Electrostatic Painting & Metalwork

Painting Metal Conservatories: A Complete Guide

How professional spray painting restores deteriorated metal conservatories on hotels, restaurants, and commercial properties, covering electrostatic application, colour matching, glass masking, preparation, and the full project process explained.

Anthony Jones, Vanda Coatings Updated February 2026 9 min read Electrostatic Painting Metalwork Colour Matching

A metal conservatory in good structural condition, but with a deteriorated, faded, or incorrectly coloured coating, is an expensive and disruptive problem if approached as a replacement project. Replacing a well-built metal conservatory structure on a commercial property, whether a hotel, restaurant, private members club, or residential block, can cost many thousands of pounds and creates significant disruption to the building's operations and appearance during the works.

Professional on-site painting of metal conservatories offers a different approach: restore and transform the structure rather than replace it. With the right preparation, the right application method, and the right coating system, a metal conservatory that looks tired, poorly maintained, or in the wrong colour can be returned to pristine condition, or given an entirely new colour identity, in a matter of days, at a fraction of the cost of replacement.

This guide explains how professional conservatory recoating works, why electrostatic spraying is the application method of choice for intricate metal frames, and what the full process looks like from initial survey to sign-off.

Why metal conservatories deteriorate, and what can be done about it

Metal conservatories, whether steel-framed, aluminium-framed, or a combination of both, deteriorate over time for several reasons:

UV degradation of the coating, even high quality factory-applied coatings fade, chalk, and lose gloss over years of UV exposure, particularly on south-facing elevations
Moisture ingress and corrosion, on steel frames, coating damage that allows moisture contact with the bare metal leads to rust formation beneath the coating, causing blistering and further coating failure
Mechanical damage, chips, scratches, and impacts from maintenance activity, plants, or building work damage the protective film and create points for moisture entry
Incorrect original colour, renovation projects, brand changes, or simply a change of preference leave structures in colours that no longer suit the property
Mismatched colour between sections, where parts of a conservatory have been repaired or replaced over time using different products or application methods, colour inconsistency is common

In the majority of these cases, the structural integrity of the conservatory is not compromised, only the coating has failed or become aesthetically unsuitable. Professional recoating directly addresses the coating condition without touching the structure, and delivers a result that is both protective and visually excellent.

15–30%

of replacement cost, typical budget saving when recoating vs replacing a commercial metal conservatory

90%+

transfer efficiency of electrostatic spraying on metal, the highest of any spray application method

Any

BS or RAL colour, including Chartwell Green, Anthracite Grey, Sage, and custom architectural matches

10–15

years, typical service life of a 2K acrylic system applied over correctly prepared metal frames

Why electrostatic spraying is the method of choice for conservatories

Metal conservatories present a specific application challenge that conventional spray methods do not handle as well as electrostatic spraying: the metalwork is intricate, slender, and highly intermixed with large glass panels that must be protected from overspray at all costs.

Conventional airless or HVLP spraying on a conservatory produces significant overspray, atomised paint particles that miss the narrow metal frames and drift onto adjacent glass surfaces. Masking large areas of glass to protect against this overspray is time-consuming and costly, and even with thorough masking, fine overspray particles can find their way onto glazed surfaces if conditions are not perfect.

Electrostatic spraying changes this fundamentally. In the electrostatic process, the atomised coating droplets are given a negative electrical charge as they leave the spray gun. The metal frames, earthed through their contact with the building structure, carry a natural positive charge relative to the charged droplets. The result is that the coating droplets are strongly attracted to the metal surfaces and wrap around them, coating the sides and even the back faces of profiles that the spray gun is not directly aimed at. This wrap-around effect provides two key advantages for conservatory work:

Dramatically reduced overspray, because the coating is attracted to the metal, far less of it passes through the metalwork and onward to the glass panels beyond
Superior coverage on slender profiles, the wrap-around attraction means that all faces of a glazing bar or frame profile receive coating coverage, including the faces that are angled away from the gun, without the operative needing to work around to every angle manually

These properties make electrostatic spraying the most efficient and most precise application method for conservatory work, and the one that produces the best result with the least glass cleaning required after completion.

Colour matching for conservatory recoating

Colour selection and matching is one of the most important conversations in any conservatory recoating project. Getting the colour right, and confirming it with the client before the main application begins, is essential to project success.

