Why do Class C's always leak in the front upper bunk area?

[Likes_to_tow]

Came close to buying a new Class C late last year but instead purchased another 5th wheel. Not so much because of their tendency to leak in the front overcab area but there was some other things that made us stick to another 5th wheel. Maybe sometime in future we will get a small c.

My friend found an unbelievable deal on a used 2011 with only 3800 miles on the clock and wanted me to go look at it with him. It was in unbelievable condition for a 2011!! It had been stored under a roof mostly out of sunlight and rain. I could find nothing anywhere from top to bottom that looked questionable until I looked under the mattress in the over the cab bed. There were water stains on each end of the mattress on the bottom side. Close examination on the outside revealed water oozing out from the edge trim molding when you pushed on it. A classic example of lack of proper maintenance sealing. The owner was really shaken up by our findings and had no idea Class C's are famous for this. Now he was faced with a huge repair bill before he could sell it unless some poor unsuspecting buyer did not look under the mattress. I've notice a major change in some higher end models where the front cap is all solid fiberglass and actually wraps around the side a few inches. Looks like this would be much better than just having a piece of molding on the edges. At any rate, if you
are in the market for a used C I suggest you pull the cab over mattress and check for stains!!

[Mich_F]

A lot of problems with cab over leaks start with poor design and cheap construction. This pic of what was a totally rotted out Class C Coachmen cabover, shows very little support with super thin walled aluminum tubing. This MH had a combination entertainment center and bed in the cabover. It originally had a large heavy TV on the right side, It had windows on all three sides, yet no metal framework around the windows. The flex in this cabover was unbelievable, before rebuilding started the front right corner was bowed down 3" from where the cabover met the transition wall of the house. This MH had years of non maintenance and even if you tried to reseal it, before it was torn apart it would still leak because of all the flexing of driving down the road. The cabover is being rebuilt with thicker walled aluminum braces/supports, and won't have any of the windows replaced.

[Harvey51]

I see few new trailers with flat roofs but quite a lot of Cs with them. It shouldn't be very expensive to peak the roof a few inches, which would certainly help the water run off the roof.

[ron_dittmer]

Hi Likes-To-Tow,

I post this once in a while and it seems to address your initial question. It is long-winded....my apologies for that.

Ron
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New, used, or well used, when shopping for a conventional class B+ or C, the most important consideration is how it is constructed. This post outlines construction methods which are most affordable and methods that cost more, but are built to hold up much better to the elements and also the punishment of the road.

Some motor home manufactures offer different levels of quality through their various model lines. Instead of providing a list of brands to consider, it is best to identify what "Better" is.

When shopping for a motor home, don't get distracted with what I call "Eye Candy" or "Square Footage". You want to pay close attention to how the house is constructed. Water infiltration is the number one killer of motor homes, rotting them away long before anything is worn out. Once water gets inside, it is like termites. By the time you realize there is a problem, a lot of damage has already occurred. Also consider that mold & mildew can grow inside the walls which then you have a health hazard. My advise focuses on identifying a reliably well sealed motor home.

#1 BEST (Very Expensive, Can Be 1.5 times the cost of Second Best)
NO structural seam work. The brand Coach House is a fine example. It is seamless, made from a mold. The only places where water can leak is cutouts for windows, entry door, roof-top vents & a/c unit, storage compartments & maintenance access, all of which are in areas of very low stress. Because they have a seamless shell, these motor homes have a limited selection of sizes.

#2 SECOND BEST
Common, Affordable, & comes in Many Sizes so this is my main focus
I own an example of this type. My Rig Here manufactured by Phoenix USA.
Made in sections, but assembled in a way that greatly reduces the threat of water damage. Here are the good things you want to look for.

a) Structural Seams Away From Corners
When a motor home is driven, the house bounces, resonates, shakes, and leans countless times, representing a series of extended continuous earthquakes. Corner seams see greater stresses than seams located elsewhere. Corner seams are more easily split, especially when the caulk gets brittle with age & exposure to the sun. One extremely bad bump in the road can instantly breach a corner seam. Seams hold up much better when they are brought in from the corners in lesser stressed areas.

b) A Seamless Over-The-Van Front Cap
A huge bed above the van’s roof is the most vulnerable area of a motor home. No matter how well they are made, that long frontal over-hang resonates when the RV is driven. It is common for seams to split there, most troublesome with age & exposure to the elements. HERE is a more recent example, one of many I have read. The small front aerodynamic cap of a B+ design HERE eliminates the overhang which eliminates most of the resonation, along with most seam work.

