## [seo] Meta & structured data - [meta-title] UV-protective coating for polycarbonate CovaTherm Light | Covalba - [meta-description] CovaTherm Light, the solar-control coating with UV protection for polycarbonate skylights and barrel-vault rooflights. Blocks heat, preserves 65% of natural light. - [product-schema-name] UV-protective coating for polycarbonate CovaTherm Light - [product-schema-description] Non-opacifying solar-control coating for polycarbonate and polyester skylights and barrel-vault rooflights. Filters UV and infrared, preserves 65% of natural light. Reflective coating from Covalba. - [product-schema-brand] Covalba - [product-schema-category] UV-protective coating for polycarbonate - [breadcrumb-1] Home - [breadcrumb-2] Our solutions - [breadcrumb-3] CovaTherm Light ## [hero] Product hero - [tag] UV-protective coating for polycarbonate - [product-name] CovaTherm Light - [tagline] The solar-control coating that blocks the heat without stealing the light. - [description] High-reflectivity white acrylic coating from Covalba. Applied to your polycarbonate or polyester skylights, barrel-vault rooflights and light wells, it filters UV, infrared and glare while preserving up to 65% of natural light. - [hero-image-alt] Application of CovaTherm Light UV-protective coating on a polycarbonate skylight - [primary-cta] Request a quote - [secondary-cta] Download the spec sheet - [badge-1] 98% of UV filtered - [badge-2] 65% of light preserved - [badge-3] 5 to 8 years - [stat-1-value] -5°C - [stat-1-label] Under the skylights - [stat-2-value] 65% - [stat-2-label] of light preserved - [stat-3-value] 10 to 20% - [stat-3-label] less cooling energy - [breadcrumb-nav-home] Home - [breadcrumb-nav-solutions] Our solutions ## [showcase] Positioning - [eyebrow] Positioning - [heading-line-1] CovaTherm Light, - [heading-line-2] the non-opacifying solar-control coating. - [card-eyebrow] The translucent solar-control coating - [card-title] CovaTherm Light - [card-body] The only cool roof coating designed for surfaces that cannot be painted opaque white without sacrificing natural light. It selectively filters UV and infrared while letting the visible spectrum through. - [card-bullet-1] Polycarbonate — skylights, barrel-vault rooflights, modern dome skylights. - [card-bullet-2] Translucent polyester — barrel-vault rooflights and older dome skylights. - [card-cta] Request a quote - [showcase-image-alt] Covalba CovaTherm Light solar-control coating in pails, for polycarbonate skylights - [footer-note] Are your skylights creating an overhead-heat effect in summer? Our technician runs an on-site diagnosis. - [footer-note-link] Free quote ## [before-after] Before / after - [eyebrow] Before / after - [heading-line-1] Comfort, - [heading-line-2] before and after CovaTherm Light. - [intro] Drag the handle to compare the atmosphere under a polycarbonate skylight before and after applying the solar-control coating. Natural light is still there, but glare and radiant heat are gone. - [after-image-alt] Skylight treated with CovaTherm Light: natural light preserved, glare eliminated, an average gain of 5°C - [before-image-alt] Untreated skylight: plenty of light but glare and radiant heat over the workstations - [label-before] Before - [label-after] After - [range-aria-label] Position of the before / after comparator - [caption-before] Before. Light is abundant, but the translucent material causes glare and heat. The workstations below it are uncomfortable. - [caption-after] After. Light is preserved, glare is gone and heat is blocked. An average gain of 5°C under the treated surfaces. ## [compatibility] Compatible substrates - [eyebrow] Compatibility - [heading-line-1] The substrates compatible - [heading-line-2] with CovaTherm Light. - [intro] A solar-control coating only delivers on its promise if it bonds durably to the translucent substrate without blocking its light. Every project starts with a preliminary diagnosis, to be entrusted to a professional applicator. - [coverage-note] CovaTherm Light is formulated for the translucent materials used in building roofing. - [footer-note] For the opaque part of your roof, see our CovaTherm cool roof coating. - [roof-1-type] Polycarbonate - [roof-1-detail] The predominant material on modern skylights and barrel-vault rooflights, highly sensitive to UV. Core target. - [roof-2-type] Translucent polyester - [roof-2-detail] Used on barrel-vault rooflights and some older dome skylights. - [roof-3-type] Translucent fiberglass - [roof-3-detail] Compatibility confirmed after an on-site technical