Module 3: Structural Repairs & Restoration
1. Diagnosing & Repairing Structural Issues
Structural integrity is critical in carpentry—identifying and fixing problems early prevents catastrophic failures.
Sagging Floors, Cracked Beams, and Foundation Settling
Sagging Floors – Often caused by undersized joists, moisture damage, or termite infestation.
Diagnosis: Use a level or laser to measure deflection; inspect for rot or insect damage.
Solution: Reinforce with sister joists or install new support beams.
Cracked Beams – Result from overloading, wood shrinkage, or improper installation.
Diagnosis: Visual cracks (horizontal cracks are more serious than vertical).
Solution: Epoxy injection for minor cracks; replacement or steel plating for severe damage.
Foundation Settling – Causes uneven floors and wall cracks.
Diagnosis: Check for diagonal cracks in drywall or brick mortar.
Solution: Underpinning (helical piers/concrete piers) or mudjacking to lift and stabilize.
Sistering Joists and Beam Reinforcement
Sistering Joists – Adding a new joist alongside a damaged one to restore strength.
Process: Glue & bolt new lumber to the old, ensuring full-length support.
Beam Reinforcement – Options include:
Flitch plates (steel sandwiched between wood).
LVL (Laminated Veneer Lumber) splices for added strength.
2. Historic Woodwork Restoration
Preserving antique woodwork requires balancing authenticity with structural soundness.
Matching Antique Moldings and Trim
Replicating Profiles – Use a contour gauge or router bit set to duplicate historic trim.
Material Matching – Source old-growth wood or use reclaimed lumber for consistency.
Aging Techniques – Distressing new wood with stains, shellac, or hand tools to mimic patina.
Traditional vs. Modern Repair Techniques
Traditional Methods
Hide glue for reversible repairs (used in museums).
Hand-cut joinery (dovetails, mortise & tenon) for period accuracy.
Modern Methods
Epoxy consolidants for rotted wood.
CNC routing for precise molding reproduction.
Structural adhesives when hidden strength is needed.
Key Takeaways:
✔ Structural repairs require proper diagnosis—sistering joists, beam reinforcement, and foundation fixes restore stability.
✔ Historic restoration blends old-world craftsmanship with modern adhesives and replication techniques.
✔ Matching antique woodwork demands attention to detail in profiles, materials, and aging methods.
.svg)
