mer studs form the rough opening for
the door.) Finally, cut a 27¾-in.-long
2x4 temporary header to span across
the top of the trimmer studs. Screw
the parts together with 3-in. deck-
ing screws. Once the wall is installed,
remove the header. Use a paint pad to
apply a coat of solid-color stain to all
surfaces of each part [ 9 ]. A llow the
stain to dry overnight.
ATTACH THE POLYCARBON-
ATE PANELS
Doing this to the wall frames prior to
erecting them will save you time and
trouble. Begin by peeling off the clear
protective film from the back side of
each polycarbonate panel. Lay the
polycarbonate across the walls, start-
ing in the center of the wall frame.
Make sure all seams align with the
center of a stud, but leave a 1⁄8 -in.
expansion gap between the panels.
Fasten the polycarbonate panels to
the wall frames with 1¼-in. decking
screws spaced about 16 in. apart.
Slide the polycarbonate pan-
els into place at each end of the wall
frame [ 10 ], and then use a router fit-
111013 161415ted with a f lush-trim bit to cut away
the overhanging polycarbonate [ 11 ].
A router provides the quickest and
most accurate way to trim the poly-
carbonate, but if you don’t own a
router, lay the polycarbonate panel in
place, mark where it overlaps the wall
frame, and then trim it to size using a
circular saw or jigsaw.INSTALL FOUNDATION
AND WALLS
Set the timber frame foundation on
the ground and use a 4-ft. level to con-
firm that it’s level across its width and
length. If necessary, dig out or build up
the underlying soil until the frame is
level. Next, bore ½-in.-diameter holes,
spaced about 24 in. apart, through
the timber frame. Use a small sledge-
hammer to pound ½-in.-diameter
x 18-in.-long steel reinforcing bars
through the holes and into the ground
[ 12 ]. The bars will keep the founda-
tion from shifting. Cover the ground
within the timber frame with land-
scape fabric; then add 3 in. of gravel
or bark mulch to create the floor.
Install the prefabricated walls,
starting with one of the sidewalls.
Stand the wall on the timber framefoundation, aligning the sole plate
f lush with the outer edge of the 4x6
foundation timber [ 13 ]. Secure the
wall to the foundation by driving 3-in.
decking screws down through the
sole plate and into the 4x6 below [ 14 ].
Space the screws about 24 in. apart.
Repeat to install the opposite sidewall.
Raise the rear wall, sliding it
between the two sidewalls, and con-
firm that the walls are plumb. Screw
the rear wall down to the foundation
with 3-in. drywall screws, and then
screw through the studs at each end
of the rear wall and into the sidewall
[ 15 ]; space the screws 16 in. apart.
Repeat to install the front wall [ 16 ].
Then use a handsaw or reciprocating
saw to cut out the 2x4 sole plate that
runs across the doorway threshold.12