Dad has agreed to lose the bathtub. Good. Do not reward this outbreak of cooperation by showing him three estimates that describe three different jobs.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
A tub-to-shower bid can look low because it leaves half the decisions for demolition day. Another can look high because it already includes the plumbing, wall repair, permit, and cleanup the first bidder has not named. The useful comparison is not the total at the bottom. It is what each contractor promises to leave behind.
Start with the opening, not the shower package
Before anyone quotes the work, measure the room and photograph the tub, faucet wall, floor, doorway, access panel, and the ceiling below if there is one. Ask Dad where the nearest plumbing access is. Contractors need to know whether they can reach the valve and drain through an existing panel, an adjoining closet, or a finished wall that must be opened and repaired.
Tell every bidder the same result Dad wants. For example: remove the tub, install a shower in the existing opening, keep the present bathroom floor if it can remain sound, repair every surface opened by the work, and leave the bathroom usable. Do not begin with a product name. That lets the product become the job description.
Find the five places where the price moves
First, ask whether the drain stays where it is. A tub drain and a shower drain may not land in the same place. The bid should say whether drain relocation is included, excluded, or subject to an allowance after the floor is opened.
Second, ask what happens to the valve. Keeping the old valve may reduce the first number. Replacing it may require opening the faucet wall or the wall behind it. Each bid should identify the valve work, the access route, and who closes the opening afterward.
Third, make the wall system specific. Ask how high it runs, what backs it, how corners and penetrations are sealed, and what happens where the new surface meets the remaining wall. A bid that says only “install surround” has left the expensive edges blank.
Fourth, price the floor under the tub. Nobody can promise what demolition will reveal, but the contract can state how damaged subfloor or framing will be documented, priced, and approved. Ask for a unit price or a written change-order process. “Additional work as needed” is not a price.
Fifth, name the finish work. The quote should assign responsibility for drywall, trim, paint, flooring patches, debris removal, and protection of the route through the house. Those small exclusions have a habit of becoming a second contractor.
Make allowances visible
An allowance is not a fixed price. It is a placeholder for an item that has not been selected or fully measured. Put every allowance in one list. For each one, record what it covers, whether labor is included, and what happens if Dad chooses an item above or below the allowance.
Also separate known work from concealed-condition work. A sensible bid can say what is included now and how surprises will be handled. It should not need to pretend the contractor can see through the floor.
Check the permit line before choosing the low bid
Plumbing permit and licensing rules depend on the address and local authority. The City of St. Louis directs plumbing permit applications through licensed plumbing contractors. Elsewhere in the metro, the county or municipality serving Dad’s address may control the permit. Call the building department for the property, describe the drain and valve work, and ask whether a permit and inspection are required. Then make every bidder state who obtains the permit, who pays the fee, and who schedules the inspection. See the site’s source notes for the government materials behind this check.
A contractor saying no permit is needed does not settle the question. The office that issues the permit settles it. This is not a reason to turn the bathroom into a courthouse. It is a reason to make one phone call before demolition.
Keep Dad on the correct side of the contract
If Dad owns the house and can make this decision, the contract belongs to Dad. You may collect bids, take photographs, and keep the comparison sheet. Do not sign as the customer or promise payment in your own name unless you intend to take on that obligation and have authority to do so.
Missouri’s mechanic’s lien statutes require an original contractor to give the owner specified notice before taking payment, and they tell owners they may ask for lien waivers from people supplying labor or materials. For an owner-occupied home, subcontractor lien rights can also depend on a separately signed owner consent. Those papers deserve to be read, not treated as delivery receipts. This is general information, not legal counsel; the statute citations and official materials are collected in the source notes.
Ask the contractor to identify every subcontractor expected on the job. Before final payment, ask what lien waivers will be provided and from whom. If a contract, consent, financing paper, or lien notice does not make sense, stop and have a Missouri lawyer review the actual document.
Do not count on a cancellation period
Missouri provides a cancellation right for certain sales personally solicited and presented in the home, with exceptions that can matter when the buyer requests immediate emergency work or work has substantially begun. Whether a particular agreement qualifies depends on how the sale happened and what the papers say. Do not sign on the theory that Dad can unwind it later. The Missouri Attorney General’s consumer guidance also recommends written estimates, written terms, credential checks, and holding full payment until the contract has been met, as noted in the source notes.
Compare the finished job
Put the bids into rows: demolition, disposal, drain, valve, wall system, waterproofing details, base or floor, door clearance, permits, inspection, finish repair, cleanup, warranty, exclusions, allowances, change-order method, payment schedule, and projected bathroom downtime. A blank is not free. It is merely waiting for an argument.
Ask each bidder to revise the quote until every row has an answer. Then compare totals. If Dad wants the cheapest acceptable version, the sheet will show which choices actually lower cost: keeping the drain location, using an accessible plumbing wall, limiting finish changes, or selecting standard materials. It will also show whether the low bid is low because part of the bathroom has quietly become Dad’s problem.
Tonight, take six photographs, write the five required outcomes on one sheet, and send that same sheet to every bidder. Your next move is not choosing a contractor. It is making sure they are all pricing the same shower.