We recommend removing insulation very strongly. We are ok if clients don’t do it, but we inform them that any failures in the project are 100% on their shoulders at that point and ask them to sign saying they acknowledge that fact. Haven’t left insulation in an attic yet. =)

Donald, fiberglass is not an
Donald, fiberglass is not an air seal. There are ways to seal the ceiling, but first be sure to define the goal. If there aren’t any problems you might want to leave it alone.

Thanks Allison and everyone
Thanks Allison and everyone else too. Solid advice.

You got it, Jeff! You win the
You got it, Jeff! You win the award for being the first person to spot the reference.

RJ and David Butler gave good advice about spraying foam in your attic. Don’t just settle on the first contractor who shows up. Verify that they do good work. Call their references. Require blower door testing. If you’re going to pay a lot of money to do it, make sure you get the most qualified contractor you can find.

@Jeff, clearly the best way
@Jeff, clearly the best way to find out is to invite an insulation contractor to inspect your attic. But in my experience, what you describe is not uncommon. These guys (and gals) are used to difficult access and have ways to deal with it.

If you decide to encapsulate, be sure to do your diligence on the contractor you select. Just like any other contracting work, quality control is not something you can take for granted. However, in the case of spray foam, a botched job can lead to repair costs far beyond the cost of the foam. For example, if the foam isn’t mixed or applied correctly and fails to fully cure, it can make your family sick. Also keep in mind that some people are much more sensitive than others to the chemicals involved.

It can be sprayed but it
It can be sprayed but it really requires an experienced two man team in the attic and someone in the truck. I might think twice about encapsulating ac wiring other than at the soffits. Being able to seal and then inspect the work at the soffits is an important consideration in a tight space.

I have a question about converting attics to conditioned space. My attic is a nightmarish obstacle course of pre-fab trusses used to create semi-vaulted ceilings in the three front upstairs rooms. I’ve done a fair amount of work up there installing cables over the years, and I can say that access is very, very cramped and difficult. Does an attic like like mine present too much of a problem for spray foam installation? To give you an idea there is really no place in the attic where a person can stand up and movement is always hampered by the forest of truss members. Plus the trusses were assembled using those sharp-edged steel cleats so it’s danerous too. I really want to do a major energy upgrade on this house someday so I need to get an idea what what is possible. And yes, the existing insulation is filthy and absolutely would be removed. I’m in Austin, Texas so the humidity is very high here most all year.

Morgan, it’s not about dew
Morgan, it’s not about dew point. It’s about IAQ, and that’s for everyone, not just “the rich guy.”