6.0 FEATURES OF FIRE PROTECTION

6.1 BASE FIRE RATINGS

The proposed Doha Executive Staff Accomodation to be constructed in Al-Khaleej Street Doha Qatar is an apartment building comprising of four Basement floors, Ground floor, Mezzanine Floor, ten (10) typical Apartment floor levels, Service floor and Roof / Pool deck level. The proposed floor area of the building is approximately 23,612 m2.

The design basis for structural fire rating of the proposed development is to be based upon the prescriptive provisions of QCD Fire Safety Guidelines Rev2015.

The proposed development comprising of Apartment (Residential) shall be constructed to comply with the Type I (332) Construction as per Table 7.4.1 of NFPA 5000 Building Construction and Safety Code – 2018

Base Fire Ratings

STRUCTURAL MEMBER	FIRE RESISTANCE RATING (HOURS)
Exterior bearing walls
Supporting more than one floor, columns, or other bearing walls	3
Supporting one floor only	3
Supporting Roof only	3
Interior bearing walls
Supporting more than one floor, columns, or other bearing walls	3
Supporting one floor only	2
Supporting Roof only	2
Columns
Supporting more than one floor, columns, or other bearing walls	3
Supporting one floor only	3
Supporting Roof only	3
Beams, Girders, Trusses and Arches
Supporting more than one floor, columns, or other bearing walls	3
Supporting one floor only	2
Supporting Roof only	2
Floor / Ceiling Assemblies	2
Roof / Ceiling Assemblies	2
Interior / Exterior Non-bearing Walls	0

 

Assessment

The design team shall ensure that compliance with the prescriptive code requirements is achieved.

6.2 HORIZONTAL SEPARATION

Exterior walls shall require a horizontal separation utilising fire rated barriers where the distance to any fire source feature (plot line adjoining other plots, or other buildings) is less than 3m.

The horizontal separation shall be measured at a 90 degrees angle to the exterior wall,

Assessment

To check actual site condition.

6.3 CONSTRUCTION / ENCLOSURE OF EXIT STAIRWAYS

Following requirement shall be complied with as per NFPA 101-2018 and QCD Fire Safety Guidelines Rev2015-

(a) Exit stairways are required to be separated from other parts of the building and the separating construction shall have a minimum 2-hour fire resistance rating;
(b) The structural elements, or portions thereof, that support exit components and either penetrate or are installed within a fire resistance – rated wall or assembly shall be protected as a minimum, to the rating of the wall / assembly;
(c) Where nonrated walls or unprotected openings enclose the exterior of a new stairway, and the walls and openings are exposed by other parts of the building by less than 180 degrees, the building enclosure walls within 3050mm horizontally of the nonrated wall or unprotected opening shall be constructed as required for the stairway enclosures,
(d) Construction shall extend vertically from finished ground level to a point 3050mm above topmost landing or roofline, which is lower;
(e) The fire resistance rating of the separation extending 3050mm from the stairs shall not be required to exceed 1-hour where openings have a minimum 45-min rating; and
(f) Exit stairways connecting four or more stories shall be constructed of RCC (Reinforced Concrete) with a minimum of 2-hour fire rated construction.

Assessment

The design team shall ensure that compliance with the prescriptive code requirements is achieved.

6.4 SPECIAL PROVISIONS

6.4.1 Hazard Protection

Protection of any area having a degree of hazard greater than the normal to the general occupancy, such as electrical distribution boards / electrical communication rooms, essential services rooms and storage areas should be protected in accordance with QCD Fire Safety Guidelines Rev2015.

For the generator room to be proposed on the 1st basement, it shall be ensured that the not less than two remotely located exits shall be provided if the room area is greater than 18.6 sq.m. Swing of the exit doors shall be in the direction of egress. Further, the means of egress requirements shall be in accordance with the requirements mentioned in Chapter 4 of this report. If the fuel is proposed to be stored within the room, then additional MAQ requirements shall be considered. Further, room shall be provided with relevant fire rated construction / separation based on the fuel storage quantity (but not less than 2 hour) as per NFPA 37.

Table below provides the hazardous area fire separation requirements for compliance with the QCD Fire Safety Guidelines Rev2015.

