Wondering about Bigfoot Construction

[Byron Kinnaman]

I'm kind of wondering about the construction of Big Foot. Isn't it a fiberglass shell, with wood furring strips and wood paneling? Insulation between furring strips. If my assumption is correct at least one of the advantages of Scamp, Casita, Trillium construction is lost, that is moisture can accumulate behind the paneling and rot out the furring without you even knowing you have a leak.

I apologize if my assumption is all wrong.

[Bigfoot Mike]

Byron,

ALL Fiberglass RVs have areas hidden behind stuff. My Casita had a leak between the shower and the outer wall. I didn’t notice until I saw water dripping out the bottom. Scamps et al have benches, cabinets, showers, closets, all kinds of areas where water can leak in and not be seen.

On the forum here we have had discussions on replacing Scamp floors, moisture here and there. Hey, these are hand made at the factories and no two are exactly alike. The fit and finish is so much better on my Bigfoot, but I did have a leak when I picked it up three weeks ago and had to re-caulk an access door.

[Byron Kinnaman]

I believe there has to be furrings to attach the paneling to, is this correct.
So the question is are the furrings glassed in (sealed) or or attached some other way to the shell?

Where I'm going it appears that there's three main types of travel trailer construction.

The oldest and most common is what we call a "sticky". A wooden frame and paneling on both inside and out side, with lots of seams and potential leak points. Lots possible leak caused damage areas inside.

Then there's the typical molded fiberglass trailer. Fiberglass shell with a wall treatment directly attached to shell on the inside or painted walls. Possible leak caused damage areas greatly reduced along with a big reduction in possible leak points.

I'll the Big Foot, Escape type as hybrid, where the leak points are greatly reduced as compared to a "sticky", but interior construction is the same. Still superior to sticky construction by a long shot, in my opinion.

Correct if I'm wrong about the construction of Big Foot and Escape.

If I'm correct, I still NOT saying which is better for any individual. Every trailer is a compromise in construction, cost, size, towability, type of rving, etc. and each person or family has to decide which items are more important for them. However the more information less surprises later.

[Per Walthinsen]

Interesting discussion. I'd like to add the Burro double-wall construction to the mix. Commonly available "pink" insulation with foil facing is in between the two shells, so that is what is going to "rot." Except it won't rot, but that still makes it vulnerable to moisture retention to some degree, meaning mold, mildew, etc. is possible. It is unclear to me how much the insulation prevents water from draining down to the floor area and how much gets retained in it.
I admit to being a bit anal about the subject, and I try to cultivate a vigilant eye for leaks plus a few ways to easily check for moisture penetration. Just fixed two: bathroom vent had a crack in the hinge area, demanded a replacement, and moisture came in through the front window area. This turned out to be the hinge bar for the front gravel shield. It was sealed and attached in the BBT era (Before Butyl Tape) and the moisture paths were clearly visible on disassembly. Maybe I'm done with it now.
It would seem to me that wooden framing is particularly vulnerable to the effects of leaks because by the time the leaks show up the framing has probably been saturated for some time, with nowhere for the water to go. Stickies, if they have been leaking, must require an inordinate amount of time and money to fix. I really would not want to go there.

[DanPatWork]

Interesting discussion. I'd like to add the Burro double-wall construction to the mix. Commonly available "pink" insulation with foil facing is in between the two shells, so that is what is going to "rot." Except it won't rot, but that still makes it vulnerable to moisture retention to some degree, meaning mold, mildew, etc. is possible. It is unclear to me how much the insulation prevents water from draining down to the floor area and how much gets retained in it.

I have wondered about this part of the burro construction, and whether or not a rebuilder/owner could remove the "pink" and then re-asemble without. Now with the placement of a few small holes, have the void filled with the expanding closed-cell insulation.

Would this eliminate the moisture trap created by the pink, and would it provide better insulation? Is it even do-able?

Here I am, not even completed with the first MFRV rebuild, and considering taking on another. Is this the first sign of an addiction?

[Rob M]

The Escape is like the Boler, it has a insulation with a vinyl front glued to the fiberglass shell.

[Byron Kinnaman]

The Escape is like the Boler, it has a insulation with a vinyl front glued to the fiberglass shell.

Thanks for setting me straight.

[Per Walthinsen]

Dan: (while not really wishing to get off thread)

I would see no advantage in getting the pink out, the foam would create its own problems, such as unwanted expansion or voids. One of the main advantages of the "pink" to me is that it works just fine to insulate the unit and more importantly it allows one to snake wiring practically anywhere. I'm still curious whether the Oliver will allow that. At least the pink won't soak up water then start to deteriorate. Wood is like a moisture sponge.

[Roger H]

A couple of comments here... all of the trailers have wood in them to one degree or another. All of the manufacturers use wood to reinforce parts of the trailers where there will be a stress load (like the roof air) and glass the wood in. It's great until a seam develops a leak, or a screw hole leaks, fills up the void with water, and then the wood rots as the water has no way to dry out. Floors are particularly vulnerable to that (Burro, Casita) when they're glassed in.

