Staircase Spraying & Interior Metalwork

How to Paint Stairs in Commercial Buildings

Q: What is the correct primer for bare steel on a commercial staircase?

For bare mild steel exposed during preparation, where the existing coating has been removed back to the substrate, a two-component epoxy primer is typically specified for commercial staircase metalwork. Epoxy primers provide excellent adhesion to clean, prepared steel, good corrosion resistance, and a sound foundation for the 2K acrylic topcoat. For aluminium components (handrail extrusions, aluminium balusters), an etch primer appropriate for aluminium substrates must be used before the topcoat, a standard epoxy primer will not adhere reliably to aluminium without this step.

Q: Can you spray paint an internal commercial staircase without closing the whole building?

Yes, with proper containment, planning, and communication. On-site airless spray application of 2K coatings on internal metalwork requires appropriate masking of all adjacent surfaces (floors, walls, glass, and any non-target metalwork), temporary access controls during application (to prevent unmasked personnel entering the spray zone), and adequate ventilation to manage solvent vapours in the air. For sensitive occupied environments, low-VOC or waterborne 2K systems can significantly reduce odour during application. Working in sections and outside occupied hours where necessary allows the staircase to remain in partial use throughout the programme.

Commercial staircase metalwork, balustrades, handrails, spindles, and stringers, is among the most-handled and most visible metalwork in any building. Getting the coating right requires correct preparation, a substrate-appropriate primer, and a durable topcoat applied to a consistent standard. This guide covers every stage of the process.

Anthony Jones, Vanda Coatings Updated February 2026 9 min read Staircase Spraying Interior Metalwork How-To Guide

The staircase is one of the hardest-working surfaces in any commercial building. In offices, retail spaces, hotels, and mixed-use developments, the stairs are used by every person in the building multiple times each day. The metalwork, handrails, balustrades, balusters, and structural steelwork, receives constant physical contact, and the coating condition is visible to everyone who uses the building.

A freshly painted staircase signals that a building is well-maintained and cared for. A staircase with peeling, chipped, or faded metalwork, regardless of how well maintained the rest of the building might be, consistently registers as a maintenance failure and affects visitor and occupant perception of the space.

This guide covers what is involved in painting commercial staircase metalwork correctly, from the survey and preparation stage through to coating selection, application, and access planning. It is written from the perspective of a professional on-site commercial coating contractor with nearly three decades of experience on commercial staircase projects across the UK.

The components of a commercial staircase

Before specifying or discussing a staircase painting project, it helps to be precise about the individual components, each has slightly different requirements in terms of preparation, coating access difficulty, and finish expectation.

Handrail

The continuous graspable rail running along the top of the balustrade, the component that receives more direct hand contact than any other. The coating on a handrail must be extremely abrasion-resistant and have good resistance to body oils, cleaning products, and the mechanical wear from daily sliding hand contact. A clear lacquer or a gloss 2K acrylic topcoat is typically specified for handrails, the gloss level also makes wear visible quickly, allowing maintenance to be scheduled before the coating deteriorates to bare metal.

Balusters and spindles

The individual vertical members filling the gap between the handrail and the base rail or floor. Balusters may be circular section tube, square section bar, flat bar, or decorative forged profiles. The complex geometry of a balustrade, particularly where sections intersect at different angles, makes brush painting impractical for achieving even coverage. On-site airless spray application from multiple angles is the standard approach for achieving complete, consistent coverage on baluster arrays.

Stringers

The inclined structural members on either side of a staircase flight that support the treads and risers and carry the load of the balustrade. Stringers are typically rolled steel sections, channel, flat plate, or fabricated box sections, and are a primary structural element of the staircase. Stringer sections are often the most deteriorated part of an older staircase because they are close to ground level and subject to cleaning water, spillages, and abrasion from cleaning equipment.

Risers and treads (metal)

On all-metal or steel staircase structures, the risers (vertical faces between steps) and treads (horizontal walking surfaces) may also be included in the painting scope. Metal treads require a coating with anti-slip properties, either a textured anti-slip topcoat, or the application of anti-slip aggregate into the wet topcoat immediately after application. Standard smooth topcoats must never be applied to metal stair treads without anti-slip provision, the liability and safety implications are serious.

Newel posts

The principal posts at the start, end, and intermediate landing positions of a balustrade run, typically larger in section than the balusters and serving as the primary anchoring points for the handrail. Newel posts are structurally critical elements and are often the most decorative part of an ornate balustrade. They require careful preparation and coating at their base, where contact with the floor or landing surface creates a difficult-to-reach, moisture-retaining joint.

