Many or all of the products featured here are from our partners who compensate us. This may influence which products we write about and where and how the product appears on a page. However, this does not influence our evaluations. Our opinions are our own. Here is a list of our partners and here's how we make money.
A do-it-yourself approach for home improvement projects may reduce your initial costs — but for certain jobs, the risks far outweigh any potential savings. If any of these projects are on your to-do list, call in the pros unless you’ve got plenty of related experience.
1. Roof replacement
Roofing is extremely hard and dangerous work. Any upfront savings you might get with a DIY roof replacement could easily be eclipsed by the costs of making expensive mistakes or causing dangerous accidents. Aside from having the skills and tools needed to do a decent job, you'll also need to climb ladders, lift heavy materials and navigate a steeply pitched surface high above the ground. Risks include:
Severe injury or death: Roofers face among the highest risks of work-related injuries and fatalities of any profession, according to the Bureau of Labor Statistics — and that's for trained professionals. In addition to possible slips and falls from significant heights, there's also risk of burns from hot bitumen (a petroleum-based roofing material) and electric shock from accidentally touching power lines.
Warranty issues: Manufacturer warranties for roofing materials may cover workmanship for a limited time if the materials are installed by qualified contractors, but they generally don't cover DIY installation.
Costly damage: Improper material choice or installation may damage the roof — and if water leaks in, your home’s ceilings, walls, flooring, furnishings and wiring will suffer too.
Cost of hiring a pro
Roofers charge about $150 to $300 per roofing square in addition to the cost of materials, which typically brings the total price of installing a new roof over your existing one to about $5,400 to $10,900, according to the home services company HomeAdvisor. Removing the old roof or repairing damage can add to that cost.
In some cases, homeowners insurance might cover some or all of these expenses. Opting for less-expensive materials can also lower the bill. And if you’re installing an energy-efficient roof that meets certain criteria, you might qualify for a tax credit.
2. Mold removal
Everyone's cleaned up a bit of mold at some point, and even the U.S. Environmental Protection Agency gives the green light on DIY mold removal for areas under 10 square feet. But once mold infestation becomes widespread, it might become necessary to open up walls, lift up carpeting or take out fixtures to fully remove it and clean and dry the space thoroughly. A DIY approach, in this case, means risking:
Mold exposure: Contact with mold may cause asthmatic reactions, sore throat, skin reactions, allergic reactions, eye and nasal irritation, cough, wheezing, shortness of breath and other lung issues. This is especially a concern if you don't have access to the proper protective gear. During the COVID-19 pandemic, N95 respirator masks — which offer protection from exposure to mold and other particles — have been largely unavailable for public purchase.
Harsh chemical exposure: Chemical cleaners commonly used to kill mold are also harmful to lungs, eyes, nasal passages, throats and skin.
Making the problem worse: Improper removal or sealing may release mold spores into the air. If spores get into HVAC systems, mold will blow throughout the house. DIYers may also miss mold lurking in unexpected places like crawl spaces or flooring, which could lead to further damage.
Incomplete cleanup: Not properly cleaning up after the job may leave traces of mold behind that will just grow back again.
Cost of hiring a pro
Professional mold remediation generally costs about $1,500 to $3,150, or $15 to $30 per square foot, according to HomeGuide, a home services referral website.
To make sure that money is well-spent, go with an experienced, well-reviewed mold remediation specialist who can do a thorough job.
3. Toilet replacement
To install a new toilet, you'll have to shut off the water; disconnect, drain and remove the old toilet; and seal and connect the new one. That's a manageable task for someone with basic plumbing knowledge. But if you're a DIY newbie, it's trickier. Risks include:
Injury: A toilet can weigh about 100 pounds and is awkward to handle. Homeowners may become injured lifting or carrying the toilet.
Fumes: Sewage gasses are odorous, unhealthy and potentially flammable. Failing to stuff a rag in the exposed drain pipe after the old toilet is removed may expose you to dangerous fumes — especially in poorly ventilated spaces. (And forgetting to remove the rag before seating the new toilet will cause a very disturbing plumbing issue.)
Toilet damage: Improper installation, overtightening connections or simply dropping the toilet may cause serious damage.
Leaks and mold: If the base isn’t sealed properly, water can leak into the floor, damaging and weakening the area while creating just the right conditions for mold and mildew growth.
Cost of hiring a pro
The average labor cost for basic toilet installation runs between $70 and $190, according to the services marketplace website Thumbtack, and that doesn’t include the price of the toilet. Underlying problems your plumber finds (such as leaky pipes, a cracked flange or leaky valves) can increase costs; disposing of your old toilet also runs about $50 to $200, the site notes.
If you're installing a water-saving toilet, you might qualify for a rebate from your state, which could defray some of these costs.
4. Window replacement
Replacing drafty old windows can reduce your utility bills — but only if it’s done correctly. Installing a window is a meticulous process, and any mistakes may leave your home unexpectedly vulnerable to the elements. Other pitfalls include:
Injury: Windows are heavy and fragile, bringing risk of injuries from broken glass and lifting. Falls from ladders are also a concern, along with harming passersby if a window falls out to the street.
Poor energy efficiency: Improper fit or sealing can result in drafts, air leaks and higher energy bills.
Water damage: A poor seal could allow water leaks that damage your home’s wood, drywall and even wiring.
Home damage: You could accidentally hit a plumbing or electrical line.
Warranty issues: Installing your own windows improperly may void all or part of the manufacturer's warranty.
Cost of hiring a pro
Professional window installation usually runs between $175 to $700 per window, but can be much more expensive for high-end windows, according to Angie's List, a website that provides referrals for home services pros. If the frame needs to be replaced, that's extra.
Choosing less-expensive materials reduces upfront costs. And if you're switching to more energy-efficient windows that meet certain specifications and are professionally installed, you might qualify for rebates in some states.