AskCodeMan

In condominiums with pier and beam foundations with no separation between units in the crawl space is the fire-resistance-rated wall required to extend from the soil surface to the roof deck?
Ref: R302.2.1 Continuity. The fire-resistance-rated wall or assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

For a townhouse, that would be a yes as each townhouse is its own structure, but for a condominium building where there is just one structure the answer is no*.

*Depending on the design - I have seen condominium buildings constructed like townhouses which were, for all intents and purposes, constructed as though they were each separate townhouses, yet they were condos and the structure was a common owned structure.

The typical condominium building is a large box with smaller boxes inside it, and the large box and the smaller boxes are all one common structure. When the inside of the walls are painted (the inside of each condo is painted), the owner of each "space" contained within a smaller box only owns from paint to paint, but not the walls, floors, or ceilings.

As such, the crawlspace and attic are each part of one common structure and no fire separation would be required, however, draftstop walls would likely be required, and those draftstop walls should line up with the vertical walls between condo units above.

A typical draftstop wall is just a frame wall with 1/2" gypsum board on one side, not required for both sides. The only intent is to break up the larger horizontal area of the crawlspace or attic into smaller areas so a fire could not create a drafting situation where the fire would spread quickly and easily from area to area.

- DRAFTSTOP. A material, device or construction installed to restrict the movement of air within open spaces of concealed areas of building components such as crawl spaces, floor/ceiling assemblies, roof/ceiling assemblies and attics.

The draftstopping walls should basically reduce the crawlspace or attic into areas of 3,000 square feet or less, or two condo units or less, and should line up with the separation walls between the condo units.

There is a lot more to draftstopping than the above, and there are exceptions, such as for fully sprinklered building, etc.

And what effect, if any, would the building being fully-sprinklered have on the requirement for complete separation requirement for townhouses?

One other question, if I may. Does this townhouse separation requirement precede the 2006 version of the IRC?

Thanks,

Aaron

aaronm wrote:One other question, if I may. Does this townhouse separation requirement precede the 2006 version of the IRC?

Thanks,

Aaron

Sorry, I meant the 2009 version of the IRC.

Yes, townhouse separation pre-dates the 2009 IRC.

I will have to check on the sprinkled question when I get back to my office, my initial response would be 'no', but I need to check the code to make sure.

Jerry Peck - Codeman wrote:Yes, townhouse separation pre-dates the 2009 IRC.

The reason I asked is that 302.2 does not appear in my IRC books prior to '09. What am I missing? Where should I look?

Thanks,

Aaron

aaronm wrote:

Jerry Peck - Codeman wrote:Yes, townhouse separation pre-dates the 2009 IRC.

The reason I asked is that 302.2 does not appear in my IRC books prior to '09. What am I missing? Where should I look?

In the 2006 IRC, look at R317.2
In the 2003 IRC, look at R317.2
In the 2000 IRC, look at R321.2

aaronm wrote:And what effect, if any, would the building being fully-sprinklered have on the requirement for complete separation requirement for townhouses?

As I thought, no affect as there is nothing about sprinklers in R317.2. The reason I thought this would be the case is because of the part which I have underlined and made bold.

From the 2006 (basically the same from 2000-2009, may be slight differences as I did not thoroughly read each edition):
- R317.2 Townhouses. Each townhouse shall be considered a separate building and shall be separated by fire-resistance-rated wall assemblies meeting the requirements of Section R302 for exterior walls.
- Exception: A common 2-hour fire-resistance-rated wall is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. Electrical installations shall be installed in accordance with Chapters 33 through 42. Penetrations of electrical outlet boxes shall be in accordance with Section R317.3.

JP: As always, access to your expertise is greatly appreciated!

Aaron