diagnosis. - [roof-4-type] Glazing - [roof-4-detail] Glass, glass roof, sunroom: a bonded interior solar film is the appropriate solution, not the solar-control coating. - [badge-compatible] Compatible - [badge-incompatible] Not compatible - [incompatible-callout] Do not apply CovaTherm Light on glazing. On glass, glass roofs or sunrooms, a bonded interior solar film offers a far better aesthetic finish and greater durability. For translucent polymers (polycarbonate, polyester), CovaTherm Light remains the appropriate solution. ## [specs] Technical specifications - [eyebrow] Technical specifications - [heading-line-1] The specifications - [heading-line-2] of CovaTherm Light. - [intro] High solar-reflectivity acrylic resin, applied by roller or airless sprayer, preserving the translucency of the substrate. CovaTherm Light is designed specifically for translucent roof surfaces, where an opaque cool roof coating cannot be applied. - [column-header] CovaTherm Light - [column-badge] Solar-control coating - [spec-1-label] Technology - [spec-1-value] High-reflectivity acrylic resin - [spec-2-label] Substrates - [spec-2-value] Dome skylights, skylights, barrel-vault rooflights in polycarbonate or polyester - [spec-3-label] UV rejection - [spec-3-value] Up to 98% of UV filtered - [spec-4-label] Solar energy rejected - [spec-4-value] 75% - [spec-5-label] Natural light preserved - [spec-5-value] Up to 65% - [spec-6-label] Coating system - [spec-6-value] 200 g/m² (1 to 2 coats) - [spec-7-label] Maintenance coat to plan within - [spec-7-value] 5 to 8 years on a sound substrate - [spec-8-label] Enhanced protection against soiling - [spec-cta] Request a quote - [disclaimer] Performance measured on a polycarbonate substrate · Manufacturer warranty · Covalba R&D data ## [certifications] Certifications and compliance - [eyebrow] Certifications - [heading-line-1] Certifications and - [heading-line-2] compliance. - [intro] CovaTherm Light fits within the regulatory framework for industrial and commercial buildings, with a low-environmental-impact formulation and compatibility with recent thermal requirements. - [cert-1-label] Low-VOC formulation - [cert-1-desc] Compliance with the environmental requirements of certified buildings and sensitive facilities. - [cert-2-label] Certified UV filtration - [cert-2-desc] Up to 98% of UV filtered, slowing the yellowing and degradation of polycarbonate. ## [advantages] Advantages - [eyebrow] Advantages - [heading-line-1] The advantages of the UV-protective coating - [heading-line-2] for polycarbonate CovaTherm Light. - [intro] Applying CovaTherm Light to your skylights transforms your building's interior atmosphere from the very first summer: radiant heat disappears, glare stops, but natural light remains. Here are the six benefits observed on projects. - [adv-1-title] Natural light preserved - [adv-1-desc] Filters UV and infrared, retains up to 65% of visible light. Your teams work in daylight, with no glare or overheating. - [adv-2-title] Overhead-heat effect eliminated - [adv-2-desc] Removes the sensation of discomfort under skylights, responsible for headaches, dizziness and reduced alertness. The workstations become usable again in summer. - [adv-3-title] Reduced eye strain - [adv-3-desc] Reduces the glare that forces your teams to squint or wear sunglasses indoors. A direct benefit for concentration and the prevention of vision problems. - [adv-4-title] Measurable thermal gain - [adv-4-desc] Up to 5°C cooler on average under the treated surfaces, with no additional air conditioning. Rejects 75% of solar energy. - [adv-5-title] Extended skylight lifespan - [adv-5-desc] Blocks the UV that yellows and weakens polycarbonate. Pushes back skylight replacement by several years. - [adv-6-title] Reduced electricity bill - [adv-6-desc] Air-conditioning consumption reduced by 10 to 20% depending on the activity, thanks to the elimination of localized overheating under the translucent elements. ## [comparison] Comparison - [eyebrow] Comparison - [heading-line-1] Solar-control coating or - [heading-line-2] skylight replacement? - [intro] The choice between CovaTherm Light and a full skylight replacement depends on the age of the translucent elements, their level of degradation and the available budget. The criteria that matter are summarized below. - [col-a-header] CovaTherm Light - [col-a-badge] Recommended - [col-b-header] Skylight replacement - [row-1-label] Project duration - [row-1-a] 1 to 3 days - [row-1-b] 1 to 3 weeks - [row-2-label] Natural light preserved - [row-2-a] up to 65% - [row-2-b] Full (new skylights) - [row-3-label] Anti-heat effect - [row-3-a] -5°C on average - [row-3-b] Depending on the model chosen - [row-4-label] UV filtration - [row-4-a] Active for 8 to 10 years - [row-4-b] If UV additives included - [row-5-label] Waterproofing - [row-5-a] Unchanged - [row-5-b] New seals - [row-6-label] Activity interruption - [row-6-a] None - [row-6-b] Partial - [row-7-label] Lifespan - [row-7-a] 8 to 10 years - [row-7-b] 15 to 20 years - [row-8-label] Average ROI - [row-8-a] Short - [row-8-b] Long - [cta] Request a quote - [conclusion] CovaTherm Light is the appropriate solution when skylights are still structurally sound but cause thermal and light discomfort. For barrel-vault rooflights that are heavily yellowed, deformed or near the end of their life, a targeted replacement of the affected elements is preferable before considering a solar-control coating on the rest. For the opaque part of your roof, the CovaTherm cool roof coating completes the treatment. ## [faq] Frequently asked questions - [section-title] Your questions about CovaTherm Light - [section-subtitle] A question that isn't here? Contact us or request a quote. - [section-cta] Free quote - [q1] CovaTherm Light or CovaTherm: how to decide? - [a1] CovaTherm is an opaque cool roof coating, designed for the solid part of your roof (bitumen, steel deck, concrete, tiles). CovaTherm Light is a non-opacifying solar-control coating, formulated for polycarbonate or polyester skylights, barrel-vault rooflights and light wells. The two products do not compete with each other, they complement each other: on a building fitted with both an opaque roof and translucent surfaces, the two are often applied in the same project to treat the entire roof. - [q2] How much natural light remains after application? - [a2] Up to 65% of natural light is preserved, depending on the condition and level of translucency of the substrate before treatment. Your building retains enough light input to remove or reduce artificial lighting during the day, while eliminating the glare and radiant heat that disturbed the workstations below. - [q3] Why do skylights cause the overhead-heat effect? - [a3] Polycarbonate or polyester skylights are translucent materials that let visible light, UV and infrared all pass through. As soon as the sun strikes vertically, the rays converge directly onto the workstations below and heat people far more intensely than the surrounding air. The typical symptoms are headaches, dizziness, localized hot flushes and a rapid drop in concentration. CovaTherm Light filters UV and infrared at the source, without depriving the building of its natural light. - [q4] From what proportion of skylights should the roof be treated? - [a4] The more roof surface your skylights occupy, the greater the measurable impact of solar-control treatment on the interior atmosphere. A building with 25% or more of its roof in translucent elements achieves very visible comfort gains after applying CovaTherm Light. Below 20%, it is often more relevant to start by treating the opaque part of the roof with CovaTherm, then complement it with CovaTherm Light if the need remains. - [q5] Can CovaTherm Light be applied on glazing or a glass roof? - [a5] No. For glass (windows, glass roofs, sunrooms), the aesthetic finish of a solar-control coating applied by brush or sprayer is not satisfactory, and durability over time is lower. For these substrates, a bonded interior solar film remains the recommended solution. CovaTherm Light is specifically designed for translucent polymers (polycarbonate, polyester), which make up the vast majority of skylights and barrel-vault rooflights in industrial and commercial buildings. - [q6] Why does CovaTherm Light last 5 to 8 years and not 20 like the other Covalba products? - [a6] The substrate determines the lifespan of a coating. CovaTherm 20, CovaSeal 20 and CovaMetal 20 are protected by an anti-UV top coat that lets them last two decades on a stable opaque surface. On polycarbonate, the substrate itself ages under the effect of UV, even when protected by a solar-control coating. After 5 to 8 years, the degradation of the underlying polycarbonate requires a system refurbishment or skylight replacement. An annual rinse with clean water extends the reflective performance during this period. - [q7] Do you need a professional to apply CovaTherm Light? - [a7] Yes. Application on skylights presents three specific challenges: the surfaces are often sloped or curved, their load-bearing capacity is low (you do not walk directly on them, you