Tip- Walk/Crawl through the area looking at the floor joists. Look for joists that been notched out on the bottom side or that have holes in the center. Refer to chart below for guidelines for notch placement and depth and acceptable hole sizes. Look for water damage especially around plumbing lines. Water damage can weaken the structural integrity and cause mold issues. Next look for any joist that may be cracked, sagging, or twisted. Look for any joist that have had whole sections cut out and do not have a full length and appropriated sized sister joist. If any of these issues are found, you should have them assessed by a licensed and insured carpenter or structural engineer. Additional support or a sister joist may need to be installed for structural integrity. Finally look to verify the rim joist cavities have at least a R-10 value of insulation in them. The cavities are susceptible to thermal deficiencies. Foil-faced polyisocyanurate (Styrofoam type) insulation is recommended to insulate and help prevent moisture build up in rim joist cavities over fiberglass batt insulation.

Joist Notch and Hole Chart
Joist Notch and Hole Chart
Water Damage and Cracked Joist
Water Damage and Cracked Joist
Sagging Joist
Sagging Joist
Uninsulated Rim Joist Cavity
Uninsulated Rim Joist Cavity