7 replies to this topic

[Brad Graber]

Anyone able to point me in the right direction with Townhouse designs with a basement.  There is 4 units total per building.   I'm assuming some type of a double wall all the way up through the structure with a drywall detail of sorts.  In the basement would there need to be a concrete wall between the units or can the double wall extend all of the way down.  Anyhow... this is a first for me and I need a bit of direction.

 

 

[Martin Livingston]

Hi,

 

This would be a building code issue which changes from area to area. In my case each unit of a 4 unit freehold townhouse would need to be separated by a 1 hour fire rated assembly which could be many different options. Our preference is a poured concrete wall in the basement with CMU's above that. We frame a 2x4 insulated wall on either side of that.

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[Don Gibbons]

We use 8" concrete in the basement and a 2x4 staggered stud with 2x6 plates and Roxul Safe 'N Sound for about grade. Metal resilient channel helps with the sound transmission.

[Brad Graber]

Thanks for the input so far.  That gives me enough information to get some prelim's together.  I can deal with the particular's once this project comes to fruition.

[Tom Rogers]

Not sure about the basements but I have use the UL 336 firewall detail in the Atlanta area with great success.  

[Michael Collazo]

  If you follow the IRC or IBC for that matter, you will need a total of 2 hours of fire separation, assuming it is a fee simple townhome with lot lines. If its a condo, its an hour. 

CMU can get you 2 hours prescriptively and is by far the easiest until... you get to the roof. Assuming you do not have a flat roof, it is challenging to get a shell company to rake a poured beam that follows the stagger of a roof, better yet, the vault. In Florida, we have certain parts of the state that do not do that too well, and others that can do it all day. Otherwise, shaftliner assemblies are the most popular. UL U336 as mentioned or U373 (both the same) are fine. They depend on the manufacturer of the panels. Since the fire separated walls are interior, you could take the walls all the way to basement slab unless theRE IS a FEMA flood restriction. In that case, you could have a masonry or poured wall to support the first floor joists and then have the shaft liner panels attached to the top of the basement wall. 

 

[Keith Almond]

Where are you Brad? ... What I'm really asking is what Code are you designing to?

[Brad Graber]

Indiana.  My assumption is it would be the IRC... unless it has to go through the state level then it would be the IBC.