Starting June 1, 2009, State of Michigan Residential Builder’s and Maintenance and Alteration Contractors will be required to fulfill continuing education coursework in order to renew their licenses.
Licenses will also be renewed for a period of 3 yrs instead of the current 2 yrs.
The contractor is required to successfully complete not less than 3 hrs of “activities demonstrating continuing competency” per calendar year during the first 6 calendar years of licensure and 21 hrs per 3-yr cycle since the issuance of his or her license. Any contractor who has had a license for more than 6 years is only required to complete 3 hrs of CE per license cycle. These hrs include 1 hr of codes, 1hr of safety and 1 hr of legal issues. New licensees after June 1, 2008 will be required to take a 60 hr prelicensure class. Applicants will also have to state that they own a current copy of The Michigan Residential Code.
Currently, Michigan’s Builder’s Licenses are on a 2-yr cycle with approximately half renewing this May, and the other half in May 2009. Neither one of these renewals will require the continuing education. Your renewal will be for three years and it is during that time that CE credits must be taken.
Jeannine Benedict of The Michigan Department of Labor and Economic Growth told me her Department is still in the process of developing rules and procedures for the program. Renewal applications (which are customarily sent out 120 days prior to expiration) will contain information on these requirements.
Michicode.com will be developing and providing these classes once the rules and procedures are in place. Keep an eye on our CLASSES page.
Recently, I performed a preliminary inspection on an eight story building whose upper 5 floors were being converted into residential lofts. Framing was near completion on one of the upper floors and trade work had been started. One of the first things I look at any residential use in a multistory building are:
Where does the bathroom exhaust go?
Are there clothes dryers and if so where do they vent? And…
Where does the heating and cooling come from?
I am looking to see if shaft requirements have been met.
On this occasion I found both the dryer duct and the bathroom exhaust entering into a single shaft. The bathroom exhaust was protected by a fire damper at its penetration to the shaft. The 4’ dryer duct was only firestopped at its penetration. The shaft and ducts terminated at the 7th floor where an undampered 10” duct penetrated the shaft and terminated at an exterior wall of the building. The building was of type 1B construction and was fully sprinklered. The design was reviewed under the 2003 Michigan Existing Building Code.
Smoke and Fire Dampers Required
Section 716.5.3.1 is very specific in requiring both fire and smoke dampers where ducts penetrate a shaft. There are many exceptions but none that allow either penetrations to be installed without a smoke damper. Although the building code does not address dryer ducts, I know that dryer ducts cannot be dampered in any way. This would create surfaces for lint to accumulate and create a fire hazard.
Catch 22
While the State of Michigan had not adopted the 2006 International Building Code at the time, it had adopted the 2006 International Mechanical Code. Under the ICC, chapter 6 of the Mechanical Code and chapter 7 of the Building code have been nearly identical for the section on “Ducts and Air Transfer Openings”. The 2006 now allows an exception for smoke dampers for dryer ducts, kitchen and bathroom exhaust in Groups R and B (previously this exception had only been for bathroom exhausts in B uses only). This exception is allowed under the following conditions:
The building is sprinkled with an NFPA13 system.
The openings into the shafts are installed with steel subducts at least .019 inch thick.
The subducts must extend at least 22 inches vertically into the shaft.
An exhaust fan is installed at the top of the shaft. This fan must continuously run and be connected to an approved “standby” power source.
With some modifications (subducts and exhaust fan at top of shaft) this installation can bypass both the fire and smoke dampers. (There is an exception for fire dampers in any use group if you install subducts-provided there is a continuous airflow upward to the outside. The only foreseeable problem is the 10 inch duct at the upper floor. Subducting would be not be practical because of constraints of air flow, lint accumulation and height. The shaft could be continued horizontally to the exterior wall of the building bypassing any fire/smoke damper requirements. The final issue is the renovation was reviewed under 2003 IBC and these changes do not exist in that code. The builder would have to apply for administrative relief through the local Authority Having Jurisdiction.
On a recent visit of a renovation of a high rise building, I noticed smoke dampers installed in transfer openings in a wall which formed a required elevator lobby. As the construction documents were approved under 2006 Michigan Building Code, an elevator lobby is required at each floor where an elevator connects 3 or more stories. Previously, International Building Code and Michigan Building Code required these lobbies only when the elevator opened into a rated corridor.
Existing 2-hr masonry walls formed 3 sides of the lobby and approximately 6 ft of metal stud wall made up the remaining wall which I was inspecting. 2 HVAC penetrations were made in this wall one was ducted and the other was the transfer grille.
IBC/MBC 2006 require the walls that make up this elevator lobby to meet the requirements of fire partitions. There is an exception, when the building has an NFPA 13 or 13R fire suppression system, that allows these walls to be smoke partitions. The design professional chose to take this exception. Let’s review the requirements for both.
