CORRECT WAY TO INSTALL BLOWN-IN INSULATION AND VENTILATION
QUESTION FROM JACKY, NEW BEDFORD, MA
A government funded weatherization program installed blown in insulation in my home 3 years ago. In the attic, they blew in cellulous insulation behind Tyvek easy guard paper which is stapled to my rafters.
I thought I was finally ready to have the drywall installed however I was told that there is not adequate ventilation. I do not have any existing vents and the company did not install any form of ventilation during the insulation process. I recently have had moisture droplets form on the overhead florescent light and the drywall contractor found moisture in the overhead insulation.
There is about a two foot wide overhead flat space running the whole length of the roof before the rafters slope down. It appears that they put traditional insulation here. The organization who hires the insulation contractors is adamant that the insulation is installed properly and there is no need for ventilation when the blown in insulation is compressed to the degree in which it is.
What are your thoughts on that?
ANSWER FROM THE INSULATION DOCTOR:
Regarding your question about the way your insulation was installed, there are two theories as to the correct way to install blown-in insulation. One is the way that your contractor installed it and the other is to provide ventilation between the underside of the roof and the top of the insulation itself.
Our philosophy has always been to install an air space between the top of the insulation and the underside of the roof.
I would suggest that you seek legal advice rather than a contractor's point of view in this situation.
The Insulation Doctor