# Compressive Strength OF Masonry: Building Code Definition > How the IBC 2009 define compressive strength of masonry, where the wording differs, and which chapters depend on the term. - Canonical: https://harth.build/resources/glossary/compressive-strength-of-masonry/ - Last updated: 2026-09-07 - Data source: Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control. ## Key facts | Fact | Value | | --- | --- | | Defined in | IBC 2009 (2009 editions transcribed in this corpus) | | Primary source | IBC 2009 Masonry (model text, not a jurisdiction's adopted text) | | Chapters using the term | 3 (counted across the codes hosted here) | | Wording identical across codes | Single code (compare before citing one code's wording under another) | ## Direct answer Compressive strength OF masonry is a defined term in the International Building Code (IBC) 2009, in Masonry. The code's own words are: “Maximum compressive force resisted per unit of net cross-sectional area of masonry, determined by the testing of masonry prisms or a function of individual masonry units, mortar and grout.” No other I-Code in this corpus defines it, so the IBC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Masonry (IBC 2009), Soils and Foundations (IBC 2009), Definitions (IBC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it. *Content and cited inputs reviewed by [Scott Barrington](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.* ## What does this term mean? **Compressive Strength OF Masonry** — IBC 2009, Masonry: > Maximum compressive force resisted per unit of net cross-sectional area of masonry, determined by the testing of masonry prisms or a function of individual masonry units, mortar and grout. ![Labeled code-term definition diagram: Compressive Strength OF Masonry: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/compressive-strength-of-masonry/diagram-1344.webp) *How the IBC 2009 define compressive strength of masonry, where the wording differs, and which chapters depend on the term.* ## What must be verified before using this guidance? **Compressive Strength OF Masonry** is defined once in this corpus, in the [Masonry](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/masonry.md) chapter of the International Building Code (IBC) 2009: > Maximum compressive force resisted per unit of net cross-sectional area of masonry, determined by the testing of masonry prisms or a function of individual masonry units, mortar and grout. ## Where compressive strength of masonry is used in the code The term appears in 3 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next. | Chapter | Code | Mentions | | --- | --- | --- | | [Masonry](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/masonry.md) | IBC 2009 | 22 | | [Soils and Foundations](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/soils-and-foundations.md) | IBC 2009 | 3 | | [Definitions](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/definitions.md) | IBC 2009 | 2 | ### The term in use How the code actually writes about compressive strength of masonry, quoted from the 2009 text hosted here: > Compressive strength of masonry shall be considered satisfactory if the compressive strength of each masonry wythe and grouted collar joint equals or exceeds the value of I'm for clay and concrete masonry and I'AAC for AAC masonry. — [IBC 2009 §2105.2.1](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/masonry.md) > f'm = Specified compressive strength of masonry at age of 28 days, psi (MPa). — [IBC 2009, Masonry](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/masonry.md) ## The terms compressive strength OF masonry is built out of The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what compressive strength OF masonry covers: - **[Masonry](https://harth.build/resources/glossary/masonry.md)** — IBC 2009: A built-up construction or combination of building units or materials of clay, shale, concrete, glass, gypsum, stone or other approved units bonded together with or without mortar or grout or other accepted methods of joining. - **[Mortar](https://harth.build/resources/glossary/mortar.md)** — IBC 2009: A plastic mixture of approved cementitious materials, fine aggregates and water used to bond masonry or other structural units. ## Compressive Strength OF Masonry: what to open, and in what order Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows. | Check | Where | Confirmed | | --- | --- | --- | | Read the definition in the adopted IBC | Masonry | | | Re-check the requirement that uses it | Masonry (IBC 2009) | | | Re-check the requirement that uses it | Soils and Foundations (IBC 2009) | | | Re-check the requirement that uses it | Definitions (IBC 2009) | | | Confirm the dependent definition | Masonry | | | Confirm the dependent definition | Mortar | | | Local amendment to any of the above | Jurisdiction's amendment list | | **A research aid, not a code determination.** The authority having jurisdiction decides which edition and which amendments apply. ## Where can you explore related guidance? - [Explore all glossary guidance](https://harth.build/resources/glossary.md) - [Masonry: Building Code Definition](https://harth.build/resources/glossary/masonry.md) - [Mortar: Building Code Definition](https://harth.build/resources/glossary/mortar.md) ## Sources and method Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control. ### Source links - [codes.iccsafe.org](https://codes.iccsafe.org/codes) - [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/) ## Frequently asked questions ### What is the code definition of compressive strength of masonry? The International Building Code (IBC) 2009 defines it in Masonry as: “Maximum compressive force resisted per unit of net cross-sectional area of masonry, determined by the testing of masonry prisms or a function of individual masonry units, mortar and grout.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally. ### Which parts of the code depend on compressive strength of masonry? In this corpus the term is used across 3 chapters, led by Masonry in the IBC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own. ### What is the compressive strength of masonry? In the 2009 I-Codes hosted here it is a defined term rather than a description. The IBC 2009 states, in Masonry: “Maximum compressive force resisted per unit of net cross-sectional area of masonry, determined by the testing of masonry prisms or a function of individual masonry units, mortar and grout.” It is defined in IBC 2009. Because it is a defined term, whatever the adopted edition says it means is what every section using it means — so check Chapter 2 of that edition and any local amendment before relying on this wording. ### What is the standard IS code for the compressive strength of mortar? Mortar is a separate defined term. The IBC 2009 defines it as: “A plastic mixture of approved cementitious materials, fine aggregates and water used to bond masonry or other structural units.” That is not the same as compressive strength OF masonry, which the IBC 2009 defines as “Maximum compressive force resisted per unit of net cross-sectional area of masonry, determined by the testing of masonry prisms or a function of individual masonry units, mortar and grout.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted. --- - Continue in Harth (open this topic in the Harth agent): https://app.harth.build/agent?context=%2Fresources%2Fglossary%2Fcompressive-strength-of-masonry%2F - View this page in a browser: https://harth.build/resources/glossary/compressive-strength-of-masonry/ - All resources for agents: https://harth.build/llms.txt