# Structural wood IBC 1707.3 for SFR



## Bootleg (May 5, 2010)

Can the IBC 1707.3 be required for SFR shear wall nailing of panels where the fasteners spacing of the sheathing is 4 inches or less on center?


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## peach (May 5, 2010)

sure .. if you are in a seismic zone, it's a periodic inspection.. (which you can also do during the framing inspection).  4" or less on center fasteners are going to split the framing members.


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## Mule (May 5, 2010)

Why are you wanting to use the IBC when you need to use the IRC?

Are you in a state that requires you to use the IBC?


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## Bootleg (May 5, 2010)

Mule said:
			
		

> Why are you wanting to use the IBC when you need to use the IRC?Are you in a state that requires you to use the IBC?


Mule,

That’s what I want to know.

I'm in Washington State and want to know how we can use the 2006 IBC in SFR in place of the 2006 IRC?


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## Mule (May 5, 2010)

Okay, I take it that you want to use the IBC instead of the IRC.

Has Washington State adopted the IRC. If so, does it let AHJ's ammend the code "if" the ammendments are more stringent than the code adopted?

In order to use the IBC section over the IRC, it would take the AHJ ammending specific sections in order to use the IBC vs the IRC

You would have to ammend the State version of the code (if that is even allowed)

Is it because you are wanting a special inspector to inspect the shear walls?

Are you wanting the contractor to secure the panels closer than 4" oc?

I don't quite understand what you are trying to do here.


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## Bootleg (May 5, 2010)

Mule said:
			
		

> Okay, I take it that you want to use the IBC instead of the IRC.Has Washington State adopted the IRC. If so, does it let AHJ's ammend the code "if" the ammendments are more stringent than the code adopted?
> 
> In order to use the IBC section over the IRC, it would take the AHJ ammending specific sections in order to use the IBC vs the IRC
> 
> ...


Mule,

That’s what I think is hard with the web!

Here is what the story is, I have worked in this small town for five years as the building inspector and know all the builders in this town.

Now we have a new BO (for one year now) and I was on a shear wall nailing inspection yesterday and when I looked at the approved set of plans that the BO reviewed it said Special Inspector required for the shear wall nailing 4" on center or less.

I called the BO from the job site and asked him why is this required?

He said if you want to sign it off go ahead. I wrote a correction for Special Inspector required as per approved plan.

When I got back to the office I ask him to show me what code he is using.

 That’s when he said the 2006 IBC. I said this is a SFR and shouldn’t this be under the 2006 IRC?

He said NO.


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## mtlogcabin (May 5, 2010)

Unless it is some oddball McMansion or the designer specified the IBC I believe your BO is off base on that requirement

2006 IBC 101.2 Scope.

The provisions of this code shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures.

Exception: Detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories above grade plane in height with a separate means of egress and their accessory structures shall comply with the International Residential Code.

1707.1 Special inspections for seismic resistance.

Special inspections itemized in Sections 1707.2 through 1707.10, unless exempted by the exceptions of Section 1704.1, are required for the following:

1704.1 General.

Where application is made for construction as described in this section, the owner or the registered design professional in responsible charge acting as the owner’s agent shall employ one or more special inspectors to provide inspections during construction on the types of work listed under Section 1704. The special inspector shall be a qualified person who shall demonstrate competence, to the satisfaction of the building official, for inspection of the particular type of construction or operation requiring special inspection. These inspections are in addition to the inspections specified in Section 109.

Exceptions:

1. Special inspections are not required for work of a minor nature or as warranted by conditions in the jurisdiction as approved by the building official.

2. Special inspections are not required for building components unless the design involves the practice of professional engineering or architecture as defined by applicable state statutes and regulations governing the professional registration and certification of engineers or architects. Is it engineered?

3. Unless otherwise required by the building official, special inspections are not required for occupancies in Group R-3 as applicable in Section 101.2... What is the reason to require it? 

I suggest you approach the "new" BO with a humble attitude of wanting to be educated. You should be able to explain to the contractor why something out of the ordinary is being required. If he does not provide code sections as to why he wants a special inspection for a SFR then I suggest you hand out his business card when asked and let him field the questions.

This is a good example of what brudgers gets worked up about and why he wants to call the man with a tie.


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## Bootleg (May 5, 2010)

mtlogcabin,

2. Special inspections are not required for building components unless the design involves the practice of professional engineering or architecture as defined by applicable state statutes and regulations governing the professional registration and certification of engineers or architects. Is it engineered? YES, _and I told the contractor to have the engineer inspect the nailing._3. Unless otherwise required by the building official, special inspections are not required for occupancies in Group R-3 as applicable in Section 101.2... What is the reason to require it? THIS IS WHAT EVERYONE WANTS TO KNOW.


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## peach (May 5, 2010)

well.. look at IRC chapter 3 (specifically R301.1.1 and R301.1.3).. "Where engineered design is used in conjunction with these standards, the design shall comply with the International Building Code"... it's all structural provisions.


