Demolition & Abatement

Demolition and abatement are among the most hazardous activities on any construction site. Unlike new construction, you are dealing with the unknown — hidden structural connections, concealed hazardous materials, and aging assemblies that may not behave the way you expect. On church renovation projects, the stakes are even higher: many of Ontario’s church buildings date from the 1940s through the 1970s, an era when asbestos, lead paint, and other designated substances were used routinely. This guide covers the 11 core skills needed to perform demolition and abatement work safely, legally, and effectively.

1. Selective & Structural Demolition

Church renovation projects almost always require selective demolition — removing specific elements while preserving the surrounding structure. This is not a sledgehammer-and-crowbar free-for-all. Selective demolition demands careful planning, a thorough understanding of the building’s load paths, and constant communication between the crew and the superintendent.

Church-Specific Demolition Considerations

Imagine you’re expanding a sanctuary by removing the back wall of a 1965 fellowship hall to connect it to a new addition. The existing wall may carry roof trusses, support a masonry veneer, and contain electrical and mechanical services. Before a single cut is made:

• Engage a P.Eng. to prepare the demolition sequence and temporary shoring design
• Complete the hazardous materials survey — that 1965 wall likely contains asbestos drywall compound, and the floor tiles in the fellowship hall are almost certainly 9″ × 9″ vinyl asbestos tile
• Protect what stays — install plywood hoarding, poly sheeting, and padding around stained glass, feature walls, AV equipment, and any architectural features
• Isolate the work area from occupied spaces — churches often remain in use during renovations, so dust barriers, negative air, and sealed doorways are essential
• Notify the congregation — vibration and noise from structural demolition will be significant

Selective Demolition Sequence — Best Practices

Selective interior demolition should always follow a disciplined sequence. Rushing the process leads to damage to retained elements, uncontrolled dust, and safety incidents. The standard sequence is:

1. Disconnect services: Confirm that all electrical circuits, gas lines, water supply, and HVAC ductwork serving the demolition area have been de-energized, locked out, and capped by qualified trades
2. Remove salvage items: Take out all designated salvage pieces (pews, fixtures, hardware, stained glass) before any destructive work begins
3. Install protection: Erect plywood hoarding, poly barriers, and padded protection around all retained elements
4. Remove finishes first: Strip ceiling tiles, light fixtures, drywall, flooring, and trim before touching any framing
5. Remove non-structural framing: Take out partition studs, blocking, and non-load-bearing headers
6. Address structural elements last: Only after shoring is in place per the P.Eng. plan
7. Clean as you go: Remove debris continuously — a cluttered demolition area is an unsafe demolition area

2. Concrete Sawcutting & Core Drilling

Many church renovation and expansion projects require cutting through existing concrete — floor slabs, foundation walls, footings, and grade beams — to create new openings, install services, or connect new construction to existing. This work generates significant dust (including silica) and requires precision to avoid cutting through reinforcing steel, post-tensioning cables, or embedded services.

3. Hazardous Material Identification (Pre-Demo)

Before any demolition work begins, a designated substance survey must be completed by a qualified person. Ontario’s Occupational Health and Safety Act (OHSA) and its regulations — particularly O. Reg. 490/09 (Designated Substances) — require employers to identify and manage 11 designated substances before work that may disturb them. On church buildings constructed before 1985, you should assume hazardous materials are present until the survey proves otherwise.

Common Hazardous Materials in Ontario Churches (Pre-1985)

4. Asbestos Awareness & Abatement

Asbestos is the single most regulated designated substance in Ontario construction. O. Reg. 278/05 (Designated Substance — Asbestos on Construction Projects and in Buildings and Repair Operations) establishes a detailed framework of operation types, worker training requirements, exposure controls, and notification procedures. Every crew member working on renovation or demolition projects must complete Asbestos Awareness training at a minimum.

Ontario Asbestos Operation Types (O. Reg. 278/05)

5. Lead Paint, Mould & Silica

While asbestos gets the most regulatory attention, lead paint, mould, and silica dust are equally dangerous to workers and building occupants. All three are common on church renovation projects, and all three have specific Ontario regulatory requirements.

