Fire-rated drylining for HMOs in St Helens: what Article 4 means for your conversion

St Helens has been quietly busy with HMO conversions for the past five years. The pattern is familiar: a Victorian or Edwardian terraced house in WA10, a landlord splits it into three or four letting rooms, and a household of unrelated tenants moves in. Most conversions in the borough follow the same template, and most of them fall under the additional HMO licensing scheme that St Helens Borough Council has had in force across the whole borough since 2019.

The complication in 2026 is that fire safety rules for HMOs have moved on. Approved Document B was updated again on 16 September 2026 with a fresh set of amendments that tighten the compartmentation requirements between letting rooms, and landlords who started their conversion before the update are now finding their specifications need to be revised before the licence inspection. This guide is what we tell landlords on the phone when they ring about HMO fire safety, what the Article 4 direction does to your permitted development rights, and what wall and ceiling build-ups the council will actually accept during the licence inspection visit.

What Article 4 means for HMO conversions in St Helens

Article 4 of the General Permitted Development Order lets a local council remove some or all of the permitted development rights that would otherwise apply to a class of development. In St Helens, an Article 4 direction has been in force since 2019 covering the change of use from a C3 dwellinghouse (a single family home) to a C4 small HMO (three or four tenants from two or more households).

In practice, the Article 4 direction means you can no longer convert a house into a small HMO without first applying for planning permission from St Helens Borough Council. The planning application is straightforward, but it does require a design and access statement, a site plan, and the standard planning fee. The bigger practical impact is that the council will look at the conversion before it happens, not after, which is when fire safety and amenity issues are cheapest to fix.

Separately, the council has an additional HMO licensing scheme under section 56 of the Housing Act 2004, which covers the whole borough. This is what is colloquially called the borough-wide Article 4 HMO scheme, although technically the licensing scheme is separate from the planning Article 4 direction. The combined effect is that any HMO in St Helens with three or more tenants from two or more households sharing facilities needs both planning permission and an HMO licence. Five-year HMO licences are issued by the private rented sector team at the council, and the licence fee is set by the council each year.

Fire-rated drylining: what the Building Regulations actually require

Fire-rated drylining in an HMO is part of the compartmentation strategy. The Building Regulations require that a fire starting in one letting room is held back from the rest of the house for a defined period of time, usually 30 minutes for the walls and ceilings between letting rooms and 60 minutes for the walls and ceilings that separate the HMO from the stairwell or from an attached property.

Two pieces of regulation apply. The first is Approved Document B (fire safety), volume 1 for dwellings and HMOs that are single stair houses up to two storeys, which sets out the construction details for the 30-minute and 60-minute fire-resisting elements. The second is the Housing Health and Safety Rating System (HHSRS), which is the framework the council uses during the licence inspection to assess whether the property is a hazard to the health and safety of the tenants.

The 2026 amendments to Approved Document B

The 2026 amendments to Approved Document B were published on 16 September 2026 and apply to all new building control applications submitted after that date, plus any conversion work where a building control application is still open. The headline change for HMO conversions is that the fire-resisting specification for the wall between letting rooms now requires an independent test certificate from a UKAS-accredited laboratory rather than the older route of relying on a generic plasterboard manufacturer's data sheet.

The practical effect for St Helens landlords is that the plasterboard specification on the planning drawing needs to be backed up with a test certificate before building control will sign off the work. British Gypsum, Knauf, and Siniat all publish the relevant test data, but the specific build-up you choose has to match the test report exactly. A standard 12.5 mm plasterboard on a timber stud does not achieve 30 minutes on its own, and a single layer of 15 mm Fireline on a metal stud does not achieve 60 minutes without a second layer on the room side.

The 30-minute and 60-minute standards, in plain English

The 30-minute standard means the wall or ceiling holds back a fire for 30 minutes before flames or hot gases pass through. The 60-minute standard means the same wall or ceiling holds back the fire for 60 minutes. For an HMO, the typical specification is 30 minutes between letting rooms and 60 minutes for the stairwell enclosure and for the party wall with the attached property.

