What Approved Document B says about the ceiling above your loft hatch
Approved Document B paragraph 2.5 asks for a protected stairway in a house with a storey more than 4.5 m above ground, and for a fire-resisting ceiling of at least EI 30 above that stairway. EI 30 describes how long the ceiling is expected to hold back fire and smoke, in this case half an hour.
A loft hatch sits inside that ceiling. Where the protected stairway runs up to the loft, the hatch is part of what the ceiling has to achieve, because an opening cut into a fire-resisting ceiling has to match the ceiling around it or the ceiling stops doing its job at that point. The document never uses the word hatch. It describes the ceiling as a whole and leaves the opening in it to be read in.
Why the gap is worth knowing about
No Building Regulation or Approved Document sets a size, a rating or a fixing method for a loft hatch by name. The requirement comes to the hatch sideways, through the ceiling it sits in.
For a house with a storey more than 4.5 m above ground, that means the hatch has to carry whatever fire resistance the surrounding ceiling has been given, with nothing in the document spelling out how to check that a particular hatch does. Building control is the body that decides, on a given job, whether the hatch in front of them meets that standard.
Fire-rated hatches compared by maker and standard
The two fire-rated ladders on the market are rated against different standards, so they are not read the same way. EN 13501 gives a classification built from test data; EN 1634 is the test itself, expressed as a number of minutes.
| Maker and model | Rated to | What it covers | What the rating means |
|---|---|---|---|
| Fakro LWF 60 | EI1 60 / EI2 60 to EN 13501 | Fire-resistant on one side | A classification: a category given after testing, covering the hatch as a type of construction |
| TB Davies FireFold | EN 1634, 30 minutes | Fire resistance for a stated period | A test result: a direct reading of how long that specific hatch held up under fire in a test |
Figures are as published by Fakro and TB Davies. Neither ladder has been tested or inspected here, and a classification under one standard cannot be read straight across to a test result under the other.
Why a two-storey conversion often needs a fire-resisting ceiling
A loft conversion on a two-storey house usually turns a boxroom above the stairs into a second escape route problem. The stairway below a loft conversion is often the only way out for the floors beneath it, and Approved Document B paragraph 2.5 treats any storey more than 4.5 m above ground as needing that stairway protected: walls, doors and the ceiling above it have to resist fire for long enough for everyone below to get out. In a typical two-storey house with a loft turned into a third usable storey, the landing ceiling crossed by the hatch sits directly above that stairway, which is why the fire-resisting ceiling comes up at all.
Why this is a building control decision
Converting a loft is building work, and building work on an existing house goes through building control, either the local authority or an approved inspector. Building control looks at the whole route out of the house.
That also means the question cannot be answered from the hatch alone. Storey height, what is above the stairway, and how the rest of the escape route is built all feed into it, and building control is the body that weighs them together before signing off the conversion.
Before buying anything
- Check whether a storey in the house is more than 4.5 m above ground, since that is the trigger Approved Document B uses for protecting the stairway.
- Check what sits directly above the stairway once the loft is converted, since that is the ceiling the regulation is concerned with.
- Raise it with building control before fitting a ladder or hatch, since they decide what the conversion needs.
If you are still working out whether a hatch needs to be fire-rated at all, Enlarging a Loft Hatch: Cut Roof or Trussed Roof covers the structural side of opening up a hatch, and what that does or does not have to do with the roof above it.