd spend some effort figuring out how to keep the connection snug, not to have the gravity and bouncing pull the Trex and the joists apart. On a normal deck, the force of gravity doesn't try to pull the screws out. In this situation, the force of gravity (and bouncing, etc.) is going to try to pull the decking and the joists apart, possibly loosening the screws by pulling them down into the Trex. This could be tough to manage especially as moisture comes and goes, and the joists expand and shrink. I'm not sure if that would be a problem, or how to deal with it.

Edit: I'll bet there are clips for attaching stuff to grid. Maybe use from below to keep the joists snug to the metal?

 

[CarpenterSFO]

What was the outcome?