Plasterboard on its own does not give you 30 minutes. The board has to be on the correct stud, with the correct fixings, with the correct number of layers, and with the correct treatment at junctions, service penetrations, and around the perimeter. This is why fire-rated drylining is a specification-driven trade, not a generic plasterboarding trade.

Wall and ceiling build-ups for HMO compartmentation

The four build-ups we use most often on HMO conversions in St Helens cover the vast majority of the wall and ceiling types we encounter. Each is matched to the structure of the existing house.

Partition walls between letting rooms

For a partition between two letting rooms in a Victorian or Edwardian terrace, the standard 30-minute build-up is a 75 mm British Gypsum Gypframe metal C-stud, one layer of 12.5 mm Gyproc Fireline on each side of the stud, with 25 mm of mineral wool in the cavity. This build-up is in the British Gypsum White Book and has the relevant UKAS test certificate. For the 60-minute stairwell enclosure, the same stud is used with two layers of 15 mm Fireline on the staircase side and one layer of 12.5 mm Fireline on the room side.

Ceiling build-ups under the floor above

For ceilings in an HMO, the floor above is usually the original timber joists at 400 mm centres. The 30-minute ceiling build-up is a single layer of 15 mm British Gypsum Fireline fixed to the underside of the joists with 25 mm of mineral wool in the joist cavity. For the 60-minute ceiling under the top floor, the build-up is two layers of 15 mm Fireline on the underside of the joists, again with the mineral wool in the cavity.

Service penetrations and fire stopping

Service penetrations through fire-rated partitions and ceilings have to be fire-stopped to the same standard as the wall or ceiling itself. The most common products are intumescent acrylic sealant around the penetration and rock mineral wool pillows in larger openings. The fire stopping has to be installed by a third-party-certified contractor, and the contractor has to issue a completion certificate for the fire stopping work before the HMO licence can be issued.

Where in St Helens HMOs are converting in 2026

The bulk of HMO conversions in St Helens are clustered around the WA10 town centre postcodes, particularly the streets that run off Westfield Street and Duke Street towards the Town Hall. Other active areas include the older parts of Thatto Heath and the eastern edge of Windle, where the housing stock is a mix of Victorian terraces and 1930s semi-detached homes that lend themselves to subdivision.

Further out, conversions are picking up in WA9 around the corridor between St Helens town centre and the Totally Wicked Stadium, where demand for rental housing from shift workers at the hospital and the retail parks is steady. WN4 (Ashton-in-Makerfield and the Garswood side of the borough boundary) sees occasional conversions, but the housing density is lower and the demand profile is different. WN5 (Billinge and the western edge of the borough) sees very few HMO conversions because the housing stock is mostly detached and semi-detached post-war housing that does not lend itself to subdivision.

What St Helens Council checks during the licence inspection

The HMO licence inspection is carried out by the private rented sector team at St Helens Borough Council, based at the Town Hall on Victoria Square (WA10 1HP, 01744 676789). The inspection is booked once the landlord has submitted the licence application and paid the fee. The inspector walks the property with the landlord or the landlord's agent and checks the fire safety provisions against the schedule in the application.

The four items the inspector almost always checks are:

• Fire doors between letting rooms and on the stairwell enclosure. Every door has to be an FD30 fire door with intumescent strips and a self-closing device. The inspector will physically check the door closers and will look for the manufacturer's label on the top edge of the door
• Fire detection and alarm system to BS 5839-6, Grade D1 or D2 with a heat detector in the kitchen and interlinked smoke detectors in the letting rooms, hallway, and stairwell. The system has to be tested at the inspection and the test log has to be on site
• Means of escape from each letting room to a final exit, with the route kept clear at all times. The inspector will check that the escape window in each first-floor letting room opens without the use of a key
• Fire-rated partitions and ceilings between letting rooms, with the test certificates and the fire-stopping completion certificate available on site for the inspector to copy

Common pitfalls we see on HMO fire-rated drylining

Three pitfalls come up on the majority of HMO conversion projects in St Helens. Each is avoidable if it is caught at the design stage.