As you can see, the fire partition will require a 20 min door, a fire damper and some firestopping, but by using the exception and denoting the wall as a smoke partition a smoke damper will be required for the transfer grill. Smoke dampers are a more costly item, not only for materials but for labor charges because of its motorization and activation requirements. The cost of the smoke damper would greatly outweigh the costs of upgrading to a fire door and joint/penetration firestopping.
You’ve just failed another rough inspection due to insufficient fireblocking….or is it firestopping. Confused on what is required around those holes through the top and bottom plates. (Didn’t I squirt enough of that red caulk around it?) How do I frame around bathtubs and soffitts? Hopefully I can answer these questions and demystify firestopping.
Fireblocking
Let me start with the simplest explanation and begin with buildings covered by the International Residential Code(IRC). These include one and two family dwellings and townhouses under 3 stories. The only place firestop is mentioned in the IRC is Section 317-Dwelling Unit Separations. Through and membrane penetrations of fire-resistance-rated walls or floor assemblies need to be protected by an “approved” firestop system…. There are some exceptions which I will discuss later.
Since one family dwellings have no rated assemblies, we can leave these out. Two-family and townhouses have rated assemblies between the dwelling units. These are the only areas in IRC buildings which need firestopping. Again, I said I would start with the simple explanation, so I’ll leave a detailed explanation of firestopping to discussion about International Building Code buildings for later. That brings us to fireblocking.
We’ll start with the Code’s definition. “Building materials installed to resist the free passage of flame to other areas of the building through concealed spaces.” Section 602.8 lists 6 places where fireblocking in wood frame construction is required:
1. In concealed stud spaces vertically at floor and ceiling levels.
2. Connections between vertical and horizontal spaces (soffitts, coves, suspended ceilings).
3. Concealed spaces between stair stringers at top and bottom of run.
4. Openings around vents, pipes, ducts, cables at ceiling and floor levels.
5. Chimneys and fireplaces.
6. Cornices of two family dwelling at line of dwelling separation.
602.8.1 goes on to explain what materials can be used for fireblocking: 2 inch nominal lumber, ¾ plywood or OSB, ½ drywall and even unfaced fiberglass insulation. All these items and more can be used for fireblocking 4 of the 6 areas required to be fireblocked. For item #5 masonry chimneys and fireplaces we must go to chapter 10 where specific clearance dimensions(2” for chimneys, front and sides of fireplace, and 4” from back of fireplaces) from combustibles is required. The gap still must be fireblocked but it must be done with non-combustible materials .
Item 4-openings around vents, ducts…. is special and the most confusing. The fireblocking material around bottom and top plate penetrations must be …”approved material to resist the free passage of flame and products of combustion.” Let’s start with the definition (in the IRC) of approved. The 2006 edition of the Codes have changed this to a simple “Acceptable to the building official”. The easiest way to find out what to use is to ask the building official. When I asked an inspector of the jurisdiction I was moving to (and renovating the house I was moving in to) he gave me the standard “firecaulk” answer. Since he was near retirement and I did not want to delay my job, I did like any contractor would do and bought a couple of $16 tubes of 3M firecaulk at Home Depot and squirted them in the holes. But I must ask, why do we (inspectors) make contractors use expensive caulk around a duct or electrical penetration that will feasibly stay intact for a 2 or 3 hours in a fire, while the surrounding wood has burnt away?
When inspecting most IRC buildings and some IBC buildings, I allow tightly packed mineral wool or insulation, unfaced fiberglass insulation filling the cavity up to 16”, structolite(or similar products) and spray foam insulation as long as the penetration is not through a fire resistant rated assembly. At this point I can hear the grumbling from my fellow inspectors….spray foam insulation? Yes, the International Code Council approved a number of Dow Chemical products (mostly the Great Stuff family of foams) as an alternative fireblocking material in Type V construction (All wood framing). The conditions of use are contained in ICC’s evaluation service, Inc. report-NER-645. This report refers to the 2000 IBC and IRC, but since there has been no changes in fireblocking material requirements, this should still be a valid method of blocking.
Firestopping
Now I’ll turn our attention to firestopping and specifically firestopping of penetrations of rated assemblies (walls and floor/ceiling/roof). As in the IRC, the IBC requires penetrations to be protected by an approved firestop system which is installed as it was tested… To simplify, a product which was tested under certain conditions, was shown to maintain the rating of the assembly at the point of penetration.
Let’s say you have a 1hr wall separating a 2-family dwelling, your plumber installs the vent stack in this wall and a 1 ½ “pvc penetrates the membrane (one side) of the wall. This “membrane penetration” needs to be firestopped to maintain the 1-hr rating.
