Demolition & Selective Demo
Demolition is reverse engineering — you can't un-remove a load-bearing wall. The floor sags slowly over 6 months, not immediately, so you don't realize the mistake until the damage is done.
Written by Pavel Vysotckii
BCIN-certified building designer & Quantity Surveyor · Updated June 2026
Project Overview
Fixed Milestone Pricing
You approve each stage before it's paid
What is demolition & selective demo?
Demolition is controlled deconstruction — removing building elements while preserving structural integrity, managing hazardous materials, and minimizing damage to surrounding areas. The job breaks into three categories:
**1. Selective demolition** (surgical removal): taking out specific walls, ceilings, or floors while leaving the rest intact. This is renovation prep work — removing a kitchen, opening up a wall between rooms, stripping a basement to studs. The challenge is knowing what's load-bearing. Follow the load path: roof load → rafters or trusses → top plate of wall → studs → bottom plate → beam or foundation. If a wall sits directly over a beam in the basement, or if floor joists run perpendicular and bear on the wall, it's carrying load. Removing it requires a beam (steel W-shape or engineered lumber LVL) sized by an engineer, installed with temporary shoring (Acrow props, strongback beams) to carry the load during the swap.
**2. Hazardous material abatement**: asbestos and lead are the big two. Homes built before 1980 likely contain asbestos in multiple forms — vermiculite attic insulation (especially from Libby, Montana mines), 9x9" vinyl floor tiles, pipe insulation, textured ceiling coatings, cement shingles. Ontario Regulation 278/05 governs asbestos work: if you're disturbing more than 1 square meter or removing more than 1 linear meter of asbestos-containing material, you need an abatement contractor with MOL certification. Lead paint is in almost every home built before 1960, and common until 1978. Sanding or scraping releases lead dust — wet methods, HEPA vacuums, and containment are required. XRF guns test for lead instantly; lab analysis is more accurate but takes 1-2 weeks.
**3. Structural demolition and shoring**: removing or altering load-bearing elements. This requires engineering: calculate loads (dead load from structure + live load from occupancy + snow load on roof), size the replacement beam, specify bearing points and footings, design temporary shoring. Steel W-beams (W8x18, W10x22) are common for residential spans up to 20 feet. Engineered lumber (LVL, PSL) works for lighter loads. The beam must bear on adequate support — either existing foundation walls (with bearing plates to distribute load) or new posts with footings. A 10" steel beam carrying two floors requires footings at least 24"x24"x12" deep to prevent settling.
The demolition sequence matters: **top-down, perimeter-in**. Remove roofing before roof structure, roof before walls, upper floors before lower. Work from outside edges toward the center to maintain bracing. Cutting floor joists or rafters in the wrong order can cause collapse — temporary bracing (strongbacks, Acrow props) holds the structure stable until permanent framing is in place.
When you need demolition & selective demo
- Opening up a floor plan by removing walls between kitchen, dining, and living areas
- Gutting a kitchen or bathroom to studs for a full renovation
- Removing a load-bearing wall to create an open-concept space (requires engineer and beam installation)
- Stripping a basement to foundation walls for waterproofing, underpinning, or second unit conversion
- Removing hazardous materials (asbestos, lead) before renovation
- Tearing down an old garage, shed, or accessory structure
- Removing a deck, porch, or exterior stairs that are rotted or unsafe
- Demolishing a house for new construction (full teardown)
The Process
What happens from start to finish
1. Hazardous Material Assessment
3-5 days for testing, 1-5 days for abatement depending on scopeBefore touching anything, test for asbestos and lead. Hire a designated substance survey (DSS) consultant to sample suspect materials — vermiculite insulation, floor tiles, drywall joint compound, pipe wrap, textured ceilings. Lab analysis takes 3-5 days. If asbestos is present and you're disturbing >1 m², hire a certified abatement contractor (O.Reg 278/05). Lead paint testing: XRF gun gives instant results, or send paint chip samples to a lab. Homes built before 1960 assume lead is present. Encapsulation (covering with new drywall) is cheaper than removal; removal requires containment, HEPA vacuums, and certified disposal.
2. Structural Assessment and Engineering
1-2 weeksIf removing or altering walls, hire a structural engineer to assess load paths. The engineer will identify load-bearing walls, calculate loads (dead + live + snow), and design replacement beams and support posts. Expect drawings showing beam size (W10x22 steel or 3-ply 2x12 LVL), bearing points, footing sizes, and shoring plan. Cost: $800-$2,500 for a typical residential beam design. Submit drawings with building permit application — structural modifications require permits and inspections.
3. Permit Application (if required)
1-3 weeksDemolition permits are required for: removing load-bearing walls, structural modifications, full building demolition, and asbestos abatement in some municipalities. Non-structural interior demo (cabinets, drywall, flooring) typically does not require a permit unless it's part of a larger renovation. Submit engineer's drawings, pay permit fee ($200-$800), wait for approval (1-3 weeks). Emergency demolition (unsafe structure) can be permitted retroactively in some cases.
