The Plumbline guide
How your Plumbline room works
Everything the room can do, how to use it, what to do when something goes wrong, and what it cannot do. Every button pictured here is drawn exactly as it appears in your room.
💡 Quick tips📖 Manual🎙️ Voice💬 Sample sessions🛠️ Troubleshooting✅ Can & ⛔ cannot
💡 Quick tips
- Save your code the moment you see it. It looks like PL-7K4M-R2QH. If you lose it, Lost your code? in the room shows it again with your purchase email and the last four digits of your card.
- Open the room first on the computer you will study on. That computer becomes your licensed one when you set your password.
- Sit the full exam once, cold, before you study. Your results show which of the 12 PSI subject areas need you most.
- Answer every question. There is no penalty for guessing. Use ⚐ Flag for the ones to revisit.
- The clock never stops. If you close the window mid-exam, the time keeps running, just as it does at PSI.
- Aim for the benchmark, not the cut. PSI requires 81 of 115. Plumbline's benchmark is 92 (80%), so a practice pass means a real margin.
- Study with your own references open. The real exam is open book; 📚 References lists what PSI allows and where to put your tabs.
📖 The manual of the room
🔑 Getting in
| Step | What you do | What happens |
|---|---|---|
| 1 · Your code | Open plumblinegc.com/app, type your code, click Continue | The room checks the code and asks for the next step. |
| 2 · First time | Choose a password (8 or more characters), type it twice, click Set password and enter | Your access binds to this computer and the room opens. |
| 3 · Every time after | Type your password, click Open my room | You are signed in for up to 12 hours on this computer. |
| New computer | Type your password, click Move my access to this computer | Your access moves here; the old computer stops working. Allowed once in any 30 days. |
| Leaving | Click Sign out (top right) | Your progress is saved first, then you are signed out. |
🗂️ The tabs
🏠 Home📝 Practice Exam📊 My results📖 Manual🧮 Workbook📚 References📐 Formula sheet❓ Guide
| Tab | What it is for | Who has it |
|---|---|---|
| 🏠 Home | Days left in each room, your last score, chapters read, and a five-step study plan. If an exam is running, Return to it appears here. | Everyone |
| 📝 Practice Exam | The full 115-question, 330-minute exam. | Practice Exam and Bundle |
| 📊 My results | Your score, the 12 subject areas, every sitting, and every question with its reasoning and source. | Practice Exam and Bundle |
| 📖 Manual | The 24 chapters in six parts. | Manual and Bundle |
| 🧮 Workbook | Appendix A: all 62 worked calculations from the chapters, in one place. | Manual and Bundle |
| 📚 References | Appendix B: the exam as PSI publishes it, the 12-area outline, PSI's approved books with editions, and tabbing advice. | Manual and Bundle |
| 📐 Formula sheet | Appendix C: the formulas, constants and conversions to carry. | Manual and Bundle |
| ❓ Guide | This page. | Everyone |
A tab that is not part of your purchase, or whose days have run out, is greyed and cannot be clicked.
📝 Sitting the practice exam
- Click 📝 Practice Exam, then Start the 330-minute exam, then OK. The clock starts.
- Read the question and click a choice. Your choice turns blue: BPayment bond
- Move with ← Previous and Next →, or click any number in the Navigator: 12 answered · 13 flagged · 14 where you are.
- The clock at the top 5:12:40 turns amber at 30 minutes and red at 5 minutes. At zero your answers are submitted for you.
- When you are done, click Review & submit. It shows what is unanswered and flagged; click a number to go back, or Submit my answers.
Every sitting draws the same 115 questions in a new order, with the four choices reshuffled, so you cannot learn positions.
📊 Reading your results
- Your percentage and score out of 115, against PSI's 81 and Plumbline's 92.
- A bar for each of the 12 subject areas: green 80% or better, navy 60–79%, red under 60%.
- Every question with your answer (✗), the right one (✓), the reasoning and the source. Filter with Missed All 115 Flagged Unanswered.
- With more than one sitting, All sittings lists them; Open shows any earlier one. Sit a fresh exam starts another.
📖 Reading a chapter
Open 📖 Manual and click a chapter. Each one runs the same way: orientation · teaching · 🧮 worked calculations · 🏗️ On the jobsite (try it, then Show the walkthrough) · ⚠️ The common trap · a Decoder to copy onto your tabs · six Check yourself questions (click a choice to see the answer and why). At the bottom, Mark this chapter read puts a ✓ beside it in the list.
