Observation on the NL/Bigfoot Clamshell Design

The BF or NL construction does not trap moisture in the walls any different than other construction methods. Any construction method that is so lose as to let the moisture out, will let plenty in. The inside of a BF or NL is just as "breathable" as other methods.

Production boats are almost all built with a joint at the deck/hull, and these are notorious for leaking. Boats also have numerous deck penetrations for hatches, hardware and rigging - more even than an RV - but they are sealed much differently than a typical RV. Not without problems, but no where near the problems that RVs seem to have. In this respect, a BF or NL can be sealed like boat deck hardware, to the extent the particular piece of hardware allows. The factories do not do it unfortunately, you have to do it yourself.

whizbang wrote:
... What's the advantage of a water proof design/structure if the water proof surface is pierced in 20 places and relies on conventional caulk to keep the rain out?

Have you not noticed the potential leak areas all around the outside of non-clam shell designed TCs? There is a seam where the roof meets the sides, where the roof meets the back of the TC, seams where the sides meet the bottom, seams where the top meets the front cap seams where the front cap meets the bottom. I say on a 11.5 foot TC, there is about about 70 feet more seams for leaks.

Also consider there is no other roof as solid as the molded fiberglass. Not easily damaged.

Wayne

Yes, NL & BF still have the potential to leak due to penetrations thorough the clamshell. And I too would tend to minimize the number of penetrations through the most susceptible surface, the roof. Unfortunately, I got my BF off a dealer's lot after the original company went bankrupt and so had to take it as it sat ... with a ladder, roof rack, AC, refrigerator vent, 2 plumbing vents, 2 fantastic fans, and two skylights. However, these are items all TC tend to have and the fiberglass clamshell design does eliminate the seam along all the edges between the roof, sides, front, rear, and bottom and their leak potential. I hear all the time about the problem with wing rot on such units but have never heard of this occurring on a NL or BF.

A lot of boats are built in two halves also , split in two halves at the rub rail . With fewer penetrations at below the water line , but there are some , sealed with caulk that is for continuous immersion .
Good design for TC`s , just need good maintenance to go along with it

One could argue there are less seams/holes with a clam shell design. As noted, clamshell does not mean "no holes"...so they must be maintained as any camper.
You might also infer that I if they do leak any moisture can be trapped inside the walls which are not easily accessible as other types of construction.

My opinion is both NL and BF are high quality units and are probably less likely to leak than other types of construction. If we did not need the room of a slide out we would likely own one of these right now.
DW really like the NL's last time we were TC shopping. Who knows? Maybe when we are just "2" (plus dog) we will look again...

Right now really happy with our current unit...and the added room of a slide.
B

I share this observation and concern. I have owned three Bigfoots. The 9.6 camper I ordered new from the factory. I specifically ordered no luggage rack, no ladder, no antenna - no unnecessary roof penetrations. It turned out to be a requirement to have the ladder, since the roof vent was the fire escape. You cannot avoid some things like vents. I did this because my previous Bigfoot 5th wheel had numerous gratuitous roof penetrations. The ones for the awning eventually leaked, rotting some of the paneling and wood stiffeners embedded in the wall. My current camper (BF10.4) I found new (but sitting at a dealer for 4 years). It has an antenna, roof rack, ladder, awning; counting them up there must be 40 or 50 screws through the roof that need not have been there.

Another issue is the quality of the vents. The plumbing vents in particular (but also some of the others) are very pliable plastic. Screwing down the flanges simply squeezes the sealant out of the joint under the screw, bowing the flange. And afterward they flop about so easily there is really no way to seal them long term. The sealing rim of these things needs to be stiff enough to put to pressure on the sealant, otherwise you must use an adhesive sealant and a lot of Faith.

On the fiberglass top of a BF or NL, it is feasible - and not that much work - to simply remove the unnecessary junk from the roof and patch the holes by fiberglassing them over. On the roof, the patches don't have to look good. I've been thinking about doing that at least for my awning, which I never use, and involves at least 20 holes.