Questions to Ask a Bathroom Contractor
A bathroom remodel hides most of its cost behind walls and under the floor. These 20 questions help homeowners compare bids honestly, pin down waterproofing and permits, and find the gaps before anyone signs.
The questions
Open any question for the note
Are you licensed and insured for this kind of work in my state, and can you email me the certificates?
Why ask it
Asking for the actual certificate of insurance rather than a yes or no is the fastest filter, because uninsured crews stall here. Check that the general liability policy is current and that workers' comp covers everyone who will be in the house.
How many full bathroom remodels did your crew finish in the last twelve months?
Why ask it
Bathrooms are small, wet, and dense with trades, so volume matters more than years in business. A contractor who did fifteen bathrooms last year has hit your surprises already.
Can you point me to two or three bathrooms you finished in the past year, ideally ones I can see, with owners I can call?
Why ask it
Recent work shows current crew quality, not the quality of a team that has since turned over. Ask those owners specifically whether the shower still looks the same and whether the final price matched the contract.
Will your own employees do this work, or will you subcontract the plumbing, electrical, and tile?
Why ask it
Most bathroom jobs use subs, which is fine, but you want to know whether the tile setter is a long term partner or whoever was available. It also tells you who to chase when the plumber and the tile setter both blame each other.
Who is my day to day contact, what hours will the crew be here, and how will I hear about progress?
Why ask it
Bathroom projects run two to five weeks with constant small decisions, so an unclear contact turns every question into a delay. Agreed hours also matter when the work is fifteen feet from your bedroom.
Which permits and inspections does this job need, and will you pull them under your license?
Why ask it
Moving plumbing or adding circuits usually triggers a permit, and work pulled under your name as the homeowner leaves you holding the liability. Unpermitted bathroom work also surfaces later during a home sale.
How many working days from demo to final inspection, and how many of those days will someone actually be in my house?
Why ask it
A four week calendar can hide only twelve days of real labor, and the gaps are where projects quietly die. The answer separates contractors who schedule realistically from ones who start your job to hold you and then vanish onto another site.
How will you keep dust out of the rest of the house, and which bathroom will we be using while ours is torn apart?
Why ask it
Demo dust from tile and drywall travels through the whole house unless someone hangs plastic and runs an air scrubber. This also forces a plain conversation about how many days you will be without a shower or a toilet on that floor.
Will you wait to start demo until the tile, vanity, and fixtures are physically on site?
Why ask it
The classic bathroom stall is a torn out room waiting on a vanity with a nine week lead time. A contractor who insists on staging materials first is protecting your schedule, not stalling.
What is the deposit, how is the rest tied to completed stages, and will you provide lien waivers from subs and suppliers?
Why ask it
You want money released after verifiable milestones like passed rough in inspection, not on dates. Lien waivers matter because an unpaid tile supplier can put a lien on your house even after you paid the contractor in full.
Which lines in this bid are allowances, and what dollar figure did you assign to each?
Why ask it
Allowances for tile, vanity, and fixtures are where a low bid becomes an expensive job, since a 4 dollar per square foot tile allowance will not cover what you picked on Pinterest. Comparing bids only works once you normalize these numbers.
What waterproofing system will you use in the shower, and will you flood test the pan before tile goes on?
Why ask it
You are listening for a specific named system and a method, for example a sheet membrane like Kerdi or a foam board system, not just green board and thinset. A 24 hour flood test on the pan is cheap insurance against a leak you only discover through the ceiling below.
How will you build and confirm slope to the drain, and are you setting a center drain or a linear drain?
Why ask it
Water that sits on a flat shower floor eventually finds a way out through grout and into framing. Asking how they verify the slope, roughly a quarter inch per foot, tells you whether they measure or eyeball it.
What are you replacing behind the wall: the shower valve, supply lines, drain, and shutoffs?