Hazard Area Protection for proposed design

HAZARDOUS AREA DESCRIPTION	SEPARATION	DOOR FIRE RESISTANCE RATING (MIN)
Generator Room	2 hours	90
Store Rooms	1 hour	60
GSM Room	1 hour	60
Chiller Room	1 hour	60
LV Room	3 hours	180
Transformer Room	3 hours	180
Pump Room	2 hours	90
Fire Command Centre	2 hours	90
Garbage Room	2 hours	90
HV Room	3 hours	180
AHU Room	1 hour	60
Electrical Rooms	1 hour	60
Telephone Room	1 hour	60

 

The MEP team shall ensure inclusion of sprinklers in Electrical, Storage and Services areas to limit the required fire resistance rating to 1 hour.

Assessment

The design shall readily achieve compliance with the prescriptive code requirements noted above.

6.4.2 Risers, Shafts & Passageways

NFPA 101 requires compliance with Table below –

Fire Rating Requirements of specific areas / locations

LOCATION	FIRE RATING REQUIREMENTS
Vertical shafts and chutes	2 hours with 90-minute access openings
Elevators	2 hours with 90-minute lift landing doors
Exit Access Corridors	1 hour with 1-hour self-closing fire rated door sets
Exit Passageways	2 hours with 90-minute self-closing fire rated door sets

 

Assessment

The design shall readily achieve compliance with the prescriptive code requirements noted above.

6.4.3 Corridors and Internal Walls

The internal walls separating the hotel guest rooms and the corridor walls shall be constructed of 1-hour fire resistance rated construction as shown in Table below -

Fire Rating of Corridors and Internal Walls

LOCATION	FIRE RATING REQUIREMENTS
Corridor walls	1 hours with 60-minute access openings
Internal Wall	1 hours with 60-minute access openings

 

Assessment

Doors in the 1-hour fire resistance rated construction shall ensure 60-minute fire rating.

Fire separation shall also be provided for 1 hour between interconnecting units and any doors installed within the 1-hour fire rated walls shall also ensure 1-hour fire resistance rating.

The design shall readily achieve compliance with the prescriptive code requirements noted above.

6.5 PENETRATIONS & OPENINGS INTO EXIT ENCLOSURES

Penetrations into and openings through each of the fire rated exit enclosures / stairways shall include each of the fire rated corridors that lead or discharge from each of the exit enclosures and be limited to the following –

(a) Electrical conduits serving the stairways;
(b) Required exit doors;
(c) Ductwork and equipment necessary for independent stair pressurisation;
(d) Water or steam piping necessary for the heating or cooling of the exit enclosure;
(e) Sprinkler piping;
(f) Standpipes;
(g) Penetrations for fire alarm circuits, where the circuits are installed in metal conduit.

Assessment

The design shall readily achieve compliance with the prescriptive code requirements noted above.

6.6 OPENING PROTECTIVE

Fire Stopping

Spaces between sleeves and pipes shall be sealed with fire rated sealant or similar materials that accord with ASTM E-814 or ANSI/UL 1479 so that the fire resistance of the element is not impaired.

Fire stopping shall also be provided between the external façade and each of the intervening floors of the building so as to restrict the interior vertical passage of flames and hot gases from one floor to another, at the location where the floor intersects the interior of the exterior curtain wall assembly.

In addition to the above requirements, Chapter 8 of NFPA 5000 – 2018 provides the overall prescriptive requirements relating to FIRE RESISTIVE MATERIALS AND CONSTRUCTIONS within buildings that need be complied with.

Further, Clause 8.3.1.2 Ducts and Air Transfer Openings refers to the provisions of Clause 8.8.8 which governs the materials and methods of construction required to be used to protect ducts and air transfer openings in walls.

Fire Stop Systems & Devices

The following penetrations must be protected with a fire stop system or device-

(a) Cable penetrations;
(b) Cable trays;
(c) Conduits;
(d) Pipes;
(e) Tubes;
(f) Combustion Vents;
(g) Exhaust vents;
(h) Electrical;
(i) Mechanical;
(j) Plumbing;
(k) Communication systems.

