4b slab floors built directly on the ground.
How to install insulation in floor joists.
Insert the insulation into the space between the joists carefully.
Hold the insulation in place from below using insulation support wires or by stapling chicken wire to the bottom of the joists.
4c as an alternative to floor insulation foundation walls of unvented crawl spaces.
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.
Install the insulation with the vapor barrier facing up toward the heated living area of the house.
Measure between joists if insulating a floor or attic or studs if insulating unfinished walls to find the correct width for the insulation.
Paper facing provides a moisture barrier and is always placed facing the space that is warmer in.
Fit the insulation pieces into the joist bay with the paper facing up toward the living space.
Cut pieces of insulation just large enough to fit along the rim joist the framing material into which all the floor joists are nailed.
Start at one end of the floor joist where it joins the vertical support wall.
When you re using fiberglass batting insulation material run it about 6 inches or so onto the crawl space floor.
In crawlspaces and basements make sure there are no cracks in the foundation.
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.
Also insulate 4a any portion of the floor in a room that is cantilevered beyond the exterior wall below.
The sill plate is the first piece of framing lumber and it runs on top of the crawl space wall.
If the crawl space is ventilated which is ideal because it aids in the elimination of moisture then fiberglass insulation can be easily installed under the subfloor between the floor joists.
In older homes where the spacing of the floor joists varies you may need to cut the insulation to width as well.