Exterior Wall Assembly

[jrboter]

Can someone help me with a plan check comment I have received regarding an exterior wall that is within five feet of the property line. City is asking for the "approved listing number for the 1-hour fire-rated assembly. The approved listing number can be in the form of a GA File # or ESR report #". 

[Gawdzira]

If you are using stucco, this will work. Do a web search for One Hour Wall assembly and refine your search for exterior side. Basically, you are going to need to use a Class 1 siding material and have a layer of Denseglass or similar over your sheathing. There are some fire rated sheathings that you can use to avoid the extra layer.

 

 

UL U387 Wall Assembly one hour with mineral sheets.pdf

[jrboter]

Thank you, much appreciated. I've shown on the plans an exterior wood 2x4 wall with James Hardie lap siding, Tyvek, insulation and Type X gypsum. It seems they want an approved listing # for that wall detail. 

[JKEdmo]

Take a look at the Calculated Fire Resistant method outlined in the CBC, Chapter 7, 722.6 Wood Assemblies.  It applies to walls up to 1 hour rating.  It essentially allows a way to demonstrate a one-hour wall rating without the need to cite a tested assembly number.  I think this method is often overlooked and is easier.

 

Alternately, Section 721 "Prescriptive Fire Resistance" should have a good assembly I believe.  Table 721.2(2), Item 15.

[jrboter]

I appreciate your input. Thank You

[joey_martin]

https://www.usg.com/content/usgcom/en/design-studio/wall-assemblies.html

[GeneDavis]

Those GA type and ESR type reports are Gypsum Association docs, and won't be any help with your Hardie Plank finished wall.

 

I looked here, in a web page from James Hardie, linking to Warnock Hersey reports of fire-rated wall assemblies faced with Hardie products.  I was in the entry door business (ThermaTru) and we did all our fire door testing at Warnock Hersey labs and they provided reports such as these.

 

I could not find a wall assembly making a 1-hour rating that did NOT have 5/8 GWB (gypsum wall board) on the exterior side of the framing layer.  

 

Recommend you ask the AHJ plans review person if a Warnock Hersey doc will do for your project, where the 1-hour wall is needed, and that you study the information at the link.

https://www.jameshardie.com/product-support/resource-center/technical-documents/fire-wall-assemblies?loc=refresh

 

[jrboter]

Thank You Gene. Couldn't find one either. This isn't even for a residence. It's for utility pool shed!!