Questions to Ask Before Hiring a Mold Removal Company

The most useful questions to ask a mold removal company are about the moisture source, containment, what gets removed, how dry is dry, and what paperwork you get at the end. A company that does the work properly can answer all of them in plain words without hesitating. Here are ten, with what a good answer sounds like.

Questions about the cause

1. What caused the mold, and how will you confirm it? A good answer names a likely source and a way to check it, such as moisture meter readings or a thermal camera. A weak answer skips the cause and goes straight to treatment.
2. What needs to change so it does not come back? Expect something specific to your house: a fan ducted outside, an air leak sealed, a downspout moved, a dehumidifier. If the answer is only a product they spray, the cause is not being addressed.

Questions about the method and the proof

1. How will you contain the work area? Listen for plastic barriers and negative air through a HEPA-filtered machine. Without containment, the removal spreads dust and spores to the rest of the house.
2. What will be removed and what will be cleaned in place? Porous materials with growth, like drywall, insulation and carpet pad, are normally removed. Solid wood framing and sheathing are normally cleaned. Be wary of a plan that keeps moldy drywall or tears out sound lumber.
3. How will you clean what stays? Good answers include HEPA vacuuming and physical cleaning such as sanding, brushing or blasting. Fogging or spraying alone leaves the growth in place.
4. What standard do you follow? The recognized reference is IICRC S520 for mold, with S500 for water damage. The company should know both by name.
5. How will you know the structure is dry? You want a number and a tool. We dry until the framing reads under 16% wood moisture content and log the readings daily. A reply like it will feel dry is not a measurement.
6. What documentation do I get? Ask for before and after photos, the moisture readings and an itemized invoice. You may need these for an insurer, a buyer or your own records. If the house is being sold, ask how quickly the report is issued.

Questions about price and scope

1. Is the price firm, and what could change it? The quote should be written, state the area and the tasks, and list what is excluded. Ask what happens if more mold is found once a wall is open. A fair answer is that they stop, show you and price the extra before going further.
2. What is not included? The usual gaps are fixing the leak itself, the rebuild and any testing by a third party. Some companies rebuild and some do not. We do not, and we refer that part to local contractors.

Also ask about payment terms before you book. A deposit is normal. Ours is 50% to book and 50% on completion. Full payment up front is not something you should agree to.

Other questions to ask a mold removal company

A few more are worth a minute each, depending on your situation.

• Do you carry liability insurance, and can I see proof? Any legitimate company can send a certificate.
• Who will be in my house, and will anyone other than your own staff be doing the work?
• Can we stay home during the work, and which rooms will be off limits?
• What do I need to move or cover before you arrive?
• How do you handle a house old enough to have asbestos in the materials you plan to remove? The right answer involves testing before disturbing suspect materials.

Answers that should make you keep looking

• We kill the mold with our special product, so nothing needs to come out.
• You do not need containment for a job this size, said about a whole basement wall or an attic.
• We cannot give you a written scope until you sign.
• This is toxic black mold and your family is in danger tonight. Health Canada's guidance is that mold should be removed whatever the type. Fear is a sales tactic, not an assessment.
• You must pay for lab testing before we can quote, when the growth is plainly visible.
• We guarantee it will never come back, with no mention of the moisture source.

How to use this list

You do not need to interview anyone for an hour. Send the same photos to two or three companies, then ask each one the ten questions above by phone or email and write down the answers. Email is better, because you end up with the answers in writing.

Put the replies side by side. The company whose answers are specific to your house, and who put the scope, the dry target and the price in writing, is usually the right one even if it is not the cheapest. Keep the answers with your quote. They become the checklist you hold the company to on the day of the work.

Common questions