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Code change mid build- need fireproofing ideas

Posted by Kiwigem (My Page) on
Wed, Jul 23, 14 at 7:06

Hi, everyone!
We are building a home and had our first little hiccup this week when we discovered that the residential code has changed since our plans were drawn, and we now are required to fireproof the truss joists in our floor.

It actually doesn't sound like a bad idea : ), but it was not built into our budget. Can anyone suggest an economical way to fireproof the joists?

Thanks!


Follow-Up Postings:

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RE: Code change mid build- need fireproofing ideas

If you are referring to the requirement of section R501.3 of the 2012 IRC, it does not require "fire-proofing" or even a "fire-rating" of a floor assembly.

What it requires is a fire-protection "membrane" below a floor assembly consisting of 1/2" non-fire-rated drywall or 5/8" combustible OSB or plywood.

The intent is to avoid exposed floor trusses, I-Joists, etc. (i.e., members smaller than 2x10's) unless they are over a crawlspace, a sprinklered space or an area smaller than 80 s.f.

2012 IRC
R501.3 Fire protection of floors
Floor assemblies, not required elsewhere in this code to be fire-resistance rated, shall be provided with a 1/2-inch gypsum wallboard membrane, 5/8-inch wood structural panel membrane, or equivalent on the underside of the floor framing member.

Don't be confused by the casual use of terms like "fireproofing", "fire-resistance-rating" or "fire-rated assembly." None of them apply. This requirement is simply for an un-rated "fire-protection membrane" that will allow light weight trusses and I-joists to resist collapse in a fire for at least as long as standard unprotected 2x10 (or larger) dimensioned lumber joists. Equivalent protection is allowed when accepted by the local building official.

This post was edited by Renovator8 on Wed, Jul 23, 14 at 10:02


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RE: Code change mid build- need fireproofing ideas

Is this an official notification from the building dept?

If so, ask for a copy of the adopted ordinance.

While It is not uncommon for municipalities to adopt changes to building codes, it is just as common for them to allow existing approved, permitted and under construction projects to continue to completion, as approved and only those future projects to be affected.

It will be in the language of the ordinance, not hearsay, or someones interpretation.


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RE: Code change mid build- need fireproofing ideas

Ok here is the law in the OP's jurisdiction:

"502.14 Fire Resistance of floors
Floor assemblies, not required elsewhere in this code to be fire resistance rated, shall be provided with a 1/2 inch gypsum board membrane or a 5/8 inch wood structural panel membrane or an equivalent material on the underside of the floor framing member which complies with section 302.14."

Section 302.14 provides equivalent material options for fire protection that is not required to be fire resistance rated. The exceptions to this requirement are the same as in the 2012 IRC.

This law was obviously taken directly from the 2012 IRC and renumbered and needs no explanation or interpretation.

Make of it what you will but please don't call it "fire proofing" or suggest that the assembly is "fire-resistance rated"; it is just an unrated fire protective membrane.

This post was edited by Renovator8 on Wed, Jul 23, 14 at 11:44


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RE: Code change mid build- need fireproofing ideas

"Can anyone suggest an economical way to fireproof the joists?"

Over a crawl space or a basement?


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RE: Code change mid build- need fireproofing ideas

The building code in the OP's jurisdiction says that no protection is required below floor framing over a crawl space that is not used for storage or fuel-fired appliances.

Anywhere else 1/2" gypsum board would obviously be cheaper than 5/8" OSB or plywood.

The requirement for floor protection first appeared in the 2013 residential code which became effective on Jan 1, 2013. It should not have been possible to get a building permit after Jan 1st without the required protection.

This post was edited by Renovator8 on Wed, Jul 23, 14 at 13:10


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RE: Code change mid build- need fireproofing ideas

"This law was obviously taken directly from the 2012 IRC and renumbered and needs no explanation or interpretation."

You and I both know that in the approval process for adoption, sections of the code can be exempted from implementation, while under review.

So, has the project been permitted?

However, why was this a surprise to the client, when/if there was a competent person preparing the plans?

