Technical Procedures Disclaimer
Prior to inclusion in GSA’s library of procedures, documents are reviewed by one or more qualified preservation specialists for general consistency with the Secretary of Interior Standards for rehabilitating historic buildings as understood at the time the procedure is added to the library. All specifications require project-specific editing and professional judgement regarding the applicability of a procedure to a particular building, project or location. References to products and suppliers are to serve as a general guideline and do not constitute a federal endorsement or determination that a product or method is the best or most current alternative, remains available, or is compliant with current environmental regulations and safety standards. The library of procedures is intended to serve as a resource, not a substitute, for specification development by a qualified preservation professional.
We’ve reviewed these procedures for general consistency with federal standards for rehabilitating historic buildings and provide them only as a reference. Specifications should only be applied under the guidance of a qualified preservation professional who can assess the applicability of a procedure to a particular building, project or location. References to products and suppliers serve as general guidelines and do not constitute a federal endorsement nor a determination that a product or method is the best alternative or compliant with current environmental regulations and safety standards.
- This procedure includes guidance on resecuring a loose wood handrail.
- See 01100-07-S for general project guidelines to be reviewed along with this procedure. These guidelines cover the following sections:
- Safety Precautions
- Historic Structures Precautions
- Quality Assurance
- Delivery, Storage and Handling
- Project/Site Conditions
- Sequencing and Scheduling
- 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).
- The stair balustrade is composed of the handrail and the balusters. The handrail usually connected to the newel post with a rail bolt and star nut.
- In an open string stair, the outer stringer is cut to reveal the stepping of the stairs. The balusters are dovetailed into the treads and the handrail is bored to receive the balusters.
- In a closed string stair, the treads and risers connect to the stringer from one side. The balusters are fit into a groove in the top of the stringer and the bottom of the handrail and then toenailed in place.
- Replacement stock for new dovetail (if needed)
- Wood shims
- Wood spacers cut to fit between balusters
- Wood glue
- Finish nails
- Pry bar
- Claw hammer
- Wood driving block
- Chisel, or solvents to remove old glue and varnish
- Dovetail saw
- Dovetail plane
3.01 ERECTION, INSTALLATION, APPLICATION
- For a loose balustrade in open string stair:
NOTE: IN THIS TYPE OF STAIR CONSTRUCTION, THE BALUSTER IS USUALLY DOVETAILED IN PLACE. A DOVETAIL IS A SPLAYED TENON, SHAPED LIKE A DOVE'S TAIL - BROADER AT ONE END.
- Pry off return nosing and cove moulding from tread.
- Remove any visible nails holding the baluster in place.
- Shim as required between the tread and baluster to tighten connection.
- If shims don't work, ease the baluster out of position and remove all old glue and varnish from the surfaces of the connection.
- Glue the surfaces of the connection and replace baluster. Drive a single nail into the dovetail to secure. Toenail baluster into handrail.
- If dovetail is open or split, make a new dovetail to fit opening and attach to baluster with a glue-soaked dowel.
- Using a dovetail saw, cut a piece of wood in the dovetail shape to fit securely in the dovetailed mortise of the tread.
- Drill a small hole in the bottom of the baluster and in the dovetail.
- Pour wood glue into hole so that it is half full. Insert dowel into the dovetail and allow to dry.
- Pour wood glue into hole so that it is half full.
- Connect baluster and new dovetail by inserting dowel into glue-filled end of baluster.
- Wipe excess glue from the surface using a clean cloth and allow to dry.
- Reset baluster in between tread and nail. Drive a single nail into the dovetail to secure. Toenail baluster into handrail.
- After baluster is securely in position, replace return and cove moulding. For guidance on silencing a squeaky stair tread, see 06430-03-R.
- Loose baluster on a closed string stair:
NOTE: INDIVIDUAL BALUSTERS ARE USUALLY NAILED TO GROOVE IN STRINGER AND HANDRAIL, AND ADDITIONALLY SECURED BY SPACERS THAT FIT BETWEEN THE BALUSTERS IN THE BALUSTER GROOVE.
- Remove and replace spacers.
- Drive wood shim between baluster and closed stringer with a hammer and driving block.
- Carefully toenail through baluster into stringer and/or handrail.
- Remove and replace spacers.