In my first year running water jobs, my crew cut into a wall to dry it out and hit an electrical line. I paid an electrician out of my own pocket for the emergency fix. That’s the kind of lesson nobody warns you about.

After 5,000+ water jobs since 2012, and after mentoring plumbers, HVAC techs and beginners, I see the same mistakes over and over. None of them come from bad drying. They come from skipping the business side. Here are the seven that cost the most.

1. Cutting before checking

Wires, plumbing lines and gas lines live inside walls. Before any flood cut, check what’s behind the drywall: look at outlets and switches above, use a scanner, and cut shallow. One bad cut can wipe out the profit on the whole job.

2. Not asking who’s paying

Insurance, the homeowner directly, a landlord, an HOA? If you don’t know on the first call, you’ll find out when the invoice goes unpaid. Ask before you roll the truck, and get it in writing before you start.

3. Weak documentation

No “before” photos, readings in your head instead of on paper, no drying log. When an adjuster questions a line item, documentation is your only defense. Every day of drying should have readings, photos and notes.

4. Buying equipment too early

A full trailer of air movers and dehumidifiers sitting in a garage doesn’t make money. Rent at first. Buy one piece at a time, paid for by jobs you’ve already done.

5. Pulling equipment before it’s truly dry

The wall feels dry, the customer wants their house back, so the equipment comes out. Then mold shows up and the callback is on you. You’re done when the readings match a dry area of the same material, not before.

6. Never following up on invoices

Most unpaid invoices aren’t disputed. They’re forgotten. Invoice the day the job closes, then follow up at 30, 60 and 90 days, and actually make the calls.

7. Spending on ads before building relationships

Ads can work, but referral partners are cheaper and last longer. Property managers, realtors, plumbers and HVAC techs see water damage every week. One good partner can send you work all year.

The pattern

Every one of these is a process problem, not a skill problem. That’s why I built the 6-Figure Launchpad around the process: the first call, documentation, drying, invoicing and referral partners. Start with the free playbook below, which walks one job from leak to paycheck in 7 steps.

Keep reading: What it costs to start · Is water restoration profitable?