Best way to raise up slide-in camper?

[JRPR]

We need to raise up our camper so that the cabover doesn't hit the roof of the cab when we go over a bump. This is especially important because the truck has a skylight. We were told we could place either 2X8s or a piece of rigid foam in the bed of the truck under the camper. We'd like advice on this. What's the optimum spacing between the cabover and the roof of the cab? (It's currently only about an inch.) And what's the best method for raising it up? If it's the foam, what type of foam and where can we get it? (We looked at Home Depot and they only had 1" (15 psi) and 2" (25 psi).) There are currently 2x4s attached underneath the camper that tilt it backwards to raise the front up.

 

[Buddha.]

I would think foam would be better, not sure what kind.

 

[WOODY2]

I wouldn't rely on foam as it will compress as time passes. Use rubber horse mats or 2x pressure treated lumber.

 

[Porkchopexpress]

I wouldn't rely on foam as it will compress as time passes. Use rubber horse mats or 2x pressure treated lumber.

The advice above is pretty standard across forums and manufacturer recommendations. Considering you have a 1st generation Tundra, I'm guessing you are already overweight so I would look for light weight solutions. I would use foam and maybe add more if it compresses. Maybe look at home depot and lowes and use your best judgment.

 

[JRPR]

The advice above is pretty standard across forums and manufacturer recommendations. Considering you have a 1st generation Tundra, I'm guessing you are already overweight so I would look for light weight solutions. I would use foam and maybe add more if it compresses. Maybe look at home depot and lowes and use your best judgment.

Thanks for your input. I'm not sure which advice you're refering to that is standard. That we should use foam? Or that we shouldn't because it will compress, as the person you quoted suggested?

 

[john61ct]

Most foam has pretty good compressive strength (psi) and can be stacked.

Putting even a thin plywood sheet over the foam will help spread the load, preventing significant compression and puncture loads where weight is concentrated.

 

[Mundo4x4Casa]

Figure how much more height you need. This is kind of tricky as different truck frames exhibit different flexibility. If you have a 3/4 to 1-1/2 inch foam backpacking pad (or whatever, a Yoga mat), slide it into the slot between the cab top and the bottom of the cabover part of your camper to protect your moonroof. With the camper on, have someone else drive it around on undulating dirt roads, over slow dips, getting your axles twisted up with you following to see how much rocking and rolling you get from your setup.

I have no idea how much you get from your Tundra. With as low a payload rating as they have, I'd be surprised if it didn't have movement.

Older Ford frames were notorious for flex. With a lot of negative input from the truck camper community, Ford stiffened their frame by completely boxing them and adding more cross member strength. My new F-350 came with the 5-er prep package (28K pound GCVWR) which by default further strengthens the frame under the bed with more cross members. I have virtually no frame flex with the Northstar aboard and no eyes on ever using a 5-er.
Back about 30 years to the present, because of Fords taller cab in relation to the bed, they have needed more riser height for the camper, any camper to clear the cab.

Do you have a bed mat? A thin one works best with a TC. Less squirm.

So, say you need 2 more inches of altitude to keep your camper from whacking your moonroof.
1. Inquire from a Truck Camper Sales and Service establishment as to what number they use with your specific year truck and specific camper. If they won't tell you, estimate how much more you need and add an inch. It's better to be too high than banging on your cab.

If you have open framing underneath the camper:
1. Drywall screw together a 2x frame with cross members that matches the under framing strength points of your camper. That would be 1-1/2" inches laying flat or 3-3/8 inches on end. Lay this over the 1st, thin (3/8ths inch) bed mat.
You could rip some 2x4's to get in between height, but making a riser sandwich is preferred.
If 1-1/2 inches is a little short, screw a 3/8's to 1/2" weather resistant plywood panel to the framing to increase the height.
Then lay a 2nd rubber bed mat on top of it to keep things from moving around.
Then, apply Camper Guides, screwed to the bed at each side corner of the camper. Will protect the camper from sliding around on god-awful roads, which I'm assuming you be plying. Leave about an inch on each side for ease of loading.

2. If your camper has a smooth closed fibreglass bottom, you might consider the 2 inch, 25 pounds per square inch non-compressability foam with a 3/8 inch plywood top and the single rubber bed mat on top of that.
I've done a complete writeup for this on Truck Camper Adventure online magazine.
This is my state of affairs with the riser: 4 inch foam with 2x4 under the framing on he camper. Another 4 inches of foam glued into the camper framing giving the floor an R-40 insulation value.

Your dilemma is all fixable with experimentation to find the just-right sandwich result.
jefe

 

[Porkchopexpress]

Thanks for your input. I'm not sure which advice you're refering to that is standard. That we should use foam? Or that we shouldn't because it will compress, as the person you quoted suggested?

My advice is probably worth what you paid for it but I would go with foam to save weight. Manufacturers, (at least northern lite) recommend plywood but I have heard people using horse mats too. I just think that in your situation, they are too heavy so I would go with foam.

 

[JRPR]

Figure how much more height you need. This is kind of tricky as different truck frames exhibit different flexibility. If you have a 3/4 to 1-1/2 inch foam backpacking pad (or whatever, a Yoga mat), slide it into the slot between the cab top and the bottom of the cabover part of your camper to protect your moonroof. With the camper on, have someone else drive it around on undulating dirt roads, over slow dips, getting your axles twisted up with you following to see how much rocking and rolling you get from your setup.

I have no idea how much you get from your Tundra. With as low a payload rating as they have, I'd be surprised if it didn't have movement.

