Live Load Roof Deck

Dead load is basically the load created by the weight of the deck itself.

Live load roof deck.

I have never seen calculations that use both s and l added together for design of roofs or decks. There wasn t a clear answer in the international residential code until the 2015 version where a footnote to the ledger fastener table r507 2 reads snow load shall not be assumed to act concurrently with live load which means you only have to design. One shortcoming of the span tables in the international residential code and the american wood council s prescriptive residential wood deck construction guide dca 6 is that they re limited to decks with a live load of 40 psf and a dead load of 10 psf. Yes a deck is a special purpose roof with a live load equal to the floor load.

The tank calculation sheets showed the load combinations for supporting lugs are 1 long term is dead load of roof live load 122kg m2 25psf 2 short term is dead load of roof rain fall 250mmaq. The live load on a roof is the weight of any temporary objects on the roof. A smaller area is liable to have a higher live load than the regular residential floor live 40 psf. People furniture and any other movable physical objects on the deck are covered under live load.

That means they won t work for areas with heavier snow loads for decks with heavy decking materials like stone or in numerous other circumstances. Live loads for assembly spaces other than those described in this table shall be determined from the occupant load requirements as established by section 1004 of this code using the formula 1 000 net floor area per occupant but shall not be less than 50 psf nor more than 100 psf. This is the common practice in my area where the base snow load is 60 psf and goes up from there. This is usually about 10 psf.

If a balcony over 100 sf can be designed for residential live 40 psf and a balcony 100 sf is designed for 60 psf it follows the roof deck should be the same i e. In commercial buildings the minimum live load required by the international building code is determined by the anticipated use of each space and thus the anticipated density of people in the space. Some code officials engineers and contractors have added the two loads together when designing decks and others have just done as you suggest basing the calculations on the larger of the two loads either snow load or live load. The load that is placed on your deck is expressed in pounds per square foot psf and the total load or more appropriately the design load is comprised of the dead load and the live load.