When is a Sleeve Required for Sprinkler Riser?

5/17/2022

When is a sleeve required (or not required) at the base of a sprinkler riser when it comes through a floor?

Is there a requirement I'm missing in NFPA 13, NFPA 24, or the plumbing code?

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16 Comments

Alex

5/17/2022 05:47:35 am

Hi,

780CMR 1023.2 (2015 IBC) states that interior exit stairways must be constructed as fire barriers in accordance with Section 707 or 711. The stairway must be enclosed with a fire-resistance rating of 2 hours when serving four or more stories and 1 hour where connecting less.

This rating is throughout the entire stairwell. Therefore, if you have a parking garage that is not connected via this stairwell, but a pipe that penetrates the fire barrier, you require a firestop.

Also, you may want a sleeve depending on construction method (cast in place, PT slab, etc). The sleeve here is to reduce coring, more so when rebar is installed.

Thanks,
Alex

5/17/2022 08:07:51 am

In my local codes, it is not explicitly required. However the fire stop assembly drawings usually call for a steel pipe sleeve of some sort to maintain the rating between floors or walls.

schulman

5/17/2022 08:08:11 am

i require sleeves in all pipe penetrations through concrete, cmu walls or floors, above, on, or below grade
good practice

Wes

5/17/2022 08:21:54 am

Not saying it's bad to do, but why do you require sleeves? Mechanical damage to the pipe itself? Protect the walls/floors?

I don't personally have experience where something went wrong and a sleeve would have helped, so just curious on the reasoning here.

Colin Lusher

5/17/2022 08:30:34 am

It's for seismic protection; see section 9.3.4 of NFPA 13 (2016)

If the building moves during a seismic event, the space around the piping provided by the sleeve allows the piping to be independent from the movement of the building floor.

Wes

5/17/2022 08:37:22 am

Agreed that the clearances are required for seismic; but couldn't you have clearance around the pipe from a core-drilled hole?

A sleeve can provide clearance, but so could a drilled hole.

This came up on a project of mine that wasn't seismic, but the contractor had core-drilled holes through the stair landing and had some clearance between the sprinkler riser and the core-drilled hole. The specifications required a sleeve; but I couldn't find a reason (again, non-seismic project) where the sleeve would substantially help the situation and justify reinstalling the entire vertical riser.

Now I think having sleeves for poured walls/floors is a good idea and I think it can help protect the pipe, but I'm not so sure that I really understand what benefit the sleeve is providing.

Colin Lusher

5/17/2022 09:12:04 am

Yes, sorry my response was unclear. Clearance doesn't need to be provided by a sleeve, it's just the most common solution. Sleeves are great if you can set them correctly before concrete is poured or cmu is placed. However, core drilling is fine. For underground stub-ups you can wrap it in bubble wrap or foam insulation before the concrete is poured. Anything that provides the clearance required in 9.3.4 is acceptable.

Unless you're placing the sleeve before the wall is constructed, it provided no up-side to this that I can anticipate. I see many military specifications that require sleeves in core drilled holes; there is no purpose or advantage for this unless your fire-stop system requires a sleeve, however, it's pretty easy to find one that does not require a sleeve.

Wes

5/17/2022 09:18:57 am

Thanks Colin - and agreed. I ran into it on a military specification and came to the same conclusion. Thanks for the input!

Colin Lusher

5/17/2022 08:34:49 am

The sleeve would be required anywhere "Piping is Subject to Damage Due to Earthquakes" per Section 9.3; see specifically section 9.3.4 of NFPA 13 (2016) which is where this requirement originates.

If the building moves during a seismic event, the space around the piping provided by the sleeve allows the piping to be independent from the movement of the building floor.

Todd Wyatt

5/17/2022 08:38:26 am

Through-penetrations of a fire-resistant rated (FRR) horizontal assembly (HA) including floor construction shall be protected with an approved through-penetration firestop system per 2021 IBC 714.5.1 Through Penetrations. The rating of the HA is determinate on the building's Type of Construction (TC) per Chapter 6, Table 601. Floor Construction's FRR range from 2-Hours to 0-Hours per it's TC

714.5.1 Through Penetrations includes exceptions for "penetrations by steel ... pipes ... through a single FRR floor assembly ... where the annular space is protected with materials that prevent the passage of flame and hot gases sufficient to ignite cotton waste ... Penetrating items with a maximum 6-inch nominal diameter shall not be limited to the pentration of a single FRR floor assmebly, provided the aggregate area of the openings through the assembly does not exceed 144 sq in in any 100 sq ft of floor area."

The Specifications typically identify the Contractor as the responsible party to submit firestopping assemblies for every penetration of a FRR assembly. Some projects require a firestopping subcontractor to be responsible for all firestopping instead of having each trade perform this scope.

Matt C

5/17/2022 08:42:05 am

The short answer is... never.

Sleeving is just one way to make life easier down the line. Coring a lot of the time requires x-ray/GPR of floor areas and then marking out areas that are safe to cut or core. It's a lot of extra work, and as a fitter on-site, usually requires permission from the GC as a result of the scanning process noted above. If the slab is being poured, and you know where you need to be, then sleeving saves fitters and GCs and their subs time and money in the long run. If you are penetrating a fire separation you will still always be required to firestop the openings, in which case there are a boatload of products that help with this issue.

It can also save fittings and fitter time another way - if scans are done and you can't core exactly where you want or if another trade is already running there, then you may need to make additional offsets etc, to get to the core location. When sleeving you might be able to 'claim' that space beforehand.

In my experience it's sometimes called out in the specs by the GC in order to reduce the amount of coring required after the fact.

Wes

5/17/2022 08:50:59 am

I wasn't the OP, but this is why I come here. Great explanation and I appreciate the perspective I didn't have Matt!

Jesse

5/17/2022 09:05:28 am

I came in a little late today and by the time I opened this up, everyone had answered. Great answers by all. This is what makes this forum so valuable.

Joe Chadwick

5/17/2022 09:37:46 am

Sleeves in floors, raised an inch or so above the finished floor to serve as a dam, are frequently required in lab buildings and certain high hazard occupancies where spills are possible.

AHJ

8/9/2023 03:57:10 pm

This is a great response that I had never even considered. What a great point. Thanks very much.

Manny Rios

5/17/2022 02:23:22 pm

In our jurisdiction the architects include the piping clearance requirements on the plans and project specifications. By either core drilling or by the use of a sleeve with sufficient size to be in compliance with the IFC and NFPA requirements. NFPA 13 section 9.3.4.2.

When is a Sleeve Required for Sprinkler Riser?

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