Regarding structure, most all of these trailers depend on the interior for hull support. Casita and Scamp both rely on the closets and vertical panels to support the roofs. The fiberglass structure is seldom adequate to support it's own weight. I can't think of any of these trailers that don't depend on the interior for support. As Mike mentioned, a lot of those support things are hidden and vulnerable to leaks just like a stickie.

All trailers that have through-hulls are vulnerable to leaking at those locations; windows, power cord access ports, air conditioners and roof vents. Scamps have a few more vulnerabilities because they use through-hull rivets with a silicone seal and plastic cap. As the cap and silicone deteriorate, water can leak in.

So.. the bottom line is that none of these trailers are totally waterproof, it's just that some are more vulnerable than others. The various construction methods all have equal parts strong and weak points. What they all have in common that makes them superior to any other construction method is a lack of roof seams, both at the sides and at the panel joints... the most common failure points in stickies.

Roger

[dsheets70]

Since this thread seems to be concerned with leaking, is there an ideal method for preventing leaks when having to drill through the shell. From what I see in the construction silicon sealant seems to be the method of choice, but I'm wondering if there is anything better.

[McClure]

If I am reading this correct Byron you have an excellent point here which a design difference from the Boler, Casita, Burro and Scamp and the likes. Everywhere my Scamp has a water pipe and a puncture within my fiberglass shell I can get to it to see whats going on, but if a BF is able to pond moisture between walls....eek...bad news. That seems to be one of the major problems with stickies.

Blair

[Byron Kinnaman]

A couple of comments here... all of the trailers have wood in them to one degree or another. All of the manufacturers use wood to reinforce parts of the trailers where there will be a stress load (like the roof air) and glass the wood in. It's great until a seam develops a leak, or a screw hole leaks, fills up the void with water, and then the wood rots as the water has no way to dry out. Floors are particularly vulnerable to that (Burro, Casita) when they're glassed in.

Regarding structure, most all of these trailers depend on the interior for hull support. Casita and Scamp both rely on the closets and vertical panels to support the roofs. The fiberglass structure is seldom adequate to support it's own weight. I can't think of any of these trailers that don't depend on the interior for support. As Mike mentioned, a lot of those support things are hidden and vulnerable to leaks just like a stickie.

All trailers that have through-hulls are vulnerable to leaking at those locations; windows, power cord access ports, air conditioners and roof vents. Scamps have a few more vulnerabilities because they use through-hull rivets with a silicone seal and plastic cap. As the cap and silicone deteriorate, water can leak in.

So.. the bottom line is that none of these trailers are totally waterproof, it's just that some are more vulnerable than others. The various construction methods all have equal parts strong and weak points. What they all have in common that makes them superior to any other construction method is a lack of roof seams, both at the sides and at the panel joints... the most common failure points in stickies.

Roger

Yes, all the support mounting is vulnerable to leaks in all trailers, but some support is more vulnerable to rot than others. I contend that instead of two major construction types, there are 3.

1 Roof and side panels with an interior wood framing.
2 Molded fiberglass shell with an interior wood framing.
3. Molded fiberglass.

It appears to me that the only real difference between a Big Foot and a true sticky is Big Foot uses a molded fiberglass shell rather than panels. I agree that that is a big difference, but not as big as those with a lot less wood. Yes any wood is vulnerable to rot if moisture gets into it. But a moisture path is less likely when there's no direct path to exterior of the shell. Not all molded fiberglass trailers have a A/C so have even less wood. A window leak is not going to rot out part of the wall like one of our members experienced.

My whole point is when purchasing a trailer try to understand the whole ramifications of different styles, including construction. All molded fiberglass trailers are not the same.

It seems to me that you've got bit defensive on this issue. I by no means intended to insult either you or Mike's intelligence. You've owned enough trailers that you've made your choice abased the compromises that best suits your needs. I assume that Mike has also.

[Frederick L. Simson]

I contend that instead of two major construction types, there are 3.

1 Roof and side panels with an interior wood framing.
[b]2 Molded fiberglass shell with an interior wood framing.
3. Molded fiberglass.

#2 could describe my Fiber Stream. The single shell is molded fiberglass with the inside surface merely painted. The partition walls and cabinetry are wood framed with paneling surfaces.

[Gina D.]

4. Molded glass shell, molded glass interior walls and furniture.

Burro, UHaul.

[Bigfoot Mike]

4. Molded glass shell, molded glass interior walls and furniture.

Burro, UHaul.

...and Oliver

[Jay Moeller]

Here is one more category of fiberglass construction that Bigfoot makes in the 3000 series (not in the molded series 2500) - aluminum sticks and fiberglass walls. See the message and attachment below from Tim Kipers about the "Columbia River"
1999_Bigfoot_CR.pdf
series that Bigfoot used to manufacture in Oregon.

