fakro LWS-M Manuel D'installation page 9

Bebee
thedistancebetweenthejoistsshouldbethe sameasthe widthof installation opening. All cutjoistsmust b e attachedto the ioiststhathavenot
been cut.
WAR•JING!
withstandload. In orderto makea workingarea placeseveral b oardsacross the ceilingjoists.
If noneof theioistswerecutproceedto section"singleheader".
Ifoneor moreioists werecutproceedto section "doubleheaders"
on page 8.
STEP
Measurethe distancebetweenthe ceiling ioists. Themeasurement
shouldbe doneperpendicular t o the joist(Figure 12).
STEP 2
Cut 2 boards for headersto the measuredlength. Usetimber
material similar in size to the ioists.
STEP 3
Position the header at one
(Figure 13). Theheadermust t ightlyfit betweenthejoists.
ed usea hammer t o positionthe header.
SÉp 4
Alignthe headerat 900angleto thejoistsand drive3 nails(16D)
at each end.
STEP 5
Positio n the second header 31", 47" or 54" apart fromthe first
one and repeat step 4 (Figure 14).
headers dependson ladder model.
STEP 6
The frame must have four sides w here the headers are two of
them. If the ceiling joistsare positionedas the other two sides
checkthe anglesby measuring the diagonals. Bothmeasured
dimensions shouldbe within 1/8" to consider themequal.
If the ceiling ioistsdo not makethe Othertwo sidesOfthe frame,
you shouldinstallone or Wvo woodenelements in order to make
theframeinthe ceilingopening.Proceed to section"installation of
stringers
w. FRAMING THE INSTALLATION
end of the installation
opening
If need-
The distance between
OÆNING
Do not siton theceiling- it isnot designedto carry load. Only joistswill
Fig. 1 2.P Distance b etween theceiling joists.
eade
Fig. 1 3.Nail the headerat both ends.
the
Fig.
9
nails
ea
t
cel
Dl=D2
D2
nails
header
EN
t