3667 Strawberry Hill Street, Suite #107 Halifax, Nova Scotia, Canada
HAZARDS IN OLDER HOMES
Restoring or renovating an older home is rewarding, but it comes with its own set of risks and challenges. Many houses built before modern codes contain hidden materials and conditions that can pose serious health and safety concerns if not identified early.
The goal of this section is to help outline some of the most common hazards we face in older homes and to bring to light the safety considerations that come with handling them. By understanding these risks, homeowners can make better decisions, plan responsibly, and ensure their project is both safe and successful.
Asbestos
Asbestos
One of the most common mistakes we see from new homeowners is the urge to grab a crowbar and start ripping things apart. Please Don't. DIY demolition might feel exciting, but in an older home it can be dangerous. That’s because many homes in Nova Scotia built before the 1981 contain asbestos — a material that is now a known cause of cancer when its fibers are inhaled.
Asbestos was once valued product for being durable, heat-resistant, and affordable. But when disturbed during demolition, sanding, or cutting, asbestos fibers can become airborne and pose serious long-term health risks.
Where Asbestos Might Be Found
Asbestos isn’t just in insulation — it was used in a wide variety of building materials, including:
- Pipe insulation and boiler wrap
- Vermiculite attic insulation
- Vinyl floor tiles, sheet flooring, and adhesives (black mastic)
- Drywall joint compounds, plaster, skim coats, and patch/repair products
- Acoustic ceiling tiles, “popcorn” ceilings and textured paints
- Cement siding, shingles, soffits, and fascia
- Asphalt roofing shingles and roofing felts
- Bricks, mortar, and cement blocks
- Window caulking, glazing, and sealants
- Gaskets in furnaces, stoves, and appliances
- Backing boards, panels, and sheathing
Even in updated homes, asbestos may still be present in patched walls, skim coats, or repair materials applied over time.
Risks of Ignoring Asbestos
- Health Risks – Long-term exposure can cause lung cancer, asbestosis, and mesothelioma.
- Legal Risks – Renovating without testing violate safety regulations.
- Financial Risks – Discovery mid-renovation can halt projects and add costly abatement delays.
Due Diligence Before You Renovate or Tear Down
If you are considering a major renovation or even a full tear-down, environmental testing is essential due diligence. Testing upfront ensures you know exactly what you’re dealing with before any demolition begins. This allows for proper planning, safer worksites, and fewer costly surprises.
Best Practice
- Plan demolition first — don’t rip and tear.
- Hire a third-party professional to collect and test samples from the areas you’ll renovate.
- Review the lab report before starting demolition or abatement.
- Provide and post a clean air test report after abatement.
- Develop a demolition strategy — often it’s smarter (and more cost-effective) to fully gut an area rather than attempt multiple spot abatements, since most of the cost comes from setting up safe containment.
How We Help
At BG Custom Homes, we treat asbestos seriously because protecting our clients, trades, and team is non-negotiable. Our process integrates:
- Developing a clear demolition and abatement plan
- Coordinating with certified third-party testers
- Strategically planning safe and cost-effective abatement
- Making it our priority to keep our team out of harm’s way while keeping your project safe and on track
With this approach, you don’t just get a builder — you get a partner who ensures your renovation is planned with safety, compliance, and long-term health in mind.
🔗 Learn more about asbestos from Health Canada:
Photos of Asbestos
Lead paint
Lead Paint
Many older homes — especially those built before the 1980s — contain lead-based paint. While intact paint might not pose immediate danger, once it begins to chip, peel, or is disturbed during renovations, lead dust becomes a serious health hazard.
Why Lead Paint Is Dangerous
- Toxic Dust & Chips — Scraping or sanding painted surfaces can release microscopic lead particles into the air.
- Health Risks — Lead exposure is especially harmful to children and pregnant women. It can impair brain development, nervous system function, and cause long-term issues.
- Invisible Threat — You can’t see or smell lead dust, and it can spread beyond the immediate work area if not properly contained.
How to Spot It
- Age of the Home — If your house was built before the early 1980s, there’s a strong chance lead paint was used somewhere, often under newer layers.
- Condition of Painted Surfaces — Chipping, cracking, or “alligatoring” (scaly patterns) are common in old lead paint.
- High-Contact Areas — Window sashes, door frames, trim, and stair railings are frequent sources of lead dust because of repeated friction.
- Testing Kits — While visual clues can help, the only way to be certain is through testing. Hardware-store kits can give a quick indication, but certified lab testing is the most reliable.
A Few Historical Facts Worth Knowing
- Lead in paint has centuries of use — “White lead” pigment dates back to ancient Greece and Rome.
- Dangers were known early — Benjamin Franklin and 18th-century physicians documented health risks from lead exposure.
