Floor Joist Above Garage

Lay the joists on edge across the width of the floor.

Floor joist above garage.

If you need a storage area above your garage strong ceiling joists are necessary to support the added weight. The notching and boring rules of thumb for solid lumber are shown in fig. True floor joist span calculations can only be made by a structural engineer or contractor. If hvac ducts are routed through the floor assembly the floor joists must be deep enough to install several inches of insulation under the ducts.

In addition there is a requirement for a tji joist supporting a point load from above in excess of 1500 lbs within the span to have a web stiffener at that location per esr 1153 table 4 footnote 4. Air seal the floor above a garage when there is living space above the garage and make sure floor insulation is in full contact with the underside of the subfloor. If your home is more than 20 years old your floor joists are most likely solid wood 2x8s 2x10s or 2x12s. Building a framed wood floor over an existing concrete slab can provide the space needed for electric wiring heat venting plumbing drain lines and added insulation when remodeling a basement or garage space.

Seal all seams gaps and holes in the subfloor air barrier with caulk or foam. The wooden joists or beams over your garage help hold your roof in place. Air seal rim joists and any holes in the top plate of the garage walls. If you have an attic over your garage these joists also bear the load of your attic flooring and any materials you store in the attic.

Place them 16 inches apart. Nail cross blocking boards to hold the joists together every 4 feet. The taller the joists the more room for insulation and warmth of the floor. 1 5 to 2 inches above garage floor.

This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction. Install either 2 by 2 2 by 4 or 2 by 6 joists over the garage floor depending on how much room you have floor to ceiling. This will eliminate the need to worry about shimming an uneven floor vapor barriers ect. Tji joists in garage floors.

Can you not eliminate touching the garage floor at all and simple secure a 2x8 to perimeter walls and use joist hangers to build a deck sitting approx. You can notch and bore joists without sacrificing critical strength but you must follow the rules.