Let’s talk about Prohibited Penetrations (part 5)

Just for this post I have unleashed the code geek. Be scared (no…not really- its painless I promise). After we talk about the code we will discuss the things to look for to ensure your team is conforming to the code.

 

First let’s clear up the difference between an opening and a penetration. An opening (IBC 2015 713.7) is a hole with a purpose such as a door or a window. Doors and windows are tested to their own standards when acceptable for use in a rated assembly. Note that there is a difference between the test for a horizontal and a vertical opening protection the same way as there is a difference between firestop assemblies. You cannot use a horizontal and a vertical assembly interchangeably. For instance, if you have an access door that you want to put in a mechanical shaft you cannot use that same door in a rated horizontal assembly, unless it is tested for that specific application. Its all about fire dynamics; they simply are not the same in each orientation.

 

IBC 2015 713.8.1 is on prohibited penetrations and basically says that any penetration in a shaft has to have something to do with the purpose of that shaft.

Here are a few things I have seen.

I was looking at a set of plans with an architect. I asked him if his fire extinguisher cabinets were surface mounted or recessed. Turns out they were semi-recessed and they created a code violation because they were located in the shaft wall assemblies. He relocated them outside of the shaft and all was well with the world (or at least with the extinguisher cabinets).

I mentioned this scenario in a class and someone asked if they could just use a rated extinguisher box. It is a great question, because this is a common misconception. Please remember that the rated extinguisher box or hose box allows you to have a giant hole in a rated wall and not have a code violation, except if that wall is a shaft…then it’s a prohibited penetration. If you have a hose box or an extinguisher box in a rated wall it must be a rated box as well. This is a whole different blog for another time though because there are a whole series of issues we need to talk about related to membrane penetrations. We will get to that later though.

 

What other things should you look for that are common prohibited penetrations?

Interestingly enough, most of these are membrane penetrations like the extinguisher cabinet. It could be corridor lighting, the magnetic hold open apparatus on smoke doors, exit signs and anything along these lines. These are not serving the purpose of the shaft, so they are prohibited in the wall assembly. This needs to be addressed early in a project or it can create serious headaches down the road.

 

Now if these same membrane penetrations are in your means of egress, they are relevant to the means of egress and therefore not a code violation. A mechanical shaft has to have mechanical pipes coming out of it to service the floors, it may need to have an access door and all of that is okay provided you are using a rated access door. The mechanical shaft does not have to have corridor sconce lighting and if it does, then you, my friend have a code violation.

 

Heads up gang, that prohibited penetrations section that we talked about with shafts relates to means of egress as well. If you have a duct or pipe that runs from one side of the corridor to the other side and doesn’t service that area then you have a code violation. In this case, however, the exit sign, mag hold and corridor lighting would not be a code violation because those things presumably serve a purpose in the corridor.

 

In our next post we will do an imaginary field walk and talk about what we might see.  If you would like some help pulling all of this together don’t hesitate to contact us so we can help on your project.

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Are your Firestop Submittals Missing Shaft Details? (part 4)

Thanks for reading along so far. We have covered a lot in this series on shafts and hopefully you have been able to put some of this to use in the field. Next up, let’s look at what you should see when you are walking in the field looking at all that firestop stuff. Let’s put all this information to work for you.

 

First, you need to have the firestop submittals that show the firestop requirements for all of these shaft applications. If you don’t have the details, you can’t properly evaluate the installations.

 

Let’s walk a site together (You will need to use your imagination here). Say we are on the 5th floor of a hotel project. We are looking at a mechanical shaft. We have bare pipes and insulated pipes stubbing out of the wall to provide water to the bathroom. The shaft liner is up, but there is no firestop on the pipes. We go up to the 6th floor, the drywall is on the outer layer of all the shafts, but they have firestopped only about half of them. As you walk down the hall you see an area where they have not yet firestopped the penetrations into the shaft wall and you can see that they have not firestopped the shaft liner side. This is a problem. Firestop is required on both sides of a wall, even a shaft wall.

