# Porch  Columns



## globe trekker (Apr 12, 2011)

I have an existing house that wants to add a patio area and build a "new"

roof over it. The "new" roof will be approx. 24 ft. long by 19 ft. wide.

The plans indicate 4 - separate 4" x 4" wood columns to be installed for

support of the span.

*QUESTION:* Is there somewhere in the IRC that requires anchorage

to the foundation ( i.e. - some type of anchorage device / components )

if there is no clear indication that the vertical columns / posts will be

installed sub-grade?  I'm looking for a code section to refer the builder to!

Thanks for any input!  

.


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## Pcinspector1 (Apr 12, 2011)

Globe,

Try, IBC 2006 sec. 2304.9.7, columns to resist uplift.


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## TimNY (Apr 12, 2011)

R802.11 Roof tie-down.  

"A continuous load path shall be designed to transmit the uplift forces from the rafter... to the foundation"


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## permitguy (Apr 12, 2011)

*R407.3 Structural requirements.* The columns shall be restrained to prevent lateral displacement at the bottom end. Wood columns shall not be less in nominal size than 4 inches by 4 inches (102 mm by 102 mm). Steel columns shall not be less than 3-inch-diameter (76 mm) Schedule 40 pipe manufactured in accordance with ASTM A 53 Grade B or approved equivalent.

Exception: In Seismic Design Categories A, B and C, columns no more than 48 inches (1219 mm) in height on a pier or footing are exempt from the bottom end lateral displacement requirement within under-floor areas enclosed by a continuous foundation.

*R301.1 Application.* Buildings and structures, and all parts thereof, shall be constructed to safely support all loads, including dead loads, live loads, roof loads, flood loads, snow loads, *wind loads* and seismic loads as prescribed by this code. The construction of buildings and structures in accordance with the provisions of this code *shall result in a system that provides a complete load path that meets all requirements for the transfer of all loads from their point of origin through the load-resisting elements to the foundation.* Buildings and structures constructed as prescribed by this code are deemed to comply with the requirements of this section.


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## TimNY (Apr 12, 2011)

Nice permitguy... I think we got 'em coming and going.


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## steveray (Apr 12, 2011)

PG and Tim Nailed it...


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## globe trekker (Apr 12, 2011)

Much thanks to you all for your input! Ya'll are "the best!"  

The listed sections will do nicely!

.


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## steveray (Apr 12, 2011)

Now if we can just get them to put allowable column loads in the IRC.....


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## brudgers (Apr 12, 2011)

TimNY said:
			
		

> R802.11 Roof tie-down.   "A continuous load path shall be designed to transmit the uplift forces from the rafter... to the foundation"


"Foundation? I was just plannin' to use the slab."


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## RJJ (Apr 12, 2011)

I just had the same issue and use the sections referenced.


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