This post was edited by snoonyb on Wed, Jul 23, 14 at 13:43


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RE: Code change mid build- need fireproofing ideas

You might also ask how the plans got approved by the building department if floor trusses or I-joists were specified.

It might help you to know that:
- the required protective layer is not required to be taped or sealed with gypsum joint compound.
- the layer components can be butted to ductwork, other membrane sheets, piping, the plate at walls, or other structural or non-structural elements.
- When butted to these elements, the elements themselves are a part of the thermal protection and do not constitute an opening in the membrane.
- if the protective membrane attached to the bottom of the engineered lightweight framing members is not continuous above ductwork, no fire blocking is required if the space between the bottom of the engineered lightweight framing members and the top of the ductwork is a maximum of 1½” or less.

This post was edited by Renovator8 on Wed, Jul 23, 14 at 13:36


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RE: Code change mid build- need fireproofing ideas

"You and I both know that in the approval process for adoption, sections of the code can be exempted from implementation, while under review."

I have not known that to be true for any building code but, in this case, the revised code was approved in March of 2012 and became effective Jan 1, 2013. If anyone wanted to review or appeal the requirement, it would have been done in the 9 months preceding the effective date. Some municipalities might have implemented this requirement before the effective date but they could not have delayed implementation.

As for alternative methods of meeting the code requirement, what is required is a written proposal from a licensed design professional documenting why and how it might be equivalent. I can't think of anything cheaper than drywall but if the trusses are difficult to cover with drywall, the building department might accept intumescent paint with the proper documentation.

You only need to make the trusses/I-beams last as long as 2x10's in a fire. All the code is attempting to achieve is to prevent firemen from suddenly falling into the basement with no warning. They're quite concerned about things like that and apparently think homeowner should be too.

This post was edited by Renovator8 on Wed, Jul 23, 14 at 14:32


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RE: Code change mid build- need fireproofing ideas

Thank you all for all your detailed input (detective work figuring out my jurisdiction? Woah!), I really appreciate it.

I too wonder how the plans were approved in the first place, but I haven't had a chance to find out how the mistake was made/found. It does seem like a worthy code change, so I'm not too bent out of shape about it.

I think we will end up going the gypsum board route, but it may mean having to choose beefier beams to avoid deflection problems, our architect says. Seems to me if we were that much on the bubble weight-wise we'll be glad for the stronger beams anyway- blessings in disguise.

Thanks for your insight!


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RE: Code change mid build- need fireproofing ideas

The original answer was all that was needed but I am continually accused of offering my opinion or interpretation of these matters instead of the facts even when the code speaks for itself.


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RE: Code change mid build- need fireproofing ideas

"Some municipalities might have implemented this requirement before the effective date but they could not have delayed implementation."

This is incorrect.

Municipalities have the absolute right to continue to delay the implementation pursuant to the standards for implementation instituted by their charter.

They also have the right to make any provision of the code more stringent, for application, where needed, but cannot lessen the requirements.

"The original answer was all that was needed but I am continually accused of offering my opinion or interpretation of these matters instead of the facts even when the code speaks for itself."

From your localized perspective, not universally.


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RE: Code change mid build- need fireproofing ideas

You must be thinking about the wrong state.

In 2006, the state of Ohio gave its Board of Building Standards the responsibility for adopting a STATEWIDE MANDATORY RESIDENTIAL BUILDING CODE. Prior to that time each jurisdiction had the authority to adopt its own regulations.

Only the Ohio Board of Building Appeals has the authority to grant a variance from the requirements of the state code on an individual project basis.


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RE: Code change mid build- need fireproofing ideas

Thank you all for your input, but I think Renovator8 is correct for my location. Talked to GC and we are now leaning toward pretreated beams. Thank you, everyone. It's wonderful of all of you to be so generous with your time and expertise.


