Box truck window installation - cutting ribs?

[KevinLee]

I went down to my local building material salvage store and found a couple of RV windows in good shape and picked up the pair of them for $25. Seems like a score, but I started having second thoughts when I realized that the windows are 26" and 32" long, but the ribs in my truck are 24" on center. Has anyone done an installation like this that involved cutting a section out of the ribs? The ones in my van are nice aluminum I-beams and I'm a little hesitant. Way back in the seventies I did van conversions and we routinely cut the ribs in regular vans, and they don't have nearly as many spaced farther apart, so I'm leaning towards thinking it would be OK, I'd just like a little reassurance from someone who's done it before.

 

[highdesertranger]

ha, I did van conversions too back in the day. 99% of the time it's fine to cut a rib out. if you have any doubt reinforce the rib you cut. in other words just cut the minimum and run a horizontal brace above and below the window connecting the rib you cut to the rib in front of and behind it. highdesertranger

 

[KevinLee]

Thanks for the vote of confidence. It's been a long time since I did anything like this, and being a completely unmolested aluminum box, I'm worried about screwing it up. I'll have to get used to it though, because besides the windows I'm going to need roof vents, side vents, antenna holes, shore hookup doors, etc.

 

[MrNoodly]

I would guess the windows are stronger than the box walls. But, yeah, like HDR wrote, run horizontal braces just like you were putting a window in a building.

 

[LoupGarou]

Just add new metal framing to support the window frames. Keep in mind the window frame thickness. They may be thinner than what your finished walls will be.

You can only cut the holes for the windows once, so make sure the placement is where you want them. This goes for height as well. If your plans include cabinets, mount the windows low. If not, mount them higher up on the wall.

 

[Gr8ful]

I do the same trun an alum header above & below where the cut will be & weld it to the ribs on bothsides, As for height if you have plenty the top of window openings are 84" from the floor just like a house.