How To Install Insulation In Floor Joists

4b slab floors built directly on the ground.

How to install insulation in floor joists.

Cover the walls with insulation from the sill plate to the plastic covered dirt floor. Install the insulation with the paper vapor barrier facing up toward the heated living space and make sure the insulation fits tightly between the joists. If the insulation is too wide for the space cut it. Paper facing provides a moisture barrier and is always placed facing the space that is warmer in.

When you re using fiberglass batting insulation material run it about 6 inches or so onto the crawl space floor. Also insulate 4a any portion of the floor in a room that is cantilevered beyond the exterior wall below. Hold the insulation in place from below using insulation support wires or by stapling chicken wire to the bottom of the joists. It is important to secure insulation and cover it with a vapor barrier in order to prevent moisture and the mold that often follows close behind.

If you re insulating framed walls make sure the insulation is the correct thickness for your wall studs. 4d extend insulation into joist space to reduce air flows. In crawlspaces and basements make sure there are no cracks in the foundation. Insert the insulation into the space between the joists carefully.

Start at one end of the floor joist where it joins the vertical support wall. Fit the insulation pieces into the joist bay with the paper facing up toward the living space. Measure between joists if insulating a floor or attic or studs if insulating unfinished walls to find the correct width for the insulation. 4c as an alternative to floor insulation foundation walls of unvented crawl spaces.

Install the insulation with the vapor barrier facing up toward the heated living area of the house. In older homes where the spacing of the floor joists varies you may need to cut the insulation to width as well.