There are a few conventional “C” Designs (big over-van bed) where that area is seamless. If you absolutely must have that huge bed, then look for a seamless bucket-like design. Born Free offers a seamless bucket design as seen in This Model. The Itasca Navion Here is another fine example. Some manufactures as of late offer a partial bucket design with fewer seams located in less-stressed areas. Some manufacture models like the Minnie Winnie and the Nexus Phantom utilize a compromising partial bucket design, making it a better choice compared to a fully seamed cab-over bed.

If you plan to accommodate more than 2 people, having that large extra cab-over bed will be extremely useful.

c) A Crowned Roof
Rain and snow melt runs off a crowned roof. A flat roof will sag over time, then water puddles around heavy roof-top items like the a/c unit. Water eventually finds it's way inside after gaskets & caulk have degraded from age, sun, and change in seasons.

d) Rolled-Over-The-Edge seamless Fiberglass Roof Sheathing
A single sheet of fiberglass as shown HERE that rolls over the right & left sides of the roof, down to the wall. The overlapping of fiberglass to the wall provides a good water seal and the fiberglass sheathing holds up better than roofs made of sheet rubber or thin plastic called TPO, which require more attention to keep your RV well protected.

e) A Five Sided Rear Wall Cap
A five sided back wall moves the seams around to the sides to areas of much less stress as seen HERE. The rear wall resembles a shallow rectangular cooking pan standing on it's side. Like the example, some rear wall sections are constructed with an integrated spare tire compartment and rear storage compartment. Not only are they convenience features, but that rear wall/cap offers a solid double-wall for exceptional strength which is more resistant to flexing the adjoining seam work.

Don't be fooled. There are a select few manufactures who add rear wall sectional styling pieces over an entry level rear corner seam design which gives the appearance of a 5-sided pan design. You can easily tell by noting the sections & seams between them and the flat back wall that remains exposed.

Bigger Will Be Weaker
The size & floor plan you select MUST FIRST meet your needs before this consideration.
The bigger the house, the weaker the structure will be. Consider two cardboard boxes made from the exact same corrugated material. The smaller box would naturally be stronger. It will be more resistant to bending, twisting, and other types of flexing. So if you are on the fence between models, the smaller one will be your stronger choice.

Potentially Troublesome Construction
Entry level motor homes are made with seams in corners and finished off with trim, including the massive cab-over bed. Their roof is flat and finished with rubber or TPO. They are most affordable, and come in all sizes. HERE is one such example. If considering this construction type, keep in-mind they require more regular care with bi-annual inspections. Plan to use a caulking gun now and then. When buying a used one, consider that you really don't know how well the previous owner maintained it. Buying new or used, that construction method will be counting on you to be a good non-neglectful owner.

There are also the rare exception of the Lazy Daze which has seam work in the corners, but the substructure and sealing method is of the highest quality that it holds up like a seamless body. It's excellent sectional construction methods are not commonly found in other brands. I am no expert on this, but I'd give it a #1.5 Almost Like Best

About The Chassis
The most popular is the Ford E-Series with the V10 engine. The Sprinter diesel is a popular alternative to the E350 in the smaller sizes. Also within this past year is the recent introduction of the Ford Transit. The GM chassis is not popular, but is a very good choice for the right application. Any of these chassis made since 1998 are real good, new or used. If you plan to tow a car or heavy trailer, be aware that the Sprinter & Transit will be least powered. People who tow with them naturally take it slower.

If considering a current-day “small” class B+ or C motor home, here is a comparison between the two current main contenders, the Sprinter with the V6 diesel engine and the Ford E350 with the V10 gasoline engine.

Advantages Of The Mercedes Sprinter With Diesel Engine
- Offers a 35%-50% improvement in fuel economy over the Ford-V10, when both are loaded and driven identically.
- More ergonomic driver compartment with more leg room.
- Comfort continues with a car-like feel & quiet ride.
- A grander view out the windshield
- Made by Mercedes which people are attracted to.

