The 10 Most Common DIY Repairs That Went Wrong
- Jun 22
- 6 min read
I Appreciate the Effort, But Please Don't Do This to Your House
As a home inspector with Midwest Inspect, I want to start by saying something important:
I love DIY projects.
Some homeowners are incredibly talented.
I've seen beautiful decks, impressive renovations, custom woodworking, and repairs that rival professional craftsmanship.
And then...
I've seen the other stuff.
The repairs that make me stop, blink twice, and quietly say:
"Well that's certainly one way to do it."
Most DIY disasters don't happen because people are lazy.
They happen because homeowners are trying to save money, solve a problem quickly, learn a new skill, or avoid the cost of hiring a contractor.
And honestly, that's understandable.
The challenge is that houses are complex systems. Plumbing affects framing. Roofing affects insulation. Electrical work affects safety. A repair that seems simple on the surface can create bigger issues behind the walls, under the floors, or above the ceiling.
Unfortunately, houses have a way of exposing shortcuts eventually.
Here are some of the most common DIY repairs I encounter that didn't exactly go according to plan—and why they can become bigger problems over time.
10. Duct Tape Plumbing Repairs
Because It Has "Duct" In The Name, Right?
At some point, a pipe started leaking.
Someone grabbed duct tape.
One thing led to another.
And suddenly the home's plumbing strategy became:
"Let's see what happens."
Spoiler alert:
Water usually wins.
Duct tape is excellent for many things.
Permanent plumbing repairs are not one of them.
The problem is that even a small leak can cause significant damage over time. Water doesn't need much space to create issues. A slow drip can damage drywall, flooring, insulation, cabinetry, and even structural framing if left unchecked.
I've seen situations where a five-dollar plumbing repair eventually turned into thousands of dollars in water damage because the temporary fix lasted far longer than intended.
Midwest Inspector Translation:
If your plumbing repair came from the office supply aisle, we should talk.
9. Flex Pipe Used as a Permanent Drain Repair
Flex pipe has its place.
A very small place.
A temporary place.
Yet somehow I continue finding accordion-style flex pipe installed permanently under kitchen sinks.
The problem?
Those ridges collect:
grease
food debris
soap residue
enough mystery sludge to start a new civilization
Unlike smooth drain piping, flex pipe creates countless places for debris to accumulate. Over time, this buildup slows drainage, increases the likelihood of clogs, and can create unpleasant odors.
Many homeowners install it because it's easy to bend into place when drain components don't line up correctly. Unfortunately, the easier solution often creates a maintenance headache later.
Midwest Inspector Translation:
If your drain pipe resembles a bendy straw, it's probably not ideal.
8. Painted-Over Mold
This one is surprisingly common.
Homeowner discovers staining.
Homeowner discovers mold-like growth.
Homeowner discovers paint.
Problem solved?
Not exactly.
Painting over mold is like spraying air freshener on a garbage can.
You've changed the appearance.
The problem remains.
Mold growth is usually a symptom, not the actual issue. The real concern is often excess moisture caused by roof leaks, plumbing leaks, poor ventilation, condensation, or water intrusion.
Until the moisture source is identified and corrected, mold often returns.
In some cases, the paint can actually make it harder to recognize the extent of the problem because it hides visible warning signs.
Midwest Inspector Translation:
Mold doesn't disappear because it changed colors.
7. Deck Screws Used for Structural Connections
I love deck screws.
Deck screws are fantastic.
For decking.
What they're not designed for is replacing structural hardware.
I've seen deck screws used where:
lag bolts should be
carriage bolts should be
structural connectors should be
The problem is that deck screws can snap under loads they weren't designed to handle.
A deck may appear solid during everyday use, but structural connections experience significant forces from weight, movement, weather, and seasonal expansion and contraction.
Proper structural fasteners are engineered to resist those forces.
When the wrong hardware is used, the deck may perform adequately for years—until one day it doesn't.
Midwest Inspector Translation:
Your deck should not rely entirely on hope and drywall screws.
6. Extension Cords as Permanent Wiring
We've all used extension cords temporarily.
But "temporary" should not mean:
"Since 2017."
I've found extension cords running:
through walls
across attics
under carpets
through ceilings
At some point the extension cord became part of the home's electrical system.
Which is definitely not its intended purpose.
Extension cords are designed for temporary use and open-air conditions. When they're hidden inside walls or covered by flooring, heat can build up and damage may go unnoticed.
Additionally, cords can become pinched, worn, or overloaded over time.
Electrical fires often begin with seemingly harmless shortcuts that remained in place far longer than intended.
Midwest Inspector Translation:
If your electrical upgrade came from aisle 12 at the hardware store, there may be concerns.
5. The Mystery Support Beam
Every inspector eventually finds one.
