Sure did surprise Before The Architect: Residential elevators are installed without a shred of fire safety code to be had across the fruited plain far as one can tell.
An elevator shaft or hoistway could make a swell chimney and double the peril by bearing what could be the most vulnerable folks in the house.
Much codified ado is made of fire-blocking wall and floor structure (and stairway structure to an extent), but not the eminently more airflow-permissive elevator shaft or for that matter the stairwell itself.
Laundry chute fire (and physical) safety will have to wait another time.
In regard to residential elevators and stairwells, what's at stake is fire-degraded wood stud walls and wood ceiling joists collapsing within hoistway or stairwell, engaging cab or stairway. Mid-landings in winders and longer runs, too.
As for residential elevator fire safety, this passage is from Before The Architect's House Construction Design Standards 1Q06 draft (edited from outline form):
A residential elevator shaft, or hoistway, shall be framed with lightweight, or cold-formed, steel. Where exterior surfaces are available for wallboard application, exterior walls shall be finished with 1 layer-5/8" Type-X gypsum wallboard taped and mudded not less than 3 coats, and where the interior wall surface with 2 layers-5/8" Type-X gypsum wallboard taped and mudded not less than 3 coats (remembering to adjust shaft framing dimensions to accommodate thicker interior clad).
Similarly, the shaft ceiling shall be framed and sheathed on exterior and interior by a door at each stop fire-rated, self-closing, self-latching, and smoke-sealed.
Within the cab and outside the door at each stop a smoke detector shall be applied according to manufacturer instruction, shall be permanently connected to each other overall throughout the residence such that when one or more alarm, all alarm throughout the entire house, shall run on both permanent 120V and replaceable battery with each alarm to feature a combination of ionization and photoelectric sensors and shall not disconnect by wall switch.
As for residential stairway fire safety particularly to structure, this passage also is from Before The Architect's 1Q05 e-book: For other than the spiral staircase, sheathing shall be fastened underneath from outer stringer to outer stringer including header cleat with 1 layer, 5/8" Type-X gypsum wallboard [existing standard].
Where walls run below or immediately next to outside stringers, walls shall be framed with lightweight, or cold-formed, steel and exterior sheathed with 1 layer-5/8" Type-X gypsum board.
If continuous Type-X envelope cannot be applied on the vertical below a staircase, then contractor shall frame with lightweight, or cold-formed, steel and sheathe the interior with 2 layers-5/8" Type-X gypsum wallboard and where applicable on the exterior of the wall sheathe with 1 layer-5/8" Type-X gypsum wallboard.
Where stairwell wall extends above a stringer or below a stringer as, for example, a mid-landing, contractor shall frame the wall in lightweight, or cold-formed, steel and sheathe the interior with 2 layers-5/8" Type-X gypsum wallboard and, where applicable on the exterior of the wall sheathe with 1 layer-5/8" Type-X gypsum wallboard.
Wallboard seams shall be taped and seams and nail or screw pocks shall be taped and all shall be deeply mudded. Protrusions shall be sealed with firestopping materials conforming to not less than ASTM E84 and E814 and shall not exclude consideration of tumescent sealant.
In sum, the steel's there to break down more slowly when engaged, to wrack and sag but not to cinders and ash; the extra layers of Type-X are there to better hold its form and hold flames from you on your way down the steps or hoistway.
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An elevator shaft or hoistway could make a swell chimney and double the peril by bearing what could be the most vulnerable folks in the house.
Much codified ado is made of fire-blocking wall and floor structure (and stairway structure to an extent), but not the eminently more airflow-permissive elevator shaft or for that matter the stairwell itself.
Laundry chute fire (and physical) safety will have to wait another time.
In regard to residential elevators and stairwells, what's at stake is fire-degraded wood stud walls and wood ceiling joists collapsing within hoistway or stairwell, engaging cab or stairway. Mid-landings in winders and longer runs, too.
As for residential elevator fire safety, this passage is from Before The Architect's House Construction Design Standards 1Q06 draft (edited from outline form):
A residential elevator shaft, or hoistway, shall be framed with lightweight, or cold-formed, steel. Where exterior surfaces are available for wallboard application, exterior walls shall be finished with 1 layer-5/8" Type-X gypsum wallboard taped and mudded not less than 3 coats, and where the interior wall surface with 2 layers-5/8" Type-X gypsum wallboard taped and mudded not less than 3 coats (remembering to adjust shaft framing dimensions to accommodate thicker interior clad).
Similarly, the shaft ceiling shall be framed and sheathed on exterior and interior by a door at each stop fire-rated, self-closing, self-latching, and smoke-sealed.
Within the cab and outside the door at each stop a smoke detector shall be applied according to manufacturer instruction, shall be permanently connected to each other overall throughout the residence such that when one or more alarm, all alarm throughout the entire house, shall run on both permanent 120V and replaceable battery with each alarm to feature a combination of ionization and photoelectric sensors and shall not disconnect by wall switch.
As for residential stairway fire safety particularly to structure, this passage also is from Before The Architect's 1Q05 e-book: For other than the spiral staircase, sheathing shall be fastened underneath from outer stringer to outer stringer including header cleat with 1 layer, 5/8" Type-X gypsum wallboard [existing standard].
Where walls run below or immediately next to outside stringers, walls shall be framed with lightweight, or cold-formed, steel and exterior sheathed with 1 layer-5/8" Type-X gypsum board.
If continuous Type-X envelope cannot be applied on the vertical below a staircase, then contractor shall frame with lightweight, or cold-formed, steel and sheathe the interior with 2 layers-5/8" Type-X gypsum wallboard and where applicable on the exterior of the wall sheathe with 1 layer-5/8" Type-X gypsum wallboard.
Where stairwell wall extends above a stringer or below a stringer as, for example, a mid-landing, contractor shall frame the wall in lightweight, or cold-formed, steel and sheathe the interior with 2 layers-5/8" Type-X gypsum wallboard and, where applicable on the exterior of the wall sheathe with 1 layer-5/8" Type-X gypsum wallboard.
Wallboard seams shall be taped and seams and nail or screw pocks shall be taped and all shall be deeply mudded. Protrusions shall be sealed with firestopping materials conforming to not less than ASTM E84 and E814 and shall not exclude consideration of tumescent sealant.
In sum, the steel's there to break down more slowly when engaged, to wrack and sag but not to cinders and ash; the extra layers of Type-X are there to better hold its form and hold flames from you on your way down the steps or hoistway.
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