Advantages Of The Ford E350 with V10 Engine
- Given identical motor homes both brand and model, the Ford is around $13,000 MSRP cheaper
- The Ford V10 engine has 50% more horse power and torque
- The Ford E350 chassis handles 1430 pounds more weight.
- The E350 is able to tow a heavier load.
- The E350 rear axle is significantly wider which translates to better stability.
- In most places traveled, gasoline costs less than diesel fuel
- The Sprinter diesel has limited mechanical service shops around North America
- The Sprinter diesel is typically outfitted with a propane generator. Propane is a critical fuel for RV operations, and generally needs to be rationed when dry camping.
- This Next Point Is Debatable But Still Worth Noting....The V6 Sprinter diesel engine is not allowed to idle for extended periods. This limitation is detrimental when you need a/c but there are generator restrictions or you are dangerously low on propane, or you have a mechanical failure with the generator or roof a/c. The Ford V10 can safely idle for hours on end, heating, cooling, and battery charging, all valuable if you have a baby, pets, or health/respiratory issues.

You decide what your priorities are, and pick the appropriate chassis. There are some really sweet motor homes being built exclusively on the Sprinter chassis, such as the Winnebago Via, View and View Profile. Others like Phoenix USA build their model 2350 and 2400 on both the Sprinter and Ford E350. They will even build it on the heaviest duty E450 upon request for a nominal fee. People who request an E450 for a small motor home, tow heavier things like for example, a multi-horse trailer. You can even special order a E350 & E450 4x4.

There is so much cool stuff offered in recent years on the Sprinter and most recently on the new Ford Transit.

The Ford Transit Chassis
This chassis has the potential to dominate the class B+ & C motor home market in the smaller sizes. According to Ford's website, the Transit DRW chassis is offered in the 156", and 178" wheel base, and is rated as high as 10,360 GVWR. Ford offers a motor home package specific for the RV industry. It's diesel engine compares to the Sprinter in power and fuel economy, but is more affordable and is easily serviced at Ford service centers, just like the E350/E450. The cab has a much lower stance than the Sprinter making it much more friendly to get into and out from for people in their later years. It's more like a mini-van rather than a standard van. The Transit's lower cab also offers roomier over-head bunks that are easier to access.

The Dodge Promaster 3500 Cut-Away Chassis
This front wheel drive chassis is another recent entry in the RV industry. I am concerned over it's lack of load capability as reflected with single free-wheeling rear wheels. I have been reading posts written by new Promaster RV owners stating they are over-weight with just two people, some personal effects and food. They say they can't carry water and never a 3rd person. I would not be comfortable with such a limited load range in a B+ or C. This chassis does seem ideal for the straight "B" motor home market.

The Chevy 3500/4500 Chassis
Unfortunately this chassis is not more popular, primarily because GM sort-of gave up on competing with the Ford E350/E450. It offers more interior comfort than the Ford, but not as much as the Sprinter. It's power & weight ratings are a little less than their Ford counter-parts making them a great chassis for all but the heaviest of class Cs. They are also a little better on fuel consumption. One thing to keep in-mind, if you are counting inches in storing your rig, the Chevy is a little longer than the Ford by a number of inches which was critical for us with our garage as seen HERE with our Ford 2007 E350 rig. That could be the reason why the Chevy has a little more interior driver/passenger leg room.

Engine Power Ratings of Ford, MB-Sprinter, Chevy, and Dodge
Ford E350/E450 - 6.8L-V10, 305hp, 420ft
Ford Transit Diesel - 3.2L-I5, 185hp, 350ft
Mercedes Sprinter Diesel - 3.0L-V6, 188hp, 325ft
Chevy 3500/4500 - 6.0L-V8, 323hp, 373ft
Dodge Promaster - 3.6L-V6 (GVW only 9,300 pounds)

[Newbiecampers]

Likes to tow wrote:
Yes it was!! My friend was ready to make a deposit but after we raised the cushions and saw the stains we made a closer inspection of the outside. The caulk had open cracks in it along the aluminum trim strips and there was mold on the underside along some seam caulking. I'm afraid some unsuspecting buyer is going to get burnt!!

Ha, small world.

When I saw the listing description changed to mention the staining on the mattress in the overhang, we figured we might pass.

Then I saw the seller's answer in the description to a question asking if the roof seams had ever been re-caulked. The answer was no. 6 years of no roof seam re-caulking to me equals "run away!"

Glad we didn't waste our time. Hopefully nobody gets burned on this unit.

Edit: I should give the owner some credit on the situation. When the water-stained mattress in the cabover was discovered (apparently by Likes to tow and their friend) the ebay listing was updated to provide that information. I saw the change occur as we were watching the auction.

[Likes_to_tow]

Photomike wrote:
Someone told me a few years ago: "Imagine if your stick house was subject to an earthquake for 4 or 5 hours a day, it would start to leak and fall apart like a RV does".