Staircase soffit

The underside of the staircase structure, the sloping ceiling visible beneath the flight from the floor below. In commercial buildings with concrete or steel-framed staircases, the soffit may include exposed structural steel, concrete, or a combination. The soffit is frequently included in staircase painting scopes where it forms part of the same visual environment as the staircase itself. Spray application is particularly effective on staircase soffits, the complex geometry and overhead working position make any other method impractical.

4×

faster than brush painting complex balustrade profiles, airless spray versus hand application

100+

RAL colours available for commercial staircase metalwork recoating, exact brand colour matching also available

1–2 days

typical programme for a 3-flight commercial staircase with preparation and two topcoats

10 yr

typical design life of a correctly specified 2K acrylic coating on interior staircase metalwork

Why preparation is the most important stage

No commercial staircase painting project produces a durable result without correct preparation. The quality of the finished coating is determined more by preparation than by the topcoat applied, a premium coating over a poorly prepared surface will fail early, while a well-specified coating over thoroughly prepared substrate will provide years of service.

For an existing staircase being recoated, as opposed to a newly fabricated structure being coated for the first time, the starting point is an assessment of the existing coating condition. This determines what preparation approach is needed and how much time should be budgeted for the preparation phase.

Sound, well-adhered existing coating: The existing film provides a suitable foundation for a new topcoat. Preparation involves degreasing, abrasion to create a mechanical key, and spot-priming of any bare metal areas exposed by wear or minor corrosion. The new topcoat is then applied over the prepared surface.
Partially failing existing coating: Areas of delamination, rust bleed, or heavy wear must be treated as bare metal, spot-stripped back to sound material, treated for corrosion, and spot-primed before the overall topcoat is applied. The transition between stripped and sound areas must be feathered to avoid visible edges in the finished result.
Heavily deteriorated or extensively corroded coating: Full strip-back to bare metal may be the only sound approach. Mechanical preparation, grinding, wire brushing, and abrasive blasting where practical, removes all existing coating and corrosion products, allowing a full primer coat to be applied to the clean substrate. This is the most thorough and durable approach but requires the most time.

The choice between these approaches must be made at survey stage, after a thorough physical inspection of the staircase. Skimping on preparation to save cost or time consistently produces premature coating failure and ends up costing more than the money saved.

Substrate preparation: step by step

Mask off all adjacent surfaces

Before any preparation or application begins, all surfaces that are not being painted must be protected. Floor surfaces, whether carpet, tile, or screed, must have dust sheets laid across the full area beneath the staircase and at each landing. Treads and risers that are not being coated (typically rubber or timber-clad treads on commercial staircases) must be masked. Glazed balustrade panels must be fully masked. Skirtings and wall finishes at the base of the staircase must be protected. On commercial sites where the staircase is adjacent to public areas, barrier systems must define the exclusion zone. Thorough masking at this stage avoids damage to adjacent finishes and speeds the overall project.

Clean and degrease the substrate

The staircase metalwork must be thoroughly cleaned and degreased before any abrasion or coating begins. Handrails in particular accumulate body oils from daily contact that are invisible to the eye but will prevent adhesion if left in place. A commercial degreaser applied with clean cloths, working from the handrail down to the stringers, removes grease, dust, and light surface contamination. After degreasing, the surface must be allowed to dry fully. Any residual degreaser must be removed, do not proceed with abrasion or coating until the surface is clean and dry. Even a top-quality primer will not adhere to a greasy or contaminated substrate.

Fill, sand, and key the surface

Any structural defects in the metalwork, welds with porosity, surface pitting, or mechanical damage, should be filled with an appropriate metal filler and allowed to cure fully before sanding. Protruding weld spatter should be ground flush. The entire surface must then be abraded, either manually with appropriate abrasive paper, or mechanically with a random orbital sander on accessible flat sections, to remove any residual gloss from the existing coating and create a mechanical key for the new primer and topcoat. After sanding, all dust must be removed thoroughly with a tack cloth or vacuum, any residual sanding dust trapped under the new coating will cause pinholes and adhesion loss.

Treat bare metal and apply primer

Any areas of bare metal, whether from preparation or pre-existing coating failure, must be primed before topcoat application. The correct primer depends on the substrate: for bare mild steel, a two-component epoxy primer provides the best adhesion and corrosion resistance; for aluminium components (handrail extrusions, aluminium balusters), an etch primer appropriate for non-ferrous metals is required. Applying a standard primer to bare aluminium without an etch primer stage will not produce a durable bond. Spot-prime all bare metal areas first; allow the primer to cure to the required overcoating hardness before applying the topcoat. Do not rush the primer curing stage.

