Van hightop install - structural stability on '02 Chevy Express

[liandri]

Hi all,

I wasn't sure where to post this, but since it's somewhat technical and relating to the mechanics of the car, it seems to fit.

So we've already had the 24" Fiberine high top installed on our extended 2002 Chevy Express 3500.

My co-builder really wants to cut out the space over the driver and passenger seats. The high-top installer in San Jose, CA declined cutting out that much of the roof. They say they used to, and we are welcome to do it ourselves, but "the walls can get wobbly," such that over time the doors may have trouble latching correctly.

I'm looking to establish the legitimacy of this claim, as my co-builder insists on cutting out every possible inch of the roof on the inside for maximum standing room.

I do think our van may be different from most cases the installer had in mind: our bed is lofted 30" from the floor. There are 6 2x4 cross-beams, bolted into the ribs of the van, for the entire back 80" of the van body. My thought is this could differentiate us from other cases, making it safe to remove the final section of the roof above the front seats.

Thoughts?

 

[SternWake]

My Dodge conversion van originally left the ~ 30 inches of roof in the back and everything else was removed upto 8 inches from windshield, and when slamming the side doors one could see the body bend inward. I had an oak curtain rod behind front seats, and pulling downward on this rod would pull the van walls inward, visibly.

I used the back portion as a shelf, but this proved not strong enough for the wieght I put up there( just clothes tightly folded and packed in underbed plastic storage boxes). Later on, I built a new shelf, front and rear, with the intentions of not only having a strong shelf front and rear, but to increase strength and rigidity. The first side door closing after the front shelf, 3/4 plywood was properly attached, was night and day difference.

I can't really say if the later model chevy is strong enough for more structure removing, but in the worst case scenario, a rollover, one would certainly want all the roof integrity possible as the fiberglass top will pop off like wet toilet paper.

Removing metal structure in along the roof can be equated to removing part of the foundation of a house for a bigger basement.

 

[mayble]

How often do you envision standing between the front seats?  
Personally, I'd go for structural integrity and possibly storage space over an extra square foot of standing space.  In the event of a major collision or roll over it could make a tremendous difference in keeping the cockpit area from crumpling. 
A little peace of mind, if nothing else.

 

[liandri]

Indeed. My argument has been to always keep it as a car first.

Without captain's chairs, I think the extra standing space would be convenient for getting up to run to the back. but I think if we can find the captains chairs we want that maneuvering fore and aft will be much easier.

Thanks for the real-world experience, that's the info I was hoping for.

 

[Almost There]

The area over the drivers compartment is a definite keep!!

It provides much needed protection in case of roll over. This is in addition to the reasons given to you by the fiberglass roof installation firm about rigidity for door alignment.

The roof should be kept back to the first rib rear of the driving compartment. I have never seen a van where that area was removed!!

I installed a bumper pad made of pool noodle covered in fabric over the raw edge to protect my head when moving from the rear of the van to the drivers' seat.

When my passenger seat is turned around facing the rear there is no problem in sitting down on it, I've not yet bumped my head in doing so.

The van I bought already had the fiberglass roof in place. The installers, in addition to the front area, left about 36" of the rear van roof in place. I had not seen that done before. My previous high top had the van roof removed  all the way back. I can't begin to tell you how much I appreciate all the extra storage that this area has given me. As a full time van dweller, I store my backpacking equipment up there, my off season clothing, a tote with 'go out to dinner' clothing as well as way more clothes than I should be carrying. It all fits.

It sounds like it's a little too late to save the rear part of the van roof but definitely do NOT cut out the front section.

 

[liandri]

Almost There, yea our bed platform is pretty high up for storage underneath instead of overhead. Basically our strategy was to have just enough space above the bed to sit up straight. With that plan, we wouldn't be able to fit in the bed if we left anything in the rear. I figure if we wanted a little more rear storage (or anywhere else), we can bolt it in ourselves exactly where we want it. But I'm sure to a degree that the inherent metal supports in the van are the strongest, lightest, and most compact.

We still have exposed metal edges at the moment and are also living in it. More interior work will be done this weekend to clean things up. The edge is pretty rough and jagged, it's as if the installer just hacked at it with one of those pocket knife can openers.

Once we get the captains seats, I think we'll be much happier with the roof as it is now.

 

[Mobilesport]

I don't see how you could lose much structual intregity cutting away the sheet metal down close to the esdges ( edges meaning  like 6 inches left ) 
It aint like you cut away any of the thick tubing that runs around the top edge .
That being said I don't think it would be a good idea to remove that sheet metal above the cab in case the event of a roll over because it would weaken it slightly but more importantly if you go upside down and lose your fiberglass hightop there's nothing to keep your head or face from skidding on the concrete or grass.

 

[highdesertranger]

the usual SOP is to leave the front sheet metal and the first rib. the rib that's right to the rear of the drivers head. it is also advisable to do this in the rear for the same reason, structural integrity. when I used to do van conversion this is the way we did it. we would then enclose that area and put doors on the enclosure to keep stuff in place in case of an accident to keep your stuff from getting airborne. highdesertranger

 

[BlueWeezle]

If you really want to cut everything out, you might be able to if you weld in some 1x1 steel tubes following the shape of the hightop to replace the support that you lose by cutting the roof.

If you look a this video you can see a factory hitop with this type of structure under it. (he is removing it in this video)

[video=youtube]

 

[DannyB1954]

You could possibly fabricate a roll bar to go across the top giving you more head room. My opinion is you need something tying the sides together besides the high top. In the above video that was not a stock roof member he was cutting out. Someone made that structure to reinforce the body.