work from gangways or aerial work platforms), and the dosage must be adjusted to preserve translucency without compromising reflectivity. We recommend entrusting the application to a professional applicator familiar with these specific constraints of translucent surfaces, and we provide your installer with detailed application instructions. This is a condition of the manufacturer warranty. - [q8] What is the price of a UV-protective coating for polycarbonate per m²? - [a8] The price of a professional UV-protective coating for polycarbonate, installed, is calculated by quote, based on three factors: the accessibility of the skylights (technical gangway, aerial work platform, lifeline), their geometry (flat, curved, vaulted) and their condition before application. Compared with a full skylight replacement that runs into hundreds of euros per m², CovaTherm Light remains a particularly cost-effective solution, completed in 1 to 3 days with no interruption of activity. - [q9] What maintenance does a solar-control coating require? - [a9] CovaTherm Light has self-cleaning properties. We recommend an annual visit and a rinse with water to clear away dust and optimize solar reflection. No chemical product is needed. A visual inspection of the polycarbonate substrate's condition every 2 to 3 years allows early detection of any underlying degradation. ## [editorial] Editorial feature - [eyebrow] Feature - [heading-line-1] The UV-protective coating for polycarbonate, - [heading-line-2] explained. - [intro] UV-protective coating for polycarbonate, solar-control coating, translucent anti-heat coating, reflective coating for skylights: several names for one and the same family of products formulated to address a very specific problem, that of overheating and glare under the translucent elements of a professional roof. Used where an opaque cool roof coating cannot be applied, the solar-control coating makes it possible to keep the benefit of natural light while removing the thermal penalty that comes with it. - [h3-principle] How a solar-control coating works: filtering heat without blocking the light - [principle-p1] A solar-control coating works by selective filtration of the solar spectrum. It lets visible light through, which is responsible for the natural light input, and blocks two specific wavelengths that degrade comfort and materials: - [principle-bullet-1] Ultraviolet (UV) rays, which heat imperceptibly but degrade the molecular structure of polycarbonate (yellowing, embrittlement) and cause eye strain in humans. - [principle-bullet-2] Infrared rays, responsible for nearly all of the radiant heat felt by people located under the skylights. - [principle-p2] By blocking these two bands while letting the visible spectrum through, CovaTherm Light transforms the indoor experience without depriving the building of its natural light. The substrate thus keeps its primary usefulness (free light input, savings on artificial lighting) without its drawbacks (radiant heat, glare, accelerated degradation). - [h3-use-cases] The skylights CovaTherm Light was designed for - [use-cases-p1] CovaTherm Light is the UV-protective coating for polycarbonate suited to the following situations: - [use-cases-bullet-1] Workstations under skylights that are uncomfortable in summer, with recurring complaints from teams about heat or glare - [use-cases-bullet-2] Aging polycarbonate or polyester barrel-vault rooflights or dome skylights that are visibly yellowing or degrading - [use-cases-bullet-3] Workshops, production halls, warehouses with a significant share of translucent roof surface (from 20 to 25%) - [use-cases-bullet-4] Commercial buildings fitted with light wells that create localized overheating zones - [use-cases-bullet-5] Stores and showrooms where glare disrupts the reading of labels, screens or displayed products - [use-cases-p2] For an opaque roof with no translucent elements, the CovaTherm cool roof coating remains the solution. Conversely, for glass or glass-roof surfaces, a bonded interior solar film is more appropriate. - [h3-budget] The budget for a solar-control coating per square meter - [budget-p1] The price of a professional UV-protective coating for polycarbonate, installed, depends mainly on the accessibility of the skylights, their geometry (flat, curved, vaulted) and their condition before application. The price per m² is not public; it is calculated by quote based on the access constraints and the geometry of the translucent elements. - [budget-p2] Compared with traditional alternatives, CovaTherm Light remains a