no vapor barrier

[Kevin C]

What determines is a vapor barier is needed or not, soil, dranage, ventilation, etc?Also, what does the type of siding have to do with a vapor barrier? If the installation manual calls for a vapor barier but the dealer/installer says one isn't needed, what should the buyer do before the sale.
Thanks in advance.

[Scott]

A vapor barrier is needed depending on the state guidelines for installations go. If the home has underpinning than it is supposed to have a vapor barrier installed but that may be different state to state. It also may depend on the manufactureres installation guidelines. If the home has Smartpanel siding on the exterior and there is no vapor barrier installed, you have got some serious warranty issues.

[rmurray]

More and more manufacturers are requiring vapor barriers..(Many still only recommend the use of vapor barriers...in this case it would be an option for the dealer and customer to work out..)...If the manual calls for one..the dealer should be putting it on...Some manufacturers make strong statements about the barrier...Horton makes it very clear that warranty dependent on a vapor barrier..

All the lawsuits concerning mold have made manufacturers much more careful about this...Mold is caused by uncontrolled moisture and many suits have resulted because of the lack of good moisture control...

Are the plants over reacting....maybe...but the cost is low and there is hardly nothing lost for the additional protection..