Upgrading of Fire Resistance to Architectural Heritage Escape Route Timber Doors

Figures & data

Figure 1. Typical stairwell door from a historic masonry residential building in Oslo, view from the stairwell side. In this example, the original glass panels have been replaced earlier with wired fire-resistant glass. Photo: Caroline Lundegaard Hannisdal, Murbyen, 2022.

Figure 2. Dimensions of door configurations in mm. Door I was used in test 01A, 01B and 02B. Door II was used in test 03A, 03B, 04A and 04B. Door III was used in test 02A.

Figure 3. Mounting of fire-resistant glass inside the rebate on the stairwell side (a) of the door or (b) on the apartment side of the door, using steel angles (test 03A and 04A). (c) shows mounting of fire-resistant glass inside the rebate with steel frame on the apartment side of the door (test 03B). (d) shows mounting of fire-resistant glass outside the rebate with steel frame (test 04B).

Figure 4. (A) shows a detail of mounting of fire-resistant glass with steel angles and (b) a detail of mounting of 30 mm steel frame.

Table 1. Summary of the design of the different door configurations used in the test series.

Test no.	Thickness of door leaf	Frame	Glass	Fielded panel	Swing Direction	Intumescent strip	Silicone gasket
01A	45 mm	Yes	No	No	Inwards	Frame only	Frame only
01B	40 mm	Yes	No	No	Inwards	Frame only	Frame only
02A	40 mm	Yes	No	Yes	Inwards	No	No
02B	40 mm	Yes	No	No	Inwards	Door leaf only	No
03A	40 mm	No	Yes, secured with steel angles on exposed side	No	Not applicable	No	No
03B	40 mm	No	Yes, secured with steel frame on exposed side	No	Not applicable	No	No
04A	40 mm	No	Yes, secured with steel angles on exposed and unexposed side	No	Not applicable	No	No
04B	40 mm	No	Yes, flush with gypsum board and secured with steel frame on exposed side	No	Not applicable	No	No

Figure 5. The fire resistance test furnace used for the tests.

Figure 6. Photo showing positioning of thermocouples on the unexposed side of test specimens 04A and 04B.

Table 2. Positioning of thermocouples (TC) on the unexposed side of the test specimens, where x = 0 (width), y = 0 (height) marks the bottom left corner of the element as viewed from the unexposed side.

Test no.	Test specimen	Thermocouple and position
01	A	TC1, on door leaf: x=½, y=½
	B	TC2, on door leaf: x=½, y=½
02	A	TC1, on door leaf: x=¾, y=¼
		TC2, on door leaf: x=¼, y=¾
	B	TC3, on door leaf: x=¾, y=¼
		TC4, on door leaf: x=¼, y=¾
03	A	TC1, on glazing: x=¾, y=¼
		TC2, on glazing: x=¼, y=¾
	B	TC3, on glazing: x=¾, y=¼
		TC4, on glazing: x=¼, y=¾
04	A	TC1, on glazing: x=¾, y=¾
		TC2, on glazing: x=¼, y=¼
	B	TC3, on glazing: x=¾, y=¾
		TC4, on glazing: x=¼, y=¼

Figure 7. The temperature measurements [°C] as a function of time [minutes] for test specimens (a): 01A (TC1) and 01B (TC2), (b): 02A (TC1-TC2) and 02B (TC3-TC4), (c): 03A (TC1-TC2) and 03B (TC3-TC4), (d): 04A (TC1-TC2) and 04B (TC3-TC4).

Table 3. Summary of test results measured against the integrity and insulation criteria.

Test no.	Integrity criteria			Insulation criteria
	Sustained flaming [min]	Gap gauge [min]	Cotton-wool pad test [min]	Maximum temperature increase below 180°C [min]	Maximum temperature increase [°C]
01A	42	42	42	42	49
01B	42	42	42	42	7
02A	39	39	39	39	104
02B	38	39	39	39	75
03A	30	30	29	30	141
03B	30	30	30	30	115
04A	29	30	30	29	211
04B	33	33	33	33	114

Figure 8. Close ups from the tests (a): 03A/03B after test termination. Cotton wool ignited in the marked area after 29.5 minutes, (b): 04A after 29 minutes, with sustained flaming and failure in temperature criteria.