Negative keywords that stop contractor ad waste
The fastest way to lower your cost per lead usually isn’t a higher bid or a new keyword — it’s telling Google who not to show your ad to. Here are the negative keyword lists that quietly drain contractor budgets, why they matter, and a simple process to keep the waste out for good.
Updated July 2026 · Engineered Reach
Negative keywords tell Google which searches should never trigger your ad, so you stop paying for clicks that can’t become customers. For contractors, five buckets waste the most budget: DIY / “how to” searches (people fixing it themselves), jobs / careers (people wanting employment, not service), free / cheap (price shoppers who won’t pay), wholesale / supply / parts (people buying materials, not hiring), and training / school / salary (research, not intent). Add these as negatives, then run a simple monthly search-terms review to catch new waste. It’s often the single highest-ROI hour in a Google Ads account.
What negative keywords actually do
When you bid on “AC repair,” Google can match your ad to far more than that exact phrase — “AC repair jobs,” “how to AC repair yourself,” “free AC repair.” Each of those is a click you pay for and a person who will never book you. A negative keyword is an instruction that says “never show my ad when this word appears,” so that spend goes to real buyers instead.
This is why negative keywords are often the highest-ROI lever in the whole account: you’re not spending more to get more leads, you’re spending the same and cutting out the clicks that were never going to convert. Your cost per lead drops because the denominator of wasted clicks shrinks. It pairs directly with the channel choices in our LSAs vs Google Ads guide.
1. DIY and “how to” searches
Someone searching “how to fix a leaking faucet” or “DIY furnace reset” is looking for a YouTube video, not a contractor. They’re actively trying not to hire you. This is usually the single largest source of wasted contractor ad spend.
Common negatives: how to, DIY, do it yourself, myself, my own, tutorial, video, youtube, guide, steps, fix it yourself, instructions.
2. Jobs and careers
“HVAC technician jobs,” “plumber hiring near me,” “roofing careers” — these are job seekers, and they can be a surprisingly large slice of your traffic because your trade keywords overlap heavily with employment searches. Every one of those clicks is pure waste for a lead-gen campaign.
Common negatives: job, jobs, career, careers, hiring, employment, salary, apprentice, apprenticeship, resume, hourly, pay, wages, near me hiring.
3. Free, cheap, and price-only shoppers
“Free AC repair,” “cheapest roofer,” “discount plumbing” — searchers leading with price are usually looking for something you can’t profitably provide, or a giveaway that doesn’t exist. Filtering the extreme price-only terms protects your budget and your margins.
Common negatives: free, gratis, cheap, cheapest, discount, coupon, low cost, lowest price, bargain, giveaway. (Be selective — “affordable” can still be a real buyer, so test before blocking it.)
4. Wholesale, supply, and parts
People searching “furnace parts,” “wholesale roofing shingles,” or “PVC pipe supplier” want to buy materials, not hire a contractor. Unless you sell supplies, these clicks never convert into service jobs.
Common negatives: wholesale, supply, supplier, parts, part, materials, equipment, distributor, buy, for sale, rental, rent, manufacturer.
5. Training, school, and research
“HVAC certification,” “plumbing school,” “how much do electricians make” — these are students and researchers, not homeowners with a broken system. They overlap with your terms and quietly drain spend.
Common negatives: training, course, courses, school, class, classes, certification, certificate, license, licensing, exam, degree, definition, meaning, what is, reddit, forum.
The simple ongoing process that keeps it clean
Negative keywords aren’t a one-time setup. New wasteful search terms appear constantly as Google matches you to phrasings you never anticipated. The single most valuable recurring task in a contractor Google Ads account is a monthly review of the search terms report — the actual queries that triggered your ads — adding anything irrelevant as a new negative.
The whole process, monthly:
- Open the search terms report and sort by spend.
- Read the queries. Any that could never become a paying job — add as a negative.
- Group your negatives into a shared negative keyword list so it applies across campaigns at once.
- Watch for false positives — make sure a broad negative isn’t blocking real buyers (this is why you review terms, not just guess).
Fifteen minutes a month compounds into a materially lower cost per lead over a year, because every negative you add keeps saving money on every future search. Combine it with the cost-per-lead benchmarks to see the impact on your real numbers.
Want us to audit your search terms report and build your negative keyword lists before you spend another dollar? Book a free 30-minute Revenue Plan with Engineered Reach — wasted ad spend is one of the most common opportunities we find.