Construction Framing Mr. Brock

Lumber 2x4s are not actually 2” by 4”

Lumber The lumber is cut 2” by 4” but after being planed and dressed the actual dimensions are 1 ½ by 3 ½ inches. 1 inch boards are only planed and dressed to ¾ of an inch, so a 1x4 is actually ¾ by 3 ½ Any boards 8 inches or more are trimmed ¾ of an inch, so a 1x8 is actually ¾ by 7 ¼

Lumber 1x4 = ¾ x 3 ½ 2x4 = 1 ½ x 3 ½ 2x 6 = 1 ½ x 5 ½ 2x8 = 1 ½ x 7 ¼ These sizes are very important when framing because if you add wrong you could throw everything off.

Lumber 1 x 12 x 1 = 1 board foot Calculating Board Feet T” x W” x L’ = Board Feet 12 Ex: 1 x 12 x 12 12 = 12 BF

Calculate the following 2 x 4 x 12 2 x 6 x 8 1 x 10 x 8 2 x 12 x 12 4 x 4 x 10 6 x 6 x 10 10 pieces 2 x 4 x 12 24 pieces 1 x 12 x 12

Wall Framing

Framing The main wall supports in a wall are called studs. Studs are generally 2x4s, and are usually 8 or 9 feet long. Studs are spaced on 16 inch centers to provide proper support. Cripple Studs are short studs cut to go under windows, and trimmer studs line the windows to support the Header.

Framing A Header consists of two 2x4s turned edgeways with a strip of ½ inch plywood in between. The purpose of the ½ inch plywood is to make the header the same thickness as the studs. The purpose of the Header is to carry the weight of the ceiling and roof over window and door openings. The Header should be cut to the length of the opening plus the two trimmer studs. Ex: 34” opening = 37” (2 trimmers 1 ½ each)

Framing At the base of the wall is the Sole Plate. At the top of the wall is the Top Plate. All of the studs are nailed at the bottom to the sole plate and at the top to the top plate. After all of the interior and exterior walls are constructed and erected the 2nd or double top plate is nailed on. The purpose of the double top plate is to tie the walls together and it should be nailed on in a way that accomplishes this.

Floors and stairs Floor Joists are commonly 2x8s or 2x10s on a 16” spacing. The floor joists support the structure and are very important. ¾” tongue and groove subflooring should be used over the joists. Stairs can be cut out a 2x10. Specific stair layout is covered in Unit 39 pg 570.

Trusses

Trusses The inclining or vertical pieces are the Top Cords. The horizontal pieces that sit on top of your walls are the Bottom Cords. Gussets are the metal or wood brackets used to fasten and hold the truss together. Although not pictured in the diagram sometimes a Birds Mouth is notched into the truss where it would sit on the exterior wall.

Shingles The most common residential roofing material is asphalt shingles.

Shingles A standard asphalt shingle is 36” or 3 feet long. Each shingle has 3 tabs, so each tab is 12” or 1 foot long. A Square of shingles consists of 3 bundles and covers 100 square feet. A starter strip is laid first under the first row of shingle to fill in between the tabs of the first row. 3 inches of shingle should be exposed on the 1st row, and 5 inches on each row thereafter.

Framing Nails 16d nails are used to nail floor joists, studs and rafters. 16d nails are 3 ½ inches long and provide more strength for the thick lumber used in framing. 8d nails are used to nail plywood. 8d nails are 2 ½ inches long, that is all that is necessary because plywood is generally ¾ or less.