 

Let’s take the same scenario, but this time they did have firestop on the shaft liner side on the 6th floor. However, when you were on the 5th floor you noticed that the hole that was cut for the small insulated copper pipe is just big enough to get the pipe and the insulation through. The insulation was almost touching the cut edge of the drywall all the way around. You don’t have firestop submittals for the project so you can’t tell that the detail requires annular space of 0-1/2” and what you have in your field condition is continual point contact. The other thing you can’t see is that the firestop detail calls for 5/8” of firestop in the annular space. Since there is no annular space there is no way to achieve this depth requirement. You have some problems. The first problem is that you don’t have your firestop submittals so you can’t reference what is required when you talk to the installer. Second, they have created an installation that can not be finished correctly. Remember those blogs where we talked about continual point contact and the importance of proper annular space?

Please also remember, if you are looking at a block wall, they will have to firestop both sides of the wall, or one side but do it two times. This is true both for joints and for through penetrations. If it is a shaft, you likely can’t get to the inside to check on the installations so you may need to go to the bottom of the shaft before it is closed off to get a look, or you can conduct destructive testing to confirm that it was done right. Please also remember that the firestop details have to match the field installations. If they don’t, it is non conformant.

If you are working on a project and you have questions about your firestop submittals, or installations please do not hesitate to give us a call.  We are happy to help when we can and if you are close enough we might even swing by to help out if our schedule is open.

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Cautions and Codes Related to Shafts (part 3)

The 2015 IBC code section …don’t worry, it will be painless and its SUPER useful information. Stick with me please!

Section 713 is on shaft enclosures and there are a few things you really need to know. I’m going to generalize and just tell you to go online for the specifics when you really need them (or hire me and I can give them to you).

Generally a shaft has 4 sides, a top and a bottom. Your shaft may have 3 sides or it may have 10 sides, but for simplicity we will assume it is like most shafts and has 4 sides. It MUST have a top and a bottom because remember your floors are required to have a 2 hour rating (in most concrete buildings) and the shaft has to match the floor’s rating so that you can have an unprotected hole in the floor that could potentially run the height of the building.

It has to have a bottom, which could be the ground floor, or it could be a horizontal rated assembly made of concrete, gypsum or in some cases firestop materials.

It also has to have a top. That can be the roof or again it could be one of the rated assemblies we talked about. If you have a penetration through the top or bottom of the shaft you will have to firestop those penetrations.

Guess what! If you use a horizontal gypsum assembly then there are no UL listed details for penetrations through a horizontal shaft wall assembly. You automatically have to get an EJ. Is that included in your firestop submittals? It should be!

Now the top or bottom of your shaft could be part of a room, for example if you have a trash chute or linen chute then the bottom of the shaft can be the laundry or trash room provided the surrounding walls are rated and you have no prohibited penetrations.

More on prohibited penetrations in our next post! If you have shafts on your project or are concerned that your firestop submittals might be missing something, as always contact us here.

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NJ DCA CEU Classes

If you want to learn more about protecting commercial kitchen exhaust or the new requirements for AHJ’s with the need for firestop special inspection or when they are required we have some classes for you to consider.  If you want information on other classes provided by DCA please see this brochure.  Sharron is excited to be teaching these two classes again this year.  I know  we will be talking about codes and standards but we actually manage to have a bit of fun.

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Are your firestop submittals missing something for shafts? (part 2)

In our last blog post we talked a little about shaft walls, what they are made of and some things to keep an eye out for. We will build on that as we go.

Today we are going to look at firestop submittals as they relate to shaft wall assemblies, so the next time you are reviewing project documents you will have a better idea if something is missing. The easiest way to understand this discussion is to quickly review the UL nomenclature post found here so this will be easier to follow. If you do not know this nomenclature its much more difficult to conduct this exercise.

