| Deck building is a polular do-it-yourself | | | | |
| project with homeowners who can take | | | | Under the right conditions, technically it is |
| advantage of how-to-do-it clinics and tools | | | | alright for beams or joists to cantilever up |
| rentals at home improvement retail outlets to | | | | to 40% of the distance that they are spanning |
| construct the decks of their dreams. | | | | between supports as long as the cantilever |
| | | | does not exceed four times the beam or joist |
| Cantilevering is a deck construction | | | | depth. An example of this would be a joist |
| technique that can be used by | | | | that spans 10 feet between supports. |
| do-it-yourselfers on almost all decks. It | | | | Theoretically it could cantilever .40% x 10 = |
| allows the builder to add several feet to the | | | | 4 feet beyond the supporting beam. Thus a 10 |
| width of the deck without increasing the | | | | + 4 = 14 foot joist would be possible. But if |
| maximum span rating for the beams or the | | | | the joist is a 2x8 (with an actual width of |
| joists. This is especially true when | | | | 7.25 inches) then the cantilever would be |
| homeowners are building bigger and bigger | | | | limited to 4 x 7.25 = 29 inches. |
| decks with more levels and more complex | | | | |
| shapes. | | | | Unless you like bouncy construction it would |
| | | | be a wise decision to limit the cantilever to |
| In some instances cantilevering makes it | | | | about 25% of supported beam or joist length. |
| possible for a smaller beam size to be used | | | | An even wiser decision would be to never |
| to support the deck. As far as the joist size | | | | exceed 3 feet of cantilever in the |
| is concerned a smaller size could also be | | | | construction of the deck. This will result in |
| used by the using this innovative | | | | the deck feeling solid even when one is |
| construction method. | | | | standing over the cantilevered ends. |
| | | | |
| Another advantage of incorporationg | | | | Cantilevering more than 3 feet would be |
| cantilevering into the construction of a deck | | | | better achieved by moving up to the next |
| is that the location of foundation columns, | | | | larger dimensional size of beam or joist. |
| support posts and beams can be less precise | | | | |
| than in the conventional method of | | | | In the initial deck design process it is a |
| construction. This is an important | | | | good idea to consult with the local building |
| consideration for do-it-yourselfers who are | | | | department regarding building codes and |
| not as proficient as professional contractors | | | | construction methods. Once you submit your |
| especially in this area of deck building. | | | | application for a building permit along with |
| | | | your deck design drawings, building |
| However, it is important to remember that | | | | department staff will make alterations in |
| there are still guidelines that limit the | | | | your design where necessary. Cantilevering |
| distance that a beam can extend beyond a | | | | can be incorporated into this design and |
| support post or that a joist can extend past | | | | their expertise will ensure that the deck |
| a beam. These guidelines also assume that | | | | design will adhere to construction |
| there will be no unusual loads placed at the | | | | requirements and result in the building of an |
| other end other than the deck occupants. | | | | outstanding deck that will meet the needs and |
| These guidelines are there to provide | | | | tastes of its occupants. |
| necessary standards to ensure the proper and | | | | |
| safe construction of outdoor deck spaces by | | | | Cantilevering can be an important and very |
| amateurs and pros alike. | | | | practical part of that process. |