Quote:
Originally Posted by matstam13
went up on the roof of our new alpine last night and noticed it to be kind of spongy when you walked on it until you got to one of the cross bars is this normal? we just switch from a motor home to the 5th wheel and the roof of the motor home was solid with no give, so i'm a little curious as to why or what the difference is
|
Is your roof "spongy" all over or just in a few spots? If it is just a few places, it may be a sign of leakage and damage to the underlayment.
However, if it is uniformly spongy across the whole length and width of the roof, read on:
Some rigs are built with 1/2" or thicker plywood under the membrane and are considered to be "walk on" roofs. However, others are built with materials that are thinner and are not recommended for walking on without extra support like a piece of 1/2" plywood large enough to span two or more roof joist intervals. On some product lines, the walk on roof is an option, but is standard with others. The thinner roofs are fine for snow load because it is uniform across the whole roof.
My '99 Sunline had the thinner roof. The Dicor membrane was bonded to a sheet of material not unlike an industrial grade of shirtboard about 3/16" thick. This was then laid down over 1/4" luan which was fastened to the roof joists. It worked fine as a roof, but not as a place to walk.
If you want to verify how your roof is constructed, drop the the inside plastic frame of one of the roof vents. You will be able to see the roof construction with a little poking about.
__________________
'11 Cougar 326MKS loaded with mods
'12 Ford F250 SuperCab 6.7 PowerStroke Diesel
Amateur Radio: KD2IAT (146.520)
GMRS: WQPG808 (462.675 TPL 141.3)