Older Ford frames were notorious for flex. With a lot of negative input from the truck camper community, Ford stiffened their frame by completely boxing them and adding more cross member strength. My new F-350 came with the 5-er prep package (28K pound GCVWR) which by default further strengthens the frame under the bed with more cross members. I have virtually no frame flex with the Northstar aboard and no eyes on ever using a 5-er.
Back about 30 years to the present, because of Fords taller cab in relation to the bed, they have needed more riser height for the camper, any camper to clear the cab.

Do you have a bed mat? A thin one works best with a TC. Less squirm.

So, say you need 2 more inches of altitude to keep your camper from whacking your moonroof.
1. Inquire from a Truck Camper Sales and Service establishment as to what number they use with your specific year truck and specific camper. If they won't tell you, estimate how much more you need and add an inch. It's better to be too high than banging on your cab.

If you have open framing underneath the camper:
1. Drywall screw together a 2x frame with cross members that matches the under framing strength points of your camper. That would be 1-1/2" inches laying flat or 3-3/8 inches on end. Lay this over the 1st, thin (3/8ths inch) bed mat.
You could rip some 2x4's to get in between height, but making a riser sandwich is preferred.
If 1-1/2 inches is a little short, screw a 3/8's to 1/2" weather resistant plywood panel to the framing to increase the height.
Then lay a 2nd rubber bed mat on top of it to keep things from moving around.
Then, apply Camper Guides, screwed to the bed at each side corner of the camper. Will protect the camper from sliding around on god-awful roads, which I'm assuming you be plying. Leave about an inch on each side for ease of loading.
View attachment 681644
2. If your camper has a smooth closed fibreglass bottom, you might consider the 2 inch, 25 pounds per square inch non-compressability foam with a 3/8 inch plywood top and the single rubber bed mat on top of that.
I've done a complete writeup for this on Truck Camper Adventure online magazine.
This is my state of affairs with the riser: 4 inch foam with 2x4 under the framing on he camper. Another 4 inches of foam glued into the camper framing giving the floor an R-40 insulation value.
View attachment 681646View attachment 681645
Your dilemma is all fixable with experimentation to find the just-right sandwich result.
jefe

Wow! Thanks for all the great advice! Would you send me a link to your article? I searched it but couldn't find it.

 

[JRPR]

My advice is probably worth what you paid for it but I would go with foam to save weight. Manufacturers, (at least northern lite) recommend plywood but I have heard people using horse mats too. I just think that in your situation, they are too heavy so I would go with foam.

Thanks for the clarification and the advice!

 

[Mundo4x4Casa]

jrpr, jefe4x4 is my internet name.

Out With the Old Truck and Camper, in With the New | Truck Camper Adventure

Out With the Old Truck and Camper in With the New, RV, Recreational Vehicles, Ford F350, Tremor, Dodge, 2500, Cummins Northstar Laredo SC,

www.truckcamperadventure.com

is one of several articles about fitting truck campers to trucks.
For other pieces, search for jefe4x4
jefe
Here is our former truck with our current camper: no riser needed.

 

[billiebob]

With the overhang over the cab vs the lack of camper length, I'd think the issue is either the rear tie down or frame flex.

The camper should be rigid enough to not flex.
Either the pruck frame is flexing or the rear mounts are not holding the rear of the camper tight/secure to the box.
But the leverage is massive. In the 1970s camper overhangs were often stabilized with shock mounts from the front overhang to the a-pillar/base of the windshield. I'm not sure any amount of lift will help. You need to secure the rear of the camper better. ps if the rear mount is allowing enough movement to hit the cab roof..... there are likely worse structural issues developing at the rear camper mounts.

 

[billiebob]

Foam for under foundation slabs comes in different compressive strengths. High 40 vs High 60 vs,,,, but most'all of the loading in your situation is at the front of the box. The excessive bunk overhang concentrates the flexing loads under way. I would use lumber at the front of the box. And double the rear tie downs.

ps, it looks like that camper is designed for a longer pickup box. Did you buy it used? No ethical dealer should have sold that camper for your truck.

Call the manufacturer.... Sierra? for advice..... and very nice looking rig.

When lifting the camper it is all about point loads which need to be concentrated on the bed to frame mounts. Look at how/where a fifth wheel mounts. Nothing is bolted to the box. Everything needs a foundation.

More than the weight is the leverage.

 

[JRPR]

jrpr, jefe4x4 is my internet name.

Out With the Old Truck and Camper, in With the New | Truck Camper Adventure

Out With the Old Truck and Camper in With the New, RV, Recreational Vehicles, Ford F350, Tremor, Dodge, 2500, Cummins Northstar Laredo SC,

www.truckcamperadventure.com

is one of several articles about fitting truck campers to trucks.
For other pieces, search for jefe4x4
jefe
Here is our former truck with our current camper: no riser needed.

Thanks! I'll check it out

 

[JRPR]

With the overhang over the cab vs the lack of camper length, I'd think the issue is either the rear tie down or frame flex.

The camper should be rigid enough to not flex.
Either the pruck frame is flexing or the rear mounts are not holding the rear of the camper tight/secure to the box.
But the leverage is massive. In the 1970s camper overhangs were often stabilized with shock mounts from the front overhang to the a-pillar/base of the windshield. I'm not sure any amount of lift will help. You need to secure the rear of the camper better. ps if the rear mount is allowing enough movement to hit the cab roof..... there are likely worse structural issues developing at the rear camper mounts.

Thanks. I just found out about the shock mounts yesterday from a guy at one of the local RV service centers. Lance still makes them and they fit my truck so I'm going to have them installed. I think that will take care of the problem.