# Deck Construction



## skipharper (Aug 24, 2010)

Townhouses built under the 2006 IRC with correct seperation as spelled out by chapter 3. Now we come back and add decks of the back of the units. Is anything special required of the decks as fire as fire seperations?


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## mark handler (Aug 24, 2010)

[F] 903.3.1.2.1 Balconies and decks. Sprinkler protection

shall be provided for exterior balconies, decks and ground floor

patios of dwelling units where the building is of Type V construction.

705.5.2 Horizontal projecting elements. Fire walls shall

extend to the outer edge of horizontal projecting elements such as balconies, roof overhangs, canopies, marquees and similar projections that are within 4 feet (1220 mm) of the fire wall.

2006 INTERNATIONAL BUILDING CODE® COMMENTARY

in a contiguous residential structure with interior lot lines and fire walls between each dwelling unit, and where balconies (decks) are provided for each dwelling unit and these balconies are within 4 feet of the fire wall, then the fire wall must be extended to the outer edge of the balcony.


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## skipharper (Aug 24, 2010)

Where in the IRC doe's it allow us to refer to the IBC???


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## mark handler (Aug 24, 2010)

skipharper said:
			
		

> Where in the IRC doe's it allow us to refer to the IBC???


Sorry misread post


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## mtlogcabin (Aug 24, 2010)

R317.2.1 Continuity.

The fire-resistance-rated wall or assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

Depending on design this is all I could find


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## texasbo (Aug 24, 2010)

Are these second floor decks that create usable space below them, or decks at grade? If 2nd floor decks, are they built within the fire separation distance specified in Table 302.1?

Edit: mtlogcabin posted while I was writing. R317.2.1 was the reasons for the questions I asked.


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## mark handler (Aug 24, 2010)

R302.1 Exterior walls. Construction, projections, openings

and penetrations of exterior walls of dwellings and accessory

buildings shall comply with Table R302.1. These provisions

shall not apply to walls, projections, openings or penetrations

in walls that are perpendicular to the line used to determine the

fire separation distance. Projections beyond the exterior wall

shall not extend more than 12 inches (305 mm) into the areas

where openings are prohibited.


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## Francis Vineyard (Aug 24, 2010)

Skip

In the city we view open decks and porch coverings under Va USBC R302.1 Exceptions: 1. fire separation distance shall not apply to projections perpendicular to the lot line.


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## TJacobs (Aug 24, 2010)

Since a deck is parallel to the lot line, we hold them off the property line at least 2 feet (Projections beyond the exterior wall shall not extend more than 12 inches (305 mm) into the areas where openings are prohibited.)  Since Table 302.1 says openings not permitted <3 feet, I say the deck cannot be closer than 2 feet.

Fire away!


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## Francis Vineyard (Aug 24, 2010)

Virginia deleted "Projections beyond the exterior wall shall not extend more than 12 inches into the areas where openings are prohibited."  Amended as follows;

R302.1 Exterior walls. Construction, projections, openings and penetrations of exterior walls of dwellings and accessory buildings shall comply with Table R302.1.

Exceptions:

1. Walls, projections, openings or penetrations in walls perpendicular to the line used to determine the fire separation distance.

2. Walls of dwellings and accessory structures located on the same lot.

3. Detached tool sheds and storage sheds, playhouses and similar structures exempted from permits are not required to provide wall protection based on location on the lot. Projections beyond the exterior wall shall not extend over the lot line.

4. Detached garages accessory to a dwelling located within 2 feet (610 mm) of a lot line are permitted to have roof eave projections not exceeding 4 inches (102 mm).

5. Foundation vents installed in compliance with this code are permitted.

But it's worthwhile to get others opinions on decks construed as projections.


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## Uncle Bob (Aug 24, 2010)

Skip,

"Where in the IRC doe's it allow us to refer to the IBC??? "

Not sure this is applicable to your situation, however;

2006 IRC;

*"R301.1.1 Alternate Provisions*. As an alternative to the requirements in Section R301.1 (DESIGN CRITERIA) the following standards are permitted subject to the limitations of this code and the limitations therein. Where engineered design is used in conjunction with these standards the design shall comply with _the International Building Code._

1. American Forest and Paper Association (AF&AP) _Wood Frame Construction Manual (WFCM)._

2. American Iron and Steel Institue (AISI). too lazy to type it all out tonight; and probably not applicable."

I beleive the Building Official has the authority to accept engineered design of decks reqardless. See Section R106.

Hope this helps,

Uncle Bob


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