# OSB Interior Wall Covering



## snowroski (Feb 27, 2015)

I have someone who wants to finish the inside of their single family dwelling with OSB.  I am of the belief that this is not a good idea and I'm not interested in permitting.  What do you think?

Pennsylvania SFR under the 2009 IRC.

Thanks!


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## mjesse (Feb 27, 2015)

R702.5 - Other finishes (paneling)

R302.9.1 flame spread index <=200

R302.9.2 smoke index <=450

http://www.awc.org/Publications/dca/dca1/DCA1.pdf


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## Inspector 102 (Feb 27, 2015)

Since we are under the 2003 edition, I would use:

R309.2 Separation required.

The garage shall be separated from the residence and its attic area by not less than ½-inch (12.7 mm) gypsum board applied to the garage side. Garages beneath habitable rooms shall be separated from all habitable rooms above by not less than 5/8-inch (15.9 mm) Type X gypsum board or equivalent. Where the separation is a floor-ceiling assembly, the structure supporting the separation shall also be protected by not less than 1/2-inch (12.7 mm) gypsum board or equivalent. Garages located less than 3 feet (914 mm) from a dwelling unit on the same lot shall be protected with not less than ½-inch (12.7 mm) gypsum board applied to the interior side of exterior walls that are within this area. Openings in these walls shall be regulated by Section R309.1. This provision does not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.

However I see that 2009 does not require this anymore? So I see nothing that prohibits OSB for an interior finish.


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## ICE (Feb 27, 2015)

OSB doesn't paint well.


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## steveray (Feb 27, 2015)

MJ has it.....if it meets the requirements it does not matter what anyone likes....like OSB.

I had a DSW shoe store where the rear "feature wall" is spaced cedar boards and looks like a fancy pallet....I know it would burn like crazy, but there was nothing I could do about it.


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## JBI (Feb 27, 2015)

A lot of things are 'not good ideas' in the Code(s)... Compliance is all that matters.


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## mjesse (Feb 27, 2015)

snowroski said:
			
		

> I am of the belief that this is not a good idea and I'm not interested in permitting.  What do you think?


I think you're walking a slippery slope.

Code says it's okay. Unless you have an ordinance or amendment prohibiting OSB as an interior finish, they can do it.


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## mjesse (Feb 27, 2015)

steveray said:
			
		

> MJ has it.....if it meets the requirements it does not matter what anyone likes....like OSB.I had a DSW shoe store where the rear "feature wall" is spaced cedar boards and looks like a fancy pallet....I know it would burn like crazy, but there was nothing I could do about it.


We have the same interior DSW here.

However, commercial may be a different animal. OP specifically notes project is SFR, IRC.

IBC and combustible finish requirements vary. See §803


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## steveray (Feb 27, 2015)

Different code, same concept....I am sure they use that design nationally....


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## mtlogcabin (Feb 27, 2015)

Any foam insulation?

R316.4 Thermal barrier.

Unless otherwise allowed in Section R316.5 or Section R316.6, foam plastic shall be separated from the interior of a building by an approved thermal barrier of minimum 1/2 inch (12.7 mm) gypsum wallboard or an approved finish material equivalent to a thermal barrier material that will limit the average temperature rise of the unexposed surface to no more than 250°F (139°C) after 15 minutes of fire exposure complying with the ASTM E 119 or UL 263 standard time temperature curve. The thermal barrier shall be installed in such a manner that it will remain in place for 15 minutes based on NFPA 286 with the acceptance criteria of Section R302.9.4, FM 4880, UL 1040 or UL 1715.


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## snowroski (Feb 27, 2015)

Totally skipped looking in 302!  If it's permitted I wouldn't prohibit.  I guesses this guy will get his dream of an OSB home.


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## JCraver (Feb 27, 2015)

A local SIP manufacturer uses OSB on both sides of his panels.  Framers set the panels, then the hangers come in and hang the rock right over the interior OSB.

I see no code problem with that, or the OP's situation.


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## cda (Feb 27, 2015)

and you use to see knotty pine on the walls, and tongue and groove and,


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## Sifu (Feb 27, 2015)

DCA 1 2010 has osb at flame spread of 86 to 150 for 7/16 and less than the 450 for smoke.  Sadly I have encountered this issue before and I too was a little surprised to find it met the criteria.


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