I think a lot of time it is build quality but a lot is also we just don't take into account how much stress we are putting on these units and how much we need to do to keep them in good shape.

A very good point!! You must constantly be vigilant about caulking and sealing any RV, even a Class A. They flex, twist and vibrate as you travel. This breaks the seal and allows water intrusion on all seams

[Likes_to_tow]

Newbiecampers wrote:

Likes to tow wrote:
My friend found an unbelievable deal on a used 2011 with only 3800 miles on the clock and wanted me to go look at it with him. It was in unbelievable condition for a 2011!! It had been stored under a roof mostly out of sunlight and rain. I could find nothing anywhere from top to bottom that looked questionable until I looked under the mattress in the over the cab bed. There were water stains on each end of the mattress on the bottom side. Close examination on the outside revealed water oozing out from the edge trim molding when you pushed on it. A classic example of lack of proper maintenance sealing. The owner was really shaken up by our findings and had no idea Class C's are famous for this. Now he was faced with a huge repair bill before he could sell it unless some poor unsuspecting buyer did not look under the mattress.

Yes it was!! My friend was ready to make a deposit but after we raised the cushions and saw the stains we made a closer inspection of the outside. The caulk had open cracks in it along the aluminum trim strips and there was mold on the underside along some seam caulking. I'm afraid some unsuspecting buyer is going to get burnt!!



Was this by chance the 21qb that was recently on ebay in Ohio? We had thoughts of going to see it but changed our mind due to a few issues regarding it.

[navegator]

There is another way to check for leaks on the over hang, go to one of the corners underneath and push up on the bottom, if the panel flexes it is a sign that there is rot from leaks, or they placed a couple of drain holes.

Also check the sides if you notice any waves or bulging that is also water damage, another area is where the cab meets the house part inside the vertical panel 90 degrees to the frame, any sponginess and also in the back area where the roof meets the sides, they may have painted inside but rot is spongy wood.

navegator

[Newbiecampers]

Likes to tow wrote:
My friend found an unbelievable deal on a used 2011 with only 3800 miles on the clock and wanted me to go look at it with him. It was in unbelievable condition for a 2011!! It had been stored under a roof mostly out of sunlight and rain. I could find nothing anywhere from top to bottom that looked questionable until I looked under the mattress in the over the cab bed. There were water stains on each end of the mattress on the bottom side. Close examination on the outside revealed water oozing out from the edge trim molding when you pushed on it. A classic example of lack of proper maintenance sealing. The owner was really shaken up by our findings and had no idea Class C's are famous for this. Now he was faced with a huge repair bill before he could sell it unless some poor unsuspecting buyer did not look under the mattress.

Was this by chance the 21qb that was recently on ebay in Ohio? We had thoughts of going to see it but changed our mind due to a few issues regarding it.

[Biggyniner]

Biggyniner wrote:

Desert Captain wrote:
A properly designed/engineered and built RV should need no additional caulking whatsoever. If they got it right you should have no leaks for years. Using a one piece fiberglass roof is getting it right. It's the same for one piece fiberglass end caps that do no have any upward facing gaps.

IMHO: Re caulking a Class C to stop leaks is like having to add modifications to the suspension... there simply should be no need to do either. I have yet to encounter another Nexus owner with leaks and the same holds true for Born Free, Phoenix Cruiser and Lazy Daze {to name just a few of the better designed/built C's out there}.

When builders {who know better}, continue to build coaches with rubber roofs, Luan, 2 X 4 framing and host of other cost saving shortcuts it quickly shows in the overall quality {or lack thereof}, of the coach.

As always.... Opinions and YMMV

:C

I guess it depends on your definition of "proper". In my manual it states to inspect and re-caulk as necessary, at least twice a year. That is what is in my owners manual.

So I guess my philosophy of inspecting twice a year may be overkill for say, someone who owns a Fiberglass one piece rig.

In the end, read your owners manual and do as it says...

I can't believe it took them 20+ years to figure out maybe the nose should be 1 piece of fiberglass lol 😛

[T18skyguy]

crasster wrote:
Yes, they are notorious for front bunk leaks. Many MFG's even quit putting windows on the bunk area, but still, they can tend to leak. The best think IMHO to do with a C if you like them is to keep them in covered storage and so that it won't be victimized by the elements all the time. Does it stop leaks? No, but water won't get in it if it's covered under storage. It's a great way to "stop leaks" and preserve the coach.