💾 Your progress
Sittings, scores, chapters read and your chapter answers are saved with your access code, so they are there when you sign in again, even after a move to another computer.
🔁 Renewing after a non-pass
If you sit the real exam and do not pass, write to support@plumblinegc.com with your PSI score report and your access code. Once we have checked it we send you a renewal link, good for 14 days: $59 adds 60 days of the Practice Exam; $79 adds 60 days of the Manual and Exam. It renews the same code; your password and progress stay as they are.
🎙️ Voice commands
⛔ The room has no voice. Everything is a click or a tap, and it works the same on a computer, a tablet or a phone browser. (Your access is bound to one device at a time, so choose the one you will study on.)
💬 Sample sessions
You: pay for the Bundle.
The page: "Payment complete — Your access code PL-7K4M-R2QH · Manual open through … · Practice Exam open through …"
You: write the code down, click Open my Plumbline room, set a password.
The room: opens on 🏠 Home with 90 days left in each room.
You: 📝 Practice Exam → Start the 330-minute exam, answer for two hours, close the laptop for lunch.
Back after lunch: 🏠 Home says "A practice exam is in progress … minutes left" → Return to it. Your answers are where you left them; the clock ran on.
You: finish and submit. 📊 My results shows 74% — 85 of 115 — "You cleared the live cut but not the benchmark."
You: see Site Construction in red at 8/15 → 📖 Manual → Part III → Chapter 14, Excavation → work the trench calculations and the six check questions → Mark this chapter read.
You: open the room on a new laptop.
The room: "This code is registered to another computer." → type your password → Move my access to this computer. You are in, with all your progress.
🛠️ Troubleshooting
| What you see | Why | What to do |
|---|---|---|
| "That code is not recognized" | A typo, or a code from another purchase. | Copy it from the confirmation page, or use Lost your code? with your purchase email and card digits. Codes never use 0, O, 1, I or L. |
| "No purchase matches that email and card" | A different email or card was used at checkout. | Check your Stripe receipt email for the address and card, or write to support with the receipt. |
| "This code is registered to another computer" | Your access is bound to the first computer you used. | Enter your password to move it here (once in 30 days), or open it on your first computer. |
| "This licence moved computers recently" | You already moved it in the last 30 days. | Use the computer it is on now, or write to support to reset it. |
| "That password is not right for this code" | A typo or an old password. | Try again carefully, or click Forgot your password? and prove the purchase with your email and card digits. |
| "Too many attempts. This code is locked for 15 minutes." | Eight wrong passwords in a row. | Wait 15 minutes, then use Forgot your password? if you are unsure of it. |
| "Your access window has ended" | The days on your code have run out. | Did not pass? See Renewing after a non-pass above. Otherwise buy again from the store. |
| "Access suspended" or "Room closed" | The publisher has closed the room for an update, or suspended this code. | The message says why. Write to support with your code if you think it is a mistake. |
| A dark screen: "Content hidden while this window is not active" | You clicked into another window. The content hides itself. | Click back into the room. |
| Copy, print or right-click does nothing | Licensed content cannot be printed, saved or copied. | Read on screen; copy what you need into your own notes by hand. |
| A greyed tab | That room is not part of your purchase, or its days have ended. | The Bundle includes both rooms. |
| The renewal link "cannot be used" | It is more than 14 days old. | Write to support for a fresh one. |
✅ Can & ⛔ cannot
- ✅ A full 115-question practice exam built item for item to PSI's published outline, 330 minutes, reshuffled every sitting, saved as you go.
- ✅ Your score against PSI's 81 and Plumbline's 92, by subject area, with every rationale and its source.
- ✅ The 24-chapter manual with 62 worked calculations, 144 chapter questions, a jobsite scenario and a decoder in each chapter, and three appendices.
- ✅ Your progress follows your code; your access moves to a new computer with your password once in 30 days; lost codes and passwords are recovered with your purchase email and card digits.
- ⛔ It is not the real exam and does not contain PSI's questions. Every question is original.
- ⛔ It does not register you for the exam. Apply to NASCLA (ned.nascla.org) for approval, then schedule with PSI.
- ⛔ It does not replace your reference books, which you bring yourself on test day.
- ⛔ Nothing prints, downloads or copies, and it works on one computer at a time.
- ⛔ It cannot promise a pass; no honest product can.
- ⛔ It does not license you in any state. Each state has its own application and usually a separate business and law exam.
Questions? support@plumblinegc.com. Plumbline is an independent study aid by SmartestDesk, not affiliated with NASCLA or PSI.