13 WEEKS IS THE RIGHT PLANNING WINDOW FOR CONSTRUCTIONKNOW YOUR CASH POSITION BEFORE YOUR BANK DOESPAY APP TIMING IS A CASH FLOW DECISIONCFOS FOR COMMERCIAL SUBS $1M–$12M13 WEEKS IS THE RIGHT PLANNING WINDOW FOR CONSTRUCTIONKNOW YOUR CASH POSITION BEFORE YOUR BANK DOESPAY APP TIMING IS A CASH FLOW DECISIONCFOS FOR COMMERCIAL SUBS $1M–$12M
CASH FLOW SYSTEM · C.F.O.S EXECUTION LAYER
HOW TO BUILD A 13-WEEK CASH FLOW FORECAST FOR CONSTRUCTION.
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A 13-week cash flow forecast for a construction subcontractor maps every pay app expected, every payroll cycle, every major vendor payment, and your LOC availability — week by week for 13 weeks. It's not a corporate finance exercise. It's an operational calendar with dollar amounts attached. Built right, it tells you when cash is tight 8 weeks before it becomes a problem — and gives you time to act.
Most subcontractors know roughly what's in the bank. They don't know what that number looks like 6 weeks from now after payroll, material purchases, and a slow GC payment cycle. That's the gap a 13-week forecast closes. This page covers exactly how to build one — what goes in it, where the numbers come from, and how to use it.
BY JOSH LUEBKERPublished: May 2026Updated: May 2026
WHY 13 WEEKS
THE RIGHT PLANNING WINDOW FOR THIS INDUSTRY.
Thirteen weeks is one quarter — 91 days. For a commercial subcontractor, that's long enough to see the full arc of a billing cycle (submit, approval, payment), two to three payroll cycles, major material purchases against active projects, and your LOC position at each point.
Annual forecasts are too long — too many variables change. Monthly forecasts are too short — they don't capture the lag between when you bill and when you get paid on commercial work, which can be 30–60+ days. Thirteen weeks is the right window. Short enough to be accurate. Long enough to see what's coming before it arrives.
The construction-specific reason: On a typical commercial pay app cycle, you submit on the 25th, get approved by the 5th, and get paid by the 30th. That's 35 days from submission to cash. A weekly forecast that only looks 4 weeks out misses the payment entirely. 13 weeks shows you the full cycle on every active project.
WHAT GOES IN THE FORECAST
THE INPUTS — INBOUND AND OUTBOUND.
The forecast has two sides: money coming in (inbound) and money going out (outbound). Every line needs a dollar amount and a specific week it hits. Ranges and estimates are starting points — refine them as you get closer.
INBOUND — MONEY COMING IN
Pay App Payments
Every submitted pay app with its expected payment date. Use the GC's stated pay cycle from the contract — typically net 30 from approval. If your GC consistently pays late, use actual historical timing. Do not use optimistic assumptions.
Retainage Releases
Retainage releases are contractually triggered — usually at substantial completion. Map each active project's projected completion date and put the retainage dollar amount in that week. Retainage is often 5–10% of contract value and can be a significant cash event.
Change Order Payments
Approved change orders billed on a separate SOV line — map their expected payment using the same GC pay cycle as the base contract. Unapproved change orders do not go in the inbound column until approved. Hope is not a line item.
T&M Billings
If you have T&M work, map when you'll be submitting invoices and when you realistically expect payment. T&M work paid by owners directly often has shorter cycles than GC subcontracts — sometimes net 15 or net 20. Use the actual contract term.
LOC Availability
Your current LOC available balance in week one. It does not go in the inbound column — it goes as a separate "buffer" row so you can see how much headroom you have at each point in the 13 weeks as inbound and outbound move through.
OUTBOUND — MONEY GOING OUT
Payroll
Every payroll date for the 13 weeks with the estimated dollar amount. This is your most predictable line — it hits on a fixed schedule and does not move. Payroll is the anchor everything else is planned around.
Payroll Taxes
Federal and state payroll tax deposits — typically due within 1–3 business days of payroll depending on your deposit schedule. These run automatically if you have a payroll processor but the cash still needs to be there. Map them separately from payroll.
Subcontractor Payments
Sub pay apps you've approved — map their contractual pay dates. If you have pay-when-paid clauses, they still need to be in the forecast even if the timing shifts slightly. You need visibility into what's coming due regardless of when the GC pays you.
Material Purchases
Large material purchases coming up — anything over $5K deserves its own line. Material lead times often mean you're paying before the material is even on site. Map purchase dates, not delivery dates.
Equipment Costs
Lease payments, rental returns, major maintenance — anything that hits on a predictable schedule or is coming up in the next 13 weeks based on project schedule.
Overhead (Fixed Monthly)
Rent, insurance, software, owner salary draws — your fixed monthly overhead prorated by week. These don't change with project volume and hit regardless of what's going on with cash from jobs.
