Encapsulation system

When an encapsulation system is installed in a crawl space, should the insulation be left between the joists. No vapor barrier on insulation just fiberglass batts.

Jim Campbell

That’s the way we do it here in KY. We use plastic floor VB lapped 3/4 way up on walls then spray foam sides to rim joist. Leave Barton insulation in floor system and one HVAC duct. And one return.

Jim, some companies leave it in, some take it out. The advantage to taking it out is if there are HVAC ducts down there, the heat from leaky ductwork can warm the space/floor.

As long as the foundation walls are insulated it’s purpose is gone. It’s like insulating between floors at that point. If the foundation isn’t insulated then there are some energy benefits to sealing the plastic just not as much as if you did the walls.

Thanks Guys. It pays to be a member!!:slight_smile:

I would take some issue with its purpose being gone but that’s based on your weather region. If you are in places the ground gets cold, plastic is not a great insulator so cold will permeate the ground and actually cause a slightly higher load on heat system. Again all based on where you live, as with many questions posed here, it can make a difference as to the answer.

Take a temperature reading of the air in the crawlspace at the floor between the joists. The temperature differential with the indoor air setpoint is directly proportionate to the heat/cooling load.

You cannot have a heating or cooling loss if there is no temperature differential.