Questions to Ask a Siding Contractor Before You Hire

Before you hire a siding contractor in California, confirm three things: an active CSLB license in a classification that covers the work, current workers' compensation and liability insurance, and a written contract that follows the state's home improvement rules, including a down payment no larger than $1,000 or 10 percent of the price, whichever is less. After that, the questions that separate good bids from bad ones are about scope: what happens to the old siding, how damaged sheathing is handled and priced, what weather barrier and flashing go behind the new siding, and who pulls the permit.

Use the list below to interview contractors and compare bids line by line.

The questions at a glance

License: how to check it, and which classification

Since January 1, 2025, California requires a contractor's license for any job of $1,000 or more in combined labor and materials, and for any job that needs a building permit, whatever the price. A full re-side always clears that bar.

To check a license, go to the Contractors State License Board site (cslb.ca.gov), choose the license check, and search by license number, business name or personal name. Look for:

• Status: active and in good standing, with the business name matching the one on your contract.
• Classification: CSLB issues licenses by trade. Siding is commonly done under a B (General Building) license, the C-61/D-41 Siding and Decking limited specialty, or C-5 Framing and Rough Carpentry, which lists siding in its scope. If the job includes windows, a C-17 Glazing or B license is typical.
• Bond and workers' compensation: the license page shows the contractor's bond and whether a workers' comp policy is on file or the contractor has claimed no employees.
• Complaints and discipline: the license page notes certain legal actions, and CSLB's Legal Action Disclosure phone lines give fuller license history.

Ask to see the contractor's pocket license and a photo ID. If a salesperson rather than the license holder signs your contract, that salesperson must be registered with CSLB as a home improvement salesperson. Contractors are also required to put their license number in their advertising, so a missing number on a truck, flyer or website is a warning sign.

Insurance

Workers' compensation insurance is required by law if the contractor has employees. CSLB's website shows whether a current policy is on file. General liability insurance isn't required for every license, but ask for a certificate anyway; it covers accidental damage to your house or a neighbor's during the job. CSLB also suggests asking your own homeowner's insurer whether you need extra coverage while work is underway.

What California requires in the contract

For home improvement work over the state threshold, the contract must be in writing and include specific consumer notices. Based on CSLB's consumer guide, make sure yours has:

• A detailed description of the work and materials, including brand, product line, profile, texture and color. "Install new siding" is not enough; the contract should name the manufacturer, product line, texture, width and color the way CSLB's guide recommends for every material.
• The contract price and a payment schedule showing what work each payment covers. Payments can't get ahead of the value of work done or materials delivered.
• A down payment no larger than $1,000 or 10 percent of the contract price, whichever is less. CSLB states there is no exception for special-order materials. The only exception is for contractors with a blanket performance and payment bond on file, which shows on their license page.
• Start and completion dates.
• Who obtains permits, and whether permit fees are included.
• The Mechanics Lien Warning, which explains how unpaid subcontractors or suppliers can place a lien on your property even if you paid the contractor. Ask for a list of subcontractors and suppliers and get lien releases as each finishes.
• Your right to cancel: three business days, or five if you're 65 or older, for contracts negotiated in your home.
• Change orders in writing, signed by both of you, for anything added or changed.

Cleanup and debris removal should be written into the scope too.

Scope questions specific to siding

Tear-off, sheathing and rot

Removing the old siding exposes the sheathing and weather barrier, which is the only way to find rot around windows, at the bottom of walls and under decks. Since nobody can see it before tear-off, the fair way to handle it is a written unit price for replacing sheathing and trim, plus a commitment to show you the damage before fixing it. A bid without any rot allowance isn't cheaper; the cost just arrives later as a change order. Our guide to moisture behind siding explains where damage usually hides.

Weather barrier and flashing

Ask which weather-resistive barrier they use, how they flash windows and doors, and whether they install kick-out flashing where roofs meet walls. These details decide whether the wall stays dry.

Manufacturer instructions and clearances

Fiber cement and engineered wood both have written installation requirements, and James Hardie states that installing outside its instructions can void the product warranty. Ask how the contractor handles clearances at roofs, decks and grade, fastening, and cut ends. Our article on what a correct Hardie installation looks like covers the specifics.

Older homes: lead and asbestos

If your home was built before 1978, EPA's Renovation, Repair and Painting rule requires that anyone paid to disturb painted surfaces be an EPA-certified firm using lead-safe practices, and the firm must give you EPA's Renovate Right pamphlet before work starts. You can confirm certification through EPA's online firm search. Some older siding also contains asbestos and should be tested before removal; see our asbestos siding guide.

Trim, paint and finish

Ask what happens to fascia, soffits, window trim and corner boards, and whether siding is factory-finished or field-painted. If it's field-painted, the number of coats and the paint product should be in the contract.

Warranties

There are two kinds, and you want both in writing:

• Manufacturer's product warranty, which covers the material. For example, James Hardie offers a 30-year limited non-prorated substrate warranty, and its ColorPlus finish has a separate 15-year limited finish warranty.
• Contractor's workmanship warranty, which covers installation. Get the length and what's covered written into the contract.

CSLB gives consumers four years to file a complaint about faulty work, and that period can be extended by written warranties.

Red flags

• Door-to-door or high-pressure sales, or a "today only" price
• A deposit request above $1,000 or 10 percent, or a request for cash
• No license number on the bid, truck or website, or a license in someone else's name
• "You don't need a permit for siding," or a request that you pull an owner-builder permit
• A one-line scope with no materials, weather barrier, flashing or rot pricing
• Reluctance to put warranties or verbal promises in writing

Comparing bids

CSLB recommends getting at least three bids. Make them comparable by asking each contractor to price the same scope: same product and profile, full tear-off, the same weather barrier, the same trim, and a unit price for sheathing repair. Then compare finished, painted prices rather than headline numbers. Our siding replacement cost guide explains what moves the price.

When you're ready, you can see how we approach siding replacement, browse finished work such as our Petaluma HardiePlank re-side, and request a free written estimate.

Frequently asked questions

What license does a siding contractor need in California?

Siding is commonly installed under a B General Building license, the C-61/D-41 Siding and Decking limited specialty, or a C-5 Framing and Rough Carpentry license. Check the contractor's classification and status on the CSLB website before signing.

How much deposit can a siding contractor ask for in California?

For home improvement work, the down payment can't exceed $1,000 or 10 percent of the contract price, whichever is less. The only exception is for contractors with a blanket performance and payment bond on file with CSLB.

Do I need a permit to replace siding?

Re-siding usually requires a building permit, so check with your building department. California requires a licensed contractor for any job that needs a permit. Your contract should say who pulls the permit and whether fees are included.

Should the contractor remove my old siding?

In most cases, yes. Tear-off exposes the sheathing so rot can be found and repaired, and lets the new weather barrier and window flashing go on correctly. Installing over old siding hides the wall's condition.

What should a siding warranty cover?

You should get the manufacturer's product warranty and a separate written workmanship warranty from the contractor. The workmanship warranty should state its length and what installation problems it covers.

Sources

• CSLB: Description of Classifications (PDF)
• CSLB: A Consumer Guide to Home Improvement Contracts (PDF)
• CSLB: AB 2622 implementation bulletin, minor work exemption (PDF)
• U.S. EPA: Lead Renovation, Repair and Painting Program