Transform Your Space with Decosill
Achieve a Stunning Granite Finish Effortlessly
Enhance your window sills with Decosill’s durable, natural stone chip render. Perfect for both DIY enthusiasts and professional installers, our product guarantees a premium finish that stands the test of time.
Simple Steps to a Perfect Finish
1
Prepare Your Sill Surface
The existing sill needs to be clean, stable and ready to accept the Decosill render. This is what makes Decosill so practical: you’re working with what’s already there.
- Remove all loose, flaking or powdering material with a stiff brush or scraper
- Clean away dirt, moss, algae and any paint that is lifting
- Fill deep cracks or voids with a suitable repair mortar and allow to cure
- Lightly dampen the surface and apply a bonding primer (SBR or equivalent) to maximise adhesion
- Mask the window frame and surrounding wall with tape and sheeting
1
Apply the Quartz primer
Before Decosill is applied, a Quartz primer coat must be applied to the prepared surface. This critical step ensures maximum adhesion between the existing substrate and the render, and creates the key the stone chip needs to bond permanently.
- Apply the Quartz primer evenly across the full sill surface using a brush or roller
- Ensure complete coverage with no dry patches or missed edges
- Allow the primer to become touch-dry before applying Decosill — do not apply onto a wet primer coat
- Do not skip this step — the primer is what gives Decosill its long-term bond and durability
2
Apply Decosill
Decosill comes ready to mix — the natural stone chip aggregate is already blended into the product. Using a drill or paddle mixer, further mix to a smooth working consistency, and apply directly to the prepared sill.
- Apply to the sill with a steel trowel, working to an even depth of approximately 1-2mm
- Build up the profile of the sill edge, ensuring consistent cover over the full surface
- While still fresh, use a damp sponge to soften any edges
- Level and close in the material to achieve a consistent natural looking smooth finish
3
Completed Decosill application
Once applied, Decosill cures to a hard, stone-like finish and and the granite appearance deepens. It is water resistant — giving you a surface built to last decades in Irish conditions.
- Allow the render to cure for a minimum of 24 hours (48 hours in cooler or damp conditions)
- Do not allow rain contact or touch during the initial cure period
- The finish will not discolour, flake or require repainting
- To prevent any possible algae or moss sitting on the sill you can apply a preventative product such as Spray and Leave, This is optional.
Why Choose Decosill?
Available sizes: 10kg & 20kg
Natural Stone Composition
Crafted from genuine stone chips, Decosill provides an authentic granite appearance that enhances any property.
UV Stability
Our formula resists discoloration from sunlight, ensuring a long-lasting, vibrant finish.
Versatile Application
Suitable for passive sills, concrete, stone, and plaster substrates, Decosill is ideal for both interior and exterior projects.
Who It's For
Our Customers
Decosill is the perfect solution for a diverse range of customers. Homeowners looking to rejuvenate their window sills will appreciate its ease of application and stunning granite finish. Contractors can enhance their service offerings with a product that is both efficient and aesthetically pleasing. Property developers benefit from a cost-effective solution that delivers consistent quality across multiple projects. Architects and specifiers will find Decosill’s natural mineral composition ideal for sustainable building designs. Finally, DIY enthusiasts can achieve professional results with our comprehensive application guide and support.
What Our Customers Say
“Decosill has completely transformed the look of our home. The sills now have a beautiful granite finish. It’s hard to believe the difference it has made!”
J. Murphy
Homeowner, Dublin
“As a homeowner, I wanted to improve the look of our old window sills without the expense of replacing them. As a DIYer I found Decosill was easy to apply, with some guidance from Decomin, and completely transformed the house. The granite finish looks fantastic”
M. Byrne
Homeowner, Longford
Transform Your Window Sills Today
Ready to give your window sills a stunning new look? Order Decosill online today and experience the transformative power of our granite-effect render. Whether you’re a homeowner, contractor, or developer, our team is here to provide expert advice on coverage and application. Don’t wait—take the first step towards beautiful, durable window sills. Contact us for more information or place your order now!
Completed Projects Gallery
Explore real Decosill installations across different properties, colours and architectural styles.
