Why wood roof trusses?
Keystone has metal roof trusses that connect to aluminum walls. ORV has wood trusses that attach to aluminum walls. Keystone roof insulation is R16 and ORV's is R21. Why do manufacturers still...
Forum Discussion
The purpose of a truss is to transfer the loads placed on it to the vertical wall members where the load is then transferred to the frame.
A roof truss has two types of loads which are applied to it. 1)live load and 2)dead load.
Dead load is the weight of the roof materials, Air conditioners, vents, etc. Once constructed, these loads will not change throughout the life of the RV.
A live load is the additional weight or stresses which are applied to the roof, such as snow, human weight, and most importantly stresses applied during transportation.
Your roof is designed to flex. If it didn't, failure would be imminent. When the roof flexes, the top part of the truss is under a compression force and the bottom under tension. In other words the top of the truss is trying to get shorter from the weight it supports and the bottom is trying to get longer. Because of these forces, a properly designed wood truss is more forgiving than a metal one...especially aluminum. Aluminum tends to fatigue and stress crack where wood will not.
Thus ends "Structural Engineering" 101.
My Salem Hemisphere has wood trusses and I am very glad it does...just sayin.
Whoops, just noticed I need to update my signature.
A roof truss has two types of loads which are applied to it. 1)live load and 2)dead load.
Dead load is the weight of the roof materials, Air conditioners, vents, etc. Once constructed, these loads will not change throughout the life of the RV.
A live load is the additional weight or stresses which are applied to the roof, such as snow, human weight, and most importantly stresses applied during transportation.
Your roof is designed to flex. If it didn't, failure would be imminent. When the roof flexes, the top part of the truss is under a compression force and the bottom under tension. In other words the top of the truss is trying to get shorter from the weight it supports and the bottom is trying to get longer. Because of these forces, a properly designed wood truss is more forgiving than a metal one...especially aluminum. Aluminum tends to fatigue and stress crack where wood will not.
Thus ends "Structural Engineering" 101.
My Salem Hemisphere has wood trusses and I am very glad it does...just sayin.
Whoops, just noticed I need to update my signature.
