Keller W2200 Serie Instrucciones De Instalación página 14

Section 1.6 (continued)
FRAMING THE ROUGH OPENING
Installing Headers:
If no joists have been cut, go to "Single Headers"
below.
If any joists have been cut, go to "Double Headers"
on page 15.
Single Headers:
STEP 1. Measure the header length "H" between
the joists (See Figure 11).
STEP 2. Cut 2 headers this length. Use
joist-sized lumber.
STEP 3. Place one of these headers at one end of
your chosen location (See Figure 12).
The header must fit snugly between the
joists. Hammer it into position if necessary;
if it is more than 1/16" too long, trim it.
If it is more than 1/16" too short, cut
another piece.
STEP 4. Square the header to one joist and drive
(3) 16d nails through the joist and into the
header. Check for squareness and drive
(3) 16d nails through the other joist and
into the header (See Figure 12).
It is very important that header board
is vertically plumb as well as
horizontally square to side joists.
STEP 5. Position the second header 54" from
the first one and repeat Step 4
(See Figure 13).
STEP 6. The frame for the rough opening requires
four sides. The headers make up two of
those sides. If your ceiling joists are
spaced so that they make up the other
two sides of the rough opening, check
the opening for squareness by measuring
across the diagonals. The measurements
should be within 1/8" to be considered
square (See Figure 13). If your ceiling
joists do not make up the other two sides
of the rough opening, you need to install
one or two additional pieces of lumber
to frame the other side(s) of the rough
opening, go to "Installing Stringers" on
page 16.
14
H
FIGURE 11
Joists
Nails
Drive (3) 16d nails
into each end of header
FIGURE 12
Diagonal
measurements
Nails
FIGURE 13 How to check for square
Header
Header
54"
Header