#12 self tapping screws

[Boanerges4]

Just took my trailer down to get insp. and get tag. Everything went great, 15 minutes tops, and I had a tag. Found a problem when I got home. I screwed my floor to the frame of trailer with 46 self tapping screws #12 and I found 3 places where screws did not hold and plywood came off the trailer about half an inch. I went over several R/R tracks on the way and glad I did. Its better to find the problem before I attach walls. Just wanted to make some noise and make everyone aware of this problem. Thanks Dennis

[terryjones1]

Just took my trailer down to get insp. and get tag. Everything went great, 15 minutes tops, and I had a tag. Found a problem when I got home. I screwed my floor to the frame of trailer with 46 self tapping screws #12 and I found 3 places where screws did not hold and plywood came off the trailer about half an inch. I went over several R/R tracks on the way and glad I did. Its better to find the problem before I attach walls. Just wanted to make some noise and make everyone aware of this problem. Thanks Dennis

I used #8 self tapping screws every 4" around the perimeter of the trailer floor & 3M 5200 adhesive/sealant to attach the floor to the frame. I also, used #8 self tapping screws every 8" in the interior areas of the floor & 3M adhesive/sealant to attach the floor interior ateas to the interior frame. I think that I used near 300 screws in all and two tubes of sealant.

I took my trailer to the DMV to have it registered with just the flooring & fenders installed. See photo below:



I had no problems with the flooring separating from the frame.

Did you also, use a sealant?

[48Rob]

Screws did not hold?
As in they fell out, or you found a gap between the frame and flooring?

When running screws in holes that haven't been pre drilled, it is critical that you run the screw in, then back it most of the way out, then drive it home.
It is common for the two pieces (wood to wood, or wood to metal) to have a gap between them when not predrilled, thus requiring you to back them off and run them in again.

What it amounts to is that you are "pre-drilling the hole the first time, and setting the screw the second.

Rob

[dh]

+1

[Boanerges4]

Thanks for the replies. Holes were predrilled. What happened was apparently the screws stripped because now I have a gap detween flooring and frame of trailer. I think theres more flex in some of these trailers than you would think. Im hesitant to just put a bigger screw in. I think I will back them out and just use the old nut and bolt system. Suggestions appreciated. Thanks

[Dale M.]

IF screwed stripped it may be because "pre-drilled" hole was too large and you reduced the "hold" the screw has in the metal...

Love them bolts & nuts........

Dale

[Danny]

May i suggest carriage bolts, down through the plywood floor, through the 2x4 or 1x4,then through the steel frame lip of the c channel.. lock tite and lock washers. check every so often..cheers.Danny

[aggie79]

Were the self-tapping screws made for trailer decks?

The reason I ask is that the trailer deck screws have little "wings" near the drill point that drill oversize holes in the wood but are knocked off by the steel.

I used #12 stainless steel trailer deck screws at 6" on center. I pre-drilled an undersized hole in the teardrop floor and frame, then use an impact driver to install the self-drilling, self-tapping trailer deck screws.

They've held fine so far, but I'll keep an eye out for pull-out.

Take care,
Tom

[dh]

Once you attach the walls, most if not all of the frame bending will go away. Think of it as bolting the trailer frame to a torsion box, not the other way around.

[48Rob]

Dennis,

As DH suggests, if you just have a floor, and no walls and "box" that in itself would be enough to rip screws loose.

You've no doubt seen the little flatbed trailers that sell all over, that have side rails to keep thing from falling off the sides.
In addition to, and more important that keeping things on the trailer, the side rails are there to reinforce the trailer deck, as without that bracing, or other bracing under the deck, the trailer floor has very little strength, and would flop around like a fish out of water!

Rob

[Boanerges4]

Thanks for the responses. I think Im going to add some carriage bolts in addition to the self tapping screws, just for peace of mind. I told myself that once I get the walls tied in that most of that flex in the trailer should go away. The more you build the stronger it gets. I hope I can post pics by the w/e, my daughter is the computer whiz so I have to wait on her to help old dad out. Thanks again