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## Mule (May 6, 2010)

Bootleg,

I understand now. Tough situation you have.

It may be engineered, and if so the engineer "should" look at it. However we perform inspections on engineered items without requiring a report from the engineer. Like post tension foundations. We inspect per the drawings but don't require the engineer to submit his inspection of the project.

Peach,

Chapter 3 does say; (your quote) chapter 3 (specifically R301.1.1 and R301.1.3).. "Where engineered design is used in conjunction with these standards, the design shall comply with the International Building Code"... it's all structural provisions.

The design...yes...the special inspector...I don't know.

However the regulations in the IRC are perscriptive. So if it's perscriptive, why go to the IBC? It's in the IRC. The entire code is engineered designs, but we don't require an engineer to inspect.

Unless there is specific engineering, sealed plans, that is outside of the perscriptive of the IRC, then the IBC would apply..

I'm just thinking out loud here...........


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## Bootleg (May 7, 2010)

Thank you,

for everyone’s help.

The engineer of record inspected and approved the shear wall nailing but I heard he wasn't happy about doing it because he is busy.


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## peach (May 7, 2010)

You can always require that the builder hire an independent 3rd party structural firm..  I've never been a fan of the structural designer inspecting their own design..

Maybe it's just me...


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## EPrice (May 10, 2010)

peach said:
			
		

> I've never been a fan of the structural designer inspecting their own design..Maybe it's just me...


I look at this differently.  By the time we get to inspections, the design has been reviewed and approved.  Hopefully any deficiencies in the design have already been addressed.  One objective of the special inspection is to verify that the construction conforms to the design.  Who is better to do this than the engineer who designed it?  Another advantage of having the engineer inspect the work, is that it gives him/her a chance to see some of the difficulties that can be encountered in the real world in trying to implement some details.  The designer may in some instances decide to come up with details in the future that are easier to implement.  Of course, there are some technical aspects of special inspection that most engineers would not be qualified to do.  Inspection of welds comes to mind.

I will say though, that around here, the engineers seldom do the inspecting.  It is usually a third party special inspector.


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## Mark K (May 13, 2010)

I do not have a copy of the IRC handy but I find the use of 4 inch or less shear wall nailing inconsistent with the conventional light-frame construction provision in the IBC.  This spacing implies that somebody did some engineering and thus the IBC would be applicable for at least the engineered portion of the building.  If the owner does not want to hire special inspectors then he should have his consultants design it so that the design does not trigger the use of the IBC.  This is the decision for the Owner and his designers to make.

Under section 1704.1 the building official may require special inspection for Group R-3 occupancies   The code section gives the BO the option of requiring special inspection in these cases.  I believe that this would be appropriate because these walls with close nail spacing are working harder and are less forgiving of workmanship problems.

Why is the building official being challenged on this?  Yes he should want the inspectors to understand his thinking and yes the inspectors can help find issues that were missed but at the end of the day after checking with the building official the jurisdiction’s inspectors should enforce what is on the permit documents and not what they thinks is right.

Special inspection of wood shear walls is required in regions of either high wind or high seismicity.  High wind and high seismic regions can occur in Washington.

Special inspections are separate from the framing inspection performed by the building department.  Not all building department inspectors will have the qualifications to perform all special inspections.  If the jurisdictions inspectors take the time to do the required special inspections it costs the jurisdiction more time and by extension more money.   If the building departments inspectors were to perform the special inspections I would think that they would also have to provide the paperwork necessary for submission of the final report as required by Section 1704.1.2

It is inappropriate to require the structural engineer to perform the inspection of the shear walls because the building code does not give the building department this authority.  Special inspections are to be performed by inspectors retained by the Owner and approved by the building official.  When the engineer is pressured to perform these inspections he may not be paid for his time if he is working on a fixed fee contract.

Many engineers prefer not to perform special inspections for many reasons but when he is qualified and interested in doing so I see no problem.  Remember the engineer should know what is required for this project better than anybody else.


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## mtlogcabin (May 13, 2010)

> but I find the use of 4 inch or less shear wall nailing inconsistent with the conventional light-frame construction provision in the IBC.


It is consistent in the IRC 

The IRC specifies nailing of alternate braced wall panels of less then 4" oc and if next to a door or window it is 3"oc. It is prescriptive and a special inspector is not required by the IRC when following the prescriptive requirements of the IRC. Just because an engineer has been used on a SFR does not automatically mean the design exceeded the IRC requirements.

R602.10.6.1 Alternate braced wall panels.

Alternate braced wall lines constructed in accordance with one of the following provisions shall be permitted to replace each 4 feet (1219 mm) of braced wall panel as required by Section 2. In the first story of two-story buildings, each braced wall panel shall be in accordance with Item 1 above, except that the wood structural panel sheathing shall be installed on both faces, sheathing edge nailing spacing shall not exceed 4 inches (102 mm) on center, at least three anchor bolts shall be placed at one-fifth points.

