BUS5 Building structures 5: Fire safety

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1 Czech Technical University in Prague FACULTY OF CIVIL ENGINEERING Deptarment of Building Structures BUS5 Building structures 5: Fire safety Excercise 3 Fire Resistance of Building materials Petr Hejtmánek

2 Fire Resistance (FR) Load-bearing and Fire separating constructions FC p v [kg/m 2 ] I VII FRG Fire Resistance FR = time (in minutes), during which load-bearing and fire separating constructions must resist fire and smoke. FR composes of two major parts: ultimate limits and time type of construction (DP1, DP2, DP3) time of fire resistance ultimate limit of fire resistance 2 / 20

3 REI 45 DP1 R 30 DP3 EI 15 DP1 C EI 60 DP3 EW 30DP3 apod. Ultimate limits Fire Resistance R = bearing capcity bearing capacity and stability of load-bearing constructions E = integrity breach of construction (cracks and holes) I = insultation limitation of temperatures on the non-burning side (~ 140 C) W = radiation limitation of heat flux on the non-burning side (15kW/m 2 ) C = self-closing (fireproof doors) S = smoke tightness limitation or exclusion of smoke development to other spaces Time (classification time) = 10, 15, 20, 30, 45, 60, 90, 120 a 180 minutes, exceptionally 240 or 360 minutes Type of construction = DP1, DP2, DP3 requirements through construction system or direct requirement (Czech standards) Required FR Real FR particular construction 3 / 20

4 Required Fire Resistance Lesson 1, Chart 9 4 / 20

5 Required Fire Resistance Lesson 1, Chart 9 5 / 20

Line 1: Fire walls and ceilings = fire separating constructions - prevent horizontal and vertical fire development Required ultimate limits REI fire ceilings, load-bearing fire walls EI partition

6 Line 1: Fire walls and ceilings = fire separating constructions - prevent horizontal and vertical fire development Required ultimate limits REI fire ceilings, load-bearing fire walls EI partition fire walls Required time Chart, according to FRG fire walls FR according to heighest FRG of neighbouring FC fire ceilings FR according to FC under this ceiling N07.01 III. FRG N07.02 VI. FRG REI 45 EI 120 DP1 REI 120 DP1 6 / 20

7 Line 2: Fire openings = fireproof openings in fire walls and ceilings (i.e. between FC doors, shaft doors, windows); must be closable (closed in case of fire) Required ultimate limits EI = exclusion of heat development openings to PEW EW = limitation of heat development openings between regular FC C = self-closing (doors to PEW, except doors from flat to PEW type A) S = smoke-tight Required time Chart, according to FRG Type of construction DP1, (DP2), DP3 N07.01 VI. FRG EW 60 DP1 EI 30 DP3 - C N07.02 III. FRG PEW A - N01.01/N09 II. FRG 7 / 20

8 Fire Openings Fire opening EI DP1 (steel frame + fireproof glazing) Source: PROMAT Praha, s.r.o. Many problems: fire openings are not fireproof fire openings do not meet requirements fire openings are open 8 / 20

9 Exterior walls must be assesed in two ways: Exterior walls interior fire = heat flux comming from FC to exterior exterior fire = heat flux comming from exterior (neighbouring building or FC) Therefore FR is assesed: interior fire REW (load-bearing walls) or EW (partition walls) ultimate limit I (i.e. temperatures on the exterior surfaces) is needless (exterior) exterior fire REI or EI. Exterior wall is in fire dangerous space of other building or other FC ultimate limit I must be fulfiled If an exterior wall has FR, fire dangerous space of this FC is reduced. 9 / 20

development on the facade between FC of buildings types of constructions DP1 + incombustible materials (A1, A2) min.

10 Vertical barriers (floor plan) Horzontal barrier (cross section) Fire barriers in exterior walls (horizontal and vertical) = horizontal and vertical parts of an exterior wall between two FC Function = elimination of fire development on the facade between FC of buildings types of constructions DP1 + incombustible materials (A1, A2) min. dimension(height) of barier 900mm can be replaced with: (1) = opening; (2) = fire wall or ceiling; (3) = fire barrier 10 / 20

11 Fire barriers do not have to be installed: small buildings, h 12m (excl. vertical barriers between buildings) one of the FC is a FC without Fire risk wider than 1500 mm horizontal barrier above last floor with fire ceiling and roof is qualified for existance in fire dangerous space (classified as B ROOF (t3)) and cornice (if any) surface (10 mm) is made of incombustible materials horizontal barrier above PEW FC is equipped with spriklers, if FC s constructions are type DP1 or DP2 (h < 22,5 m) It is used mainly at glassed facades (office buildings etc.) Assumption reality? Zdroj: PROMAT Praha, s.r.o. 11 / 20

