DIY repair videos make everything look easy. Some jobs, though, come with real consequences when they go wrong. You can end up with a safety hazard, a voided insurance policy, a failed inspection, or damage that costs far more to fix than the problem you started with.
I spent 15 years as a Home Inspector, and I've seen plenty of DIY work after it went sideways. These are the 10 jobs I'd tell anyone to leave to a professional.
1. Electrical Work (Anything Beyond Bulb Changes)
Swapping a light switch feels harmless. But wiring mistakes start house fires. In Ontario, most electrical work past very minor tasks legally needs a licensed electrician and an ESA inspection.
2. Gas Line Repairs or Connections
Natural gas leaks kill people. In Ontario, gas line work has to be done by a licensed gas technician. There's no option there, and no handyman should be touching it either. Call your gas provider or a licensed HVAC professional.
3. Load-Bearing Wall Removal
Take out the wrong wall and you can compromise the structure of the house. Figuring out which walls are load-bearing takes experience or an engineer's assessment. Get it wrong and you're dealing with a structure that can collapse. That's a lot worse than a wall that looks a bit off.
4. Roof Repairs (Anything Beyond Cleaning)
The fall risk alone makes roof work dangerous if you don't have the right equipment. Then there's the workmanship. Bad flashing, poorly installed shingles or sloppy sealant will lead to leaks, rot and mould, often months later when the source is hard to track down.
5. Foundation Cracks
A hairline crack might be cosmetic. A horizontal crack in a basement wall could mean the structure is moving. Telling the two apart takes trained eyes. If you patch a serious crack yourself, you can end up hiding the problem while it keeps getting worse behind the patch.
6. Asbestos and Lead Paint Disturbance
Homes built before 1990 may have asbestos in the insulation, floor tiles or drywall compound, and they may have lead-based paint. Disturb those materials and you release hazardous fibres or dust into the house. Removal needs certified professionals who use proper containment and disposal.
7. Drain Line Repairs
Using a plunger on a slow drain is fine. Cutting into drain lines, rerouting pipes or going after a deep blockage without the proper tools is another story. That's how you get leaks inside walls or under slabs, and those cost a lot more to repair.
8. HVAC Installation or Repair
A badly installed or badly repaired HVAC system is inefficient at best and dangerous at worst. Gas furnace problems carry a real carbon monoxide risk. Furnaces, heat pumps and central air belong with certified technicians.
9. Drywall Near Plumbing or Electrical
Cut into a wall blind and you might hit a pipe, a wire, or both. Check what's back there first, even if all you have is a stud finder and a wire detector. And when you do find something, it takes experience to know what you're actually looking at.
10. Deck Structural Repairs (Footings, Ledger Board)
Replacing a few deck boards is reasonable DIY territory. Replacing footings, reattaching the ledger board or fixing other major structural parts is not. A deck that gives way under load can seriously hurt someone.
If you're not sure, the safest move is to have a professional look at it. A consultation call costs nothing. Call (289) 928-5689 to talk through your project.
Owner of Handy Man And Home Repairs. 16 years in construction, 15 of them as a Home Inspector. Works across Durham Region, Kawartha Lakes and Northumberland.