No requirement for vapor barrier in crawlspace?

[Coder]

Been scratching my head and the code books hard on this one. Can't find anything in the 2009 IECC or IBC that states a vapor barrier is required over the dirt in a passive vented crawlspace (crawlspace with foundation vents) of a commercial building. Am I missing something? Any input is appreciated. Eric

 

[mtlogcabin]

Not required but a vapor barrier makes a big difference in the amount of ventilation required

1203.3.1 Openings for under-floor ventilation.

The minimum net area of ventilation openings shall not be less than 1 square foot for each 150 square feet (0.67 m2 for each 100 m2) of crawl-space area

1203.3.2 Exceptions.

The following are exceptions to Sections 1203.3 and 1203.3.1:

2. The total area of ventilation openings is permitted to be reduced to 1/1,500 of the under-floor area where the ground surface is covered with a Class I vapor retarder material and the required openings are placed so as to provide cross ventilation of the space. The installation of operable louvers shall not be prohibited.

 

[lunatick]

There are vapor barrier requirements and then there are Radon barrier requirements.

Is CO concerned with Radon?

 

[Coder]

Not a requirement. a concern yes but..We have adopted Appendix F in the 2009 IRC but the radon control measures in this appendix do not pertain to commercial buildings. Doesn't make a whole lot of sense to me. Has something to do with the amount of time a home is occupied versus say a school building, office, etc. I would like to see radon control techniques implemented in ALL new construction.

 

[Coder]

Not a requirement. a concern yes but..We have adopted Appendix F in the 2009 IRC but the radon control measures in this appendix do not pertain to commercial buildings. Doesn't make a whole lot of sense to me. Has something to do with the amount of time a home is occupied versus say a school building, office, etc. I would like to see radon control techniques implemented in ALL new construction.

Could anyone out there confirm for me that Radon control measures are only called out in Appenndix F in the IRC and not anywhere in the IBC? Thanks. ie: optional in commercial buildings?

 

[fatboy]

You are correct, not in the IBC.

 

[Coder]

I thought so as well. Sometimes I need to hear it from someone else smarter than me. Thanks for the quick reply!

 

[fatboy]

No problem.....don't know about the "smarter" thing. You knew it, I just was helping you through it!

 

[Sifu]

I just spent 5 days in CO looking for property (and potential places of employment) and never ran across Frigidville. Is there really a place or are you just cold?

 

[Coder]

I just spent 5 days in CO looking for property (and potential places of employment) and never ran across Frigidville. Is there really a place or are you just cold?

Cold and ruthless! JK.. I actually am referring to Gunnison, CO in the wintertime. :devil

 

[fatboy]

And it is the ice box of the state, trust me!