4. Site Setup and Protection
0.5-1 daySet up containment if working in occupied space — plastic sheeting barriers, dust control, HEPA air scrubbers if asbestos or lead work. Protect floors with Masonite or ram board (drywall on floor tears easily). Cover HVAC registers to prevent dust spread. Set up debris chute or bins — 10-yard bin for small demo, 20-40 yard for full gut. Shut off utilities if needed: electrical (panel breaker), plumbing (main shutoff or fixture shutoffs), gas (main valve or appliance valves). Verify shutoff before cutting — cutting a live wire or pressurized pipe is dangerous.
5. Demolition Execution
1 day to 2 weeks depending on scopeWork top-down, perimeter-in. For load-bearing wall removal: install temporary shoring first (Acrow props spaced 4-6 feet apart, bearing on strongback beam above and below), then cut and remove drywall, insulation, studs, top and bottom plates. Install new beam (steel W-shape or LVL) on bearing plates at each end, jack into place, secure with bolts or straps, then remove shoring. For non-bearing walls: cut drywall, pull studs, remove plates. For flooring: pull carpet/vinyl/tile, remove subfloor if needed (plywood or OSB screwed or nailed to joists). For cabinets: disconnect plumbing and electrical first, remove screws securing to walls and floor, lift out. Dispose of debris in bins — separate recyclables (metal, wood) if possible to reduce dump fees.
6. Inspection (if structural work)
0.5 dayIf you removed a load-bearing wall and installed a beam, call for a framing inspection before closing walls. Inspector will verify beam size matches drawings, bearing plates are in place, posts and footings are adequate, and shoring was done correctly. If no permit was required (non-structural demo), skip this step.
7. Cleanup and Waste Disposal
0.5-1 daySweep and vacuum (HEPA vac if lead or asbestos work), remove containment barriers, haul debris to bins. Asbestos waste must be double-bagged, labeled, and disposed of at approved facilities (not regular landfills). Lead-contaminated waste (painted wood, drywall) is usually accepted at municipal landfills but check local rules. Metal (steel beams, copper pipe, aluminum siding) can be sold to scrap yards — offset disposal costs.
Investment Guide
Demolition pricing depends on scope, access, hazardous materials, and disposal. Gutting a kitchen is straightforward; removing a load-bearing wall requires engineering, shoring, beams, and inspections. Asbestos abatement multiplies costs — $50-$100 per square meter for certified removal vs $5-$15 per square meter for regular demo.
Non-Structural Interior Demo (small scope: kitchen, bathroom, or single room)
$2,000-$5,000
Depends on: Remove cabinets, countertops, drywall, flooring, fixtures. Includes debris removal and disposal (10-yard bin). No structural work, no hazardous materials. Assumes accessible workspace.
Full Interior Gut (whole floor or whole house to studs)
$8,000-$18,000
Depends on: Strip all finishes, remove non-bearing partition walls, pull fixtures and appliances, remove flooring to subfloor. Includes debris removal (20-40 yard bins). No structural modifications, no asbestos. Typical for pre-renovation gut jobs.
Load-Bearing Wall Removal (single wall, beam installation)
$5,000-$12,000
Depends on: Includes structural engineer drawings ($800-$2,500), temporary shoring, beam supply and installation (10-20 ft steel W-beam or LVL), building permit, framing inspection. Demo and drywall patching extra.
Asbestos Abatement (vermiculite insulation, 1,000 sq ft attic)
$4,000-$8,000
Depends on: Certified contractor, containment, HEPA vacuums, PPE, double-bagging, certified disposal. Vermiculite is the most common asbestos job in residential renovations. Cost scales with volume and access difficulty.
Asbestos Floor Tile Removal (9x9" tiles, 500 sq ft)
$2,500-$5,000
Depends on: Wet methods, containment, HEPA vac, certified disposal. Encapsulation (covering with new flooring) is cheaper ($500-$1,000) but raises floor height.
Lead Paint Abatement (whole interior, 1,500 sq ft)
$8,000-$15,000
Depends on: Containment, wet scraping or chemical stripping, HEPA cleanup, certified disposal. Encapsulation (drywall overlay) is much cheaper but adds thickness to walls.
Garage or Shed Demolition (detached structure, 300-500 sq ft)
$3,000-$6,000
Depends on: Tear down structure, remove foundation or slab, haul debris, grade and fill hole. Access for equipment (excavator, truck) affects cost.
Full House Demolition (single-family home, 1,500-2,500 sq ft)
$12,000-$25,000
Depends on: Utility disconnection, permit, excavator and truck rental, labour, debris hauling, foundation removal or infill, site grading. Salvageable materials (brick, timber, metal) can offset costs.
What Affects the Price
Get a fixed-price demolition quote with hazardous material testing, structural assessment, and disposal costs included — no surprises when walls come down.
