# 0 lot lines



## BSSTG (Aug 17, 2015)

Greetings,

2012 IRC applies.   Guy wants to put single family dwellings 4' apart from each other. I figure it can be done if facing walls are rated 1 hour, no openings etc. The concern to me is the projection of the roof line being the soffit must be rated also. In reading the table 302.1(1), it looks like it's ok as long as the projection is less than 2' and it is 1 hour rated on the underside, no penetrations etc.

Could this be done?

BS


----------



## north star (Aug 17, 2015)

*& ~ ~ &*

How will you get a 1 hr. rated roof ?..........Also, are there no

soffit ventilation openings on that side ?...........Your Zoning

is going to allow this ?

*& ~ ~ &*


----------



## BSSTG (Aug 17, 2015)

north star said:
			
		

> *& ~ ~ &*How will you get a 1 hr. rated roof ?..........Also, are there no
> 
> soffit ventilation openings on that side ?...........Your Zoning
> 
> ...


IRC doesn't make mention of the roof, only the underside of the overhang. Other ventilation will have to be provided. I've got that covered. No zoning.

BS


----------



## north star (Aug 17, 2015)

*@ = @ = @*

Wouldn't the roofing material also be required to be 1 hr. rated ?

Typically, ...asphalt shingles over-hang on the edges.

I have seen the effects of when a fire jumps to a neighboring structure.

Just sayin'...

*@ = @ = @*


----------



## cda (Aug 17, 2015)

If a building wall is within 5′-0 of the property line, check projection and opening limitations under R302.1. Also, check for a fire rated construction detail for all areas that are required to have protection.


----------



## cda (Aug 17, 2015)

One city drew a picture

2012

https://www.co.pierce.wa.us/DocumentCenter/View/4409


----------



## Harscher (Aug 18, 2015)

We have dealt with this issue as well.  As long as the wall and eave are rated, they are good to go.  The idea is to provide some protection until the Fire Dept. arrives.  Otherwise I think they would have required a parapet for greater separation.  And the handout that cad linked illustrates it very well


----------



## Francis Vineyard (Aug 18, 2015)

cda, Pierce County apparently amended their 2012 because those footnotes don't show up until the 2015 IRC.

I've permitted a code modification using the 2015 IRC TABLE R302.1(1) (dwellings without fire sprinklers) footnote "b. Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave if fireblocking is provided from the wall top plate to the underside of the roof sheathing."

Not my intent to sidetrack this thread but to help; if anyone knows how footnote c works would appreciate the information;

"The roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave provided that gable vent openings are not installed."


----------



## ICE (Aug 18, 2015)

Harscher said:
			
		

> We have dealt with this issue as well.  As long as the wall and eave are rated, they are good to go.  The idea is to provide some protection until the Fire Dept. arrives.  Otherwise I think they would have required a parapet for greater separation.  And the handout that cad linked illustrates it very well


Don't worry, I'm sure he has been called worse.

Welcome to the forum Harscher.


----------



## Harscher (Aug 19, 2015)

Sorry CDA, a slip of the fingers.


----------



## north star (Aug 19, 2015)

*@ ~ ~ ~*



Francis,

I will take a WAG at your question........Possibly, the Code writers

[ may have ] believed that if the separation distance of "greater 

than 2 ft., but less than 5 ft.",  [  in Table R302.1(1)  ] is enough

separation,  so that any flames would not curl downward and

under the eaves to propagate the spreading at the eaves.

Is there an approved fire rated,  eave & roofing assembly out

there, for the Framers to use ?   



*~ ~ ~ @*


----------