Apply the topcoat, sequence matters

For airless spray application, the sequence of coating on a complex balustrade must be planned before the trigger is pulled. The correct sequence is: handrail inner and outer faces first, then top face; then balusters, working from top to bottom and ensuring coverage on all faces including the difficult-to-reach rear sections; then newel posts; then stringers. This sequence ensures that overspray from upper sections falls on still-uncoated sections below, not on freshly applied coating. Apply two thin coats rather than one heavy coat, thin coats cure properly and are less prone to runs and sags on the complex vertical and inclined surfaces of a staircase.

Allow adequate cure time before returning to service

The cured hardness of a 2K acrylic coating develops progressively over 24–72 hours after application at normal room temperature. A surface that is touch-dry after 4–6 hours is not yet hard enough to withstand the level of physical contact that a commercial handrail receives. The staircase should remain out of service, or have the handrail protected with foam lagging, until the coating has reached sufficient hardness to resist marking. The product data sheet will specify the minimum time to light traffic and to full service for the specific product used; these timings must be respected, not shortened for convenience.

Coating system selection for staircase metalwork

The coating system must be matched to the substrate, the level of use, and the environment. The following table summarises the standard approach for the main staircase component types and substrates encountered on commercial projects.

Component / substrate	Primer specification	Topcoat specification	Notes
Mild steel handrails and balusters	2K epoxy primer, full coverage on all bare metal	2K acrylic topcoat, gloss finish. Minimum 2 coats to achieve specified DFT	Gloss finish most durable and cleanable for high-contact surfaces
Aluminium handrail extrusions	Etch primer, applied to clean, degreased aluminium before any other primer or topcoat	2K acrylic topcoat, satin or gloss finish to match adjacent metalwork	Etch primer stage is critical, omitting it causes delamination on aluminium
Existing coated steel, sound condition	Spot primer on bare metal areas only; etch primer on any bare aluminium sections	2K acrylic topcoat over abraded existing coating, minimum 2 coats	Abrasion of existing coating surface is essential for inter-coat adhesion
Galvanised steel elements	Etch primer or specialist galvanised steel primer, applied after degreasing and light abrasion	2K acrylic topcoat, 2 coats minimum	Standard primers do not adhere well to galvanised surfaces without surface treatment
Metal stair treads (anti-slip requirement)	2K epoxy primer on bare metal	Anti-slip topcoat, or 2K acrylic with anti-slip aggregate broadcast into the wet film	Anti-slip provision on metal treads is a safety requirement, smooth topcoat alone is not acceptable
Staircase soffit, concrete or steel	Masonry primer (concrete soffits) or 2K epoxy (steel soffit elements)	2K acrylic topcoat, typically white or off-white to maximise reflected light in enclosed stairwell	Overhead application, ensure correct PPE for spray to face and vapour control

Why airless spray is the correct application method for staircase metalwork

The geometry of a commercial balustrade, particularly one with circular section balusters at close spacing, complex newel post profiles, or decorative ironwork, makes brush application impractical for achieving the consistent, even coverage needed for a durable commercial result. Brush painting complex profiles produces uneven film thickness, visible brush marks, and missed areas on the rear faces of balusters and between spindles that are difficult to reach with a brush.

On-site airless spray application atomises the coating into a fine fan pattern that penetrates into complex profiles from multiple angles, achieving consistent coverage across all faces of the metalwork simultaneously. The result is a uniform film thickness and a smooth, professional finish that is not achievable by hand methods on complex metalwork sections.

The practical speed advantage is also significant: a professional spray team typically applies coating to a complete balustrade four times faster than the equivalent brush operation, allowing a multi-flight staircase to be completed within a tight programme window that minimises building disruption.

Colour and design flexibility: A staircase recoating programme is also an opportunity to update the colour scheme of a key internal space. Staircases receive significant footfall and are often photographed and featured in building marketing materials. Specifying a colour that aligns with current brand guidelines, or using a contrasting accent colour on the handrail versus the balustrade, can transform the character of the space. Our spray equipment can achieve any RAL colour to a high standard of accuracy, the additional cost of changing colour versus applying the same colour is minimal.