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RE: Code change mid build- need fireproofing ideas

It would make sense that the code applicable at the date of the permit would be the code enforced, (under the grandfather clause) but the OP did not mention a previously-granted permit, only previous drawings/plans.
If your permit expires or the GC took out the permit and subsequently rescinded it, then the current updated codes would and should be applied.
Not a lawyer, FWIW,
Casey


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RE: Code change mid build- need fireproofing ideas

Perhaps there are new chemicals used for fire-retardant-treatment of structural wood but the old ones have been such a problem that I would be skeptical and extremely cautious.

Since the level of the required protection is so low, a surface coating might be a safer option.

What is the span and where are the floor trusses located? Why is a membrane a problem?

Incidentally, Laminated Veneer Lumber joists or beams (LVL's) would not require protection.

This post was edited by Renovator8 on Thu, Jul 24, 14 at 12:07


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RE: Code change mid build- need fireproofing ideas

The trusses are first floor, single story portion of house, under kitchen. Span is about 20 feet, but I am going on memory- plans are in the car. The size we were using were pretty maxed out weight-wise it turns out, so it's a good discovery really.

Why don't LVL's need protection?

Thanks!


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RE: Code change mid build- need fireproofing ideas

The purpose of the new regulation is to prevent factory-built lightweight framing from collapsing before the fire department can contain the fire.

2x10's and larger dimensioned lumber joists or any member equal to or greater in density and thickness than a 2x10 is exempt.

LVL's are thicker and considerably denser than 2x10's and will last even longer in a fire.

The regulation is basically for I-Joists (but it is written so it includes floor trusses) that have very thin OSB webs and generally fail in half the time as dimensioned lumber. However, if you are using some kind of floor truss, you should ask the manufacturer how to meet the regulation. They may have tested their product and can prove it is equivalent to 2x10's. It's a pretty low standard.

Is the reason you are using floor trusses to allow ductwork to pass through them? Is that really necessary over a basement?


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RE: Code change mid build- need fireproofing ideas

Our architects specified I joists so we could have a nice open space in the basement and because in their opinion I joists yield a better floor.

Renovator8, you were right in your skepticism of the fire retardant chemicals. Got shot down this morning by city engineer. Will ask builder to look into LVL joists. Can they span as far as the I joists?

Are LVL's more expensive? Is there a publication or website that states that LVL's last as long as wood beams?

Thank you!

This post was edited by Kiwigem on Mon, Jul 28, 14 at 9:04


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RE: Code change mid build- need fireproofing ideas

One thing needs to be clarified. An I-joist is not a truss joist. A truss joist is made up of diagonal members between a top and borrow chord. That allows utilities to be run through the openings in the joists.

An I-Joist has a thin solid OSB web between a top and bottom chord and the web must be cut for small utility runs. I-Joists are sometimes mistakenly called truss joists because one of the most common brand names of I-Joists is "Trus Joist" and builders often like to use trade names as if they were generic.

LVLs are structurally far superior to 2x dimensioned lumber because they contain laminations of very high strength wood and are therefore more expensive. Very few small holes can be drilled in them.

The only time I have used LVLs as joists (instead of as beams) was when saving a few inches in the ceiling of a renovation was worth the additional cost.

What is the span of the joists? How deep were the i-joists?


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RE: Code change mid build- need fireproofing ideas

Hi, of course you are right. I meant I joists. We determined that the best use of our money is to use the i joists and drywall the basement ceiling. Thank you for all your input. I think it was informative for more than just me!


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RE: Code change mid build- need fireproofing ideas

There are several inexpensive ways to achieve the fire protection directive of your floors assemblies under 2012 International Residential Code section R501.3 without having to apply expensive fire retardant coatings to the manufactured floor joists.

One simple method, already mentioned, is to use dimensional lumber rather than manufactured joists/trusses, usually greater than 2x8 in depth, and of a 'species' of lumber that can span the clear spans you wish to achieve. For example, IRC Table R502.3.1(2) permits 2x12 #2 SPF lumber at 12 inches on center to achieve 20 foot spans. Using this method would negate any need for fire protection of the floor system.

Likewise, using 2x12 Doug Fir or Southern Pine lumber at 16 inches on center could attain the same end without any need for expensive fire retardant coatings.