- Widespread in modern times — In the 19th and early 20th centuries, lead compounds were valued for durability and vivid color. Some paints before 1950 contained up to 50% lead by weight.
- Canada’s phase-out — Consumer paints began reducing lead content mid-20th century; by the 1970s, lead was largely removed from residential paints.
- International regulation — The White Lead (Painting) Convention of 1921 was one of the first global attempts to restrict its use.
How It Affects Renovations
- Even small DIY repainting or patch jobs can disturb lead paint layers.
- Stripping or refinishing old doors, windows, or trim may not be the DIY project you hope it is — sanding through layers of old paint can release extremely high levels of toxic dust and quickly contaminate a home.
- Due diligence matters — Just like asbestos, testing for lead paint should be part of any smart renovation plan. Something as simple as asking “Can we re-use the existing baseboard?” depends entirely on whether that trim contains lead paint and whether it can be safely refinished or is better replaced.
- Safe removal requires containment, protective gear, and specialized disposal.
- Improper handling can contaminate surfaces, dust, and adjacent areas, increasing risk and cost.
Good Practice
- Test before disturbing surfaces — Certified professionals can confirm whether lead is present.
- Plan removal or management — Depending on condition, remediation might involve encapsulation (sealing in place) or full removal.
- Use lead-safe practices — HEPA-filtered vacuums, containment barriers, protective clothing, and certified contractors are essential.
🔗 For more information, see Health Canada’s guide:
Photo examples of Lead Paint
Mold
Mold
Moisture problems are one of the most common issues uncovered in older homes, and they often lead to mold growth. Mold isn’t just unsightly — it can create serious air quality concerns that affect both comfort and health.
Unlike newer homes — which typically include mechanical ventilation systems to manage humidity and circulate fresh air, as well as capillary breaks between concrete foundations and the ground to stop moisture from wicking upward — older homes often lack these protections. Because concrete is naturally porous, old foundations can act like sponges, drawing ground moisture into basements. Combine this with poor ventilation, water leaks, or outdated vapor barriers, and you have ideal conditions for mold to thrive.
Why Mold Matters
- Health Risks — Mold spores can aggravate asthma, allergies, and other respiratory problems. Prolonged exposure may cause chronic coughing, wheezing, fatigue, or sinus issues.
- Building Damage — Mold weakens framing, drywall, and insulation if left untreated, adding cost to renovations.
- Hidden Problem — Mold is often out of sight — behind walls, in attics, under flooring, or in basements.
How to Spot It
- Visible Growth — Black, green, or white patches on surfaces.
- Musty Smell — Often the first warning sign.
- Moisture Clues — Water stains, condensation, or damp basements.
- Air Quality Symptoms — Indoor coughing, irritated eyes, or worsened asthma.
Common Types of Mold Found in Homes
- Cladosporium — Black/olive; grows on painted wood and fabrics.
- Penicillium — Blue/green; common on water-damaged materials like carpets and insulation.
- Aspergillus — Found in dust and air; some strains can cause lung infections.
- Stachybotrys chartarum (“Black Mold”) — Greenish-black, slimy; thrives on damp drywall and wood.
- Alternaria — Brown/green; often around bathrooms and windows.
How It Affects Renovations
- Mold remediation may be required before new finishes can be installed.
- Demolition without containment can spread spores throughout the home.
- As with asbestos and lead paint, testing is essential due diligence before demolition. Even simple questions like “Can we re-use the existing trim or framing?” depend on whether mold contamination is present.
Good Practice & Prevention
- Investigate moisture first — Fix leaks, correct drainage, and improve ventilation.
- Engage professional testing — Air or surface sampling can confirm contamination.
- Plan remediation — HEPA vacuuming, surface cleaning, or full removal depending on severity.
- Proactive care for older homes — Run dehumidifiers in damp spaces, use exhaust fans vented outdoors, clean settled dust, slope grading away from the foundation, and check attics and basements regularly.
- Consider upgrades — Adding modern mechanical ventilation and drainage improvements can dramatically reduce moisture problems.
- Monitor with air quality sensors — Affordable home sensors can track humidity, VOCs, and sometimes even mold risk. They provide early warnings when indoor conditions could support growth — helping you act before problems take hold.
🔗 Learn more: Mold in Your Home – Health Canada
Mold example Photos
Radon
Radon gas
Radon is an invisible, odorless radioactive gas produced by the decay of uranium in soil and rock. It can enter homes through cracks in foundations, gaps in slabs, drains, and poorly sealed penetrations. Because you can’t see or smell radon, testing is the only reliable way to detect it.
Why Radon Matters
- Health Risk — Radon is the second leading cause of lung cancer in Canada (after smoking).
