International Residential Code (IRC) vs Local Codes

[ameds (Alex Meds)]

Hi everyone,

I am having difficulties understanding the relationships between the International Residential Code (IRC) and national and/or local building codes. What’s the hierarchy? How do I determine whether my local code recognizes a clause in the IRC?

The IRC no longer recognizes moisture-resistant, paper-faced
drywall (“green board”) as a suitable tile backing material in wet areas such as tub and shower surrounds.

I’m from Canada, and I don’t think my national and local codes have this stipulation.

thanks!

[escanlan (Emmanuel Scanlan, TREC# 7593)]

@Pat_Flemming

Hi everyone,

I am having difficulties understanding the relationships between the International Residential Code (IRC) and national and/or local building codes. What’s the hierarchy? How do I determine whether my local code recognizes a clause in the IRC?

The IRC no longer recognizes moisture-resistant, paper-faced
drywall (“green board”) as a suitable tile backing material in wet areas such as tub and shower surrounds.

I’m from Canada, and I don’t think my national and local codes have this stipulation.

thanks!

These entries from the IRC might help better understand how they fit with your province or local building requirements.

R101.3 Intent. The purpose of this code is to establish minimum
requirements to safeguard the public safety, health and
general welfare through affordability, structural strength,
means of egress facilities, stability, sanitation, light and ventilation,
energy conservation and safety to life and property
from fire and other hazards attributed to the built environment
and to provide safety to fire fighters and emergency
responders during emergency operations.

The IRC is a basic guideline for the safe building of a residential structure.

R102.2 Other laws. The provisions of this code shall not be
deemed to nullify any provisions of local, state or federal law.

Any law that states other requirements than what is set forth in the IRC takes precedence over the IRC.

R102.4 Referenced codes and standards. The codes and
standards referenced in this code shall be considered part of
the requirements of this code to the prescribed extent of each
such reference and as further regulated in Sections R102.4.1
and R102.4.2.
Exception: Where enforcement of a code provision would
violate the conditions of the listing of the equipment or
appliance, the conditions of the listing and manufacturer’s
instructions shall apply.

The building codes can not account for all manufacturer specifications and as a result the manufacturer’s specifications take precedence over the contents of the IRC. Also the IRC will reference other standards for building and these are noted in the applicable section. Also at the end of the IRC in an appendix is a list of referenced standards. The IRC can not physically encompass within its pages all the various standards out there nor can they constantly change the IRC when other standards might change.

R104.1 General. The building official is hereby authorized
and directed to enforce the provisions of this code. The building
official shall have the authority to render interpretations
of this code and to adopt policies and procedures in order to
clarify the application of its provisions. Such interpretations,
policies and procedures shall be in conformance with the
intent and purpose of this code. Such policies and procedures
shall not have the effect of waiving requirements specifically
provided for in this code.

Your local Building Official (the local Building Inspections Department) can render interpretations of general or unclear sections of the codes. The BO can write amendments to the codes that take into account local variations and requirements that the IRC does not account for.

In a nutshell the IRC is a guide for governments and manufacturers to follow but either of those entities can change what the IRC states/requires. One last aspect are licensed Professional Engineers who can bypass the IRC requirements if the item the IRC covers has been “Engineered” and the Engineer provides their stamped/sealed/etc/ plans demonstrating what the change is and has used acceptable engineering practices in their design.

As for what your local Building Official recognizes you should ask them, or view their WEB site to see, if they have issued any local amendments to the IRC and what, if any. Provincial amendments they follow.

[ameds (Alex Meds)]

Emmanuel Scanlan, thanks for taking the time to post your detailed reply.

I see that the IRC does not nullify any provisions of local codes, and manufacturer’s specifications take precedence over the contents of the IRC.

So, this seems to be relevant in situations were local codes are more strict/stringent than the IRC. What about the opposite? What if the IRC mentions a clause that a local code doesn’t?

Back to my example: the IRC no longer recognizes moisture-resistant, paper-faced drywall (“green board”) as a suitable tile backing material in wet areas such as tub and shower surrounds. However, there is no such language in my local/national building code.

Do I have a case again my builder that is using green board in my shower stalls. Can I reference the IRC?

[escanlan (Emmanuel Scanlan, TREC# 7593)]

@Pat_Flemming

Emmanuel Scanlan, thanks for taking the time to post your detailed reply.

I see that the IRC does not nullify any provisions of local codes, and manufacturer’s specifications take precedence over the contents of the IRC.

The manufacturer’s requirements take precedence over the codes if they are following one of the many other standards in use, or if their materials/systems have been engineered using acceptable engineering practices, or if they have their materials/systems tested/reviewed by the ICC Evaluation Services Division (http://www.icc-es.org/) or another accepted test and evaluation organization.

So, this seems to be relevant in situations were local codes are more strict/stringent than the IRC. What about the opposite? What if the IRC mentions a clause that a local code doesn’t?

Long, long ago in a land far, far away … The IRC at one time did specify that any deviations from the building codes must meet the intent of the codes and be as strict or more strict than the basic requirements in the codes. Unfortunately the International Code Council (ICC) who are the keepers of the codes buckled under pressure and took that language out of the codes to make builders, local officials, etc., happy.

As for the codes stating a requirement that is not covered in a local building code amendments unless the local building department has specified otherwise, and they have officially adopted the codes, then the codes are to be followed. However you do need to keep in mind that the local Building Official can render a different interpretation that they have not officially written in an amendment. This can be done on a case by case basis or even through their own internal memos.

Back to my example: the IRC no longer recognizes moisture-resistant, paper-faced drywall (“green board”) as a suitable tile backing material in wet areas such as tub and shower surrounds. However, there is no such language in my local/national building code.

Do I have a case again my builder that is using green board in my shower stalls. Can I reference the IRC?

The IRC sections you are looking for are R702.3.7 and R702.4. These section numbers are from the latest 2015 IRC code cycle. If you are using a different (older) code cycle they should be in that same area of the codes.

Answers in blue above. Please do come back and let us know how it worked out with your builder.