Repair, Restoration, and Renovation Work
Renovation and repair work calls for diagnosis before repair. The exam tests how you assess an existing assembly, restore its performance, and handle hazardous materials and documentation.
Assessment
Sound the surface with a hammer or tapping tool; a dull, hollow sound means delamination or lost key. Use a moisture meter at stains and below windows. Map cracks and decide whether they are hairline, shrinkage or structural, and whether the cause has been corrected. Test adhesion of existing coatings, and look for previous patches, unbacked joints and corroded fasteners.
Repair methods
- Reattach loose plaster with plaster washers and screws into framing, then skim.
- Cut back to sound material, prefill deep voids with setting compound or patching plaster, then tape and feather.
- Remove and re-board large unstable areas rather than skimming over them.
- Structural cracks need evaluation before any cosmetic repair.
- Preserve assembly performance: if the wall is a fire separation or sound-rated, the repair must use the same board type, fasteners and firestopping as the original design.
Hazardous materials
In buildings from before the 1990s, joint compound and textured finishes may contain asbestos, and lead paint and vermiculite insulation are also possible. A survey is required before disturbance. Contain the area with poly and negative air, use HEPA equipment, dispose of debris as required, and document everything.
Worked example
A 1965 house has a sagging plaster ceiling with a water stain but no visible crack.
Reasoning: sag plus stain suggests a failed key and previous moisture. Use a moisture meter to confirm the leak is fixed, then sound the area. If delamination is limited, reattach with washers and skim; if plaster is loose over a large area or the lath is deteriorated, remove and re-board. Before any cutting, arrange the asbestos survey, because ceiling texture and joint compound of that era are suspect.
Traps
Skimming over a loose or dirty substrate; patching with a compound harder than the surrounding plaster; not finding the cause of a crack; disturbing suspect asbestos without a survey; failing to photograph existing conditions before work starts.