basement used for storage and mechanical

[omahawildcat]

2018 IBC
6000 sf dentist office with 1000 sf basement used as storm shelter, storage and mechanical

Didn't the 2018 IBC change that an accessory storage space of any size is allowed to be a part of the main occupancy meaning we are not required to have a seperation?

 

[steveray]

Mixed use non-separated is what you should be looking for most likely...Accessory is limited to 10%

508.3​

Buildings or portions of buildings that comply with the provisions of this section shall be considered as nonseparated occupancies.

508.2.3​

The allowable area of the building shall be based on the applicable provisions of Section 506 for the main occupancy of the building. Aggregate accessory occupancies shall not occupy more than 10 percent of the floor area of the story in which they are located and shall not exceed the tabular values for nonsprinklered buildings in Table 506.2 for each such accessory occupancy.

 

[RLGA]

Unless your jurisdiction amended it, look at Section 311.1.1.

 

[steveray]

Unless your jurisdiction amended it, look at Section 311.1.1.

Hunh...Steve Thomas change in 2018 that I missed....Still says accessory so the 10% of 508.2.3 is still in play IMO....committee reasoning and the "key changes" read very different in this regard...That section needs to be deleted (as Steve mentioned in his proposal)....Or if it is really a problem, raise the threshold for accessory storage...


Key Changes:

 

[RLGA]

I have an issue with the IBC in this regard: Why does it single out Group S for accessory uses when no other occupancy group section mentions them?

Also, Section 311.1.1 states, "...for storage purposes that is accessory to another occupancy..." but it does not address it as an "accessory occupancy," which Section 508.2 covers. The IBC does not define "accessory" or "accessory occupancy."

Here is what the 2018 Commentary says about Section 311.1.1:

"This provision allows accessory storage areas to be classified in the same occupancy group as the primary occupancy of a space. There are no longer limits on the size of such spaces, nor how much of the floor area such accessory storage can occupy. These storage spaces could occur in any other occupancy, such as a Group B office building, a Group E classroom or a Group M retail store. If the storage isn’t accessory to a primary use, then the storage would be classified in the Group S categories. If it then is in with a mix of other occupancies, Section 508 will be applicable. Table 509 for incidental uses would require storage rooms in Group I-2 and ambulatory care facilities with an area over 100 square feet (9.3 m2) to be separated by fire barriers or horizontal assemblies with a fire-resistance rating of at least 1 hour."​

IMO, if Section 311.1.1 were meant to be regulated by Section 508.2, then it would reference that section or be deleted entirely and let Section 508 cover it. Personally, I prefer that it be handled as an incidental use per Section 509 as it was originally provided in the 2006 IBC (although I thought 100 sq. ft. was a bit too restrictive).

 

[steveray]

then it would reference that section or be deleted entirely and let Section 508 cover it.

That is why "many of the committee felt the whole thing should be deleted" (highlighted in post #4)...Because its a mess...So I could have an accessory repair garage of 12,00 feet to a parts store of 5000ft...Or let's swap the sizes, but now it is commercial vehicles..As there is no S1 use, no sprinklers...Unless we are going to distinguish storage spaces from storage uses now....

 

[RLGA]

So I could have an accessory repair garage of 12,00[0] feet to a parts store of 5000ft...

In that case, it could justifiably be called a repair garage with an accessory parts store, but since Section 309 (Group M occupancy) does not have its own version of Section 311.1.1, the default is Section 508.2 for the accessory occupancy. I think a bit of logic and common sense should factor into most code applications and interpretations.

Although repair garages (and hangars) are classified as Group S (I think they should be moved to Group F, but that's just me), I believe the intent of Section 311.1.1 is for the basic purpose of storage (i.e., a place to keep things for future use by the main occupancy). The IBC does not define "storage" in the general sense, and Section 311.1.1 does not use "storage occupancy" which is prescribed later in Sections 311.2 and 311.3 for Groups S-1 and S-2, respectively. Therefore, its use in Section 311.1.1 would default to the "ordinarily accepted meanings as the context implies" per Section 201.4.

 

[steveray]

In that case, it could justifiably be called a repair garage with an accessory parts store, but since Section 309 (Group M occupancy) does not have its own version of Section 311.1.1, the default is Section 508.2 for the accessory occupancy. I think a bit of logic and common sense should factor into most code applications and interpretations.

But if there is no size relation, accessory can be whatever anyone wants to call it....I agree with the common sense approach and believe that 10% is reasonable for accessory and does not need to be special for storage...I do think that there maybe should be some kind of break for storage /and mechanical areas that are on their own stories as it can be limiting with a top story mechanical room if you call those an S1....

 

[omahawildcat]

All I got from the replies on this thread is more unclarity.

 

[steveray]

All I got from the replies on this thread is more unclarity.

So lets start over...Is this an existing building?

 

[steveray]

And another way to look at it is there likely wouldn't need to be a separation anyway in that small of a building....