Several routes are available for colour specification:

Standard British Standard or RAL colours

The most common approach for commercial conservatory recoating is to specify a standard BS 4800 or RAL colour. Popular choices for traditional metal conservatories include:

BS 14C35 / RAL 6005, mid dark green, often described commercially as "Chartwell Green" or similar; the most requested colour for Victorian and Edwardian-style conservatories on hotels and heritage properties
RAL 7016 / RAL 7021. Anthracite Grey and Black Grey; increasingly popular for contemporary commercial properties where a modern, architectural palette is preferred
RAL 6009 / RAL 6007. Fir Green and Bottle Green; darker alternatives to the mid-greens, favoured for countryside hotel properties
RAL 9010 / RAL 9003. Pure White and Signal White; for conservatories in classic hotel or period residential settings where white is the appropriate traditional choice
RAL 8017 / RAL 8019. Chocolate Brown and Grey Brown; for timber-framed or mixed-material conservatories where a warm, natural tone is preferred

Bespoke colour matching

Where a client requests a colour that is not a standard BS or RAL reference, for example, to match an existing architectural feature, a brand colour, or a specific heritage paint colour, bespoke colour matching can be carried out using a spectrophotometer. A physical sample of the reference colour is submitted, and the coating is mixed to match it. A sample panel is then produced and submitted for client approval before the main application begins.

Sample approval before main application

Regardless of which colour route is taken, a physical sample panel in the specified colour should always be submitted and approved by the client before the main application begins. This is particularly important for greens and blues, which can appear significantly different under different lighting conditions and in different gloss levels. The sample panel should be assessed in the actual daylight conditions of the site, not under artificial light, to ensure the approved colour will look as expected on the finished building.

On a project we undertook in Worcester, the property owners had initially been advised by their architect to specify "Chartwell Green" from a standard colour swatch, but when a sample panel was prepared in the initially specified shade, the clients were not satisfied with the result. After assessment, BS 14C35 Serpentine Green was agreed as the correct match, a sample was approved, and the full application then proceeded to the client's satisfaction. This is precisely why sample approval before main application is a non-negotiable step in any colour-sensitive project.

Common commercial conservatory applications

Metal conservatories appear across a wide range of commercial property types, and the recoating requirement in each context has a slightly different emphasis:

Hotel and hospitality properties, often the most demanding in terms of colour precision and finish quality; conservatories on hotel properties are customer-facing spaces where the visual standard of the metalwork reflects directly on the brand; colour changes to align with refurbishment programmes are common
Restaurants and function rooms, conservatory dining spaces and event rooms where visual impact is the primary concern; black and heritage green are popular choices; glass masking is critical given the ratio of glazing to metalwork in these structures
Private members clubs and heritage buildings, period metal conservatories on heritage properties often have planning or listed building constraints that preclude full replacement; professional recoating is the only practical option for restoring appearance without altering the structure
Office and commercial buildings, conservatory-style meeting rooms, atrium spaces, and link structures between buildings; typically more straightforward in colour specification, often matching the existing building metalwork scheme
Residential blocks and care homes, communal conservatory spaces on residential developments and care facilities where the condition of shared amenity spaces affects resident satisfaction and property value

The conservatory recoating process, step by step

Initial survey and specification

The estimator visits the site to inspect the conservatory structure, assess the existing coating condition, identify substrate materials (aluminium frames, steel frames, UPVC elements, or a combination), and establish access requirements. Any areas of structural concern, corrosion, cracked glazing rebates, damaged sections, are noted for client attention before recoating work commences. The specification is agreed: coating system, colour reference, number of coats, and programme.

Access and safety arrangements

Access equipment appropriate to the height and geometry of the conservatory is arranged. For roof sections and elevated frame elements, mobile elevated work platforms (MEWPs) or scaffold is required, all operatives working at height hold IPAF or PASMA certification as appropriate to the access equipment used. Where the conservatory is attached to an occupied building, working hours and access zones are agreed with the property manager to minimise disruption. The surrounding area is cordoned off during application to prevent any building users or members of the public entering the spray zone.

Surface cleaning and preparation

All metalwork is thoroughly cleaned using a specialist industrial degreaser to remove traffic film, grease, organic deposits, and any previous cleaning product residue. Areas of existing coating that are flaking, blistering, or poorly adhering are abraded back to sound material or to bare metal as required. Any areas of bare metal on aluminium frames receive etch primer before the finish coat system. On steel frames, areas of surface rust are mechanically abraded to remove loose corrosion products and treated with a compatible primer before overcoating. All preparation residue and dust is removed before masking begins.

Masking of all glass panels and adjacent surfaces

All glass panels are masked using masking tape to define the exact edge at the frame-to-glass boundary, followed by masking paper or polythene over the full face of each panel. Adjacent brickwork, stonework, and rendered surfaces that are not being coated are masked to prevent overspray deposition. The masking stage on a large conservatory with many individual glass panels is one of the most time-intensive parts of the project and requires patience and precision, any gaps in the masking at the frame-to-glass boundary will result in paint on the glass that is very difficult to remove cleanly once dry.

Environmental conditions check

Before coating begins, ambient temperature, relative humidity, and dew point are checked and confirmed to be within the coating manufacturer's specified application window. For exterior metalwork, the minimum substrate temperature is 10°C and the substrate temperature must be at least 3°C above the dew point to prevent moisture condensation on the surface during application. In the UK climate, exterior conservatory projects may be weather-dependent, rain during the masking or application stages requires postponement until conditions are suitable.

Electrostatic coating application

With masking complete and conditions confirmed, the electrostatic spray application begins. Operatives work systematically around the conservatory, applying the coating to all metalwork in controlled passes. The electrostatic wrap-around effect ensures coverage on all faces of the frame profiles, including the sides and rear faces that conventional spray would under-coat. Two coats of the specified 2K acrylic system are applied to achieve the target dry film thickness, with adequate flash-off time between coats as specified by the manufacturer.

Masking removal and clean-down

Masking tape and paper are removed carefully after the final coat has reached sufficient surface hardness, typically two to three hours after application at 20°C. Tape is pulled at an angle away from the coating edge to avoid lifting the fresh film. Any minor edge bleed onto glass surfaces is cleaned immediately before the coating reaches full hardness. The surrounding area is inspected for any overspray deposition on surfaces beyond the masked zone and cleaned as required. All masking materials and waste are removed from site.

Final inspection and client sign-off

The completed conservatory is inspected in good daylight conditions, checking for any missed areas, thin patches, runs, or edge imperfections. Any minor deficiencies are addressed before the coating reaches full hardness. The client or client representative inspects the finished result and provides sign-off. A record of the coating specification, product, colour reference, number of coats, and dry film thickness readings, is provided to the client for maintenance records.

Recoating vs replacement: the practical decision

When a metal conservatory deteriorates visually, the building owner faces a choice between recoating and full replacement. In the majority of cases where the structure is sound, recoating is clearly the better option, but it is worth understanding the conditions under which each approach makes sense.

Recoating is the right choice when

The structure is sound, frames are solid, joints are tight, glazing is intact
The coating condition is the primary issue, faded, chalking, wrong colour, or locally damaged
Budget is a significant factor, recoating is typically 15–30% of replacement cost
Disruption must be minimised, recoating takes days; replacement takes weeks
A colour change is the goal, recoating can transform the colour to any specification
Heritage or planning constraints require retention of the existing structure

Replacement may be preferable when

The frame is structurally compromised, severe corrosion through the section, cracked members, failed joints
Glazing seals and weatherproofing are failed throughout and need full renewal
The conservatory design is being significantly altered as part of a broader refurbishment
The structure is beyond economic repair and replacement is required on structural or safety grounds

What to look for in a conservatory recoating contractor

Conservatory recoating on commercial properties, hotels, restaurants, and period buildings, is a technically demanding job that requires a contractor with specific experience in electrostatic application, colour matching, and precision masking on intricate glazed structures. Not all commercial painting contractors have this combination of skills and equipment.

When assessing contractors for a commercial conservatory recoating project, the key questions to ask are:

Do you use electrostatic spraying for conservatory metalwork, and can you demonstrate this on comparable past projects?
How do you handle colour matching, and do you produce a sample panel for client approval before main application?
How do you manage glass protection, what masking method do you use, and how do you clean any residual overspray?
What coating system do you specify for exterior metal, and what service life would you expect from it?
Do your operatives hold the relevant access equipment certifications (IPAF for MEWPs, PASMA for scaffold towers)?
Do you carry a full contractor liability insurance policy with appropriate coverage for damage to glazing?

