More to ponder on wood or metal framed sidewalls. This is a paste and copy from nuwaowners.org (HH II) website a few years back;
NUWA
Why doesn't NuWa use an all aluminum structure like popular Indiana manufacturers?
NuWa made the decision to begin the use of aluminum structure based on marketing and the fact that many people were concluding that an "aluminum caged" product was superior in construction technology, weight and strength. Our 40+ years of experience as a leader in 5th wheel design suggests that may be "flawed" information. We have proven that wood construction need be no heavier or less strong than aluminum construction, that is built properly. We now build both materials, and are comfortable doing either, however our opinion is still that wood construction provides a superior product, and today we use both in the construction of our trailers. The strength of the NuWa trailer is actually created by the superior and light weight Blue Dow foam lamination concept.
NuWa uses an aluminum substructure in the sidewalls and ends of the coach only. No aluminum in the floors or attics, where metal promotes conduction of cold and moisture resulting in condensation.
90% of the walls are Blue Dow Structural Foam, rather than wood or aluminum. This creates a superior insulation and the only product with a guaranteed sidewall R Factor. (Water absorption in standard white foam reduces R Factor over time, and the use of Blue Dow Structural Foam eliminates this problem.)
NuWa's aluminum substructure sidewall is actually a "hybrid" wall, as we core fill the aluminum with wood in those areas where additional strength is required, because aluminum will not hold a screw. Not so with the lower priced brands. With NuWa's combined use of wood and aluminum substructure, you get a superior product because of NuWa's unique Blue Dow foam vacu-bond process, which makes the sidewalls virtually resistant to water penetration.
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers
'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides
