Location Roof Detail Fields

AIR's individual risk methodology follows a structured, logical approach that groups building characteristics according to their function to reflect the contribution of each characteristic to overall building performance. For information about the secondary risk characteristics that are supported in a specific model, refer to the "Model in Touchstone” chapter in the model description, which is available on AIR's Client Portal. Documentation for some AIR models includes a separate document that serves as a guide to the secondary risk characteristics (SRC) used in the model.

The following table describes the Touchstone location fields related to the roof detail for this location:

Field

Perils

Description

Validation Rules

Default Value

Roof Geometry

•       HI TC

•       US HU

•       US ST - Straight-Line Winds, Tornados

One of the following values to describe the shape of the roof of the building at this location:

•       Unknown/default (0)

•       Flat (1)

•       Gable end without bracing (2)

•       Hip (3)

•       Complex (4)

•       Stepped (5)

•       Shed (6)

•       Mansard (7)

•       Gable end with bracing (8)

•       Pyramid (9)

•       Gambrel (10)

 

The geometry of the roof affects the intensity of wind pressures and the resulting uplift resistance.

•       Optional

•       Defaults to a value in the Touchstone user interface

Unknown/default (0)

Roof Pitch

•       HI TC

•       US HU

•       US ST - Straight-Line Winds, Tornados, Hail

One of the following values to describe the slope of the roof of the building at this location:

•       Unknown/default (0)

•       Low (less than 10°) (1)

•       Medium (10° to 30°) (2)

•       High (more than 30°) (3)

 

Low pitch roofs have greater uplift forces acting on the roof as compared to high pitch roofs.

•       Optional

•       Defaults to a value in the Touchstone user interface

Unknown/default (0)

Roof Covering

•       AU WF

•       HI TC

•       US HU

•       US ST - Straight-Line Winds, Tornados, Hail

•       US WF

One of the following values to describe the material used to cover the roof of the building at this location:

•       Unknown/default (0)

•       Asphalt shingles (1)

•       Wooden shingles (2)

•       Clay/concrete tiles (3)

•       Light metal panels (4)

•       Slate (5)

•       Built-up roof with gravel (6)

•       Single ply membrane (7)

•       Standing seam metal roofs (8)

•       Built-up roof without gravel (9)

•       Single ply membrane ballasted (10)

•       Hurricane Wind-Rated Roof Coverings (11)

 

The Hurricane Wind-Rated Roof Coverings (11) option is not applicable with the Australia bushfire peril.

 

Damage to the roof covering can result in significant water damage to the interior of the building and contents.

•       Optional

•       Defaults to a value in the Touchstone user interface

Unknown/default (0)

Roof Deck

•       CA EQ

•       HI EQ

•       HI TC

•       JP EQ

•       US EQ

•       US HU

•       US ST - Straight-Line Winds, Tornados

•       NZ EQ

One of the following values to describe the material used in and the construction type of the roof deck of the building at this location:

•       Unknown/default (0)

•       Plywood (1)

•       Wood planks (2)

•       Particle board/OSB (3)

•       Metal deck with insulation board (4)

•       Metal deck with concrete (5)

•       Pre-cast concrete slabs (6)

•       Reinforced concrete slabs (7)

•       Light metal (8)

 

Roof decks transfer the roof loads to the underlying joists and purlins. Damage to the roof deck results in the breach of the building envelope, resulting in significant building and interior damage.

 

With respect to seismic performance, the weight of the roof can be critical. It is not desirable to make the roof heavy because it induces higher lateral forces in the structure during shaking.

•       Optional

•       Defaults to a value in the Touchstone user interface

Unknown/default (0)

Roof Covering Attachment

•       HI TC

•       US HU

•       US ST - Straight-Line Winds, Tornados

One of the following values to describe the type of connections used to secure the roof covering to the roof deck of the building at this location:

•       Unknown/default (0)

•       Screws (1)

•       Nails/staples (2)

•       Adhesive/epoxy (3)

•       Mortar (4)

 

Damage to the roof can result due to the improper attachment of the roof covering to the underlying roof deck.

•       Optional

•       Defaults to a value in the Touchstone user interface

Unknown/default (0)

Roof Deck Attachment

•       HI TC

•       US HU

•       US ST - Straight-Line Winds, Tornados

One of the following values to describe the type of connections used to secure the roof deck to the underlying roof support system of the building at this location:

•       Unknown/default (0)

•       Screws/bolts (1)

•       Nails (2)

•       Adhesive/epoxy (3)

•       Structurally connected (4)

•       6d nails @ 6 spacing, 12 on center (5)

•       8d nails @ 6 spacing, 12 on center (6)

•       8d nails @ 6 spacing, 6 on center (7)

 

Damage to the roof can result due to the improper attachment of the roof deck to the underlying roof support system.

•       Optional

•       Defaults to a value in the Touchstone user interface

Unknown/default (0)

Roof Anchorage

•       HI TC

•       US HU

•       US ST - Straight-Line Winds, Tornados

One of the following values to describe the type of connections used to secure the roof support system to the walls of the building at this location:

•       Unknown/default (0)

•       Hurricane Ties (1)

•       Nails/Screws (2)

•       Anchor bolts (3)

•       Gravity/friction (4)

•       Adhesive epoxy (5)

•       Structurally Connected (6)

•       Clips (7)

 

Roof anchorage establishes a load path to transfer wind loads from the roof to the walls. Hurricane straps provide such an anchorage.

•       Optional

•       Defaults to a value in the Touchstone user interface

Unknown/default (0)

Roof Hail Impact Resistance

•       US ST - Hail

One of the following values to describe the class of the hail impact-resistant roof covering material for the building at this location, based on UL2218, Impact Resistance of Prepared Roof Covering Materials:

•       Unknown/Non-impact-resistant (0)

•       Impact-resistant A (1) (least impact-resistant)

•       Impact-resistant B (2)

•       Impact-resistant C (3)

•       Impact-resistant D (4) (most impact-resistant)

 

This field only applies to the hail sub-peril.

 

UL2218 defines four classes of prepared sheets of panels installed in overlapping rows on roofs.

Optional

 

Roof Year Built

•       HI TC

•       US HU

•       US ST - Straight-Line Winds, Tornados, Hail

Year in which the roof of the building at this location was built

 

A value of 0 for this field in your import data represents Unknown/default.

 

With age, roofs lose their strength to resist wind loads and hence are more vulnerable.

•       Optional

•       Defaults to a value in the Touchstone user interface

•       Can be a numeric value between 1000 and the current year, inclusive (with a maximum year of 2100)

1000

Tank

•       CA EQ

•       HI EQ

•       US EQ

One of the following values to indicate whether there are rooftop tanks on the higher buildings adjoining the building at this location:

•       Unknown/default (0)

•       No (1)

•       Yes (2)

 

Rooftop tanks on adjoining, higher buildings are a falling hazard during earthquakes.

Optional

 

Chimney

•       CA EQ

•       HI EQ

•       US EQ

One of the following values to indicate whether the building at this location has a chimney and, if so, to describe the height of the chimney:

•       Unknown/default (0)

•       No (1)

•       Yes, height less than 2 feet. (2)

•       Yes, height 2-5 feet. (3)

•       Yes, height more than 5 feet. (4)

Optional

 

 

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Touchstone 7.0 Updated September 03, 2020