Start with the hard questions.

Not for an ordinary home improvement contract. Business and Professions Code § 7159.5 limits the down payment to $1,000 or 10% of the contract price, whichever is less, and bars payments that exceed the value of work done or materials delivered. CSLB notes an exception for contractors holding a Blanket Performance and Payment Bond, so check that before assuming a violation.

Yes. CSLB recommends stating who obtains the building permits and whether permit fees are included. Permit scope can also trigger required upgrades that should be priced in advance.

No. Cementitious grout is porous even when sealed. A shower stays watertight because of a membrane or pan liner behind and beneath the tile. If water reaches framing or a ceiling below, re-grouting does not identify the source; have plumbing, drain, enclosure and waterproofing checked.

Use the CSLB license check online. Confirm the license is active, the name matches your contract, the classification fits the work, and review the bond and workers' compensation information.

Not by itself. Sellers often repaint before listing. A patch below a bathroom or kitchen is a reason to ask what happened and to have the area tested. California sellers must answer disclosure questions in good faith.

No. City handouts such as Cupertino's and Pleasanton's say the panel may need upgrading based on verification. An electrician's load calculation, space check and condition assessment decide.

Under Business and Professions Code § 7159, change orders on home improvement contracts become part of the contract once written and signed by the parties before the work covered by the change begins, and they should state scope, price change and effect on payments or schedule.

Yes, potentially. CSLB warns that unpaid subcontractors, suppliers and laborers may record a lien even when the contractor was paid in full, which could force an owner to pay twice. Conditional and unconditional releases, joint checks and tracking preliminary notices reduce that risk.

No. Oakland's published procedure says you must stop all construction work right away. Only work the inspector directs you to do, such as making the site safe, should continue. Continuing other work can bring additional penalties.

No. Plywood holds screws well and resists moisture somewhat better, but a well-made particleboard or MDF box with sealed edges, good joinery and solid hardware can outperform a poorly made plywood box. Moisture exposure, especially at the sink base, matters more than the core material alone.

Not necessarily all of them, but the long-lead items that would stop the job should be on site or confirmed with delivery dates well before they are needed: cabinets, special-order tile, windows, shower valves and drains, and fixtures or appliances that set rough-in dimensions. Commodity items can arrive later.

Under the 2025 California Electrical Code section 210.52(C)(2), as summarized in Cupertino's current kitchen handout, an island or peninsula receptacle is not mandatory, but if none is installed, provisions for a future receptacle must be made. The wall-counter 24-inch spacing rule does not apply to islands. Confirm details with your electrician and building department.

Usually because the bids are not pricing the same job: different scope, allowances, permit assumptions, exclusions and approaches to hidden conditions. Leveling the bids reveals the real differences.

In communities covered by EBMUD's regional program, a private sewer lateral compliance certificate is required when buying or selling property, with a time extension option for sales. Check your address with EBMUD; other areas have different rules.

Not always. Many models are 240-volt, but some are low-amperage 240-volt units and others run on 120 volts using a shared or dedicated circuit. Choose based on delivered hot water for your household and your panel, then follow the model's installation instructions.

Often. The Bay Area Air District requires sampling before removing or disturbing materials such as resilient flooring, textured or skim-coated walls, acoustic ceilings, HVAC ducting, or cement siding and stucco, even in single-family homes. Check your scope against that list.

If they are paid for renovation covered by the EPA RRP Rule in a home built before 1978, yes: firm certification and a certified renovator who follows specific work practices. Jobs disturbing 6 square feet or less per room inside, or 20 square feet or less outside, can be minor repair, but only if they do not involve window replacement, demolition of painted surfaces or prohibited practices.

It helps but is not enough on its own. EPA says air cleaners work best as a supplement to source control and ventilation and cannot remove all pollutants. Choose units sized by Clean Air Delivery Rate for each room and avoid ozone generators.

No. It must discharge outside the building through a proper termination. A duct ending in an attic or other cavity can wet insulation and framing.

Generally by applying for a permit for the existing work: providing as-built plans and any engineering, exposing concealed work for inspection, correcting deficiencies and obtaining final approval. Your building department sets the specific steps.

Common causes are an uneven or flexing subfloor, a floor pinned by cabinets or heavy fixed objects, missing expansion space or transitions, temperatures outside the product's range, or locking joints damaged during installation. The gap pattern often points to the cause; compare the installation with the manufacturer's instructions.

It depends on the waterproofing system and your building department. Use the duration in the manufacturer's flood test procedure and any inspector requirement rather than a generic number. LATICRETE's TDS 169, for example, describes its own procedure for horizontal installations.