Does New Mexico require a mold license?
This site could not find a New Mexico license category that covers mold remediation specifically. It has not confirmed whether mold work falls under the general contractor license issued by the Construction Industries Division. Ask the firm which license it holds for the work and check that license yourself.
The Construction Industries Division licenses contractors under the Construction Industries Licensing Act, NMSA 1978, Section 60-13-1 et seq. Whether a particular mold job needs a particular class of that license is a question for the firm and the Division, not for this website, and a firm should be able to answer it in writing.
A van or a sign that says mold specialist is not a license. Ask for the license number, the classification and the name the license is held under, and confirm it with the Division before any work is signed.
Should I test the air for mold myself?
A home test kit can show that mold spores are present, but it does not show where the growth is, how much there is or how to remove it. Testing is useful to a professional who knows what the result means, and it is not a substitute for drying the building.
Air samples and surface samples are interpreted by someone who knows the materials, the building and the readings. A result that looks alarming can mean less than it seems, and a result that looks clear can miss a cavity that was not sampled.
The more useful step is to dry the building and record the readings. If there is a musty smell or visible growth, the technician will say what needs to be done next and who should do it.
What should I ask a firm before hiring it for mold work?
Ask for the contractor license number and the classification it holds, a certificate of the firm's own insurance, a written scope of work and the readings or observations that support it. A firm that cannot answer those questions in writing should not be hired.
Ask who will be on the site, what containment will be used to stop the growth spreading to other rooms, and how the work will be checked afterwards. A written plan that describes the removal, the drying and the clearance readings is the document to compare between firms.
Keep the paperwork. The insurer, a later inspector or a buyer may ask for it, and the firm should be willing to provide copies. The firm carries its own licenses and its own insurance, and the obligation to hold them is its own.
Why does mold keep coming back after cleaning?
Mold comes back when the moisture source is not stopped or the materials under the surface are still wet. Cleaning the visible surface removes the growth you can see, but it does not dry the cavity, the framing or the subfloor behind it.
Moisture sources include a leak that has not been fixed, a flood entry that has not been sealed, a roof that still lets water through and a room that stays humid. The mold is the symptom, and the cause has to be found and stopped before the surface work can hold.
A room that has been dried and measured is much less likely to grow mold again. The record of the readings shows the drying was done, and it gives the next person a baseline to compare against.
What does mold work cost?
This site does not publish prices, and no figure is given for mold work. The cost depends on how much material must come out, how much containment is needed and how many cavities are affected. The scope is written down and the price is approved before any work starts.
A small patch of growth on one surface is a different job from a wall cavity that has grown mold through several rooms. The first step is an assessment that says what is affected, and the price follows from that assessment.
Compare scopes, not totals. Two firms can quote very different prices for the same visible growth because one has scoped the removal and the clearance and the other has not.