Why ask it
The wall is open exactly once, so reusing a twenty year old valve or brittle supply line to save 200 dollars is a bad trade. This also reveals whether the bid assumes the existing rough plumbing is fine without having looked.
How are you sizing the exhaust fan, and where exactly does it vent to?
Why ask it
An undersized fan or one that dumps humid air into the attic causes mold and rotted sheathing years later. You want a CFM number matched to the room and a duct that terminates outside through the roof or wall.
Before demo, how do you test for asbestos in old flooring or mastic, and are you lead certified for a house this age?
Why ask it
Sheet vinyl and mastic in older bathrooms can contain asbestos, and pre 1978 homes bring lead paint rules for the contractor. If they wave this off, they either do not know the rules or plan to ignore them at your expense.
If you open the floor and find rot, a soft subfloor, or a leaking drain, what happens next and how is that priced?
Why ask it
Hidden water damage around toilets and tubs is the single most common bathroom surprise, so you want the pricing method agreed now, ideally time and materials with a written estimate before work resumes. A contractor who claims they never find surprises has not opened many bathroom floors.
Does the layout I want require moving drains, cutting joists, or building up the floor, and who signs off on that?
Why ask it
Relocating a toilet or going curbless usually means working within the floor structure, and notching a joist wrong is a structural problem. The answer should mention the inspector or an engineer for anything that touches framing.
How are change orders written, priced, and approved before the work happens?
Why ask it
Verbal changes are how a 25,000 dollar bathroom becomes a 34,000 dollar bathroom with no paper trail. Insist that every change carries a price, a schedule impact, and both signatures before the crew touches it.
What does your workmanship warranty cover, in writing, and who comes back if grout cracks or a joint leaks eighteen months from now?
Why ask it
Bathroom failures announce themselves months after final payment, so a one or two year written workmanship warranty is worth more than any promise made in your driveway. Ask how many callbacks they handled last year and what happens if the sub who did the tile is gone.
Hiring a Bathroom Contractor Without Getting Burned
Practical guidance for the conversation itself
How to Compare Bathroom Bids
Normalize the Allowances First
Before comparing totals, rewrite each bid with the same tile, vanity, and fixture numbers. A bid that is 4,000 dollars cheaper often just assumed builder grade tile and a stock vanity.
Make Them Price the Same Scope
Give every contractor one written scope: same shower size, same waterproofing method, same fan, same number of light circuits. Otherwise you are comparing three different bathrooms.
Ask for the Waterproofing by Name
The answer should be a system, for example a bonded sheet membrane or a foam board system with sealed seams, plus a flood test. Vague answers about sealing it up well predict the callback.
Buy Long Lead Items Early
Vanities, custom glass, and specialty tile drive most bathroom delays. Order them before demo day and confirm the glass shop measures after tile is set, not before.
Where Bathroom Jobs Go Wrong
The Shower Pan
Missing pre slope, unsealed seams at the curb and corners, and no flood test cause leaks that show up on the ceiling below a year later. This is the one detail worth watching in person.
Ventilation Shortcuts
Reusing an undersized fan or venting into the attic traps moisture in the framing. Confirm the CFM rating and walk outside to see where the duct terminates.
Hidden Rot Priced as a Blank Check
Subfloor damage around the toilet or tub is common. Without an agreed pricing method for discovered conditions, this becomes the most expensive line on the job.
Glass and Grout at the Finish Line
Custom shower glass often takes two to three weeks after the tile is set, so the job feels stalled at 95 percent complete. Put that window in the schedule up front instead of arguing about it later.
Payment Milestones Worth Writing Into the Contract
- Deposit at signing, typically 10 to 20 percent and never a cash only arrangement
- Payment on completed demo with the space cleared and protected
- Payment after plumbing and electrical rough in passes inspection
- Payment after waterproofing is installed and the pan passes a flood test
- Payment after tile is set and grouted
- Final payment only after the punch list is closed, the permit is signed off, and lien waivers are in hand