The entire green roof assembly, including plants and the water required to saturate the growth media, is considered part of the dead load of the structure. Water in excess of that which saturates the growth media, snow and people visiting the green roof are all considered part of the live load of the structure.
Is green roof dead load or live load?
1607.11.2.3 Green Roofs
The weight of the landscaping materials shall be considered as dead load and shall be computed on the basis of saturation of the soil. Where roofs utilize a green roof system and are used for human occupancy, the minimum live load shall be as specified in Table 1607.1 or Section 1607.11.
What is considered roof live load?
The live load on a roof is the weight of any temporary objects on the roof. … A typical roof is expected to support a live load of 20 psf; this minimum live load is in addition to the dead load that the roof must bear.
Do roofs have live loads?
The weight of temporary objects on the roof is referred to as the live load. Live loads include the roofing crew and the equipment and tools they bring with them. A roof must be able to support both its dead load and live load at any given time.
How much weight can a green roof hold?
A traditional green roof can exert a load of up to 250 kg per m2 and that inevitably means a strong building is required to support the weight. In older buildings or new-build this may require costly structural reinforcement which in some cases may prove prohibitively expensive.
What is the live load of a floor?
The International Residential Code, on which most local building codes are based, requires that floors in non-sleeping rooms must support a minimum live load of 40 pounds per square foot, and floors in sleeping rooms must be able to handle a live load of 30 pounds per square foot.
What are some examples of live loads?
Typical live loads may include; people, the action of wind on an elevation, furniture, vehicles, the weight of the books in a library and so on. A live load can be expressed either as a uniformly distributed load (UDL) or as one acting on a concentrated area (point load).
Can my roof support my weight?
While the average roof can withstand 20 pounds per square foot, there’s a huge range in the weight of snow: Fresh, light snow can weigh just 3 pounds per square foot… so your roof may be able to hold over 6 feet of it. Wet, heavy snow can weigh 21 pounds per square foot… so a foot of it could risk collapse.
What is a live load vs dead load?
The dead loads are permanent loads which result from the weight of the structure itself or from other permanent attachments, for example, drywall, roof sheathing and weight of the truss. Live loads are temporary loads; they are applied to the structure on and off over the life of the structure.
Do you add snow load to live load?
Live loads are those loads produced by the use and occupancy of a building or structure and do not include construction loads, environmental loads (such as wind loads, snow loads, rain loads, earthquake loads and flood loads) or dead loads (see the definition of “Live Load” in IBC 202).
Can you reduce roof live load?
Reduction in roof live loads is allowed per the 2012 International Building Code (IBC), section 1607.12. Live loading for awnings and canopies may be reduced and shall be designed for a minimum live load per Table 1607.1 in addition to snow and wind loads per the code. …
How much weight can a roof handle?
California building code sets minimum standards for roof load-bearing capacity. At minimum, any roof which may be used by maintenance workers must hold 300 pounds concentrated. Concentrated means that this weight can be held by any one spot on the roof.
How deep is a green roof?
Intensive green roofs
They need at least 30cm (1ft) depth of growing medium, much of which needs to be organic matter. Built-in raised beds require planning and construction by suitable architects and/or contractors.
What is the difference between intensive and extensive green roofs?
This is the easiest way to remember the difference – an extensive green roof probably has a shallow layer of substrate that covers a large area, whereas an intensive green roof often has a deeper layer of substrate, confined to smaller areas. … As the number and variety of green roofs has increased, so has the diversity.
Do green roofs need to be watered?
In general, for a green roof to be “green” in terms of being ecologically friendly it shouldn’t need to be watered after the first year. Irrigation wastes water and energy, both are what the green roof should be conserving.