Stabilizing A Sagging Wood Stair
- Procedure code:
- Hspg Prepared For Nps - Sero
- Wood and Plastics
- Stairwork & Handrails
- Last Modified:
STABILIZING A SAGGING WOOD STAIR
A. This procedure includes guidance making minor repairs to
a sagging stair by repairing and/or replacing cleats -
typically 1x6 wood boards that support the center of the
NOTE: CLEAT REPLACEMENT MAY BE PERFORMED BY A NON-
PROFESSIONAL; HOWEVER, THIS PROCEDURE REQUIRES THE
REMOVAL OF THE CEILING SURFACE BELOW THE STAIR IN
QUESTION. THEREFORE, THIS WORK SHOULD BE EXECUTED BY AN
NOTE: ALMOST ALL STRUCTURAL STAIR REPAIR INVOLVES THE
REMOVAL OF THE CEILING SURFACE UNDER THE STAIR. MAJOR
STRUCTURAL REPAIRS MAY REQUIRE BRACING AND DISASSEMBLY OF
STAIR AND SHOULD BE LEFT TO PROFESSIONALS.
B. A stair may noticeable sag as a result of building
settlement, poor original construction, or shrinking and
warpage in wood.
C. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed prior to performing
this procedure and should be followed, when applicable,
along with recommendations from the Regional Historic
Preservation Officer (RHPO).
A. A Stair is composed of stringers, either open, housed, or
skirted; carriage; kick plate (a.k.a. scantling block);
newel base; and the cleats.
B. Cleats - Cleats are used to stabilize the stair when the
carriage is not notched to receive treads and risers.
Cleats are usually 1x6s nailed to the carriage and rise
to support the center of treads.
A. Replacement 1x6 stock for cleats
C. Materials for removing and replacing plaster (see 09210-03-R)
A. Equipment for removing and replacing plaster (see 09210-03-R)
B. Claw hammer
A. Inspect for the signs of insect infestation such as mold,
fungus, bore holes, and sawdust piles.
3.02 ERECTION, INSTALLATION, APPLICATION
A. Carefully remove ceiling surface under the stair in
question. This usually entails removal of all plaster
and lath. See 09210-03-R for guidance in removing
B. After exposing structure from below, check condition of
1. Are any cleats missing?
2. Are any pulled away or loose?
3. Are cleats all nailed to the same side of carriage?
C. Reattach any loose cleats and replace missing or damaged
cleats with new stock. Attach tight with underside of
tread and back of riser.
D. If cleats are nailed to only one side of carriage, remove
every other one and attach to other side of carriage to
E. Replace ceiling surface below as required. See 09210-03-R
for guidance on replastering.
END OF SECTION