Project 1 — Brick House with Bay Windows
Project 2 — Brick House with Anthracite Windows
Project 3 — Rendered House with Anthracite Windows
Project 4 — Rendered House with Timber-Effect Window
Project 5 — Pebble-Dash House with Anthracite Windows
Project 6 — Stone-Clad House with Brown Windows
Decosill Project — Decorative Corner Quoin Stones
Phone
Contact us at 046 9017045 for all your Decosill inquiries.
Address
Unit 24 Mullaghboy Industrial Estate, Navan, Co. Meath
FAQ
Decosill FAQ
What is Decosill?
Decosill is a purpose-manufactured decorative coating system developed specifically for external window sills, reveals, plinths and related masonry details.
It is designed for the shape, exposure and visual requirements of window sills, helping create a durable granite-effect finish without replacing the existing sill.
Is Decosill specifically made for window sills?
Yes. Decosill is specifically manufactured for window sill applications. It has been developed for sill refurbishment, reveal detailing, plinths and similar external masonry features where a neat, compact and decorative stone-effect finish is required.
Where can Decosill be used?
Decosill is designed primarily for external window sills. It can also be used on suitable reveals, plinths, bands and small masonry details where the same finish is required.
Decosill should be viewed as a specialist sill and detail coating, designed for window areas and associated external masonry features.
Can Decosill be used on old concrete window sills?
Yes. Decosill is ideal for refreshing older concrete sills, provided the surface is sound, clean, dry and properly prepared. Any loose material, flaking paint, heavy dirt, algae or grease should be removed before application.
Does the surface need to be primed?
Yes. For best adhesion and durability, the surface should be primed with Decosill Quartz Primer before applying Decosill. The primer helps create a suitable key for the decorative finish.
What colours are available?
Available Decosill colours are shown in our Colour Swatches section. Current in-stock colours are D631, D031, D421 and White Base.
Please note that colour availability may change, so we recommend checking the latest swatches or contacting us before ordering for a specific project.
How much Decosill do I need?
As a guide, Decosill coverage is approximately 1 kg per linear metre of standard-width window sill.
Coverage may vary depending on the width, depth, condition and texture of the sill, as well as the application thickness. Wider sills, rough surfaces, reveals, plinths or detailed areas may require additional material.
How many coats are required?
Decosill is normally applied in one tight, even coat at approximately 1–2 mm thickness. The aim is to create a consistent, compact finish rather than a heavy build-up.
Can Decosill be applied by a DIY user?
Yes, careful DIY users can apply Decosill on small projects if they follow the preparation and application instructions. For larger projects, multiple sills, commercial work or retrofit projects, we recommend using a trained applicator.
Do you offer installer training?
Yes. Decosill installer training is available for contractors, painters, retrofit installers and exterior finish applicators. Training helps ensure correct preparation, application technique and finish consistency.
Can Decosill be used during exterior insulation or retrofit works?
Yes. Decosill is particularly suited to retrofit, repainting and exterior upgrade projects where existing or newly formed sills need a clean, consistent decorative finish.
Because it is manufactured specifically for sill and detail applications, it helps contractors achieve a refined, purpose-designed finish around windows, reveals and plinths.
What temperature is required for application?
Decosill should only be applied when the temperature is at least +5°C, with temperatures above 10°C being more ideal, and suitable drying conditions are expected.
Avoid application during frost, heavy rain, direct strong sunlight, or when rain is expected before the material has had time to dry.
Can Decosill be applied in wet weather?
No. Decosill must not be applied in wet weather or onto damp surfaces. The surface must be dry before application, and the product must be protected from rain during the drying period.
Applying Decosill to wet surfaces, damp substrates, or during poor drying conditions can seriously affect adhesion, curing and the final appearance. This is strongly advised against and may lead to failure of the finish.
How long does Decosill take to dry?
Drying time depends on temperature, humidity, airflow and the thickness applied. In good conditions, the surface will begin drying within hours, but it should be protected from rain and heavy contact until fully cured.
In normal conditions, complete drying is achieved in approximately 24 hours, with full mechanical strength achieved after approximately 48 hours.
Does Decosill need to be sealed?
A sealer is not normally required. However, for areas exposed to higher levels of water, staining or dirt, an additional protective treatment such as Aquashield may be considered where suitable.
Is Decosill waterproof?
Decosill is designed as an exterior decorative coating and, when correctly applied over a properly prepared surface, provides a durable weather-resistant finish. It should not be used as a structural waterproofing repair for cracked, leaking or defective substrates.
