Preparation to set semi trailer on ground?

[Garwood]

I just purchased a 48' refer trailer to use for storage. The axles have already been removed. The underside is completely flat, everything has been cut away sans the 5th wheel pin. It is aluminum exterior, steel crossmembers under the floor, aluminum plank floor, stainless steel walls and polyiso foam in the walls and floor and roof. There's nothing really to rot except for the wood roll up door.

Tomorrow, a friend with a crane is going to move this trailer for me.

If I set the floor beams flat on gravel with no air gap underneath will I have moisture problems? Critter problems? This is a wet climate in the NW.

This is about the same scenario as dropping a shipping container. Just no wood floor.

 

[Scottl]

Basically make sure the gravel under the container is flat and then grade the rest to slope away slightly so water runs away from the trailer. Also might not hurt to put double or triple strips of felt paper(stagger the end gaps) under the beams.

 

[henrya]

I would put it on something slightly elevated above the ground. New crossties, ground contact rated timbers, solid concrete beams might all work. I am pretty sure that I could fight the occasional critter better than a sealed up rust and rot box it’ll never dry

 

[boslab]

Sand grade pvc gravel, set on old rail ties, last forever
Mark

 

[Larry Dickman]

+1 on the RR ties

 

[DrHook]

Blocks or ties- critters dig, moisture collects where the wind can't go.

 

[Garwood]

I just went and took another good look at the bottom and it's not flat- The middle 15' has taller crossmembers so it won't sit flat on the ground regardless.

You guys have talked me out of setting it flat on the ground. I thought that would be nice for getting in and out of it, but it will probably create other problems.

At this point I'm thinking I will set it on four 6'x2'x2' concrete eco blocks. I shouldn't have more than 40K total weight trailer and contents which will keep ground pressure around 800 PSF with four blocks. I'll set the blocks so they are a foot above the gravel which will put the back tail light section even with the gravel. Then I can use that space under the trailer to store a bunch of steel siding that I was trying to figure out how to store inside the trailer.

Thanks for the guidance!

 

[michiganbuck]

Guess I would examine the grade to be sure an odd flood would not get the floor wet...and perhaps the gravel to add 2" height.
But the underside will be subject to darkness and still air so likely to mold.

 

[dalmatiangirl61]

Set it up on RR ties, you need some airflow underneath it.

 

[Drroaster]

In Cali if you set on ground it’s considered a building and then taxed if on wheels it’s a trailer. Idk about Oregon

 

[Garwood]

Why was this moved to rigging? This has ZERO to do with rigging or material handling.

 

[michiganbuck]

Could keep the axle on to avoid tax, and make it just high enough to park a lawn tractor under it.

 

[Garwood]

Could keep the axle on to avoid tax, and make it just high enough to park a lawn tractor under it.

There aren't any axles under it. Clearly laid out in the first post. I don't want it up in the air 3 feet and I could care less about a tax increase. My property is zoned Heavy agricultural in an unincorporated rural area. I maintain an agricultural tax deferral for the farming activities I do here. There's over 12K sq ft of roof on my land and property taxes are about $2k annually. 384 sq ft of trailer is not going to matter in the least to the tax assessor.

 

[Mud]

I'm a fan of asphalt millings under something like that. It packs solid, water doesn't go through it, weeds don't grow through it, it's cheaper than stone. You can build an entry ramp with it to drive a forklift into the trailer.

 

[tdmidget]

Reefer trailer with a roll up door?

 

[Steve in SoCal]

I would try to spray the X-members where they are steel to aluminum to minimize moisture/galvanic activity. Many a trailer has failed from X-member rot. Keeping good air flow under the frame will help a great deal.

Around here 'crusher' is the material I would use to sit the trailer on. It may be too late the thing may be in place?

If the nose mount is off make sure the filler is water tight. I would water test the whole trailer myself.

 

[gustafson]

5 yards of stone/stone dust mix will make a virtually imperceptible ramp up to a 1 foot height

 

[Garwood]

Reefer trailer with a roll up door?

Looks like it originally it had a swing doors, but at some point the hinges were nipped off and the rollup was stuck in there. I'm happy it has the rollup for my use.

 

[john.k]

In general,loading needs to be supported on the chassis rails of the trailer.......the crossmembers are not strong enough to support more than a couple of tons..............I use concrete piling offcuts to support containers and trailer chassis .....because they are free.........however ,you need to be able to handle the weight (around 1 ton) ,a forklift will do.

 

[Garwood]

In general,loading needs to be supported on the chassis rails of the trailer.......the crossmembers are not strong enough to support more than a couple of tons..............I use concrete piling offcuts to support containers and trailer chassis .....because they are free.........however ,you need to be able to handle the weight (around 1 ton) ,a forklift will do.

There are no chassis rails under a trailer like this. The walls form the structure.

I set the trailer on two 2x2x6 ecoblocks at the rear and one at the front just aft of the kingpin.