Another simple method (and potentially the cheapest) is to install a "Limited Area Sprinkler System" in the basement or crawlspace which can be connected to your domestic water supply....and you could still use manufactured floor joists/trusses if that is what you desire.

A 'limited area sprinkler system' is one that uses 20 sprinkler heads or less and is connected to your domestic water supply under section 903.3.5.1.1 of the International Building Code and NFPA 13D. (Many floor assemblies over basements can be fire protected with as few as 6 sprinkler heads using BlazeMaster CPVC sprinkler pipe for a few hundred dollars using this method.

You may have to submit your construction plans under the 2012 International Building Code rather than the 2012 International Residential Code to use this method, but most enlightened code officials would simply allow this sprinkler design under the IRC.

See link:

https://www.lubrizol.com/CPVC/Products/BlazeMaster.html

That said, builders in my region generally opt for dimensional lumber rather than manufactured joists to avoid expensive drywall covering or fire retardant chemical fire protection of floor assemblies for large basement areas...and the limited area sprinkler system where just a few sprinkler heads can do the trick for smaller basements.

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The intent of the International Residential Code is to get you to sprinkler the new house anyway under R313 (unless your jurisdiction/state has removed the requirement as did mine...Pennsylvania)

A limited area sprinkler system becomes, then, is often the simplest and cheapest alternative to protect I-joists, truss joists, lam beams, finger-jointed joists and all other manufactured wood floor assembly products which under IRC 2012 R501.3 MUST be protected by a minimum 1/2" gypsum board or some other approved method, and can often be done for a few hundreds of dollars by your plumbing contractor.

It is a method I highly recommend, since residential sprinkler systems here cost only about $1 per square foot installed.


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RE: Code change mid build- need fireproofing ideas

That's a great idea- I will look into it.
Thank you!


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RE: Code change mid build- need fireproofing ideas

The 2x12 joists described above will meet the building code prescriptive requirements for a 20 ft. span but that would produce a deflection at max loading of L/415 which is too bouncy for personal comfort. An acceptable stiffness would be L/600 and L/720 would be even better if you have an active family.


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RE: Code change mid build- need fireproofing ideas

Good to know as I have 5 kids, and our last house (120 year old Victorian) was very bouncy and I didn't like it. Thanks!


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RE: Code change mid build- need fireproofing ideas

The cost of residential sprinklers varies from $1 to $2.50/s.f. the average is $1.35/s.f.

What is the joist span and why can't there be a ceiling?


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RE: Code change mid build- need fireproofing ideas

The new code requirement is about firefighter safety not the protection of property.

The requirement is the result of concern by firefighters and firefighter organizations that the webs of EXPOSED I-Joists fail in a fire more quickly and with less warning than EXPOSED 2x10's. This condition is most commonly found in basements where the owner or developer does not want posts and also does not want to install a drywall ceiling.

As I mentioned earlier, if the desired clear span can be achieved with I-Joists, the simple solution is to coat the joists with intumescent paint.

Weyerhaeuser satisfies the new code requirement with an intumescent coating called "Flak Jacket" that is factory applied to their I-Joists. I have heard that it adds about $.75/s.f. to a floor system but even if it cost the same as a sprinkler system it would be a lot less trouble.

Of course, if you intend to use the basement for a high hazard use, you might prefer the sprinkler system.

This post was edited by Renovator8 on Tue, Jul 29, 14 at 9:27


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RE: Code change mid build- need fireproofing ideas

We priced the Weyerhauser joists and determined it was better to drywall the ceiling. At least that way we gain something instead of merely spending money to satisfy code. Thanks for all your input!


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RE: Code change mid build- need fireproofing ideas

The International Residential Code has required sprinklers in new homes since 2009, unless that requirement has been removed by your state or other code adoption authority.

That said, if you are already required to install sprinklers in your new house, adding a few more sprinkler heads in the basement won't break your budget.
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As for greater deflection and "bouncier" floors with dimensional lumber, I would dispute that allegation since closer spacing of joists or using denser dimensional floor joists lumber species has always easily eliminated that problem....

