My hummer's nuts are still secure. The main thing is not securing the load to the rails. I use 2 ratchet tie downs through the back seat doors opening, spread as far apart possible in the opening. Once took 8 sheets of plywood (approx. 500lbs) down the highway on a windy day and the load did not move.

 

Yeah the tracks that the roof rails sit on wont take a very heavy load esp if you factor in wind resistance (highway driving). Load rating (lb) is one thing but it doesnt take into account how that load gets acted on by the wind driving down the road at 60+ mph

 

Thanks for all the responses. I called the manufacturer of the rooftop tent and they said that I would have to have aftermarket rails done. That the weight of the tent plus the occupants would be too much for it. They said it could damage your roof. So we are going to just look into a travel trailer.

 

Not hold the weight? What did you miss? Btw, why would anyone go camping and install a tent on the roof? Pitch a tent on the ground or get yourself a camper! It must be a cjeep thing:

 

God help you if you had to get up in the middle of the night to go to the bathroom. I agree, pitch a tent on the ground, less complications. Carry the tent on the roof in a cargo carrier.

 

TRUE! the riv nut will pull right through, cracking the thin metal beneath it.

This is Nugget (long time H3 owner and avid over-lander from down under) who had 120KG (about 265lbs) on his roof every day.
He ripped the RivNuts through the metal.
Once he had sandwiched the thin roof metal with a plates above and below to distribute the load through out the entire roof rail per side he had no issues.
He also used multiple mounting points on the roof rail to distribute the weight. 2 Roof racks ain't gunna do it, OEM or not.

 

I had to remove the pics due to user error. I can guarantee that my 2 H3 OEM rails will haul 453+KG(about 1,000lbs+) with no problem as long as you secure the load properly!

 

Yeah, you keep thinking that. You are going to add 1000lbs+ to the roof, of an H3, on top of 2 OEM roof rails, and have no problems? I don't care how you secure it... Let's see it!
I want to see the tip over photos too when your center of gravity catches up with ya on the first turn...

 

As I stated above, the heaviest load so far on my 2 rails was approx. 700lbs, however that doesn't take into account of the added force weight when I lock down the load with 2 ratchet tie straps. Right,"I always drive it like I stole it" on my way home from the home improvement center, with a heavy load on top. I will be sure to take&share a pic when I have my next load.

 

700lbs on the roof?!?! I believe no matter ho you stack it up there, you will have an unsafe load. The roof of the H3 was not designed to take on that type of load. But I guess as long as I'm not driving anywhere near you, go for it. Personally I would find a safer solution, like a pick up truck or van.