Click image to enlarge.
1.
Establish the size of the shed by laying out and cutting the treated 2x4 bottom
plates. To accurately space and mark the posts, use as patterns a 2x4 cut to
the width of the window sash plus 1/8 in., and a small section of 4x4. Drive
reference stakes along the house or garage to mark the corners and establish
the floor height. Then lay the plates on the ground to establish the
approximate perimeter.
Click image to enlarge.
2. First
pound wooden stakes into the ground about 18 in. outside the perimeter of the
shed to support the 1x4 batter boards. Then establish the floor height by
leveling across from the reference stake with a string and line level. Mark
each stake.
Click image to enlarge.
3. Align
the top edge of the 1x4 batter boards with the marks and screw the boards to
the stakes. Then stretch strings between the batter boards and reference stakes
to indicate the locations of the 6x6 beams and two 4x4 support posts. Subtract
1 in. from the length of the outside wall plate and 1/2 in. from the end plates
(the plates overlap the beams 1/2 in.) to determine the beam lengths and
positions. Check that the strings form right angles by measuring diagonally
from one corner to the other. Adjust the strings until the diagonal
measurements are equal and all the sides are the correct length. Tie the
strings to nails to hold them taut.
4. Position
footings according to your plan. Then dig footing holes with a post hole digger
and set 8-in. dia. cardboard forming tubes into them. To establish the correct
footing height, measure down from the string the thickness of your 6x6 beam
plus the floor thickness, mark the tubes and cut them to this length with a
sharp utility knife. Then place them back in the holes, wedge them solidly so
the beams will center on them, and fill them with concrete. Set 1/2-in. x
12-in. anchor bolts into the center of each and smooth the
tops.
5. Transfer the layout lines to the footings by
plumbing down from the string and marking the concrete piers. Connect the marks
with a chalk line. Cut the 6x6 beams to length, allowing an extra 3 in. on the
side wall beams so they’ll fit into the existing foundation (Photo
7).
Click image to enlarge.
6. Lay the
outer beam on the footings and measure from the chalk line to the center of the
anchor bolts. Transfer these measurements to the 6x6 beams. Drill 5/8-in. holes
through the beams at these marks. Drill 1-in. holes 1/2 in. deep torecess the
washer and nut.
Click image to enlarge.
7. Bolt the
outer beam to the footings. Use a masonry blade on a circular saw to cut a
pocket in the block foundation to support the end of the 6x6 (or pour another
footing if the foundation is concrete). Spread pea gravel under the beams.
Connect the side beams to the outer beam with 3/8-in. x 10-in. lag
screws.
Click image to enlarge.
8. Pry off the soffit and fascia material in
the area of the shed. Remove full pieces if possible. Then cut and replace them
after the shed is built.
Click image to enlarge.
9. Mock up
the walls and rafter to make patterns. Position the 4x4 posts at the wall
locations (overhanging the 6x6 beams by 1/2 in.), plumb them in both directions
with a level, and brace them with 2x4s. Make a rafter pattern by cutting the
wall angle on the end of a 2x6, sliding it under the overhang, and temporarily
securing it to the wall. Use a taut string to align the 2x6 with the existing
roof and temporarily screw or nail it to the posts. Mark the 2x6 along each
side of the 4x4 posts.
Click image to enlarge.
10. Mark
the posts along the underside of the 2x6. Use these marks to establish the wall
height and length of the 4x4 posts. Take the 2x6 and posts
down.
Click image to enlarge.
11. Mark
the 2x6 to make a pattern rafter. Draw the seat cut (where the rafter rests on
the top plate) at a right angle to the post marks. Then use a Speed square to
transfer the “plumb cut” angle to the end of the rafter, 11 in.
beyond the seat cut for the overhang.
12. Cut the
outside 4x4 top plate 2 ft. longer than the outside 2x4 bottom plate to support
the overhanging rafters. Cut the end 4x4 top plates 1-3/4 in. longer than the
end 2x4 bottom plates to fit into the notch in the outside 4x4. Align the 2x4
bottom plates with the 4x4s and transfer the layout marks. Cut a 1-3/4 in. x
3-1/2 in. notch in each end of the front 4x4 to accept the side
4x4s.
Click image to enlarge.
13. Cut the
4x4 posts to length and assemble the walls. Pound two 6-in. pole barn nails
through the pre-drilled 4x4 top plate and into each 4x4 post. Drill two 1/8-in.
pilot holes through the 4x4 top plate at each post location and pound 6-in.
pole barn nails through the 4x4 into the posts. Secure the treated bottom plate
to the 4x4 posts by nailing two 16d galvanized box nails into each
post.