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Permits & Building Code
Ontario Building Code requirements
| Permit / Approval | Authority | Typical Cost |
|---|---|---|
| Building Permit (Structural Demolition) | Municipal building department | $200-$800 |
| Asbestos Abatement Notification | Ministry of Labour (MOL) | $0 (notification is free) |
| Demolition Permit (Full Building) | Municipal building department | $500-$2,000 |
| Electrical Disconnection Permit | ESA | $100-$200 |
Non-structural interior demolition (removing drywall, cabinets, flooring, non-bearing walls) typically does not require a building permit — but always check with your municipality.
Removing a load-bearing wall always requires a permit and structural engineer's drawings. Inspectors will check beam size, bearing points, and shoring during framing inspection.
Asbestos abatement >1 m² requires a certified contractor under O.Reg 278/05. DIY asbestos removal is illegal in Ontario for projects exceeding that threshold.
Lead paint removal or disturbance does not require a permit, but MOL recommends certified lead abatement contractors for projects involving >10 m² of painted surface.
Full building demolition permits often require disconnection of utilities (gas, electric, water, sewer), proof of insurance, and sometimes neighbour notification.
Vibration from demolition (jackhammering concrete, dropping heavy debris) can damage adjacent structures. Pre-demo surveys of neighbouring properties document existing cracks and defects — protects you from false damage claims.
Fixed Milestone Pricing, Approved by You
Every demolition & selective demo project runs on fixed milestone pricing. The plan is signed before work starts, and you approve each stage before it's paid.
Plan Signed Before Work Starts
Every milestone and its price is written into the contract up front — no surprise extras.
Review in the Live App
Daily photos, inspection reports, and spend vs budget land in your client app at every phase.
You Approve Each Milestone
A stage is only paid after you review the work and sign off in the app.
Project Center
Demolition & Selective Demo
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Demolition Hazards: What You Can't See Can Hurt You
- **The load-bearing wall mistake:** Removing a load-bearing wall without proper beam installation causes gradual structural failure. You won't see immediate collapse — instead, floors sag over 3-6 months, drywall cracks appear, doors stick, and in extreme cases, ceiling joists pull away from walls. The fix is expensive: install shoring, sister new joists, add beams, repair finishes. Cost: $15K-$40K. The original beam would have been $5K-$12K. Follow the load path before cutting any wall — if you're not certain, hire a structural engineer.
- **Vermiculite insulation and asbestos:** Vermiculite attic insulation, especially from Libby, Montana (sold as Zonolite), contains 1-6% asbestos. It looks like small gray-brown pebbles or kitty litter. Disturbing it releases fibers into the air. Ontario regulation requires certified abatement if you're removing >1 m². Homeowners often disturb vermiculite during attic renovations without realizing the risk — fibers settle throughout the house and remain hazardous for decades. Test before touching. Encapsulation (covering with new insulation) is an option if undisturbed.
- **Lead dust exposure:** Sanding or scraping lead paint creates fine dust that settles on surfaces and is ingested (hand-to-mouth contact, especially in children). Blood lead levels >5 µg/dL cause developmental issues in children. Wet methods (wet sanding, chemical stripping) reduce dust, but HEPA vacuums and containment are critical. Regular shop vacs spread lead dust via exhaust. After lead work, clean all surfaces with TSP solution and HEPA vac — regular cleaning is insufficient.
- **Hidden electrical hazards:** Cutting into walls without knowing wire locations risks electrocution. Use a voltage detector before cutting. Knob-and-tube wiring (common in homes built before 1950) is often buried in walls or ceilings — live wires with cloth insulation that crumbles when touched. Assume all wires are live until proven otherwise. Turn off circuits at the panel, test with a multimeter, then proceed.
- **Structural shoring failure:** Temporary shoring (Acrow props, strongbacks) must bear on solid surfaces — not drywall, not subfloor over a joist span. Props need bearing plates (2x10 planks) top and bottom to distribute load. Spacing: 4-6 feet apart for uniform load distribution. If shoring fails during beam installation, the ceiling or floor above drops suddenly — potentially injuring workers and causing major structural damage. Shoring is not optional, and it must be done correctly.
- **Vibration damage to adjacent structures:** Jackhammering concrete, dropping heavy debris, or using heavy equipment near old structures can cause cracking in neighbouring foundations, chimneys, or plaster walls. Do a pre-demo survey of adjacent properties (photos, written notes of existing cracks) to protect yourself from false damage claims. If working on a semi-detached or rowhouse, notify neighbours and consider vibration monitoring (accelerometers) if structures are fragile.
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Related Services
Concrete Works
Removing concrete floors, slabs, or foundation elements often follows interior demolition.
Learn moreHandyman
Small-scale demo and prep work — pulling cabinets, removing trim — is often handyman scope.
Learn moreBasement Second Unit
Basement conversions start with stripping existing finishes back to the foundation walls.
Learn moreCommon Questions
How do I know if a wall is load-bearing?
Can I remove asbestos myself to save money?
What's the difference between a steel beam and an LVL beam for load-bearing wall removal?
Do I need a permit to remove a non-bearing wall?
Can I dispose of asbestos or lead waste in regular construction bins?
How long does it take for a floor to sag after removing a load-bearing wall?
What is temporary shoring, and why is it needed?
Where we do this work
Based in Toronto, working across the GTA
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