- Invisible Threat — No visual or odor cues — testing is the only way to know if levels are unsafe.
- Older Homes at Higher Risk — Older foundations with cracks, porous concrete, and minimal air-sealing tend to allow more radon intrusion.
Modern Code Protections: Soil Gas Barriers & Rough-ins
- Many modern building codes require a soil gas barrier (a membrane or liner under slabs) that helps block soil gases (including radon) from rising through the floor.
- Codes often also require rough-in provisions (stub pipes or vent pathways) so that if radon levels later turn out high, a mitigation system can be installed with minimal disruption.
- But a barrier alone is not a cure — it must be properly sealed, continuous, and integrated with ventilation or mitigation systems.
Radon in Nova Scotia: What the Data Shows
- In Nova Scotia, approximately 36.8 % of homes are expected to exceed the Health Canada radon guideline of 200 Bq/m³.
- This is significantly above the national average of 17.8 %.
- In Halifax region, a 2022 survey of homes built after 2000 found that 40 % of homes in 2012–2021 had radon levels between 200–600 Bq/m³, and 27 % exceeded 600 Bq/m³.
- The Nova Scotia government also reports high-risk area statistics: in zones with high radon potential (“Rn score > 171”), 40.3 % of homes exceed 200 Bq/m³.
- Earlier estimates suggested 11 % of homes in Nova Scotia exceed the guideline; though more recent data suggests the risk is much higher.
These data points underline that no home in the province should be assumed safe without testing.
How It Affects Renovations
- Work on slabs, basements, or foundation walls can open new radon entry points if not mitigated properly.
- Energy retrofits that seal an older home (making it tighter) may trap radon unless ventilation is planned.
- Testing early is smart due diligence — it can shape structural or ventilation choices during design, avoiding costly retrofits later.
Good Practice & Prevention
- Test first — Use a long-term (3-month) radon test, ideally during the heating season.
- Seal as many entry paths as possible — Cracks, joints, gaps should be sealed, though this alone seldom solves high radon.
- If levels are high, install mitigation — A sub-slab depressurization system (fan + vent pipe) is the most common and effective solution.
- Design with prevention in mind — In new builds or large renovations, include soil gas barriers, rough-ins, and ventilation strategies.
- Retest after mitigation or changes — Ensure the system works and that radon levels remain low over time.
🔗 For further reading and official guidance:
- Radon Action Guide – Building Codes & Bylaws (Health Canada)
- Radon in Indoor Air in Nova Scotia (Nova Scotia government radon report)
- Cross-Canada Survey of Radon (2024) for national context
Knob-and-tube Wiring
old wiring
.Many older homes still contain knob-and-tube (K&T) wiring, which was common from the late 1800s to the 1940s. While it was advanced for its time, it no longer meets modern electrical safety standards and today represents more liability than value.
Why It Matters
- Fire Hazard — K&T wiring lacks a ground wire, making it more prone to overheating and unable to safely handle modern electrical loads.
- Insulation Concerns — When old wiring is buried under blown-in insulation, it can no longer dissipate heat. This creates a serious fire hazard.
- Insurance Issues — Many insurers will not cover homes with active knob-and-tube wiring, or will charge high premiums.
- Brittle Materials — The cloth insulation on the wires becomes brittle over time, breaking down when disturbed during renovations.
- Overloaded Circuits — Old systems were not designed for today’s appliances, HVAC, or EV chargers.
Other Outdated Electrical Hazards
- Aluminum Wiring (1960s–70s) — Expands and contracts at connections, creating risks of loose joints and overheating.
- Undersized Electrical Panels — Old 60-amp or fuse panels can’t support modern loads.
- DIY Repairs — Unsafe splices, taped joints, or “handyman fixes” are common in older homes.
How It Affects Renovations
- Inspection Red Flags — This is an obvious hazard for any qualified home inspector to pick up on. It’s a red mark on your home and nothing but a liability.
- Replacement Is Inevitable — If you plan any significant renovation, or simply want safe, insurable wiring, K&T needs to be fully replaced.
- Hidden Costs — Discovering knob-and-tube during a project can add unexpected costs and delays if not planned for up front.
Good Practice
- Electrical Inspection — Have a licensed electrician assess the existing system before buying or renovating an older home.
- Full Replacement — Remove all knob-and-tube wiring and replace with modern copper wiring and grounded circuits.
- Panel Upgrade — Upgrade to 100–200 amps depending on load requirements.
- Plan Ahead — Consider future needs like heat pumps, EV chargers, or smart home systems when upgrading.
- Don’t Bury It — Never insulate over knob-and-tube. It’s unsafe, and code does not permit it.
- Peace of Mind — The best practice is simple: get rid of it all.
🔗 Helpful Resources:
Knob-and-Tube example photos