First, the wall between the kitchen and the stairwell often gets missed in the specification. The kitchen is a higher fire risk than the letting rooms because of the cooking appliances, and the stairwell is the primary escape route for everyone in the house. The wall between them has to be a 30-minute fire-resisting partition, with the same specification as the wall between two letting rooms, even though it does not separate two tenancies.

Second, the soil pipe from the first-floor bathroom usually penetrates the ceiling between the ground floor and the first floor, and the penetration is almost never fire-stopped by the plumber. The penetration has to be fire-stopped to the same standard as the ceiling itself, with intumescent sealant around the pipe and rock mineral wool packed into the opening. The fire-stopping contractor will issue a separate certificate for this work.

Third, the loft hatch into the roof space above the top floor letting rooms is almost always an unsealed timber hatch. The hatch has to be replaced with a fire-rated loft hatch that sits on a frame sealed with intumescent strip. This is a small item but the inspector will always check it.

Worked example: a Victorian terrace on Dentons Green

Earlier this year we completed the fire-rated drylining programme on a Victorian terraced house on a residential street off Dentons Green Lane in WA10. The landlord was converting a three-bedroom house into a four-bed HMO with two tenants in the largest bedroom as a couple, and one tenant in each of the other two bedrooms. The kitchen and the bathroom were shared on the ground floor.

The specification we agreed with the landlord and his architect was:

• 75 mm Gypframe metal C-stud partitions between letting rooms, single layer 12.5 mm Gyproc Fireline each side, 25 mm mineral wool in the cavity, 30-minute fire resistance
• Stairwell enclosure in 75 mm Gypframe metal C-stud, two layers 15 mm Fireline staircase side, one layer 12.5 mm Fireline room side, 25 mm mineral wool, 60-minute fire resistance
• Ceiling under first floor: 15 mm Fireline fixed to underside of existing timber joists, 25 mm mineral wool in joist cavity, 30-minute fire resistance
• Ceiling under loft: two layers 15 mm Fireline to underside of joists, 60-minute fire resistance
• Fire-rated loft hatch with intumescent seal, plus intumescent seals around the soil pipe penetration through the first-floor ceiling

The licence inspection went through on the first visit. The fire-rated drylining specification, the test certificates, and the fire-stopping completion certificate were all on site in the landlord's HMO file. The licence was issued for five years.

How to plan a compliant HMO conversion in St Helens

The order of operations matters. The cheap and easy way to plan an HMO conversion is to start with the planning application, then move to the HMO licence application, then do the building work. The expensive way is to do the building work first and try to retrofit the licence afterwards. The latter almost always costs more because the inspector will require additional work to bring the property up to the current standard.

A short checklist for landlords starting out:

• Confirm with St Helens Council that the property is in the borough-wide Article 4 HMO area, which it almost certainly is
• Submit the planning application for the C3 to C4 change of use before any building work starts
• Engage a building control inspector (the council's own team or an approved inspector) for the fire-rated partitions and ceilings
• Specify the plasterboard build-ups from the British Gypsum White Book or the Knauf technical manual, with the relevant test certificates on file
• Use a third-party-certified fire-stopping contractor for the service penetrations and loft hatch
• Submit the HMO licence application to the private rented sector team at the Town Hall at least eight weeks before the first tenants move in

If you are at the start of an HMO conversion in St Helens and want a fixed-price quote for the fire-rated drylining element of the work, send us the WA10, WA9 or WA11 postcode, a short description of the existing layout, and the proposed letting room arrangement. We will run a free site survey, agree the fire-rated specification with your architect or building control inspector, and quote the full programme including partitions, ceilings, fire-stopping, and the loft hatch.

By the Drylining St Helens editorial team · 2026-09-24 · 2399 words

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Converting a St Helens terrace into an HMO?

Send us the WA10, WA9 or WA11 postcode, the existing layout, and the proposed letting room arrangement. We will quote the fire-rated drylining programme, including partitions, ceilings, fire-stopping and the loft hatch, on a fixed-price basis.