I’ve decided to use a Hilti system whose UL No. is W-L-2244. This means Hilti had this tested by Underwriters Laboratories. You‘ll see that there are a number of parameters which need to be met. First, this system is good for only a 1 or 2 hr gypsum wall. The U300 or U400 represents a series of “tested” wall assemblies which can be built with wood or metal studs (nominal 2 x 4 for wood or minimum 2 ½” for metal). The penetrating item can be up to a maximum of 2” PVC or cpvc plastic pipe. The closed system is that which usually carries fluids. Items 4 and 5 show the Hilti product used (FS-One), the amount (5/8” depth, ½” bead at point of contact) and the placement. Where there is an annular space, the caulk must be in it-between the drywall and the pipe. Under notes you will see that the maximum diameter of the opening is 3”, so if your plumber only owns a 6” hole saw, you’re out of luck with this system. Also, the annular space, the space between the PVC and the drywall can be from 0” (point of contact) to 5/8”. Again, if you have a piece of 1” pvc going through the wall and your plumber’s only hole saw was 3 inch, your annular space would be 1” if the pipe was centered. This system wouldn’t work.
So by this we can see that there are five important things to consider when deciding how to firestop a penetration.
1. What is the assembly you are penetrating made of (gypsum, wood, concrete)?
2. What is the item that is penetrating it (PVC, iron pipe, emt)?
3. What is the annular space (minimum and maximum)?
4. What is the size of the opening?
5. What is the hourly rating of the assembly?
Intumescent vs. flexible
Most manufacturers have a large number of products available. You may hear the term Intumescent. This type of caulk or putty expands when it is exposed to heat. It is typically used around combustible products like PVC and insulated pipe. Flexible sealants are typically used at rated joint (a whole other story) and penetrations by metal products-cast iron, emt, copper.
Passing Inspection
Most inspectors will ask for your “cut sheet” of the firestopping system used. If you have a number of different systems, a copy of all systems should be provided. If you don’t have the cut sheets available, my first question would be “How did you know how to install it”. The definitive wrong answer here is “The way we’ve been doing it for 20 yrs.” These cut sheets are your guide to correct installation. Firestopping decisions should be made before the first hole is cut (in the case of the plumber with the 6” hole saw)
Where do I obtain the cut sheets from?
There are a number of companies which manufacture firestopping (see our LINKS page). Each manufacturer has a catalog with their tested firestop systems. Which one to use would be based on access (who is your nearest supplier), cost and technical support. Most manufacturers have an 800 number where you can call for technical assistance. On larger jobs, most will send representatives to your sight and will also provide installation training. If your doing a lot of firestopping, it is worth the time to have a rep come in and train your employees (just make sure the employees who will actually be doing the installation are involved in the training).
What if I can’t find a system that meets my needs?
FS manufacturers can provide you with an engineering judgment. The manufacture’s engineers develop a system through test data of similar systems. Most Building departments require these be accepted by the architect/engineer of record and their department.
You say you never had to provide any specifications for your inspector. I’ve been known to approve a few metal pipes through a rated assembly when they have firecaulk around them without specs. For anything more complicated than that I require 2 inspections (initially) for the firestopping. First I check the packing material for required thickness, rate of compaction, and parameters of the system used. If the system calls for 1/2 thickness of caulk flush with the floor, the packing material must be recessed at least that amount. I will return once the sealant is in place. Performing dual inspections at the beginning of a large job ultimately saves time and money for both the contractor and the inspector.
The Exception
Both the IRC and IBC allow exceptions from a firestop system when the penetrant is steel, ferrous or copper pipes. The first is in concrete or masonry walls. The pipe has to be 6 inches or less and the total opening is no more than 144 sq inches. The annular space can be filled with grout, concrete or mortar as long as the space is filled for the full thickness of the wall or floor. The second exception allows you to use a material that has been prequalified to meet certain test standards (ASTM 119) for resisting passage of flames and hot gases.
Think Ahead
Hopefully, the most important point I have made is both fireblocking and firestopping should be considered long before you are closing in on rough inspection time. Whether it’s installing some OSB on a section of wall before framing a soffit, deciding which hole saw to use for vent stack or how the drywallers need to cut around openings in rated walls, forethought and buy-in by all trades will save time and money in the end.
Disclaimer
The Code is a complex document which is open to interpretation. It is not unlikely to be in room with 5 inspectors and hear 5 different opinions. Get your local inspectors involved in the beginning and if you disagree let them know. Just make sure you’ve done your homework and can back up your opinion. Also, I am not trying to pick on plumbers. The six inch hole saw scenario was one I lived through(and can laugh at now).
While Michicode.com does not endorse any one firestopping manufacturer