Debt Service
LOC interest, equipment loans, SBA payments, any MCA daily pulls — these go in the week they hit, not estimated monthly totals.
HOW TO BUILD IT
THE STRUCTURE — WEEK BY WEEK, COLUMN BY COLUMN.
STEP 01
Set Up Columns: Week 1 Through Week 13
Each column is one week, starting with the current week. Label each column with the week-ending date. Thirteen columns. On the left side, rows for every inbound and outbound category listed above. At the bottom: Net Cash Flow (inbound minus outbound), Running Bank Balance (prior week balance plus net), and LOC Available (your limit minus current drawn).
STEP 02
Populate Inbound First — Be Conservative
Go through every active project. Pull the pay app submission date. Add the GC's stated payment cycle (if they're routinely late, add 15 days to their stated cycle). Put the dollar amount in the correct week column. Do the same for retainage, change orders, and T&M. When you're done, every dollar you expect to receive has a specific week attached to it.
STEP 03
Populate Outbound — Payroll First, Then Everything Else
Drop in every payroll date and amount. Then payroll taxes. Then subcontractor pay dates. Then material purchases from project schedules. Then fixed overhead. Then debt service. Every outbound dollar has a week. If you don't know an exact amount, use a conservative estimate and note it.
STEP 04
Read the Running Balance — Look for the Dips
The running bank balance row tells you the story. Look for any week where the balance drops below your target minimum (CFOS recommends a $650K floor at $8M revenue — scaled proportionally for your revenue). Those dip weeks are the problem weeks. Now you have 8–10 weeks of warning instead of 8–10 days.
STEP 05
Update It Monthly — Same Day Every Month
The forecast is only useful if it's current. Update it on the same day every month — the 10th works well because books should be closed by then. Roll the columns forward 4 weeks, add new inbound from upcoming pay apps, add new outbound from upcoming project costs. The forecast is always 13 weeks forward from today.
WHAT TO DO WITH THE DIPS
WHEN YOU SEE A PROBLEM WEEK, ACT EARLY.
A dip in week 7 or 8 isn't a crisis — it's a decision point. You have 7–8 weeks to do something about it. Here's what that looks like:
Accelerate a pay app submission — if you can submit week 6 instead of week 8 on a project, the payment lands 2 weeks earlier
Call an overdue account — if there's AR sitting more than 30 days old, a collections call this week might move cash into the dip window
Negotiate a delayed vendor payment — move a large material invoice 2–3 weeks with a vendor call before the dip hits
Pre-arrange a LOC draw — if the dip is unavoidable, have the LOC draw set up in advance rather than scrambling on the day
Defer a discretionary purchase — equipment or overhead spend that can wait 3 weeks should wait
The difference between a subcontractor who manages cash well and one who's always in crisis isn't the cash — it's the timing. Same bank balance, same GC pay cycles. One owner sees the dip 7 weeks out. The other sees it on Friday morning when payroll is due.
COMMON QUESTIONS
FREQUENTLY ASKED.
Any spreadsheet works — Excel, Google Sheets, or inside your job costing platform if it has a cash flow module. The tool doesn't matter; the discipline of building it and updating it monthly matters. CFOS builds the forecast inside ControlQore for clients on the platform, or in a shared spreadsheet for clients on QuickBooks or other systems. The format is the same regardless of tool.
Use their actual historical payment pattern, not their contract terms. If your contract says net 30 but they routinely pay net 45, build net 45 into the forecast. Then any early payment is upside — not a cash shortfall when they're "late." Conservative assumptions on inbound plus aggressive follow-up on AR is a better system than optimistic forecasts and missed payroll.
The 13-week forecast is operational — week by week, specific dollar amounts, for the near-term horizon where you have real data. The 24-month forecast is strategic — month by month, based on projected backlog, projected wins, and planned overhead. CFOS builds both. Banks and bonding companies want the 24-month to evaluate capacity. You use the 13-week to run the business day to day.
Yes. Executive Financial includes monthly cash flow forecast updates as part of the engagement — 13-week forecast and 24-month projection, updated monthly after books close. You review it in the monthly cadence meeting and get 3 action items based on what the next 90 days look like. Core Financial clients get the forecast structure set up but maintain it themselves. Full pricing at constructioncfo.net/fractional-cfo-construction-companies.
Josh Luebker
Fractional CFO · The Construction CFO
Former commercial construction project manager and master electrician. Managed 150+ projects totaling $300M+ including Google data centers, military bases, hospitals, and high-rises. Now fractional CFO for commercial subcontractors doing $1M–$12M through Sulphur Prairie Management.
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If the answer is never — or if you're not sure what your cash position looks like 8 weeks from now — a 30-minute diagnostic will tell you where to start.
