Building Code Glossary
Concealed Fouling Surface: Building Code Definition
How the IPC 2009 define concealed fouling surface, where the wording differs, and which chapters depend on the term.
On this page
Last updated September 7, 2026 · 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.
Direct answer
Concealed fouling surface is a defined term in the International Plumbing Code (IPC) 2009, in Definitions. The code's own words are: “Any surface of a plumbing fixture which is not readily visible and is not scoured or cleansed with each fixture operation.” No other I-Code in this corpus defines it, so the IPC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Fixtures, Faucets and Fixture Fittings (IPC 2009), Plumbing Fixtures (IRC 2009), Definitions (IPC 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, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.
What does this term mean?
Concealed Fouling Surface — IPC 2009, Definitions:
Any surface of a plumbing fixture which is not readily visible and is not scoured or cleansed with each fixture operation.
What must be verified before using this guidance?
Concealed Fouling Surface is defined once in this corpus, in the Definitions chapter of the International Plumbing Code (IPC) 2009:
Any surface of a plumbing fixture which is not readily visible and is not scoured or cleansed with each fixture operation.
Where concealed fouling surface 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 |
|---|---|---|
| Fixtures, Faucets and Fixture Fittings | IPC 2009 | 2 |
| Plumbing Fixtures | IRC 2009 | 2 |
| Definitions | IPC 2009 | 1 |
The terms concealed fouling surface 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 concealed fouling surface covers:
- Plumbing Fixture — IRC 2009: A receptor or device that requires both a water-supply connection and a discharge to the drainage system, such as water closets, lavatories, bathtubs and sinks.
- Plumbing — IRC 2009: For the purpose of this code, plumbing refers to those installations, repairs, maintenance and alterations regulated by Chapters 25 through 33.
Concealed Fouling Surface: what to open, and in what order
Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.
| Check | Where | Confirmed |
|---|---|---|
| Read the definition in the adopted IPC | Definitions | |
| Re-check the requirement that uses it | Fixtures, Faucets and Fixture Fittings (IPC 2009) | |
| Re-check the requirement that uses it | Plumbing Fixtures (IRC 2009) | |
| Re-check the requirement that uses it | Definitions (IPC 2009) | |
| Confirm the dependent definition | Plumbing Fixture | |
| Confirm the dependent definition | Plumbing | |
| 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
- Plumbing Fixture: Building Code Definition
- Plumbing: Building Code Definition
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 publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.
Source links
Frequently asked questions
What is the code definition of concealed fouling surface?
The International Plumbing Code (IPC) 2009 defines it in Definitions as: “Any surface of a plumbing fixture which is not readily visible and is not scoured or cleansed with each fixture operation.” 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 concealed fouling surface?
In this corpus the term is used across 3 chapters, led by Fixtures, Faucets and Fixture Fittings in the IPC 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 are the plumbing code requirements for fixtures?
Plumbing is a separate defined term. The IRC 2009 defines it as: “For the purpose of this code, plumbing refers to those installations, repairs, maintenance and alterations regulated by Chapters 25 through 33.” That is not the same as concealed fouling surface, which the IPC 2009 defines as “Any surface of a plumbing fixture which is not readily visible and is not scoured or cleansed with each fixture operation.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
Related pages
- Compressed Gas System: Building Code Definition
Compressed Gas System — IFC 2009 definition: An assembly of equipment designed to contain, distribute or transport compressed gases.
- Compressive Strength OF Masonry: Building Code Definition
Compressive Strength OF Masonry — IBC 2009 definition: Maximum compressive force resisted per unit of net cross-sectional area of masonry, determined by the testing …
- Compressor: Building Code Definition
Compressor — IMC 2009 definition: A specific machine, with or without accessories, for compressing a gas.
- Concealed Location: Building Code Definition
Concealed Location — IRC 2009 definition: A location that cannot be accessed without damaging permanent parts ofthe building structure or finish surface.
- Concealed Piping: Building Code Definition
Concealed Piping — IRC 2009 definition: Piping that is located in a concealed location (see “Concealed location”).
- Concealed: Building Code Definition
Concealed — IRC 2009 definition: Rendered inaccessible by the structure or finish of the building.