"Hi Jay,

I found out some info for you:

Columbia River was the “little brother” of the 3000 Series trailers we build today… Injected wall, roof and floor, but 1” insulation in the wall vs. 1½” in the 3000s, wood framed vs. Aluminum in the 3000s now. There were some other interior and exterior differences. I’ve attach a scanned ’99 Columbia River Brochure page of this trailer to this e-mail, this should basically give you everything you need to know about it.

Take care and good luck,

Tim Kipers
National Sales Manager, USA
Bigfoot Industries
www.bigfootrv.com
tkipers@bigfootrv.com
Direct 503-789-1592 Fax 503-667-8442 "

[Roger H]

If I am reading this correct Byron you have an excellent point here which a design difference from the Boler, Casita, Burro and Scamp and the likes. Everywhere my Scamp has a water pipe and a puncture within my fiberglass shell I can get to it to see whats going on, but if a BF is able to pond moisture between walls....eek...bad news. That seems to be one of the major problems with stickies.

Blair

Blair, one of the interesting construction features of Bigfoot (at least the '04 17' and '06 25' trailers I've had) is that instead of punching holes all through the shell to put plumbing and "stuff" in where it's "convenient", all of the through-hulls are grouped together in locations with a single interior easy access; for example in the 15B17CB (the 17' model) all of the plumbing (water heater, pump etc.) and electric are located under the street side dinette seat. They're easy to service, and certainly easy to see. All of the electrical is run through chases in the walls and all the plumbing (like the Scamp) can be gotten to through cabinets. There is nothing run through the walls for the very reasons you mention. That said, Bigfoot is subject to an occasional leak just like any other trailer as their are through-hulls, but it is immediately apparent, and no more difficult to repair than any other trailer. As a matter of fact, I think my Burro was one of the worst for trying to fix plumbing issues because of the double-wall construction. It was difficult to get to a number of the fittings. I'll also say that the electrical system in the Bigfoot is well laid out, unlike the rat's nest of wires I had to sort through under the carpet in the closet of in my Scamp 16 when I blew a main fuse.

Again, each manufacturer has strong points and weak points. Your choice really distills to what manufacturer has the features you're looking for.

Roger

[Roger H]

Yes, all the support mounting is vulnerable to leaks in all trailers, but some support is more vulnerable to rot than others. I contend that instead of two major construction types, there are 3.

1 Roof and side panels with an interior wood framing.
2 Molded fiberglass shell with an interior wood framing.
3. Molded fiberglass.

It appears to me that the only real difference between a Big Foot and a true sticky is Big Foot uses a molded fiberglass shell rather than panels. I agree that that is a big difference, but not as big as those with a lot less wood. Yes any wood is vulnerable to rot if moisture gets into it. But a moisture path is less likely when there's no direct path to exterior of the shell. Not all molded fiberglass trailers have a A/C so have even less wood. A window leak is not going to rot out part of the wall like one of our members experienced.

My whole point is when purchasing a trailer try to understand the whole ramifications of different styles, including construction. All molded fiberglass trailers are not the same.

It seems to me that you've got bit defensive on this issue. I by no means intended to insult either you or Mike's intelligence. You've owned enough trailers that you've made your choice abased the compromises that best suits your needs. I assume that Mike has also.

Nope, Byron... not defensive at all. And you're right... I've had enough of them to know the differences. I think there's a misconception about how the Bigfoot interior is constructed. It doesn't have a "wood frame". My point is that there is no "choice 3" per se... they all have interior supports, be the supports wood, wood products, or fiberglass, and all have some wood reinforcement somewhere even if you can't see it. And when you can't see it (as when it's glassed in for re-inforcement), it's even more vulnerable, and a much bigger job to repair.

The interior supports in a Bigfoot are the walls and cabinetry, just as in all the others. The choice of wall coverings (basically insulation covering) is different and employs wood furring strips to attach the paneling to and cover the insulation, but it isn't structural. The basic interior construction/support isn't any different in the 2500 series than Casita or Scamp uses. The hull is the structural material, and it's held up by interior support walls. A factor that is perhaps further confusing the issue is that Bigfoot experienced problems with the flat roofs they used for years, and now have re-built their molds with shaped roofs for strength and for better water/snow/ice shedding. Some of the older Bigfoot trailers had a weak flat roof design with roofs that leaked around the vents over the years. In those, the wood used as furring strips was also structural, and the leaks caused the furring to fail, and subsequently the roof to sag. That is largely an issue of the past.

My Born Free moho is framed with wood with molded fiberglass panels and roof attached over them, and then the seams sealed. The wood is structural. That is a whole different construction method, and perhaps closer to how you may have thought the 2500 series Bigfoot trailers are built.

Roger