floor thickness 1/2 or 3/4

[Cliffmeister2000]

With all of the crossmembers you have on your trailer, 1/2" will be fine. Something to consider, though, is how your walls will fasten to the floor. 1/2" material doesn't give much thickness for fasteners.

Is anyone really attaching a wall to the floor directly by screwing into the end grain of plywood?

Not me!

My floor is 1/2 ply on 2x4 frame. I built out 1ft past the frame in back and front, and 6in on both sides. The 2x4 are essentially the frame.

[GreatPumpkin]

With all of the crossmembers you have on your trailer, 1/2" will be fine. Something to consider, though, is how your walls will fasten to the floor. 1/2" material doesn't give much thickness for fasteners.

Is anyone really attaching a wall to the floor directly by screwing into the end grain of plywood?

Check the following link for various methods of attaching the walls to the floor: http://tnttt.com/viewtopic.php?t=19442

I'm using a Dado in the wall, but my floors extend beyond the frame, so my method isn't pictured on that link. Here's what mine looks like. The grey angle you see pictured does not run the full length. They are actually about 2-1/2 inches wide. I will be using 6-8 down each side as additional bracing.

[Gage]

With all of the crossmembers you have on your trailer, 1/2" will be fine. Something to consider, though, is how your walls will fasten to the floor. 1/2" material doesn't give much thickness for fasteners.

Is anyone really attaching a wall to the floor directly by screwing into the end grain of plywood?

You mean something like this. 1 1/2" screws right up through the floor into the sides which are sitting on the floor.



You can see how I'm rebuilding a '46 KIT right HERE.

[Arne]

my floor is insulated and built like an interior luan door... 3/8 on top, 1/8 on bottom, with 1.5" insul and ribs between.

[Cliffmeister2000]

With all of the crossmembers you have on your trailer, 1/2" will be fine. Something to consider, though, is how your walls will fasten to the floor. 1/2" material doesn't give much thickness for fasteners.

Is anyone really attaching a wall to the floor directly by screwing into the end grain of plywood?

You mean something like this. 1 1/2" screws right up through the floor into the sides which are sitting on the floor.



You can see how I'm rebuilding a '46 KIT right HERE.

Gage, I would never have recommended this approach. However, it must be a good one if you are doing it! I know you do quality work, and your recommendations are not taken lightly on this forum!

[Gage]

Gage, I would never have recommended this approach. However, it must be a good one if you are doing it! I know you do quality work, and your recommendations are not taken lightly on this forum!

I also pre-drill my holes and use glue. Going into ply, you must pre-drill.

[Cliffmeister2000]

Gage, I would never have recommended this approach. However, it must be a good one if you are doing it! I know you do quality work, and your recommendations are not taken lightly on this forum!

I also pre-drill my holes and use glue. Going into ply, you must pre-drill.

You probably also use quality ply. As in, exterior grade, no voids!

[Gage]

You probably also use quality ply. As in, exterior grade, no voids!

Eight years ago you could get quality ply from 'Big Box' stores. But not today. They do have some wood that is good for use, but not plywood. Most of the ply I use is cabinet grade and like that, no voids. Yes it cost a little more but is worth it for the end result.