Rules
Part of Testing low VOC finishes: what survived contact with a real wall
Vetting a low VOC finishes contractor before signing anything
How to check a painting contractor: certification for older housing, dust containment, the products they will actually use, and what they promise in writing.
What to take away
- In pre-1978 housing, certification for renovation work is a legal requirement, not a preference.
- Ask which primer and which colorant system, because those are where the specification usually slips.
- Dust containment during sanding matters more to the household than the topcoat does.
- Get product names, cure times and cleanup standards in writing before work starts.
Certification comes first
If the building predates 1978 and painted surfaces will be sanded, scraped or otherwise disturbed, the firm doing the work needs the relevant federal certification. Ask for the certificate, the firm number, and the name of the certified individual who will be on site.
Pre-1978: Certified Firm Required
Does the building predate 1978?
Ask for federal certificate, firm number, certified individual
Federal certification not required
Ask a second question about what they do when they find something unexpected. The right answer involves stopping, testing, and bringing in the right trade. Any answer that involves carrying on because the area is small is a reason to stop the conversation.
For background before the interview, EPA maintains resources on lead exposure for communities and households, and CDC's guidance on preventing childhood lead poisoning covers the household side, including paint, dust and the practical steps families can take. Both are worth twenty minutes before you interview anyone.
Questions about products
- Which primer, by product name, and why that one for this substrate?
- Which topcoat, in which sheen, and what is its stated cure time?
- What colorant system is used, and does it change the emission profile for deep colors?
- What filler and caulk will be used, and how long do they need before coating?
- What is the plan if a stain bleeds through?
Colorant is the question most painters are not asked. Deep colors need a large volume of tint, and the tint has its own composition. A contractor who can answer this has thought about the specification rather than the color chart.
Product Questions to Ask
- Primerproduct name and substrate reason
- Topcoatsheen and stated cure time
- Colorant systemdoes it change emissions?
- Filler and caulktime before coating
- Plan if a stain bleeds through
Questions about dust and cleanup
| Question | Good answer |
|---|---|
| How will you sand? | Vacuum-extracted sanders, not dry hand sanding |
| How is the room separated? | Sealed barriers, exhaust to outdoors |
| What about the HVAC? | Returns sealed, filters changed at the end |
| How do you clean up? | HEPA vacuum, wet wipe, no sweeping |
| What do workers do with clothing? | Change on site, wash separately |
| What is the handover standard? | Named, with a walk-through |
Dust is the part of a painting job that reaches the rest of the house. A contractor who takes it seriously is usually careful about everything else.
Ask to see one of their containment setups on a current job if the timing allows. Five minutes looking at how a real site is separated tells you more than an hour of description, and contractors who work this way are generally happy to show it.
Put it in writing
The contract should name the primer, the topcoat, the sheen, the number of coats, the cure period before reinstatement, the containment method and the cleanup standard. It should also state what happens if the substrate turns out to need more repair than expected, since that is the most common cause of a mid-project renegotiation.
Apply the same structure used for envelope work in how to vet an insulation contractor, and take the product knowledge from our pillar on what held up in low VOC finish testing into the interview so the technical questions are specific.
