Vent fan install - leak & structural question

pesmith

SmithSprinter
I have a 2013 2500 170 WB. I recently had a vent fan professionally installed. After driving in my first rain storm i noticed a significant water leak dripping from the front of the fan. Upon removing the ceiling board I noticed one of the roof support beams was cut and removed for the vent fan install. (Picture attached below) I was surprised to see a structural frame member cut and removed. Using my laser level it appears the roof sags about a quarter inch in that area relative to the adjacent roof beams. There is also more vibrational movement in this area now while driving at highway speeds. I suspect this location was selected to allow a flat area to mount the fan by avoiding the longinitudal roof grooves. However on my van there are two locations (slightly forward and close to front) that allow for a flat mounting area while not having to remove a roof frame. Any comments whether it is acceptable practice and/or typical to remove a roof frame beam to install a vent fan?
 

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GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
........professionally installed...........
Cutting structural beams? ouch. Was the installation done in a Jiffy Lube? I suggest to search this site for fan installations, there are many examples but I have not seen anyone touching structural beams. There are many other places on the roof to install a fan.

Properly installed fans don't leak, in your case there could be too much flexing and seals are giving up.

To remedy you could built an engineered steel frame around the installed fan and weld/bolt it to the remaining beam elements to bring the sagged roof to its original curvature, or relocate the fan and fix the roof with its beam.


George.
 
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220629

Well-known member
Cutting structural beams? ouch. Was the installation done in a Jiffy Lube? I suggest to search this site for fan installations, there are many examples but I have not seen anyone touching structural beams. There are many other places on the roof to install a fan.
Man. I do some non-professional things DIY somtimes, but this is over the top.

Properly installed fans don't leak, in your case there could be too much flexing and seals are giving up.

To remedy you could built an engineered steel frame around the installed fan and weld/bolt it to the remaining beam elements to bring the sagged roof to its original curvature, or relocate the fan and fix the roof with its beam.


George.
With todays sealants I agree that leaks shouldn't be a problem. I also agree that flexing will continue to be a problem.

I disagree that it can be boxed for proper support unless you are willing to loose cargo area height and add support underneath. That beam has a specific arch which supports from the sides. Now that it is no longer a complete assembly I doubt the original support could be brought back.

Mean-in-Green Simon commented recently in another thread that the arched supports are very flimsy and are bonded to the roof material. In these days of lighter for economy that is common.

Maybe another OEM piece next to it would bring the support back. :idunno:

I don't think I'd trust the original "professionals" to properly repair it for me.

Good luck. vic
 

OrioN

2008 2500 170" EXT
As per the Body Builder Book:

"If there is an opening in the 'cab' rear panel, a sectional frame must be fitted in the opening. The remaining braces and pillars must be reinforced by the additional gussets and connected to the sectional frame (e.g. by bonding)."

At a minimum you will need to do the following:

Cut the remaining cross-member back to accommodate angle-bar supports (aluminum will suffice) that will attach to the adjacent cross-members. "Bonding" the angle-bars to the cross-members can be done with brackets and rivets/riv-nuts.

The goal is to add back the support need for the roof panel & the fixture, and nothing more is required, as the cross-member is not an integral part of the 'unibody'.


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GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
..........
I disagree that it can be boxed for proper support unless you are willing to loose cargo area height and add support underneath. .........
I agree, to bring the strenght back and still be reasonably light this box would certainly protrude below the ceiling height.

George.
 

220629

Well-known member
As per the Body Builder Book:

"If there is an opening in the 'cab' rear panel, a sectional frame must be fitted in the opening. The remaining braces and pillars must be reinforced by the additional gussets and connected to the sectional frame (e.g. by bonding)."

At a minimum you will need to do the following:

Cut the remaining cross-member back to accommodate angle-bar supports (aluminum will suffice) that will attach to the adjacent cross-members. "Bonding" the angle-bars to the cross-members can be done with brackets and rivets/riv-nuts.

The goal is to add back the support need for the roof panel & the fixture, and nothing more is required, as the cross-member is not an integral part of the 'unibody'.


.
:hmmm:

I haven't seen the document, but it appears to me that the text is referring to removing roof "skin" not structural support members.

I'm not suggesting that the added angle or channel you suggest is a bad idea. I just find it hard to believe that the normally very conservative Mother Mercedes would suggest removing a cross roof beam for any reason.

That said, I haven't seen the document.

I agree, to bring the strenght back and still be reasonably light this box would certainly protrude below the ceiling height.

George.
I apologize. The boxed section caused me to think of a similar depth structural member. Sorry for any confusion.

:cheers: vic
 

TomLetsinger

2006 158" DIY toy hauler
Seriously, tell us who did that! At the very least you should make it so no one else on here falls victim to this "professional". Realistically, you should seek compensation for them ruining your roof and what it will cost you to fix it.
 

OrioN

2008 2500 170" EXT
:

That said, I haven't seen the document.
The book is posted here...somewhere.

It's available on the MB Up-fitters Portal.

The whole roof panel & cross members can be removed.
THINK Mega Roof - with it's translucent & non-loadbearing composite top - that's 'glued' to the metal side panes.
 

OrioN

2008 2500 170" EXT
Realistically, you should seek compensation for them ruining your roof and what it will cost you to fix it.
The roof is not ruined.

Compensation may or only be required if he paid for services that were not completed, or satisfactorily.


For all we know, the OP may have only negotiated and paid $150 for the job...and that's what he received.









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GeorgeRa

2013 Sprinter DIY 144WB, Portland OR
I think that The Professional installing the fan started from the top without looking the roof structure below, perhaps too lazy to remove ceiling panel first, and after cutting into the beam it was too late.

The Professional used sheet metal screws to attach the fan’s flange which should be OK if true professional would be tightening them. I would suggest using SS screws with nuts.

I agree with OrioN, the roof is salvageable by folks who know what they doing. It is certainly a frustrating event.

Good luck,

George.
 

pesmith

SmithSprinter
Just reading thru some of my threads and realized I didn't respond to this properly to close it out. The vent fan install was performed by Van Specialties in Tualatin. With the help of my salesman from MB Lynnwood, Stan Pulsipher, we convinced Van Specialties to pay for replacing the roof beam and roof panel at a body shop recommended by MB. Very disappointing and frustrating experience.
 
Crazy, I'd call them and try to get your pieces back, just in case. I'm guessing you could have fab shop weld up a box to support the vent and roof.
 

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