Planning around building operations

The operational challenge of staircase painting in an occupied building is usually the most complex aspect of the project for facilities managers to manage. A few principles help to frame realistic planning:

Phase the work to maintain access: In buildings with multiple staircases, one flight can be taken out of service while others remain accessible. On a single-staircase building, work must be programmed outside occupied hours, evenings and weekends, or an alternative temporary access route established for the duration.
Provide clear advance notice: All building users and management should receive written notification of the work programme, including the specific sections affected on specific dates, well in advance. Unexpected staircase closures generate complaints regardless of how well the work itself is executed.
Control access during spray application: On-site airless spray application in an enclosed stairwell requires a strict access exclusion zone. No unmasked personnel should enter the spray zone during application or for a reasonable flash-off period after. This is a safety and quality requirement, not merely a convenience.
Communicate drying times clearly: Touch-dry does not mean fit for traffic. The coating protection on the handrail must be maintained until the 2K system has reached the hardness required for normal use. Clear signage and foam lagging protection on handrails prevents premature damage to the fresh coating and the associated remedial work cost.

Do not use metal stair treads without adequate anti-slip provision. A smooth painted metal stair tread is significantly more dangerous than an unpainted one, the coating reduces the surface texture of the metal and increases the slip risk. Anti-slip aggregate or a textured anti-slip topcoat must always be specified for metal tread surfaces. This is a safety-critical requirement, not an optional upgrade.

Frequently asked questions

Q What type of paint is best for commercial staircase metalwork?

A two-component (2K) acrylic coating system is the standard for commercial staircase metalwork, including balustrades, handrails, spindles, and stringers. 2K acrylics cure to a hard, chemically resistant film with excellent abrasion resistance, which is essential for surfaces that receive daily physical contact and regular cleaning. They are available across the full RAL colour range and in gloss levels from matt through satin to full gloss. For any metalwork that is handled regularly, a 2K system is the correct specification, single-component coatings lack the hardness and durability needed for commercial staircase use.

Q How is commercial staircase painting different from domestic staircase painting?

Commercial staircase metalwork is typically fabricated from mild steel or aluminium rather than timber, requiring different primer systems and coating specifications. Traffic volumes are substantially higher than in domestic settings, a busy commercial staircase may be used by hundreds of people daily, so the coating must withstand significantly more abrasion from clothing, bags, and hand contact than a domestic staircase would experience. Professional on-site spray application is standard for commercial metalwork because it produces a uniform, high quality finish across complex balustrade profiles that brush painting cannot match in either quality or speed.

Q Does a commercial staircase need to be shut down during painting?

Planning for operational continuity is a key part of any commercial staircase painting project. In buildings with multiple staircase routes, one flight can be taken out of service while others remain accessible. Where a staircase is the sole means of egress, working outside occupied hours, evenings or weekends, is the most practical solution. In all cases, clear advance communication with building management and users, and a detailed phasing plan agreed before work begins, allows the project to be completed with minimal disruption to building operations.

Q What is the correct primer for bare steel on a commercial staircase?

For bare mild steel exposed during preparation, a two-component epoxy primer is typically specified for commercial staircase metalwork. Epoxy primers provide excellent adhesion to clean, prepared steel, good corrosion resistance, and a sound foundation for the 2K acrylic topcoat. For aluminium components, an etch primer appropriate for non-ferrous metals must be used before the topcoat, standard epoxy primers will not adhere reliably to aluminium without this step, and omitting the etch primer is one of the most common causes of coating delamination on aluminium handrail sections.

Q Can you spray paint a commercial staircase without closing the whole building?

Yes, with proper containment, phasing, and communication. On-site airless spray application of 2K coatings on internal metalwork requires appropriate masking of all adjacent surfaces, temporary access controls during application to prevent unmasked personnel entering the spray zone, and adequate ventilation to manage solvent vapours. For sensitive occupied environments, low-VOC or waterborne 2K systems can significantly reduce odour during application. Working in sections and outside occupied hours where necessary allows the staircase to remain in partial use throughout a carefully programmed project.

Q How long does commercial staircase painting take?

Duration depends on the size and complexity of the staircase, the number of flights and landings, the extent of preparation required, the number of coats specified, and any constraints on access or working hours. A typical commercial office building staircase with 3–4 flights, requiring preparation, priming, and two topcoats, can normally be completed within 3–5 working days with a professional spray team. Larger or more complex projects, multi-storey staircases with elaborate balustrades or significant preparation requirements, are quoted on a per-project basis following a site survey.

Anthony Jones

Director, Vanda Coatings, 29 years experience

Anthony has managed commercial staircase spraying projects throughout the UK for nearly three decades, from straightforward industrial staircase programmes to complex multi-flight balustrade restorations in occupied hotels and office developments. The principles are consistent: thorough preparation, the right primer for the substrate, a properly specified 2K topcoat, and careful phasing around building operations. Get these right and the result lasts a decade. Cut corners and you are back on site within a year.