Line 4 and 11: Load-bearing constructions of roof Load-bearing construction of roof

ultimate limit R Roof (fire ceiling) FR must be fulfiled from bottom surface for example

combustible materials) Increasing of FR - wooden structures: intumescent paints also

12 Line 4 and 11: Load-bearing constructions of roof Load-bearing construction of roof visible parts of roof frame, trusses etc. ultimate limit R Roof (fire ceiling) FR must be fulfiled from bottom surface for example soffit ultimate limit EI (if roof contains combustible materials) or E (if there are no combustible materials) Increasing of FR - wooden structures: intumescent paints also transparent; but what about life cycle (renewal, function?) facing FR of soffit incl. built-in lights (limit EI) Zdroj: PROMAT Praha, s.r.o. 12 / 20

13 Line 6: External load-bearing elements Fire Compartment (FC) Window (without FR) Load-bearing elements Fire dangerous space (FDS) Left column outside FDS without requirement of FR Right column in FDS of window requirement of FR, ultimate limit R 13 / 20

14 External Thermal Insulation Composite Systems (ETICS) There are some regulation of using cobustible and incombustible ETICS on facades. Every country has different requirements, but basics are the same: contrast between mineral wool and other insulation materials. United Kingdom h < 18,0 m no limit h > 18,0 m only A1,A2 Germany h < 7,0 m no limit h = 7 22 m B or C h > 22,0 m only A1,A2 14 / 20

External Thermal Insulation Composite Systems (ETICS) Czech Republic new building h < 12,0 m no limit h = 12 30 m fire barriers h > 30,0 m only A1,A2 Czech Republic - existing h < 12,0 m no limit h =

15 External Thermal Insulation Composite Systems (ETICS) Czech Republic new building h < 12,0 m no limit h = m fire barriers h > 30,0 m only A1,A2 Czech Republic - existing h < 12,0 m no limit h = 12 22,5 m fire barriers h > 22,5 m combination Uncertified ETICS problem If ETICS does not meet some requirements, it is uncertified construction type DP2 Incombustible wall (A1, A2) + ETICS class C F (uncertified ETICS) Construction type DP2 Combustible construction system h 12m 15 / 20

stairways must fulfil fire resistance (ultimate limit R

16 Line 9: Stairway In PEW only construction type DP1 is required (no requirement of fire resistance) Other stairways must fulfil fire resistance (ultimate limit R ), if it is in FC serving as NPEW for more than 10 people 16 / 20

(1) = fire opening ( EW in flats, EI-S in PEW ), (2) = fireproof seal of piping (systém

17 Line 10: Installation shafts FC 1 FC 1 FC 2 FC 3 FC 2 Shaft comming through storeys Horizontally divided shaft Design, only if division is accesible! (1) = fire opening ( EW in flats, EI-S in PEW ), (2) = fireproof seal of piping (systém seals EI ), (3) = partition wall fire separating construction ( EI ), (4) = fire division (almost EI ), (5) = piping 17 / 20

System seal of piping The goal of fireproof seals: to close a hole after

incombustible materials to allow dilatation of piping to allow easy

intumescent paints and putties), hard, dismantling etc.

pipes (plastic) vertical from ø100mm, horizontal from ø126mm, water pipes

, for smaller diametres, seals made from incombustible material is enough

18 System seal of piping The goal of fireproof seals: to close a hole after piping is burned (cables, plastic pipes) to insulate non-burning side of incombustible materials to allow dilatation of piping to allow easy renewal (replenish) of piping Types of system seals: soft (mineral wool + intumescent paints and putties), hard, dismantling etc. Installation requirements: ultimate limit EI (tested, certified) sewer pipes (plastic) vertical from ø100mm, horizontal from ø126mm, water pipes (plastic) from ø138mm, cables from 1kg/m (of insulation) etc., for smaller diametres, seals made from incombustible material is enough FR max. 90min., harder requirements for close pipes, PEW, hospitals, assembly rooms Zdroj: INTUMEX, s.r.o. 18 / 20

19 Fire floor plan drawing of required FR 19 / 20

CERTIFICATE. No

CERTIFICATE. No ZUS TECHNICKÝ A ZKUŠEBNÍ ÚSTAV STAVEBNÍ PRAHA, s.p. Technical and Test Institute for Construction Prague Accredited Test Laboratory, Authorized Body, Certification Body, Inspection Body Authorized Body