You've found droppings in your attic, the insulation looks flattened and stained, and you know it's time to call a professional. But after a quick search online, you're staring at a dozen companies that all claim to be the best — and you have no idea how to tell who actually is. The difference between a quality attic cleaning job and a disappointing one often comes down to asking the right questions before you sign anything. In San Francisco and across the Bay Area, where older homes with complex rooflines make attic work particularly challenging, vetting your contractor thoroughly is especially important.
There are 6 attic cleaning companies in San Francisco with an average rating of 4.9 stars.Questions About Qualifications and Licensing
The first set of questions establishes whether the company is legitimate and properly credentialed. These answers should come easily to any reputable contractor.
1. Are you licensed and insured for this type of work? A trustworthy company will immediately confirm they hold a valid contractor's license and carry both general liability insurance and workers' compensation coverage. A strong answer includes specific policy numbers and an offer to provide certificates of insurance. If the response is vague, evasive, or something like "we're working on that," end the conversation. Operating without proper licensing and insurance puts your property and finances at risk.
2. How long have you been doing attic cleaning specifically? General contractor experience doesn't automatically translate to attic expertise. Look for companies with at least three to five years focused on attic services — insulation removal, decontamination, pest cleanup, and re-insulation. Experience matters because attic work involves confined spaces, contaminated materials, and building science knowledge that takes years to develop.
3. Do your technicians hold any specialized certifications? Certifications in mold remediation, pest management, or insulation installation demonstrate that the company invests in training. While not every state requires specific certifications for attic work, companies that pursue them voluntarily tend to deliver higher-quality results. This is also a good indicator of how they approach the warranty and guarantee side of their business.
Questions About Process and Scope
Understanding exactly what the company will do — and how they'll do it — prevents misunderstandings and ensures you're comparing apples to apples when reviewing estimates.
4. Can you walk me through your process from start to finish? A professional company should describe a clear sequence: initial inspection, scope of work documentation, insulation removal, decontamination, air sealing, and re-insulation. If the answer is vague or sounds improvised, that's a warning sign. The best operators in Los Angeles follow documented procedures because consistency produces reliable results.
5. What equipment do you use for insulation removal and cleanup? Professional attic cleaning requires commercial-grade vacuum systems — typically truck-mounted or large trailer-mounted units that create enough suction to remove insulation efficiently without spreading contaminants through the home. If a company describes using shop vacs, trash bags, and manual shoveling as their primary method, they lack the equipment for a thorough job. Ask whether their equipment includes HEPA filtration, which captures fine particles that standard vacuums would recirculate.
6. What's included in your service and what's considered an add-on? This question prevents surprise charges. Some companies include decontamination, air sealing, and new insulation in their base price. Others charge separately for each service. Neither approach is necessarily wrong, but you need to understand the breakdown to compare estimates accurately. Get specifics on whether pest exclusion, duct inspection, and debris disposal are included or billed extra.
Questions About Pricing and Timeline
Money conversations are uncomfortable but essential. Transparent pricing protects you from the bait-and-switch tactics that unfortunately exist in this industry.
7. Will you provide a detailed written estimate before starting work? The only acceptable answer is yes. A proper written estimate should list each service with its individual cost, material specifications (insulation type, R-value, brand), estimated timeline, and payment terms. Verbal quotes and handshake agreements offer you no protection if the scope changes mid-project. For guidance on choosing a reliable attic cleaning company, a detailed written estimate is one of the strongest indicators of professionalism.
8. What could cause the final cost to differ from the estimate? Honest companies will explain that hidden damage — mold discovered under insulation, structural issues revealed after removal, additional pest entry points — can sometimes increase costs. The key is how they handle it. A reputable company stops work, documents the finding, contacts you with an explanation and revised estimate, and waits for your approval before proceeding. Any company that says the price will never change is either inexperienced or not being truthful.
Questions About Guarantees and Follow-Up
How a company stands behind its work tells you more about its quality than any marketing claim.
9. What warranty or guarantee do you offer on your work? Look for specific answers — a one-year workmanship warranty, a two-year rodent exclusion guarantee, or a manufacturer-backed insulation warranty. Vague promises like "we stand behind our work" mean nothing without written terms. Ask what the warranty covers, what would void it, and what the process is for filing a warranty claim. In San Diego, where pest re-entry is a common concern due to year-round mild weather, exclusion warranties are particularly valuable.
10. Can you provide references from recent, similar projects? Past customers are the best source of honest feedback. Ask for three to five references from projects similar to yours — same type of work, similar home age and style. When you contact references, ask whether the job was completed on time, whether the final price matched the estimate, and whether they encountered any issues after the work was done. A company that hesitates to share references may not have a track record worth sharing.
Evaluating the Answers
After gathering responses from at least three companies, compare them side by side. The right company won't necessarily be the cheapest — they'll be the one whose answers are specific, consistent, and confident. They'll welcome your questions rather than deflecting them, and they'll provide documentation without being asked twice. Pay attention to response times during the quoting process — a company that takes a week to return your call or sends a vague one-paragraph estimate is unlikely to be more responsive once they have your money. Trust the company that treats your estimate appointment as the beginning of a professional relationship, not a sales pitch.
