Renovations reveal things you never planned on fixing. What’s hidden behind your walls can turn a quick job into a costly detour.
Here are five common (and expensive) surprises that show up mid-reno:
- Outdated Electrical Old knob-and-tube wiring or overloaded breaker panels are common in homes built before the 1970s. Once walls are open, you’ll likely need to update wiring to meet code—especially if you’re adding modern appliances or lighting.
- Water Damage or Mold You might think your bathroom just has old tile. Then the contractor pulls it out and finds rot behind the walls, a slow leak, or mold. Fixing it isn’t optional, and it usually requires replacing drywall, insulation, and sometimes framing.
- Structural Problems That wall you wanted to open? It might be load-bearing. Or maybe your basement walls show signs of settling. Hidden structural issues require permits, engineering plans, and extra time to fix safely.
- Plumbing Surprises From corroded galvanized pipes to poor DIY jobs, plumbing issues pop up fast. If you’re moving fixtures or upgrading your bathroom or kitchen, be ready to update pipes and drain lines.
- Asbestos or Lead In older homes, you might uncover asbestos in insulation or floor tiles, or lead paint under layers of latex. These materials require professional removal to stay safe—and that’s not cheap.
How to Protect Yourself
- Budget for surprises. Add 10–20% to your reno budget just for the unexpected.
- Get a good inspection. Before demo starts, a pre-renovation home inspection can flag red flags early.
- Work with experienced pros. A good contractor knows what signs to watch for and how to handle surprises without major delays.
Final Word You can’t see through walls—but you can plan like a pro. Know what might be lurking, pad your budget, and stay flexible. Renovations always hold a few curveballs. The key is being ready to catch them.