This is very well put. After spending many thousands on a rig, the best thing you can do is put a metal cover over it. Whats a couple grand more? A metal cover won't stop a leak, but will enable you to spot one on a trip before it does huge damage. Cover it, then be vigilant with inspecting it. Then when your on a trip and it rains, check inside everywhere, especially overhead bunk, windows, slide, marker lights. Be on it like white on rice.

[Mike__Rose]

Our 2008 Jayco Greyhawk 31SS had a fiberglass front cap with 2 side windows. We never had a leak up front. We did have a leak in the rear by the ladder but repaired it right away. Some new 5th wheels have front windows in their front living floor plans and we had a neighbor who had a leak at the front window seam. Constant vigilance and inspection is vital to prevent leaks.

[Desert_Captain]

Biggyniner wrote:

Desert Captain wrote:
A properly designed/engineered and built RV should need no additional caulking whatsoever. If they got it right you should have no leaks for years. Using a one piece fiberglass roof is getting it right. It's the same for one piece fiberglass end caps that do no have any upward facing gaps.

IMHO: Re caulking a Class C to stop leaks is like having to add modifications to the suspension... there simply should be no need to do either. I have yet to encounter another Nexus owner with leaks and the same holds true for Born Free, Phoenix Cruiser and Lazy Daze {to name just a few of the better designed/built C's out there}.

When builders {who know better}, continue to build coaches with rubber roofs, Luan, 2 X 4 framing and host of other cost saving shortcuts it quickly shows in the overall quality {or lack thereof}, of the coach.

As always.... Opinions and YMMV

:C

I guess it depends on your definition of "proper". In my manual it states to inspect and re-caulk as necessary, at least twice a year. That is what is in my owners manual.

So I guess my philosophy of inspecting twice a year may be overkill for say, someone who owns a Fiberglass one piece rig.

In the end, read your owners manual and do as it says...

While I could not agree more that one should always {and most don't bother}, to read your owners manual, yours is 23 years old. If I was buying a current model/new coach and the owners manual said to re caulk every 6 months I would know, without a doubt, I was buying the wrong RV. :S

I have no problem with regular inspections as preventative maintenance has always worked well for me but with the improvements made over the last 20+ years you are entitled to expect far more from the manufacturer. A new RV should perform all of the functions found in normal use without modification.

:C

[Biggyniner]

Desert Captain wrote:
A properly designed/engineered and built RV should need no additional caulking whatsoever. If they got it right you should have no leaks for years. Using a one piece fiberglass roof is getting it right. It's the same for one piece fiberglass end caps that do no have any upward facing gaps.

IMHO: Re caulking a Class C to stop leaks is like having to add modifications to the suspension... there simply should be no need to do either. I have yet to encounter another Nexus owner with leaks and the same holds true for Born Free, Phoenix Cruiser and Lazy Daze {to name just a few of the better designed/built C's out there}.

When builders {who know better}, continue to build coaches with rubber roofs, Luan, 2 X 4 framing and host of other cost saving shortcuts it quickly shows in the overall quality {or lack thereof}, of the coach.

As always.... Opinions and YMMV

:C

I guess it depends on your definition of "proper". In my manual it states to inspect and re-caulk as necessary, at least twice a year. That is what is in my owners manual.

So I guess my philosophy of inspecting twice a year may be overkill for say, someone who owns a Fiberglass one piece rig.

In the end, read your owners manual and do as it says...

[Desert_Captain]

A properly designed/engineered and built RV should need no additional caulking whatsoever. If they got it right you should have no leaks for years. Using a one piece fiberglass roof is getting it right. It's the same for one piece fiberglass end caps that do no have any upward facing gaps.

IMHO: Re caulking a Class C to stop leaks is like having to add modifications to the suspension... there simply should be no need to do either. I have yet to encounter another Nexus owner with leaks and the same holds true for Born Free, Phoenix Cruiser and Lazy Daze {to name just a few of the better designed/built C's out there}.

When builders {who know better}, continue to build coaches with rubber roofs, Luan, 2 X 4 framing and host of other cost saving shortcuts it quickly shows in the overall quality {or lack thereof}, of the coach.

As always.... Opinions and YMMV

:C

[Stefonius]

ScottG wrote:
Until the industry gets away form using goop to keep water out leaks will continue to happen.

My dad has a 1998 Chinook Concourse. The body is a one piece fiberglass tub. No seams, no caulk, no leaks. Of course, when it was new it cost as much as a 4 bedroom house in the suburbs, but it won't leak. You are absolutely right, ScottG... No goop, no leaks.