At Vanda Coatings, we have been completing conservatory recoating projects on commercial properties across the UK since the late 1990s. Our operatives are trained in electrostatic application and experienced in the precision masking that conservatory work demands. Every colour-critical project begins with a physical sample approval, we never proceed to main application without the client having seen and confirmed the exact colour in the actual site conditions.

Coating systems for different conservatory metal types

Metal conservatories are constructed from a range of substrate materials, and each requires a different preparation and coating approach to achieve reliable, long-lasting adhesion. Using the wrong primer or applying a finish coat over inadequately prepared galvanised steel or aluminium is one of the most common causes of premature coating failure on conservatory recoating projects.

Aluminium frames, the most common contemporary conservatory material; requires etch primer on all bare or freshly abraded areas before the 2K acrylic finish coat system; the etch primer reacts chemically with the aluminium oxide surface to create a chemically bonded foundation that mechanical adhesion alone cannot replicate
Steel frames, older conservatory structures are often mild steel; requires zinc phosphate primer on any bare or rust-treated areas before overcoating; the zinc content of the primer provides sacrificial corrosion protection in the event of subsequent coating damage
Galvanised steel frames, galvanised steel is widely used in commercially manufactured conservatory systems; requires T-wash chemical preparation or a specialist galvanised metal primer before any finish coat will adhere reliably; applying finish coat directly over bare galvanised steel without preparation is a common contractor shortcut that results in coating failure within 12–24 months
Cast iron decorative elements, heritage conservatories often include decorative cast iron elements such as finials, ridge cresting, or ornamental brackets; cast iron requires wire brushing to remove any loose rust or flaking existing coating, followed by a rust-inhibitive primer before the finish coat system
UPVC elements, UPVC sills, trims, or infill panels require a specialist UPVC adhesion promoter or primer before the 2K finish coat; standard primers do not bond reliably to UPVC without this surface-specific treatment

Frequently asked questions

Q Can metal conservatories be professionally repainted?

Yes, metal conservatories can be professionally recoated to a high standard using specialist on-site spray application techniques. The key to a successful result is thorough surface preparation, correct colour matching, and the use of an appropriate 2K acrylic coating system applied by electrostatic or HVLP spray. A professionally recoated metal conservatory is transformed in appearance and gains a new protective coating that extends the life of the metalwork, at a fraction of the cost of replacement.

Q Why is electrostatic spraying used for metal conservatories?

Electrostatic spraying is particularly well-suited to metal conservatories because of the intricate geometry of the metalwork, multiple slender glazing bars and frame profiles surrounded on all sides by glass panels that must be protected from overspray. The electrostatic process applies an electrical charge to the atomised coating droplets, which are then strongly attracted to the earthed metal surface. This dramatically reduces overspray compared to conventional spraying, improves wrap-around coverage on slender profiles, and means that significantly less overspray reaches the adjacent glass panels.

Q How are the glass panels protected during conservatory spraying?

All glass panels are carefully masked before spraying begins. Operatives use masking tape to define precise edges at the frame-to-glass boundary, and masking paper or polythene is applied over the entire face of each glass panel to protect it from overspray. The masking process is one of the most time-intensive stages of a conservatory spraying project, a large conservatory with many individual glass panels can take half a day or more to mask properly. Masking tape is removed after the final coat has reached sufficient surface hardness, and any minor edge bleed is cleaned before the coating fully hardens.

Q How is the correct colour matched for a conservatory recoating?

Colour matching for conservatory recoating begins with client consultation. Many clients request a standard BS 4800 or RAL colour, for example, BS 14C35 or RAL 6009 (Fir Green) are popular choices for traditional-style conservatories. Where a specific bespoke colour is requested, a sample panel is prepared and submitted for client approval before the main application begins. This avoids the significant waste and rework cost of applying a full coating system in a colour that the client rejects on completion. Colour samples are always assessed in daylight conditions, as artificial light significantly affects the perceived hue of greens and blues in particular.

Q Can UPVC conservatory components be painted at the same time as the metalwork?

Yes, UPVC components such as sills, trims, and infill panels can be professionally recoated at the same time as the metalwork, using a specialist UPVC primer and compatible 2K finish coat system. UPVC requires specific surface preparation, a light mechanical scuff and thorough degreasing, and a purpose-formulated UPVC primer before any finish coat will bond reliably. UPVC painted to match the metalwork creates a fully unified colour scheme across the conservatory.