Will Decosill repair damaged sills?
Decosill can improve the appearance of sound surfaces, but it is not a structural repair product. Cracks, hollow areas, loose concrete, failed render or serious defects should be repaired before Decosill is applied.
Can Decosill be applied over painted sills?
Yes, but only if the existing paint is firmly bonded. Any loose, flaking or peeling paint must be removed. Glossy or sealed surfaces may need sanding or additional preparation before priming.
Can Decosill be applied over render?
Yes, Decosill can be applied over suitable exterior render or masonry surfaces, provided the surface is clean, dry, sound and properly primed. Weak, dusty or cracked areas should be repaired first.
Can Decosill be used indoors?
Decosill is primarily designed for exterior sill and masonry applications, but it may be used internally on suitable decorative features where the finish is appropriate.
Is Decosill suitable for floors?
No. Decosill is not intended as a floor coating and should not be used on walkable surfaces.
Is Decosill suitable for worktops?
No. Decosill is not recommended for kitchen worktops, counters or areas subject to heavy wear, heat, food preparation or regular impact.
How should the surface be prepared?
The surface should be clean, dry, stable and free from dust, algae, grease, loose paint and weak material. Repairs should be completed first, and the surface should then be primed with Decosill Quartz Primer before application.
What tools are needed?
Typical tools include masking tape, protective sheeting, a trowel or spatula, mixing paddle, bucket, brush or roller for primer, and clean water for tool cleaning. The exact tools may depend on the size and condition of the project.
Can Decosill be applied to vertical reveals?
Yes. Decosill can be applied to suitable vertical reveals when the surface is properly prepared and primed. Care should be taken to maintain an even thickness and consistent finish.
Can Decosill be used on window heads or bands?
Yes, provided the surface is suitable and properly prepared. Decorative bands, window heads and façade details can be finished to match the sills.
How do I clean Decosill after it has cured?
Use mild soapy water and a soft brush or cloth. Avoid harsh chemicals, aggressive pressure washing or abrasive cleaning pads, as these may damage the finish.
Can I pressure wash Decosill?
Light cleaning is preferred. If pressure washing is used, it should be done carefully at low pressure and from a safe distance. Aggressive pressure washing may damage the surface.
Will the colour fade?
Decosill is composed of natural stone chips, which gives it a strong advantage over finishes that rely mainly on surface pigments or coatings. Because the visible finish is created from natural stone aggregate, the stone chips themselves will not fade in the same way that some coloured exterior coatings can break down under UV exposure.
When correctly applied over a properly prepared surface, Decosill provides a long-lasting decorative finish designed for external window sills, reveals and masonry details. As with any exterior surface, normal weathering, dirt and environmental staining may occur over time, but regular gentle cleaning will help maintain the appearance of the finish.
Can damaged areas be touched up?
Small areas can usually be repaired, but colour and texture matching may vary depending on weathering, batch, application technique and age of the original finish. For best results, repairs should be carried out carefully by someone familiar with the product.
Is Decosill available to trade customers?
Yes. Decosill is available for trade customers, including painters, plasterers, retrofit contractors, builders, EWI installers and exterior renovation companies.
Do you supply samples?
Samples may be available so customers can review colour and texture before placing a larger order. Please contact us to check current sample availability.
Can Decosill be colour matched?
Decosill colours are supplied as shown in the Colour Swatches section. Standard in-stock colours are currently D631, D031, D421 and White Base. Custom colour matching may not always be available, but please contact us if you have a specific project requirement.
Is Decosill made for Irish weather?
Decosill is designed for exterior use and is suitable for typical Irish weather conditions when applied correctly. Good preparation, correct priming and suitable application weather are essential.
What should I avoid when applying Decosill?
Avoid applying Decosill to wet, damp, frozen, dusty, loose, greasy or unstable surfaces. Do not apply in heavy rain, frost, direct strong sunlight, or when rain is expected before the material has had time to dry.
Wet surfaces and poor drying conditions are strongly advised against, as they can affect adhesion, curing and the final appearance of the finish.
How do I order Decosill?
You can order Decosill directly through our website or contact us for trade, project or installer enquiries.
Who should I contact for advice?
For product advice, trade enquiries, installer training or help with a specific project, contact the Decosill team through the website contact form or by email.
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