Questions to Ask a Deck Builder Before You Sign

Start with the basics: are they the right builder for your project?

Before you talk money, confirm you’re comparing apples to apples.

Ask for the deck builder’s license number and proof of insurance (general liability and workers’ comp, where required). Then verify it yourself with your state or local licensing/insurance sources.

Also ask: “Do you build decks like mine often?” A backyard ground-level deck is different from a raised deck with stairs, railings, and more complex footings.

Licensing, insurance, and permits (you’ll want this in writing)

Deck work is usually regulated. Permit rules and code requirements vary by city/state, so ask what the builder will do locally.

Questions to ask:
• “Will you pull the permit(s) for this deck?”
• “Will the work be inspected? Who schedules inspection—your crew or you?”
• “If the city requires changes after inspection, how do you handle that?”

Get answers in writing before you pay a deposit. If you’re told “permits aren’t needed,” that’s a red flag—still confirm what applies to your address.

Design details that affect safety and long-term performance

A deck can look similar on the surface but be built very differently behind the scenes. The questions below help you understand whether the builder is thinking about structure, moisture, and code-required details.

Ask what they plan for:

Footings and structure
• “What size/type footings and posts will you use, and how deep?” (Depth often relates to local frost line.)
• “What joist size and spacing will the deck use?”
• “How will the ledger board be installed (if applicable) and flashed?”

Railings and stairs
• “What railing height will you build to, and what baluster spacing will you use?”
• “How will stairs be framed, and what riser/tread approach will you follow?”

Deck “surface” and drainage
• “How will you handle water run-off near the house?”
• “How do you prevent trapped moisture under the deck?”

If you want to compare bids, request that these items show up clearly in the scope—not just “deck built with standard materials.”

Materials and cost: what you’re paying for (and what it costs over time)

Deck prices can swing a lot based on materials and complexity. For a quick sense of typical ranges, see deck costs. Still, treat any number as an estimate, not a final quote.

Pressure-treated wood is usually the lowest upfront cost, but it needs sealing/staining and regular upkeep. Cedar costs more than pressure-treated in many areas and also needs proper maintenance. Composite costs more upfront but usually offers lower upkeep. PVC is often the most weather-resistant option and can be the priciest.

When you ask builders about cost, also ask about trade-offs:

• “What exact materials are you pricing (brand/type and thickness, if relevant)?”
• “What finish and maintenance schedule are you recommending?”
• “Will you include stairs and railings in the same material grade as the deck boards?”
• “If I choose composite or PVC, what changes in framing or installation details?”

You can also ask for a line-item breakdown so you can compare like-for-like (labor, materials, stairs, railings, footings, hardware, and any demolition).

Timeline, communication, and the plan for problems

A good deck builder can explain the process clearly.

Ask:
• “What’s your expected start date and total timeline for a project this size?”
• “How many crews will be on-site, and how long are typical workdays?”
• “What happens if materials are delayed?”
• “Who is my main point of contact during the project?”

Since deck projects often face surprises (access issues, uneven yard, unexpected soil conditions, or changes after permit review), ask how they handle scope changes:

“Will you discuss any change before you do it? How will you price change orders?”

Finally, ask what “completion” means. For example, will they remove debris, haul away old materials (if demolition is included), and what final cleaning/finishing is included?

Get your quote/scope in writing before any deposit

Don’t rely on verbal promises. Ask for a written contract or proposal that includes the scope and key safety/permit details.

At minimum, make sure it lists:
• The deck size and layout (including stairs/railings)
• Materials (deck boards and structural components)
• Footings/post plan and any required framing details
• Permit and inspection responsibility
• Payment schedule and deposit terms
• Start/completion targets
• Warranty terms (what’s covered and for how long)

If you want help learning what to look for, use vet a deck builder and then compare the licensed deck builders we connect you with using the same questions each time. If one builder refuses to answer details or won’t put key items in writing, move on.