A random board.
A jack post.
A stack of bricks.
A pile of concrete blocks.
A suspicious-looking 2x4.
Nobody knows why it's there.
Nobody knows what it's supporting.
But everyone is afraid to touch it.
Sometimes these supports were installed to address sagging floors or structural movement.
Other times they were added during renovations and simply never removed.
The challenge is determining whether they're actually helping, causing problems, or masking a larger structural concern.
I've seen makeshift supports carrying significant loads and others doing absolutely nothing except creating confusion.
Midwest Inspector Translation:
If removing one board might collapse the universe, further evaluation is recommended.
4. Spray Foam Solves Everything
Listen.
I like spray foam.
But some homeowners view it as a magical building material capable of solving literally every problem.
Gaps?
Spray foam.
Cracks?
Spray foam.
Missing insulation?
Spray foam.
Emotional problems?
Probably spray foam.
I've seen enough spray foam used to insulate a small country.
The issue isn't the product itself.
It's using it where a proper repair is needed.
Spray foam can conceal water intrusion, pest activity, damaged materials, and air leakage pathways without actually correcting the underlying cause.
In some cases, excessive foam can even make future repairs more difficult because important components become buried beneath it.
Midwest Inspector Translation:
Spray foam is a tool, not a lifestyle.
3. The Homemade Plumbing Adventure
Every inspector has seen it.
Multiple fittings.
Random valves.
Unnecessary adapters.
Three different pipe materials connected together like an international plumbing summit.
At some point the repair stopped following logic and started following imagination.
Many of these repairs begin with good intentions.
A homeowner replaces one section of pipe.
Then another.
Then another.
Before long, copper, PEX, galvanized steel, PVC, and assorted fittings are all participating in the same project.
While mixed materials aren't always wrong, improper transitions, unsupported piping, and excessive fittings can increase the risk of leaks and reduce system performance.
Midwest Inspector Translation:
If your plumbing requires a roadmap, something went wrong.
2. The "I'll Just Cover It" Method
Cracked drywall?
Cover it.
Water stain?
Cover it.
Rotting wood?
Cover it.
Damaged siding?
Cover it.
Some repairs are less about fixing problems and more about hiding them from future generations.
Unfortunately, houses are terrible at keeping secrets.
The challenge with cosmetic repairs is that they often delay discovery of the actual issue.
A water stain may indicate an active leak.
Rotting wood may indicate moisture intrusion.
Cracked drywall may indicate structural movement.
Covering the symptom without investigating the cause allows the problem to continue growing behind the scenes.
Midwest Inspector Translation:
Out of sight is not the same as repaired.
1. The Electrical Panel Surprise
This is the undisputed champion.
Whenever a homeowner says:
"I did a little electrical work myself."
Every home inspector immediately becomes interested.
I've found:
double-tapped breakers
missing knockouts
open splices
mystery wiring
unlabeled circuits
circuits that appear to power half the Midwest
Electricity is not the best place for experimentation.
Electrical panels are the central hub of a home's electrical system. Small mistakes can create shock hazards, overheating conditions, equipment damage, or fire risks.
One of the most common issues is work that technically functions but wasn't installed according to manufacturer requirements or accepted safety standards.
Just because the lights turn on doesn't mean the installation is safe.
Midwest Inspector Translation:
If your electrical panel looks like a bowl of spaghetti, professional evaluation is recommended.
Not All DIY Is Bad
To be fair, some homeowners do amazing work.
I've inspected plenty of DIY projects that were:
✔ Thoughtful
✔ Well-built
✔ Properly researched
✔ Professionally executed
In many cases, the homeowner spent time learning proper techniques, obtaining permits when required, following manufacturer instructions, and understanding local building requirements.
The key difference?
Those homeowners understood when a project required additional expertise.
They knew the difference between confidence and overconfidence.
And that's often what separates a successful DIY project from a future inspection report.
Final Thoughts
Homeownership comes with repairs.
Repairs come with decisions.
And sometimes those decisions involve duct tape, extension cords, and optimism.
The goal isn't to shame anyone.
Every homeowner has tackled a project they probably shouldn't have.
The goal is simply to recognize that temporary fixes often become permanent problems.
When in doubt, ask questions.
Research the repair.
Consult qualified professionals when necessary.
And remember that fixing the root cause is almost always cheaper than repairing the damage that occurs when the problem is ignored.
Because eventually every shortcut gets inspected.
And trust me...
Houses always tell on you.
Inspect Today. Protect Tomorrow.
— Sean Evans, CPI
Founder of Midwest Inspect
Serving Northern Illinois with professional home inspections designed to help buyers, sellers, and homeowners make informed decisions.
Schedule your inspection today at MidwestInspect.com
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