Chapter 3: Perceptual Demonstrative Judgements and Attention to Objects
3.3. Searle’s theory of perceptual intentionality
7.3.5 When the converted dwelling is served by only one stair, and no egress windows or external doors are provided for emergency use, the upper storey should be served by a protected stair (at all levels) and should either:
a. Extend to a final exit; or
b. Give access to at least two escape routes at ground level, each delivering to final exits and separated from one another by fire-resisting construction and fire doors.
7.3.6 To achieve a protected stair in a loft conversion, the stair requires to be enclosed with fire-resisting partitions and fire doors as shown in Figure 7.5.
Protected stair to final exit Protected stair to at least two protected escape routes at ground floor level
Fig 7.5: Protected stairs
7.3.9 Where an open plan arrangement exists, new partitions will be required to enclose the escape route, or a fast response sprinkler system may be installed in the open plan area in conjunction with a fire-resisting partition and
fire door in order to separate the ground floor from the upper storeys. This door should allow the occupants of the loft room(s) to access an emergency egress window at first-floor level in the event of a fire in the open plan area.
7.3.10 The guidance in the following paragraphs has been provided regarding fire-resisting partitions.
7.3.11 Fire-resisting partitions must be capable of achieving 30 minutes’ fire resistance. Below are two options on how this can be achieved:
• Timber stud partitions – 12.5mm plasterboard and skim on 75mm timber studs (to each side).
• Metal frame partitions – 12.5mm
plasterboard and skim on 45mm metal studs (to each side).
7.3.12 Any glazing incorporated in the enclosure of a protected stair or within fire-resisting separation should achieve 30 minutes’ fire resistance in terms of integrity and insulation and should be marked with the manufacturer and product name. If the glazing achieves 30 minutes’ fire resistance in terms of integrity, only then should its use be limited to that shown in Table 7.1.
7.3.13 Further guidance can be found in A guide to best practice in the specification and use of fire resistant glazed systems, published by the Glass and Glazing Federation and available at:
www.ggf.co.uk.
Position of glazed element Maximum total glazed area
Walls Door leaf
1. Within the enclosures of a protected stairway,
or within fire-resisting separation Unlimited above 1100mm
from floor or pitch of the stair Unlimited 2. Within fire-resisting separation Unlimited above 100mm
from floor Unlimited above 100mm
from floor 3. Existing window between an attached/
integral garage and the dwellinghouse Unlimited Not applicable
4. Adjacent to an external escape stair Unlimited Unlimited
7.3.14 The following guidance has been provided regarding fire doors.
7.3.15 All doors (including those to cupboards) leading onto the protected stair are required to be fire doors designed to achieve a minimum 20 minutes’ fire resistance. Where a door serving an attached or integral garage opens onto the protected stair it should achieve a minimum 30 minutes’ fire resistance, be fitted with a positive self-closing device and incorporate smoke seals. It is generally accepted that a bathroom poses a low fire risk and therefore the door need not be a fire door unless access can be gained directly into a bedroom from the bathroom.
7.3.16 A fire door’s resistance to fire is rated by its performance under test to either:
• BS 476-22:1987, in terms of integrity for a period of minutes, e.g. FD30. A suffix (s) is added for doors where restricted smoke leakage at ambient temperatures is needed;
or
• BS EN 1634, in terms of integrity for a period of minutes, e.g. E30. A suffix (sa) is added for doors where restricted smoke leakage at ambient temperatures is needed.
Note:
From this point forward, for ease of reference, fire doors will be referred to as FD.
7.3.17 Over 75% of fire doors manufactured for use in the UK are certified under the BWF-CERTIFIRE Fire Door and Doorset Scheme, which covers fire door ratings of FD30, FD60, FD90 and FD120 tested to BS 476-22 or BS EN 1634. The scheme does not certify and supply FD20 doors as for them to work effectively they have to be installed with intumescent seals. The result is that the performance of this door specification (FD20) becomes the same as an FD30.
7.3.18 There are three ways to purchase a fire door.
They are split into types and are defined below:
1. Fire doorset – a fire door leaf supplied pre-hung, in its compatible fire door frame, hinges, glazing, intumescent fire (and smoke) seals and latch, supplied complete.
2. Fire door kits – all the required compatible components supplied in kit form, factory prepared for on-site assembly.
3. Fire door assembly – all the correct, compatible and certified elements of a fire doorset, but collated together from different sources. BWF-CERTIFIRE scheme manufacturers identify suitable components in their installation instructions.
7.3.19 A test certificate will be provided for all door make-ups and should be adhered to at installation, i.e. door/frame/hinges/seals/
hardware. When replacing existing doors, the frame should also be upgraded.
7.3.20 As this will be a labour-intensive task, at least one manufacturer has produced and received certification for a fire door that negates the need for the frame and surround to be replaced.
Thus it is ideal for the loft conversion market.
Note 1:
Fire doors are labelled with identification marks so that it is possible to inspect them to determine their fire rating and to ensure that they have been certified.
Two types of identification marks are provided in Figures 7.6 and 7.7.
Fig 7.6: Timber Fire Door Certification Scheme label
Company’s Name Company’s Own
Telephone no. CERTIFIRE
Certificate no. Sequential no.
Note 2:
Where a loft conversion is being carried out in a dwelling that has doors of historical or architectural merit, it may be possible to retain the doors or upgrade them to an acceptable standard. Upgrading is achieved through the use of intumescent paper and paint; however, each door in the conversion would have to be inspected and approved on its individual merits. Factors affecting this include:
• How the door fits in the frame.
• The actual door make-up – quality of the joints/
glue and wood itself.
• Type of hinges and door hardware present.
Because of this it is advisable to replace existing doors with actual fire doors rather than attempt an upgrade.
Option 3 – Alternative escape route (single-storey and two-storey dwellings with loft conversion):
7.3.21 When the converted dwelling is served by only one stair, the top storey should be separated from the lower storeys by fire-resisting
construction and be provided with an alternative escape route leading to its own final exit.
An alternative escape is defined as a route sufficiently separated by either direction and space, or by fire-resisting construction, to ensure that one is still available should the other be affected by fire.
Note:
A second stair, balcony or flat roof which enables a person to reach a place free from danger from fire is considered an alternative escape route for the purposes of a dwellinghouse.
fd
Key
fd Fire door
30 minute fire-resisting construction Alternative escape route
Stair separated from landing to allow access to elternative exit
Fig 7.8: Example of an alternative exit
7.3.22 When an external escape stair is provided from the alternative escape (Figures 7.8 and 7.9), the provisions outlined in Option 2 should be met where a fire door and fire-resisting construction is required as well as the following:
• Any part of the external envelope of the building within 1800mm of the flight and landing of an external escape stair should be of fire-resisting construction. The 1800mm can be reduced to 1100mm above the top level of the stair.
• There is protection by fire-resisting construction for any part of the building (including any doors) within 1800mm of the escape route from the stair to a place of safety, unless there is a choice of routes from the foot of the stair that would enable the people escaping to avoid exposure to the effects of the fire in the adjoining building.
• Glazing in areas of fire-resisting construction mentioned above should achieve 30 minutes’
fire resistance in terms of integrity, and fixed shut.
• All doors giving access to the stair should be fire-resisting except for the door at the head of the stair.
• Any stair more than 6m in vertical extent should be protected from the effects of adverse weather conditions.
Window with 30 minute fire-resisting construction at side of stair
6m max height without weather protection
1100mm zone above top landing
Fire door
Fig 7.9: Fire resistance of areas adjacent to external stairs