About and methodology
How we build Rafter Tie, check our material and handle corrections.
Who we are
Rafter Tie is part of TrueGrade Prep. We make study resources for ICC B1 candidates.
Operating company: Nori Software LLC.
What we build
We build free practice checks, calculators and guides to help you find gaps in your knowledge and plan your study time. Each exam also has a full course: lessons for every task in the published outline, a question bank, timed practice exams and a study plan.
How we write and check questions
Questions are drafted with AI assistance from the exam body's published content outline, then each answer key is re-checked by a separate blind solve and against the code section or source it cites. Questions an expert reviewer has signed say so; every question, signed or not, is corrected as errors are reported.
We write each question from scratch. Each question is mapped to a domain and its published weight, so free check question selection follows the outline's balance. Code references cite section numbers only; we never reproduce code-book text. Use your own licensed copy of any code your exam requires. We never use real or recalled exam items, and reject questions that resemble them.
A question is removed from use if its answer is unreliable, its wording is ambiguous or its reference is out of date. Questions that cannot be corrected are retired, and corrections are recorded in the errata log.
How we check facts
Facts about fees, exam formats and rules link to the exam body's own pages and show the date checked. Those pages are the source to consult before booking or applying. Reported errors go through the corrections process below.
Expert review
These questions were each signed off by a building inspection professional with 15 years in the industry, with no fixes or removals requested:
- 132 questions from the ICC B1 practice bank and course checks ()
Questions and lessons are reviewed in batches; a reviewer is credited only on the questions they signed. Pages built on signed questions say so, with the sign-off date.
Calculators
Our calculators use formulas and published reference data, cited on each tool alongside its assumptions and limits. They support study and preliminary checks; they are not a substitute for the project's engineer or authority having jurisdiction (AHJ).
Independence
Rafter Tie and TrueGrade Prep are independent and are not affiliated with or endorsed by International Code Council. Exam names are used descriptively to identify the exams our resources cover.
Corrections
Think an answer is wrong? Report it. We correct errors within 2 business days and log every change publicly.
Email norisoftwarehq@gmail.com with the page link, exam and question identifier where applicable, and what needs checking.
Errata log: no corrections logged as of 17 October 2026.