Reefer floor repair

i used to reinforse under neath with hard wood --then sometimes weld tubing in or plate over the camaged area--just be careful when welding or cutting--that insulation is toxic crap

 

Your problem is same as mine i.e. cracked floor. And I was quoted about $5K to fix it.
There are 2X4s between the floor and each crossmember or beams as you called them. And when the moisture gets through the insulation to those 2x4s the rotten wood does not support the floor in those places. The only right way to fix it is to replace damaged 2x4s first to restore the lost support and then weld the damaged upper floor. This job is really time consuming because the crossmembers need to be removed in order to get to the 2x4s. If your reefer has problems beside the floor it could be a better idea just to find and buy a different trailer.

 

IMO it depends on where the damage is and age of trailer on best way to repair. chances are if it's an old trailer a large plate welded to floor may be best. after 2003 most reefers have composite (plastic ) rather than wood. what year trailer is it ?

 

I'm not going to buy that business about "most reefers" after 2003 having composite sills. Nonsense. That's an upsell or an option. I certainly know because I just spent the last 8 days ripping out 19 feet of newer Great Dane reefer floor and removing the rotten apitong sills (the wood on top of the crossmembers that supports the aluminum floor). Probably the fiberglass "kenlite" underneath was smacked with a tire tread and the trailer spent a few years roaming around with rainwater-saturated insulation, which in turn rotted the wood. And forklifts would come along and smash it to splinters; the SIDES of the wood were half-way there, but it was completely gone from the center, which made for an awkward dip in the center of the trailer. The aluminum floor was directly on top of a crossmember or two, and forklift traffic was acting as scissors, cutting the floor a bit every time it rolled across.

The one guy who said you have to remove the crossmembers didn't make much sense to me. If you remove the crossmembers, you take down the wood sill, too, sure, but you have to dismount nails that are holding the aluminum floor to the wood also. At least on Great Danes. The aluminum floor is laid down like tongue-in-groove sections, and it's nailed down and covered over with welds so you never see the nail heads. So, sure, you could remove the crossmembers, but really you would just knock out the wood and nails and put new wood back up, and bolt it in from below.

But in my case I needed to replace the kenlite (the shower-stall-like material over the crossmembers to keep water out, so I did everything differently. I took a 7" grinder and sliced the floor 19 feet from front to back and then all the way across, and punched that entire section of floor out. It was NOT easy, because those hidden nails I mentioned were holding the whole floor in to the wood that was still remotely good. So I used bottle jacks and sliced 4x4 fence posts with foot-long 2x4's nailed to the top (for a T shape) to punch the floor out crossmember by crossmember, from the front cut to the back cut. Then I used the jacks to raise the floor against the wall and knocked off the nailed-in bad wood, knocked off the insulation, and ground off the nails.

Then came the new kenlite, which was shower-stall material from Home Depot. MAYBE it is too weak or not fiberglassy enough, but I didn't want to go shopping at Utility 100 miles away. Then came the wood sills: They were exactly 2 inches, so I had a lumber yard get me 23 2x4s sliced to 2" tall. I load-locked every one against the top of a crossmember, went below and screwed them in, went back up and load-locked the next sill and repeated the process. Then came the insulation. I read that the factory supplied R-12 and I could only get my hands on R-10, 2 inches thick, so I used it, slicing it with a drywall square and wedging it between the new wood sills.

Finally, I released the load locks from the floor, which had been pinned against the wall, and it slammed down. With crowbars I aligned it. But it was curled up like a horseshoe due to the forklift and load stress. No matter: I used load locks to jam the floor down on top of the new wood sills and used deck screws to attach the floor (and flatten the floor) to the sills & crossmembers. Then I had an aluminum welder weld the entire 19-foot cut, plus patch the hole damage.

Haven't hauled a load in it yet, but the floor sure is solid!


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I know this is an old post, but I just wanted to say I admire you taking on this project. If that is pine 2x4s you used, that is misfortunate. That stuff will certainly crush from the weight. How did the repair hold up?

 

The OP hasn't posted since 12/16.

 

do you still have this trailer ? how well did the repair hold up? did the box still hold temp and cool well with the different insulation in the floor? ask since itlook like the old stuff filled all the foids in the grooved floor. thanks thinking about doing this to a old great dane 48 ft spread axle we have sitting around not currently being used with a soft floor

 

Well, we sure wouldn't use lumber from LiweLo for the repair. Get the correct material

 

The floor repair held up but I would not do it the same as I initially did it. After about six months, I went back and drilled holes through the floor and into the crossmember I beams. That enabled me to run grade 8 bolts all the way across the cross members for every bit of flooring that I had taken up. It was a humongous chore and not fun. Somebody else had to be underneath to hold the nut while I tightened down the bolt head. I really think that using the screws I initially used to hold the floor down might have created some shearing which broke one of the suspension's air-bag saddles loose from the axle. In any case, the repair went fine, the insulation worked decently, and the only thing I would do differently is tack that floor down with grade 8 bolts to keep it super secure. When you lift that floor up away from the apitong sills or whatever sills (composite, whatever), you are compromising the structural Integrity of the whole box. ... I used a bit from Home Depot that was about a foot long. It was a DeWalt bit. Let me drill through the floor and through the edge of the crossmember.