Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 


Reply
 
Thread Tools Display Modes
 
Old 11-26-2019, 07:24 PM   #1
Senior Member
 
Drizzt's Avatar
 
Join Date: Sep 2014
Posts: 140
Garage
Hightop Buildout Questions

Background: I have a Fiberine 24" Transit style top, E350 EB. Top has the 1/2" OSB reinforcement on the ceiling and two strips of wood down each side. They told me they don't recommend any more than 300 pounds on the roof. My plan is for solar panels at the front and a rack platform at the rear for sitting, photography, stargazing, etc. One window on the drivers side, two on the passenger side. Which leads me to my questions:

How have people been attaching roof racks to a fiberglass roof? I have no experience with fiberglass, so can you just attach it directly through the glass with some bolts and a backing plate? That was my thought anyway; fabricating some brackets to hold 8020 bars, and drilling through the glass with two bolts each, and a backing plate on the inside.

I've seen plenty of pictures of people standing on their fixed high tops. I've also seen some pictures where the inside has been reinforced with a metal "roll cage" for the lack of a better term. Is this needed or is the glass actually strong enough to hold two people and not crack and/or have the mounting bolts begin to sheer the fibers?

One last question, I've seen tops with four windows, two per side, but I've never seen one with a window in the back. Is it not feasible? I'd like to have the three side windows as already mentions and one on the back. This also has me looking at fabricating some internal support structure, but don't know if it's really needed?

__________________
David
2003 E350 | 7.3PSD | U-Joint 6" - The Slow Build
Drizzt is offline   Reply With Quote
Old 11-26-2019, 08:55 PM   #2
JWA
Senior Member
 
Join Date: Jan 2011
Location: Reynoldsburg, Ohio
Posts: 3,765
Send a message via Yahoo to JWA
Raised fiberglass roofs aren't meant to be structural in and of themselves---the roll cages you mention are DOT required and necessary when/if the C-pillar is removed to accommodate taller rear doors. If that part is intact the roll cage is still a good idea but not required.

The problem is when so much of the upper factory lateral bracing is removed the distance between the B & C pillars is too great and side walls are considerably weakened. In the event of a side collision or roll over the fiberglass is an egg shell and exceptionally flimsy offering no support against those forces.

As for mounting things up there attaching them to the fiberglass isn't a huge issue but they do require some support other than the shell of the top. Without seeing the wood pieces you have its tough to say how much weight they can safely support.

Here's my own 2005 former wheel chair lift people mover with the tall rear doors, showing the roll cage DOT required for such a conversion. This type of structure would support a lot of weight but would require some additional support between the cage and actual fiberglass to tie it all together and hold solar panels etc against wind when driving. Have a look: https://imgur.com/a/kbyVF?grid

Feel free to ask any further questions.
JWA is online now   Reply With Quote
Old 11-26-2019, 09:47 PM   #3
Senior Member
 
dhally's Avatar
 
Join Date: Sep 2009
Location: SE Washington
Posts: 1,023
Garage
We had a long window in a past high top. It always rattled and leaked air. I would minimuze those windows. We store a lot of stuff in the rear and couldn't look out anyhow.
__________________
---------------------
2009 E250 RB 5.4L "SilVan"
dhally is offline   Reply With Quote
Old 11-26-2019, 10:34 PM   #4
Senior Member
 
Marcel Huijser's Avatar
 
Join Date: Nov 2016
Location: Montana
Posts: 313
We put a full size roof rack on the fiberglass top. We reinforced the fiberglass top on the inside with wood (perhaps 1.5-2 inch thick, maybe 6 inches wide, can't remember) that rests on the edge of the metal roof (which is now largely removed) and extends to the top of the side of the fiberglass roof. The wood is glued to the fiberglass. The bolts for the roof rack go through the fiberglass and the wood.
Marcel Huijser is offline   Reply With Quote
Old 11-27-2019, 06:16 AM   #5
Senior Member
 
Drizzt's Avatar
 
Join Date: Sep 2014
Posts: 140
Garage
Inside view in this post: http://www.sportsmobileforum.com/for...tml#post259848

@JWA I still have the factory doors, and I never could find any hard data that stated if I was required to build a roll cage to make up for the roof supports that were cut out. The local van converted said no, and that's as close as I got to a definitive answer. I dig the cage in your pictures, wish I still had access to a welder.

@dhally You are the first person I've heard talk about troubles with windows in the top. Do you know why it was rattling and leaking?
__________________
David
2003 E350 | 7.3PSD | U-Joint 6" - The Slow Build
Drizzt is offline   Reply With Quote
Old 11-27-2019, 10:19 AM   #6
Senior Member
 
campism's Avatar
 
Join Date: Oct 2018
Location: Richmond VA
Posts: 317
I have a 30" FGME highroof on a Dodge ex-wheelchair van. First photo shows the interior of mine and second is a found photo showing a similar roof with the liner removed and the conversion framework visible, giving me an idea if what I'll run into. I'd expect a highroof without internal framework would require an external frame if you expect to put any substantial weight on top.
Attached Thumbnails
Debbie3.JPG   FGME innards at vanlifemagazine.com.JPG  
__________________
The gone-but-not-forgotten project.
campism is offline   Reply With Quote
Old 11-27-2019, 10:45 AM   #7
Senior Member
 
Drizzt's Avatar
 
Join Date: Sep 2014
Posts: 140
Garage
Quote:
Originally Posted by campism View Post
I have a 30" FGME highroof on a Dodge ex-wheelchair van. First photo shows the interior of mine and second is a found photo showing a similar roof with the liner removed and the conversion framework visible, giving me an idea if what I'll run into. I'd expect a highroof without internal framework would require an external frame if you expect to put any substantial weight on top.
Confused on what you're saying. Your top looks like it has gelcoat on the inside and no framework. The second photo looks like raw fiberglass on the inside with an additional frame built after the fact. Are you saying you're planning on building one like that?
__________________
David
2003 E350 | 7.3PSD | U-Joint 6" - The Slow Build
Drizzt is offline   Reply With Quote
Old 11-27-2019, 11:13 AM   #8
Senior Member
 
campism's Avatar
 
Join Date: Oct 2018
Location: Richmond VA
Posts: 317
Okay, construction of the two tops in the two photos is the same; outer skin over a metal framework with an inner liner, except that in the second photo the inner liner has already been removed showing the metal framework and the inside of the outer shell above it, the raw fiberglass you mentioned.


Once a van's original roof was removed by the converter, the framework was built and then the outer and inner shells were installed. My van has the taller rear doors with modified C-pillars so needs the frame, per @JWA, and the other van has taller side doors that involved cutting into the side doors' header rail, also necessitating the frame.


I will need to drill out the rivets and remove screws holding the inner liner to the framework in order to remove my liner and then a view of my roof's interior will resemble the other one, but doing so will then enable me to insulate and run wiring, and then I can either reinstall the white liner or use different material or none.
__________________
The gone-but-not-forgotten project.
campism is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 08:04 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.