The fire stop system or device must be tested in accordance with ASTM E 814, Standard Test Method for Fire Tests of Through Penetration Fire Stops or UL 1479 and achieve the following fire ratings –

(a) Where the fire barrier is required to have a 2-hour fire rating, the fire stop system must also achieve a 2-hour fire rating.
(b) Where the fire barrier is required to have a 1-hour fire rating, the fire stop system must also achieve a 1-hour fire rating.

Ducts and Air Transfer Openings

The following provisions govern the materials and methods of construction used to protect ducts and air transfer openings in fire walls, fire resistance rated horizontal assemblies and fire barrier walls.

(a) Fire dampers must be installed to protect ducts and air transfer openings that penetrate fire barriers and fire walls;
(b) Fire dampers must be designed and tested in accordance with the requirements of UL 555, Standard for Fire Dampers and shall have a 1 ½ hour minimum damper rating.

Location of Fire Dampers

Fire Dampers are required in the following locations –

(a) Ducts and air transfer openings penetrating walls or partitions having a fire resistance rating of 2 or more hours;
(b) Ducts and air transfer openings penetrating shaft walls having a fire resistance rating of 1 or more hours;
(c) Ducts and air transfer openings penetrating floors that are required to have protected openings where the duct also is not protected by a shaft enclosure;
(d) Air transfer openings that occur in walls or partitions that are required to have a fire resistive rating of 30 minutes or more.

Fire Dampers are NOT required in the following locations –

(a) In floors that do not require protected floor openings;
(b) In a duct system serving only one floor and used only for exhaust of air to the outside and not penetrating a wall or partition having a required fire resistance rating of 2 hours or more or passing entirely through the system and contained within its own dedicated shaft;
(c) Where branch ducts connect to enclosed exhaust risers in which the airflow is upward and steel subducts at least 560mm in length are carried up inside the riser at each inlet.

Access and Maintenance

Fire dampers must be provided with an approved means of access, as follows–

The means of access shall be large enough to allow inspection and maintenance of the damper and its operating parts;

(a) The access must not affect the integrity of fire resistance rated assemblies;
(b) The access openings must not reduce the fire resistance rating of the assembly;
(c) Access points must be permanently identified;
(d) Access doors in ducts must be identified with a label having letters not less than 13mm in height;
(e) The label must read as one of the following –  FIRE / SMOKE DAMPER  SMOKE DAMPER  FIRE DAMPER
(f) Access doors in ducts shall be tight fitting and suitable for the required duct construction.

Assessment

The design team shall ensure compliance with the prescriptive requirements noted above.

6.7 FIRE DEPARTMENT ACCESS

The provision of ‘Fire Department Access’ around the perimeter of the development and access to the buildings is a key ‘fire safety design feature’ of the proposed development.

The extent of the fire engine access way shall be provided for minimum 1/6 of the perimeter of the building i.e. 26.5 m.

To this extent, the following design characteristics as a minimum, shall be incorporated within the design –

(a) A fire department access road shall extend to within 15m of at least one exterior doorway of the buildings that may be opened from the outside and provide access to the interior of the building;
(b) The Fire department access roads have an unobstructed width of not less than 6.0m;
(c) The Fire department access roads have an unobstructed vertical clearance of not less than 4.5m;
(d) The Fire department access roads shall be capable of supporting the imposed loads of 45,000 Kg and shall be an all-weather driving surface;
(e) The maximum parking distance of a Civil Defence vehicle from the breeching inlets shall not exceed 18m;
(f) The maximum road grade of the Civil Defence vehicle access shall not exceed 10%.
(g) The outer radius for turning of access way and fire engine access road shall comply with the requirement shown below –

(h) Access way and fire engine access road shall be kept clear of obstructions and other parts of the building, plants, trees or other fixtures shall not obstruct the path between the access way and access openings.

Assessment

As the proposed building's largest gross floor area falls under minimum (<4,000 m2), therefore extent of fire engine access road shall not be less than 1/6 of overall perimeter.

As the gross floor area is 1254 m2 and the perimeter length is 159 m. Therefore, the extent of fire engine access road shall be 159/6 = 26.5m. The proposed design does comply with above mentioned requirement.