particularly cost-effective solution: - [budget-bullet-1] Replacing the skylights with new anti-UV models: several hundred euros per m², including dismantling, removal and refitting in line with roof waterproofing standards - [budget-bullet-2] Bonded interior solar film: suited to glazing, but tricky to install on curved polymers and not very durable over time - [budget-bullet-3] Motorized interior blinds: a partial solution that removes light as well as heat - [budget-p3] You can estimate the savings of a solar-control coating on your building in a few minutes. - [h3-process] How a project unfolds - [process-p1] A CovaTherm Light project unfolds in four controlled steps, carried out by a professional applicator following our application instructions. - [process-step-1] Technical diagnosis. A technician assesses the condition of the skylights, measures their residual translucency, checks their load-bearing capacity and identifies the most degraded areas. Some heavily yellowed barrel-vault rooflights may require prior replacement rather than a simple treatment. - [process-step-2] Preliminary cleaning. The translucent surfaces are cleared of moss, dust and organic deposits that impair light transmission, then rinsed with clean water. - [process-step-3] Application by roller or airless sprayer. The acrylic coating is applied in thin, even coats, from a technical gangway or an aerial work platform depending on the configuration. Two cross passes ensure uniform coverage with no runs. - [process-step-4] Drying and finishing rinse. A post-drying rinse removes any residue along the edges and stabilizes the final adhesion. - [process-p2] Application is done in dry weather, at moderate temperatures. A typical project is completed in 1 to 3 days depending on the skylight area, with no interruption to the building's activity. We provide your installer with the safe-working instructions for translucent surfaces as well as the dosage parameters specific to the product. - [h3-uv] UV, the main factor in polycarbonate aging - [uv-p1] Polycarbonate, the predominant material in modern skylights, is particularly sensitive to ultraviolet radiation. Exposed without protection, it undergoes a documented physico-chemical degradation process: progressive yellowing, loss of transparency, the appearance of surface microcracks and a decline in mechanical properties (Redjala et al., 2020). A study conducted on UV-additive and UV+IR-additive polycarbonate skylights showed that the yellowing index can go from near-zero values to significant levels over a period of 21 months of natural exposure, with direct consequences for light transmission and impact resistance (Bakırcı & Kahveci, 2025). - [uv-p2] By filtering UV at the source before it reaches the polycarbonate, CovaTherm Light drastically slows this process. Your skylights keep their optical and mechanical properties longer, which pushes back the replacement bill by several years. - [h3-comfort] Team comfort, the most direct benefit - [comfort-p1] In workshops and commercial halls fitted with skylights, the radiant heat under light wells is not a trivial discomfort: it leads to a documented drop in concentration, accelerated fatigue and physical symptoms (headaches, dizziness, hot flushes) that degrade both productivity and quality of life at work. Research on cool roofing strategies also shows that an improvement in indoor thermal comfort, even without air conditioning, has a measurable effect on occupant well-being and on the building's energy demand (Santamouris, 2014). Treating the translucent elements of a roof is therefore also an investment in working conditions, not just in energy efficiency. - [h3-sources] Sources and references - [source-1] Redjala, S., Ferouk, N., Chikhi, N., & Aït Hocine, N. (2020). UV Aging Effects on Polycarbonate Properties. Journal of Failure Analysis and Prevention, 20, 1907-1915. - [source-2] Bakırcı, A., & Kahveci, S. (2025). The temporal variation of some physical and mechanical properties of different polycarbonate greenhouse covering materials and the detection of aging using thermal imaging. Case Studies in Thermal Engineering, 74. - [source-3] Santamouris, M. (2014). Cooling the cities — a review of reflective and green roof mitigation technologies to fight heat island and improve comfort in urban environments. Solar Energy, 103, 682-703. - [source-4] Akbari, H., Berdahl, P., Levinson, R., Wiel, S., Miller, W., & Desjarlais, A. (2005). Aging and Weathering of Cool Roofing Membranes. Lawrence Berkeley National Laboratory / U.S. Department of Energy.