Installation Guide

4
STEP A.3 – Brace and Block the Stringers
An important consideration for a sturdy installation is to
install sufficient bracing at key points in the rough carriage.
Points at which newel posts will be mounted, where rails
will terminate or where outside skirt boards and decorative
trim will be applied should all be carefully framed and
reinforced at this stage (see Fig. 3-1).
P
lace spacer between
stringer and adjacent walls
t
o allow for sheetrock,
skirt board, etc.
Doubled riser
blocks at base
of stairway
Riser blocks
e
very fourth
or fifth step
Ledger
Doubled rafter
a
t top of stairway
2 x 4 floor cleat
S TEP
A.3
SECTION A
3
2 x 4 cleat on floor
Hangerboard secured
t
o doubled rafter
SECTION A
S TEP
A.2
FIG. 2-1 - Cleats, ledgers and reinforced mounting
points are required for sturdy installation
FIG. 3-1 - Bracing and blocking the rough stair carriage
STEP A.2 – Install The Stringers
Sturdiness and safety demand secure mounting of the
stringers. Use of a cleat at the lower end and a plywood
hangerboard at the upper end (see Fig. 2-1) are the best
guarantee of this. Also, plan to install vertical support framing
at one or more points, consistent with future use of the area
under the stairway. If you plan to add sheetrock and/or skirt
boards, place a spacer of equal or greater thickness between
the stringer and any adjacent roughed-in walls.
ALTERNATE M ETHOD:
If no triangle cut from a stringer is available, lay a straightedge
across the tread nosings and use it to mark a piece of plywood
as shown in Fig. S-3b. Make sure the plywood is square and that
it is held f
irml
y ag
ainst the tread nosing.
NO
TE
:
The r
ise and r
un should r
emain the same throughout the
stairway; however,
IF THE RISE AND RUN VARIES FROM FLIGHT TO
FLIGHT
, make a separate pitch block for each flight of stairs.
S T AIRN O TE
T HREE
H OW TO
M AKE A P ITCH B LOCK
Pitch
block
Stringer
Rake
Rise
Run
Plywood
scrap
Straight
edge
Pitch
block
The pitch block is a right triangle cut from 2 x 12 lumber that will
become a critical measuring tool for constructing the balustrade.
Save one of the triangles cut from a stringer. (Remember that
critical measurement and cutting of stringers is a basic necessity for
a good stairway. Accuracy to within
1
/32" will make the installation
go smoother.)
The pitch block reproduces the exact angles of the stairway. Mark
its three sides as shown in Fig. S-3a, and put it aside for later use.
FIG. S-3a - Save a triangle of wood from your stringer.
Mark it as shown. It will become your pitch block.
FIG. S-3b - Making a pitch
block for an e
xisting stairw
a
y