Putting Plastic Sheeting Over Insulation

In the vapor barrier.

Putting plastic sheeting over insulation.

If you re referring to insulation in an attic you shouldn t put plastic sheeting over the top of it either for the same reason. More use the plastic these days without paper faced insulation. After the insulation is installed it is necessary to cover it up with a vapor barrier so the glass fibers are not inhaled. Plastic on the outside.

12 ft x 400 ft clear 0 31 mil plastic sheeting. Paper faced insulation is the same as using plastic vapor. Most insulation is made of fiberglass and fits into the walls between the studs before drywall is installed. Install the plastic sheeting only after the insulation wiring and plumbing have been completed.

If properly done this should not cause a condensation problem in the wall cavity unless you are leaking interior air thru gaps etc. If water vapor diffuses or infiltrates into the wall cavity and finds the cool surface moisture problems can occur. To each is own some believe the plastic works better. The plastic and the insulation will eliminate any moisture problems you have in the crawlspace such as water droplets collecting on the concrete walls.

If you want to put something on the bottom of the joists to hold the insulation in place use chicken wire landscape fabric or housewrap so any water vapor from inside the house can escape. Homeowners use plastic to cover their crawl spaces to control moisture and create a barrier against vapor. This article will show you how to add 6 mil plastic sheeting on the ground and insulate the walls in your crawlspace. We use foil faced rigid insulation to keep the space under the house dry.

Overlapping paper tabs on faced insulation and stapling is why its on there. Picture an ice cold can of soda on a sweltering hot day. The colder the contents the more beads of sweat that form on the sides. The best vapor barrier to use is roll of plastic sheeting.

Item 491792 model hslw12 400. The cool surface is the sheathing assuming no exterior insulation. Unfaced batt insulation friction fit between studs in walls with poly vapor barrier over walls and ceilings blown in attics with minimum r 40 insulation attention to detail. Plastic on the outer surface of a wall in cold weather could cause problems.

How to install poly over insulation. The humid air is indoors. Plastic sheeting can also help turn a crawl space into a usable storage area.