Existing standpipe installed 40 years ago... is it needed? Can I do away with it?

[SprinklerDesigner2]

Four story high end motel/resort built on the coastal flatlands.

Here is a cross section from the original plans dated 1970's:

The existing fire protection is four standpipes supplied from a 1,500 gpm 90 psi fire pump that also supplies one sprinkler head per floor in the 100 sq ft storage room adjacent to the standpipe. This single sprinkler head is controlled by a 2 1/2" O.S.&Y. floor control valve with tamper switch.

It's obvious to me the original design featured a full fire sprinkler system throughout but somewhere along the lines someone figured out the fire sprinkler was not required so it never went in. I don't think the entire building has more than 12 heads and that includes the ones in the trash chute.

On the drawing it appears there might be a floor above the fourth but it's really a high ceiling skylight.

Fourth floor slab is 25' above first floor slab. While there I checked the height with my laser just to make sure and it is what it is.

The existing fire pump is in deplorable condition to the point where it need to be replaced (you would have to see it to believe it) but why the expense? I did the calcs and a manual wet standpipe works great even with 100 psi at the tops of the standpipes.

Then the other question would be why the standpipe at all? We would leave the standpipe to feed only the sprinklers.... a bit of an overkill with 2 1/2" pipe feeding a single 1/2" sprinkler.

As far as calculating the standpipe to a manual wet that should be my deal but the decision regarding deleting the standpipe altogether would probably be the call of the architect of record who is no longer with us. How would you approach this?

 

[cdafd]

No matter what

It will be the ahj that decides what can be done.

Have a set down.

 

[SprinklerDesigner2]

cdafd,

So very true but the AHJ asked me for my opinion and I just want some legs under my opinion.

 

[MGXFP]

Typically buildings where the top most floor is more than 30' from the level of fire department vehicle access requires manual standpipes where the IBC is adopted. 2015 IBC 905.3.1. When the building is a high rise (75' instead of 30') automatic standpipes become required.

With this being built in the '70s that is before my time and not sure what codes were used then.

 

[TravisMack]

Is the existing standpipe in working order? If so, I would keep it for the supply to the sprinklers as you indicated. I would just give the AHJ my opinion that a manual wet standpipe is acceptable for anything other than a high rise. As such I would ask it to be a manual wet. I don't think I would demo it since it is there, as long as the piping is still solid. Will the city supply give you 7 psi at the top floor to that single sprinkler? If so, that is the route I would suggest.


Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, LLC

http://www.mfpdesign.com

 

[SprinklerDesigner2]

Travis, the existing standpipe is in service and they serve the small amount of sprinklers in utility rooms and trash chutes.

The city static is 65 psi and we have a residual of 20 psi flowing 2,250 gpm so water to the sprinklers isn't a problem.

I would like to get rid of the hose and racks.. ancient stuff the 1 1/2" fire hose is still there not having been touched for 40 plus years. The enclosures are wood.. homemade kind of work and it looks just awful. Looking at it my biggest concern would be could the fire department thread their hose to the hose valve? Looks to me like there isn't any room... But it could stay and I would suggest we delete the 1 1/2" junk and install new boxes for the 2 1/2" hose valves only.

In Georgia an owner is not allowed to have 1 1/2" hose racks for occupant use unless ALL employees attend a class on fire fighting fires at the state fire marshals's academy in Forsyth, Georgia. If you are not a trained fire fighter in the event of a fire get the heck out of the building.

I haven't heard of a pin rack unit being installed for 25 years and I might see one or two a year still in service.

Getting rid of the pin rack units will not be a problem.

 

[MGXFP]

SD2 I agree removing the 1-1/2" hose valves and hose and replacing with new 2-1/2" hose valves is the best choice.

The firefighters I know will never use a hose they find inside a building. They always use the hose they have inspected and tested.

Leaving the standpipe in place and removing the fire pump seems a solid recommendation for this building. The water supply data you provided complies with Table 11.2.2.1 of 2013 for pipe schedule sprinkler systems that are light and ordinary hazard.

Is there a remodel of the existing building triggering this investigation? If so it would be best to retrofit sprinkler systems to the building and leaving the existing standpipes in place would be a good start. The cheapest option would be to leave the standpipes alone.

 

[stookeyfpe]

More than likely the building was constructed to some edition of the Southern Building Code. Automatic sprinkler protection was not required in the sleeping units but may have been required in the gravity waste chutes.

I agree with everyone's suggestions. If I was the AHJ I would allow the fire pump to be abandoned in place as long as the controller was disconnected.

 

[chicopee]

Other then the AHJ, have you discussed the matter with the current fire insurance carrier?