Silica Exposure Control — Hierarchy of Controls

Silica dust is generated every time concrete, masonry, or stone is cut, ground, drilled, or demolished. Unlike asbestos, which is only present in specific materials, silica is present in virtually every concrete and masonry element on every project. The hierarchy of controls for silica exposure is:

• Elimination: Can the cut or demolition be avoided entirely? Consider alternative methods (e.g., mechanical breaking instead of cutting)
• Substitution: Not generally applicable — you cannot substitute the silica out of concrete
• Engineering controls: Wet cutting (continuous water supply to the blade), HEPA-filtered local exhaust ventilation on grinders and saws, enclosed operator cabs with filtered air on demolition equipment
• Administrative controls: Limit time in high-dust areas, rotate workers, schedule dusty operations when fewer workers are in the area, post silica warning signage
• PPE: Minimum N95 respirator for low-dust tasks; half-face P100 for cutting and grinding; full-face PAPR for prolonged or heavy exposure. Respiratory protection supplements engineering controls — it does not replace them

6. Debris Management & Waste Sorting

Demolition generates an enormous volume of debris, and how that debris is managed has regulatory, environmental, and cost implications. Ontario’s waste diversion regulations and landfill restrictions require construction waste to be sorted, and hazardous materials must be handled through licensed waste carriers and disposal facilities.

• Clean concrete & masonry: Crush on site for granular base or send to a concrete recycling facility
• Clean dimensional lumber: Salvage reusable stock; remainder to wood recycling or biomass
• Metals (steel, copper, aluminum): Separate by type and send to scrap recycling — this is revenue, not cost
• Asbestos-containing waste: Double-bag in labelled 6-mil poly, seal with tape, transport by licensed carrier, waste manifest required
• Lead-contaminated debris: Bag separately, dispose as hazardous waste through licensed facility
• General mixed waste: Minimize this stream — it is the most expensive disposal option

7. Salvage & Material Recovery

Church buildings contain irreplaceable elements — stained glass windows, hand-carved pews, century-old hardwood flooring, brass hardware, and stone carvings that cannot be manufactured today at any cost. Salvage is not an afterthought; it is a planned, skilled operation that must be coordinated with the demolition sequence.

Salvage Planning Checklist

• Inventory first: Walk the building with the congregation’s representative and create a written salvage list before demolition begins
• Photograph everything: Document each salvage item in place, with measurements and condition notes
• Number and tag: Apply numbered tags to each piece and record the location it came from
• Remove before demolition: Salvage items must be removed and stored safely before adjacent demolition work begins
• Protect from dust and debris: Wrap salvaged items in moving blankets or bubble wrap and store them away from the active work area
• Stained glass: Engage a specialist glazier for removal — stained glass panels are fragile, heavy, and often held in place by deteriorating lead came that can fracture during removal
• Hazmat check: Verify that salvage items are not contaminated with lead paint or asbestos before handling — painted pews may have lead paint, and ceiling-mounted fixtures may be coated in asbestos-containing fireproofing

Stained Glass — Special Handling Requirements

Stained glass windows are among the most valuable and fragile elements in any church building. Many date from the early 20th century and are irreplaceable. Removal requires a specialist glazier experienced in leaded glass, but every crew member working near stained glass must understand the basic precautions:

• Never apply pressure to the face of the glass — stained glass panels are held together by lead came, which weakens with age and can fracture under lateral pressure
• Protect from vibration: Demolition work adjacent to stained glass windows must be planned to minimize vibration — use mechanical methods rather than impact tools when working within 3 m of a stained glass panel
• Transport vertically: Stained glass must be transported standing up, never laid flat — the weight of the glass will cause the lead came to deform if the panel is horizontal
• Store in padded, vertical racks: Use A-frame racks with carpet or foam padding between each panel
• Lead came is a lead hazard: Workers handling stained glass with exposed lead came must wear gloves and wash hands before eating or drinking