Minimum Design LL for Decks

[StephNow]

In PA, under the 2009 IBC (Table 1607.1), it appears that a 4-unit apartment building with a private deck for each unit, that are not exits or have stairs, only need a minimum uniformly distributed live load of 40psf.

Is that correct? It seems as though it would be higher, like 100psf, similar to other floor systems.

 

[mtlogcabin]

We use the roof snow loads since they are higher than the 40 lbs floor load and a lot of homes are not occupied for long periods of time during the winter months

 

[StephNow]

Snow load here is 30psf, in which case you believe the 40psf is sufficient?

 

[TRBlackmore]

Have a question off topic?

 

[mtlogcabin]

Snow load here is 30psf, in which case you believe the 40psf is sufficient?

Yes,
A 480 sq ft deck will hold 17,200 lbs @ 5 sq ft per person that would be an OL of 96 or about 180 lbs per person. Use tables and chairs @ 15 sq ft per person and you have an Ol of 32 @ over 500 lbs each. I doubt you will ever see a residential deck with people standing shoulder to shoulder covering the entire deck.

 

[ADAguy]

? What did you see in the Oakland deck collapse?
Is your deck cantilevered or with living space beneath?

 

[steveray]

Balconies are 100psf.....FYI...Oakland....And construction defects (or at least bad ideas) led to that...

 

[mtlogcabin]

Balconies are 100psf..

What code section? IBC Table 1607.1 2012 IBC
5. Balconies and decks h Same as occupancy served
h. See Section 1604.8.3 for decks attached to exterior walls.

1604.8.3 Decks.
Where supported by attachment to an exterior wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable. Such attachment shall not be accomplished by the use of toenails or nails subject to withdrawal. Where positive connection to the primary building structure cannot be verified during inspection, decks shall be self-supporting. Connections of decks with cantilevered framing members to exterior walls or other framing members shall be designed for both of the following:

1. The reactions resulting from the dead load and live load specified in Table 1607.1, or the snow load specified in Section 1608, in accordance with Section 1605, acting on all portions of the deck.

2. The reactions resulting from the dead load and live load specified in Table 1607.1, or the snow load specified in Section 1608, in accordance with Section 1605, acting on the cantilevered portion of the deck, and no live load or snow load on the remaining portion of the deck.


2012 IRC

Balconies (exterior) and decks e 40

e. See Section R507 for decks attached to exterior walls.

If you require more than a 50 psf total (live & dead) loads than you cannot use the IRC 507.2

 

[steveray]

Looking in my old 03 book.....Balconies are #5 (Table 1607.1)and not addressed under residential...

 

[steveray]

We amend 2012 to:

(Add) 5. Balconies and decksh 1.5 times the live load for the area served. Not required to exceed 100 psf.

Or in other words....60#