Q How long does a professionally painted metal conservatory last?

A 2K acrylic coating system applied over correctly prepared metalwork will typically provide a service life of 10–15 years in an exterior environment before requiring attention, depending on the exposure conditions and the maintenance regime. South-facing and coastal locations, which experience higher UV intensity and salt deposition respectively, will see the coating show signs of fading and chalking at the lower end of this range. Regular cleaning of the coated surfaces, removing organic deposits and atmospheric contamination, extends the life of the coating significantly.

Q What is the typical cost of having a metal conservatory professionally painted?

Cost varies significantly based on the size and complexity of the conservatory, the amount of glazing to be masked, access requirements, and the number of coats specified. As a general guide, professional conservatory recoating typically costs between 15% and 30% of the cost of like-for-like replacement, making it a highly cost effective way to restore the appearance and protective coating of a structure that is otherwise in good condition. Vanda Coatings provides free site surveys and written quotations for commercial conservatory recoating projects.

Maintaining a professionally recoated metal conservatory

A professionally recoated metal conservatory on a commercial property is a significant investment, and a straightforward maintenance routine will protect that investment and extend the coating's service life considerably. The key actions are cleaning, inspection, and prompt attention to any damage.

Regular cleaning

Exterior metal conservatory frames accumulate atmospheric pollution, organic deposits, algae, lichen, and general dirt over time. These deposits hold moisture against the coating surface and can accelerate UV degradation and biological growth if left unchecked. An annual wash-down using a soft brush and mild detergent solution, working from the top of the structure downward, followed by a clean water rinse, removes the majority of these deposits and keeps the coating surface in good condition. Avoid high-pressure washing at close range on painted metalwork, as this can force water into joints and damage or lift coating edges.

Inspection for coating damage and corrosion

The conservatory frame should be inspected at least annually for signs of coating damage, chips, scratches, or impact marks that expose bare metal. On steel frames, any bare metal exposed to an exterior environment will begin to corrode, and rust can spread laterally under the adjacent intact coating, causing blistering and delamination. Prompt touch-in of small damage areas prevents this from developing into a larger preparation and recoating requirement. Keeping a record of the coating specification (coating manufacturer, product reference, colour code, and batch) from the original project makes touch-in straightforward, the contracts manager should provide this information at project completion.

Dealing with frame condensation and drainage

Metal conservatory frames can accumulate condensation, particularly in seasonal transitions when temperature differentials between the interior and exterior are at their greatest. Well-designed conservatory frames have drainage channels that allow condensation and rainwater ingress to clear; if these become blocked, standing water within the frame sections can accelerate coating failure from the inside out. Checking that drainage channels are clear as part of the annual inspection is a simple action that can prevent significant coating deterioration.

UV exposure and south-facing elevations

South-facing conservatory elevations receive substantially higher UV radiation than north-facing ones, this is the primary cause of faster fading and chalking on conservatories with a sunny aspect. If a conservatory is predominantly south-facing or sits in a highly exposed elevated position, specifying a high-UV-resistance 2K acrylic topcoat with enhanced UV stabiliser content, or adding a third coat to the south-facing elevations specifically, extends the coating life on those elevations toward the higher end of the service life range.

When to plan a full recoat

A professionally applied 2K acrylic system on well-prepared metalwork in an exterior environment will typically reach the end of its practical service life after 10–15 years, depending on exposure. Planning a full recoat before the coating has deteriorated to complete failure, rather than waiting until the metalwork is exhibiting widespread blistering or delamination, is significantly more cost effective. A recoat undertaken on a surface with an intact but ageing coating requires far less preparation than one where the coating has failed throughout. Periodic professional inspection of the coating condition, starting around year eight for south-facing or exposed coastal conservatories, allows the recoating programme to be planned and budgeted in advance rather than responding to a deterioration crisis.

Anthony Jones

Director, Vanda Coatings, 29 years experience

Anthony has managed conservatory and ornamental metalwork recoating projects on commercial properties across the UK for nearly three decades, from Victorian hotel conservatories on heritage properties to contemporary glass-and-steel structures on modern commercial sites. The combination of electrostatic application, precision glass masking, and careful colour management that conservatory work demands is one of the technical specialisms that Vanda Coatings has developed and refined throughout its history.