Self drill screws to repair semi trailer floor

If you’re using the black floor screws with tapered tip.
Use 7/32” drill for the 1/4”
And 9/32” drill for 5/16”.

The key is to drill thru the wood and pull the bit out and expel the wood from the bit before drilling the cross member. The wood will clog the bit and make the cutting edge on the bit overheat and burn up fast. Turn the drill slow. Air impact with good hard torx bits on the screws.

Mark where the old screws are so you don’t hit them with the drill bit. They are hard and they will ruin your bits.

 

Buy the best quality drill bits you can find to save time pre drilling. Bad
Dog drill bits supposed to be excellent,,,i use Norseman available locally

 

This size will drill the wood and metal together and the screws will run in tight to the metal and tap their own threads in the steel. No need to drill the wood larger. Lots of pressure down on the bit for tightening the screws.

 

I cut the old flooring out, using a skill saw, and a sawzall. Once it’s cut in the right places, alongside of the screws, along the T&G, about 1/2” away, then cut it through between the cross members. Then I hit the wood with a hammer, from inside, knocking it onto the ground, leaving the screws in place. Dig the T&G’s out with a screwdriver. Then, most of the screws came out, using torx bit on 1/2” drive ratchet. Vice grips on a few. A few snapped off flush. Easily removed from the bottom with vice grips, then reused the holes. Only had to drill crossmembers at the ends, where boards butt together.The cross members were easier to drill than I expected. They’re thin and flimsy. Be sure to lay boards so tounge and groove line up.

 

Those pictures make my knees hurt

 

Another thing that @Rideandrepair photos reminds me. Never line up 2 cut seams in a repair. It will create a weak point. Filling the seams with wood glue helps too.

 

I should have cut the piece nearest the wall longer. At least 1 more crossbeam towards the rear of trailer. I accidentally cut one too short. Had to improvise. There’s a visible dip in the floor now. Cross members look good. I think my new wood is 1/4” thinner maybe. I should redo the job. I’d rather just send it to auction.