Deck change orders: 6 mistakes that eat builder margin

A deck looks like the simplest job you'll quote all year. Posts, beams, joists, boards, rail. Then you pull the old deck off and the rim joist crumbles in your hand, the homeowner decides cable rail would look "so much cleaner," and somebody asks for a second set of stairs down to the yard. If you don't handle every one of those with a proper deck change order, the job you priced at a healthy margin turns into a job you paid to build.

Deck builders get hit harder than most trades here, because deck jobs are short. A two-week build has no slack in it. One unpriced change can wipe out the profit on the whole project, and there's no second phase to make it back.

What a missed deck change order actually costs you

Let's be concrete. Say you've sold a 16x20 pressure-treated deck. Here's what one handshake change looks like once it's been through the whole job:

• Materials you already bought. The homeowner switches to composite after your PT lumber is on site. Now you're stuck with a restocking fee, or a pile of boards in your yard.
• Labor you can't bill. Composite with hidden fasteners and a picture-frame border takes longer to install than face-screwed PT. If the new price never got written down, those crew hours come out of your pocket.
• Schedule slip. Special-order railing can take weeks. Your crew either stands around or leaves, and the next job slides back too.
• The final invoice fight. The homeowner remembers "you said it wouldn't be much more." You remember a number. Nobody signed anything. Guess who usually gives in.
• Your reviews. A surprise bill at the end is the number one way a happy deck customer turns into a one-star review.

None of that is rare. It's what normally happens when a change gets agreed on the lawn and never makes it onto paper.

6 deck change order mistakes that get builders burned

1. Assuming the ledger and rim joist are fine

On a rebuild, you can't see what's behind the old ledger until it's off. Rot in the rim joist or band board, missing flashing and water damage to the sheathing are all common once you open things up. If your contract doesn't spell out how hidden conditions get handled, you've got two bad choices: eat the repair or argue about it with the homeowner standing next to an open wall.

The cost: a day or two of carpentry, new lumber and flashing, and possibly a sub. That can easily be more than your profit on a small deck. We covered this in more depth in hidden damage change orders, and it applies to decks too.

2. Pricing footing changes on a guess

Ran into a buried utility, old concrete, rock or a soft spot where a footing has to go? Maybe the inspector wants a different size, or deeper footings than you planned. Every one of those means more digging, more concrete and maybe a return trip. Builders often "just handle it" to keep the job moving, then try to add it to the final bill. By then the homeowner has no context for the charge and every reason to push back.

The cost: equipment rental, extra concrete, a lost afternoon, and a disputed line on the final invoice.

3. Treating the material upgrade as a simple swap

PT to composite, wood rail to aluminum or cable, standard boards to a premium line. Homeowners think of these as "just a different product." You know they change fastening, joist spacing, blocking, the labor rate and sometimes the framing itself. A change order that only shows the price difference on the boards leaves the labor and framing changes out entirely.

The cost: the real difference is often double what the material price gap suggests. Price the full swap: material, labor, framing changes, fasteners, trim and waste.

4. Saying yes to "while you're here" add-ons out loud

A second staircase. A bench. Low-voltage lighting in the posts. A privacy screen on one side. Each request sounds small, and each one gets agreed to in the driveway. Add three of them together and you've built a meaningfully bigger deck for the original price.

The cost: the add-ons nobody wrote down tend to be the ones that never get paid for. If it isn't on a signed change order before you start it, treat it as free work. We walk through why that happens in the problem with verbal change orders.

5. Forgetting the schedule impact

Your change order says "$2,400 for cable rail." It says nothing about the three-week lead time. The homeowner planned a party on the deck for the Fourth of July and now it's your fault it's not finished. A deck change order that leaves out the new completion date is only half a change order.

The cost: an unhappy client, a crew you have to pull off and bring back, and a completion date you're blamed for missing.

6. Sending the change order after the work is done

This is the big one. The work's done, the crew's gone, and you're writing up changes from memory the night before you invoice. The homeowner now sees three or four charges they never saw coming, all at once. Even if they agreed to every one, the pile of them feels like a shakedown. Once the work is done, the homeowner holds all the cards.

The cost: discounts to "keep the peace," slow payment, and sometimes an unpaid balance you end up chasing for months.

The right way to handle a deck change order

Here's the process that stops the bleeding. It works whether you run one crew or five.

1. Stop before you build. The moment a change comes up, whether it's rot, a footing problem or an upgrade, pause that piece of work.
2. Write down what's changing. Describe it clearly: "Replace 20 LF of rotted rim joist, install new ledger flashing." Add photos of hidden damage.
3. Price all of it. Materials, labor, equipment, disposal, and your markup for overhead and profit. See how to price a change order if you need a refresher.
4. State the schedule impact. Add days, or write "no change to completion date." Always one or the other.
5. Show the new contract total. Original price, plus approved changes, equals the new total. No surprises at the end.
6. Get it signed before the work starts. A signature, a date and a copy for both of you.

You've got two free ways to do this. Pick the one that fits how you work.

Option A: the free Excel change order template

If you already run your business out of spreadsheets, our free Excel change order template is built for you. Enter your line items and markup, and it works out tax and the revised contract value automatically. It also includes a log so you can see every change on the deck at a glance. Print it, have the homeowner sign on the tailgate, and file it with the job. No login, no cost.

Option B: the free digital change order tool

If you'd rather never print anything, the free ChangeOrdersPro tool lets you build the change order on your phone while you're standing next to the rotten rim joist. Attach a photo, send it, and the homeowner signs from their own phone before you cut a single board. The contract total updates itself. No login fees, no subscription, nothing to install.

Either way, the rule doesn't change: no signature, no build. If you're wondering how a tool can be free with no catch, here's why ChangeOrdersPro is free.

Deck change order checklist

Run through this before you touch anything that wasn't in the original scope:

• Is the change described clearly enough that a stranger would understand it?
• Are hidden conditions backed up with photos?
• Did you price materials, labor, equipment, disposal and markup?
• Did you include the effect on the completion date?
• Does it show the new contract total?
• Has the homeowner signed and dated it?
• Did you log it so it shows up on the final invoice?

Seven yeses, and you build. Anything less, and you're gambling your margin. Whether you download the free change order spreadsheet or send a free digital change order from your phone, the goal is the same: a signed record before the saw comes out. For more trade-specific guides, browse all our change order guides.

Frequently asked questions

What should a deck change order include?

A clear description of the change, photos if it involves hidden damage, a full price (materials, labor, equipment, disposal and markup), the effect on the completion date, the new contract total, and the homeowner's signature and date before the work starts.

How do I handle rot I find under the old deck?

Stop work on that area, photograph the damage, and write a change order that covers the repair before you continue. It also helps to have a clause in your original contract explaining how hidden conditions will be handled and priced.

Is there a free Excel change order template for deck builders?

Yes. The free Excel change order template from ChangeOrdersPro works for any deck job. It calculates markup, tax and the revised contract value and includes a change order log. It's free to download and use.

Should I charge for switching from pressure-treated to composite decking?

Yes, and price the whole switch, not just the boards. Composite usually changes fastening, joist spacing, trim and labor time. Put the full difference on a signed change order before you order the new material.

Daisy Porter

Co-Founder, ChangeOrdersPro

Daisy writes about the unglamorous side of running a build — the paperwork, the change orders, and the conversations that keep a job profitable. ChangeOrdersPro is the free tool her team built so contractors can send a professional change order and get it signed from a phone in about 30 seconds.