Look at the following section 3 inches oc edge nailing

FIGURE R602.10.6.2

ALTERNATE BRACED WALL PANEL ADJACENT TO A DOOR OR WINDOW OPENING


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## RickAstoria (May 13, 2010)

Bootleg said:
			
		

> Mule,That’s what I want to know.
> 
> I'm in Washington State and want to know how we can use the 2006 IBC in SFR in place of the 2006 IRC?


Washington uses IRC but irregular components and elements of the building will fall under IBC.

Washington uses IBC and IRC.

The State Building Code (SBC) is the minimum construction requirement for the state of Washington and includes:

    * 2006 International Building Code with statewide amendments

    * ICC/ANSI A117.1-03, Accessible and Usable Buildings and Facilities, with statewide amendments

    * 2006 International Residential Code with statewide amendments

    * 2006 International Mechanical Code with statewide amendments

    * 2004 Liquefied Petroleum Gas Code (NFPA 58)

    * 2006 National Fuel Gas Code (NFPA 54) for LP Gas

    * 2006 International Fire Code with statewide amendments

    * 2006 Uniform Plumbing Code with statewide amendments

    * 2006 Washington State Energy Code

    * 2006 Washington State Ventilation and Indoor Air Quality Code

    * The Washington State Historic Building Code (published in 1991)

    * 2008 National Electrical Code (NFPA 70) -- Please see the Department of Labor and Industries for information on the adoption and amendment of the National Electrical Code.

http://sbcc.wa.gov/page.aspx?nid=4

They are shifting to the 2009 code set so I will advise you right NOW to move to 2009 code-set because if you are in design stage, permit will be shifting into 2009 in a few months so you will be applied to the 2009 edition. So prepare yourself for the next code set.


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## righter101 (May 13, 2010)

Bootleg, I am a plans examiner in Washington.  Just a couple of quick points.

1. RickAstoria is providing you with some incorrect information.  He states "Washington uses IRC but irregular components and elements of the building will fall under IBC".  This is incorrect.  IRC 301.2.2.2.2 (Irregular buildings) states in part:

_"Irregular portions of structures_

_shall be designed in accordance with accepted_

_engineering practice to the extent the irregular features_

_affect the performance of the remaining structural_

_system"_

You are best to refer to the IBC 1704 section listed by mule, noting exception 3, where Special Inspection is not required in R3 structures

_Unless otherwise required by the building official,_

_special inspections are not required for occupancies_

_in Group R-3_

For residential construction, in our jurisdiction, we require special inspection on welding, steel moment frames, and high strength bolting.  we do not required it on engineered nailing patterns, trusting our building inspectors to preform the necessary verification.  It would, however, be within the scope of the authority of the BO to require it, and could be supported by code.

I would suggest the previously mentioned humble approach, discussion of the why behind his ruling.  Perhaps also ask for a list of what other items should have Special Inspections.

One other note, the alarmist note from Rick Astoria, about _"I will advise you right NOW to move to 2009 code-set"_, is unfounded.  As you likely are aware, the 2009 codes will be adopted by the state of Washington July 1st, 2010.  Any application received prior to that will be reviewed and built under the 2006 codes.  I would also urge caution in listening to his advice, as from his last sentence, it is clear he hasn't read the entire post.

he states _"if you are in design stage"_.  It seemed obivious from the posts that you are not "in the design stage", in fact, you are a building inspector and this was the result of a recent inspection.

Good Luck.  welcome to the forum


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## RickAstoria (May 14, 2010)

Sorry, didn't read all of his post(s) due to it being a bit jumbled. Anyway, yes but it is still IRC as the base code and following the direction IRC says. Which may refer to IBC in portions. I answered that specific post.

righter101 - read R301.1.3

Now, regarding regarding 2009 IRC. It is not even 2 months away. Only about a month & a half. It is only a short time away. I highly doubt plans be ready by then IF the plans are not close to completion. It depends on how far along the plans are. However, I did miss noticing in a later post that he was a Building Inspector. In which case,  the 2009 I-codes comment maybe ignored.


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## righter101 (May 14, 2010)

I have read it many times.  That code section states "_Engineered design in accordance with the International Building Code is permitted...."_

The language in your post indicated that it was REQUIRED. (your post quoted here) _"building __*will*__ fall under IBC"_.

You say in your last post that  "Sorry, didn't read all of his post(s)...".

I would respectfully suggest that you don't comment on posts unless you have read them.  Picking out several key words and injecting your opinon without knowing the extent of the questions can lead to some bad advice being offered.  I was trying to warn the new poster that some of your information is factually wrong.


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## RickAstoria (May 14, 2010)

Don't forget to read R301.1.1

This is seemingly wood-frame construction with sheathing. Presuming AF&PA Wood-Frame Construction Manual standard is involved here. Kicks in IBC for any engineered elements.


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## peach (May 18, 2010)

more nails does not make more gooder


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