First let’s think about the RATED JOINTS. Let’s assume that the project has both block shafts and gypsum shafts. As you look at the firestop submittals pull out the HW (head of wall) details and look for the types of shaft walls you have on your project. For this discussion we will assume you have both gypsum and block shaft walls.

GYPSUM WALL:

You will likely have a handful of HW details but if you have gypsum shafts you need to be sure the project has a detail for firestopping this gypsum shaft. When you look at the WL details for gypsum walls, you will notice it is not like the standard gypsum wall details, namely because the shaft walls are built differently so they need to be firestopped differently as well. This will require sealant at the shaft liner as well as on the outer layers of drywall. If you allow this wall type to be firestopped when the wall construction is complete, you will not have a compliant system because you will only have protection from one side of the wall. This would create a major liability for the installer as well as the GC, building owner and building occupants.  If you are looking at a WL2000 series detail for plastic pipes, be sure to take a closer look, but do the same for all your penetration types.

BLOCK WALL

If you have access to both sides of the wall, as you would in an elevator shaft, then it is easy to firestop the head of wall joint on a block wall from either side of the wall. Likewise you can firestop your through penetrations with either a CAJ or WJ detail. If you only have access to one side of the wall, you will need what is commonly referred to as a sandwiched detail and my guess is that it will likely be a WJ detail or possibly an engineering judgement. This would allow for firestop to be installed in four steps. Typically there would be installation of mineral wool recessed maybe 4-1/2” into the joint, then firestop sealant (let’s say it calls for ½” of sealant) then another layer of 3-1/2” of mineral wool followed by another ½” of sealant. There are 4 steps to this installation, which means 4 steps to any firestop inspection as well, unless the inspector wants to try to cut into this kind of joint application, which is going to be a challenge in and of itself. This also means that the firestop detail needs to show installation from one side if this is what the installers are doing.

That is what you expect to see when you are in the field, but when looking at the firestop submittals you need to be sure that the block wall detail that is provided can actually be installed on the project. Is it physically possible? You need to be sure there is a head of wall, bottom of wall and possibly a wall to wall detail for the gypsum assembly. It is not uncommon for a contractor to miss these details, so be on the lookout for them.

Next, think about what penetrations will be going through your shaft walls. The block and concrete walls often will not have access from the inside of the shaft so a sandwiched application needs to be used in many cases, though there are devices that can be used and installed from one side. If we are working on a project with you then we can help you determine which different manufacturers products would be best for various scenarios. Let’s say your stairwell walls are block or concrete. This means the firestop details you will need will start with either a CAJ or a WJ (potentially WK for thicker walls). You will need a 1000 series detail for your sprinkler pipes and conduits, unless you have plastic sprinkler pipes then you will need a 2000 series detail as well as a 3000 series for your MC cables. You won’t need a 7000 series detail for your ducts because they are going through a 2 hour wall and will require dampers. Pull out these details and be sure that if you only have one side access that the details will allow one sided access for the installation requirements. If not, you will need an Engineering Judgment. If you are in NJ, remember DCA does not allow EJ’s- sorry NJ.

Typically firestop installers will submit details for the various penetrations through a standard wall. These may be okay if the shaft wall type is included in what is allowed in the listed detail. If it is included, then you are fine, and if not then they need to submit a new detail. This will be found in item 1 of all details. These details will start with WL for gypsum framed walls and if it is a mechanical shaft you will likely have WL 1000 for metal pipes, WL 5000 for insulated pipes, maybe WL 2000 for plastic pipes. When doing the installation or inspection of these walls you will want to be sure to check annular space and sealant depth to be sure it conforms with the details. You will also want to be sure the installer firestops the shaft liner side before the outer two layers of drywall go up as you will see in one of the later posts.

We have given you a few things to be cautious about, but in our next post we will dig deeper into this and the building code. If you have questions about a recent firestop submittal please contact us for help.

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