In fact, it has been I-joists, floor trusses, and other types of engineered joist that have garnered the most complaints about floors being bouncy since these products have been introduced than have solid lumber floor systems.

That said, there are multiple ways to build floor systems that will carry the loads and not excessively deflect...multiple ways to 'meet code'...and multiple products and systems that can be employed for one to 'believe' they are getting the best end product...

And in the grand scheme of things, 'believing' you have made the best decision(s) for your own personal build is all that matters!

Be happy with your choice and enjoy your new home!
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PS: Fire protection of floors is NOT just an item promoted by firemen and other first responders. Nor is it a code requirement there just to protect them.

On the contrary, fire protection of floors is a proven life safety concern for occupants who live in homes built using engineered wood products.

Why?

Because floor systems built of engineered wood products combust more quickly and collapse much more quickly in a fire than floors constructed using dimensional lumber.

That affects the means of egress and escape for trapped occupants in the first minutes of a fire far more than it does firefighters once they arrive... Firefighters, who are trained NOT to enter the building if they arrive more than 15 minutes after the first call anyhow!
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Statistically, most residential fires occur at night when occupants are asleep.

Unprotected engineered floor systems can completely fail within 15 minutes of fire ignition.

A sleeping occupant who may already have been delayed by becoming aware that an actual a fire is going on...and one who is awakened from sleep and already not thinking clearly...can make poor escape decisions in assessing the risk to their lives in a fire...and have very limited time to respond before unprotected floors collapse.

That is the PRIME concern here...NOT firefighter safety.

Because firefighters are not entering your house in a fire if they know the construction includes engineered joists anyhow...Because they know the risk is too great.

So let's put to rest the 'myth' that fire protection of floors by building codes is there only to protect firemen.

It isn't.

It is there to protect the OCCUPANTS...who might otherwise DIE trying to escape...when unprotected engineered floor systems collapse before they even know what is happening.


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RE: Code change mid build- need fireproofing ideas

Ohio rewrites the IRC for its statewide code and did not include the 2012 IRC requirement for sprinklers so that is not an issue for the OP's project.

The 2012 IRC Section R501.3 "Fire Protection of Floors" code change was proposed by several organizations that made it clear that the reason for it was to protect firefighters at the request of their representative organizations.

The original proposal that started the code change process for this issue was submitted by Dennis Pitts of the American Wood Council containing this explanation of his intent:

"REASON: The fire service has asked for minimum fire resistance of floor/ceiling systems equivalent to 2x lumber floor construction. The basis of the requirements assume that a floor/ceiling assembly constructed using 2x lumber and loaded to 50% of full design load will provide 15 minutes of structural fire resistance as confirmed by recent UL testing reported in Structural Stability of Engineered Lumber in Fire Conditions."

The final accepted code change proposal was from Sean DeCrane of the Cleveland, OH Fire Department, representing the International Association of Fire Fighters containing this explanation of his intent:

"REASON: On August 13, 2006 a Wisconsin fire fighter was killed, and a second fire fighter injured, when the floor they were operating on collapsed sending them into the basement. One fire fighter fell directly into the room of origin and was killed, the second fire fighter landed on the opposite side of a block wall and survived by shielding herself and making an escape through a rear window. They checked the floor to ensure it was safe and solid, just prior to collapse they heard a loud crack. The floor they were operating on was unprotected lightweight construction that collapsed without warning. In the ensuing investigation, the National Institute for Occupational Safety and Health released report F2006-261. One of the recommendations is to “modify current building codes to require that lightweight trusses be protected with a fire barrier”. This should not only pertain to truss construction. There are additional forms of construction that can be determined to be lightweight, cold form steel, bar joists, wooden engineered I-beam, etc., the recent trend in residential construction is to use products that are financially beneficial. It is the belief of many of us in the fire service that as the industry engineers products to a more finite point we are losing our safety factor."

This code change might increase the time an inhabitant has to get out of a burning house but that potential benefit was not mentioned in any of the code change proposals or in the public comments and cannot be said to be the intent of the code change.


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