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Redstone Pura Core
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Product Overview
Main purpose
High performance non-combustible, moisture-safe thermal insulation that manages moisture, regulates humidity, eliminates mould and minimises heat-loss; especially in older or historic buildings or newer buildings that suffer condensation and mould problems.
Use it on
Interior side of external traditional solid stone, masonry walls, waterproofed basements with a cement-based tanking system or ceilings.
Overview
Redstone Pura Core board is a high-performing mineral-based insulation board that helps maintain and optimise a building’s ability to breath while helping to reduce the risk of condensation and mould. It provides an A1 fire-rated, sympathetic and moisture-safe means to prevent heat loss through the solid outer walls of buildings, Redstone Pura Core is ideal for enhancing an old building’s breathable quality or newer buildings which suffer from condensation or mould issues, and provides a sympathetic means of preventing excess heat loss through the outer walls. Redstone Pura Core can be used to insulate the walls while respecting the needs of older buildings.
Where to use it
Redstone Pura Core mineral insulation board, designed to manage moisture, is used on solid stone or solid masonry walls and window reveals. It can also be used on solid concrete walls and ceilings (of any thickness), and in taller buildings or apartment blocks where a non-combustible internal wall insulation is required. It is also suitable for use in waterproofed basements where a cement-based tanking system, with no membrane, was used.
What it does
Redstone Pura Core helps alleviate condensation and mould issues that can negatively impact indoor air quality and potentially cause structural damage.
By combining effective thermal insulation with moisture and humidity control, it significantly improves internal comfort and indoor climate conditions. A 60mm application of Redstone Pura Core insulation system on a traditional 600mm stone wall with internal lime plaster can reduce heat loss through conduction by up to approximately 430%, dramatically improving energy efficiency.
Its ability to regulate humidity makes it particularly suitable for buildings with highly variable moisture levels, such as museums, churches and schools, where frequent occupancy changes can cause fluctuations in humidity. It also helps protect sensitive contents within buildings, including paintings, furniture, musical instruments, MDF products and various fabrics that may be vulnerable to moisture changes.
Why we love it
Redstone Pura Core delivers outstanding thermal insulation performance, significantly reducing heat loss through solid walls while maintaining the breathability which is essential for traditional constructions. As one of the most cost-effective natural insulation solutions of its type, the system combines energy efficiency with long-term value. Its ability to regulate moisture and humidity helps prevent condensation and mould growth, contributing to healthier indoor air quality, improved occupant comfort, and the protection of moisture-sensitive materials and contents.
In addition to its thermal and moisture performance, Pura Core offers important safety advantages. The board is non-combustible and compliant with the latest Part B Fire Safety requirements, allowing it to be used confidently in large multi-storey traditional buildings.
Practicality is another key strength. The boards are lightweight, safe to handle, and easy to work with, and can be cut to shape using ordinary hand tools. Installation is straight forward, with simple guidance to follow, and once the background is properly prepared, the process is quick and efficient. These qualities make Pura Core particularly well suited to older and difficult-to-insulate buildings, where performance, compatibility, and ease of installation are equally important.
How it works
The Redstone Pura Core boards are capillary-active and vapour-permeable interior insulation boards that absorb and release moisture and condensation. Keeping a wall dry ensures the structure can maintain a lower overall conductivity, resulting in reduced levels of avoidable heat loss. Not only does Redstone Pura Core board enhance the wall’s own thermal conductivity, but it also contributes to a large thermal improvement in the wall’s overall u-value without risk of trapping water in the fabric of a building.
- Capillary active and breathable
- Diffusion open
- Natural mould inhibitor
- Non-combustible (A1 fire rating)
- Low emissions manufacturing process
- Tested by the Institute of Building Biology
- Primer coating on one side
- Lightweight
- Hydrophilic properties ensures optimal moisture regulation in older buildings
- With a value of between µ-value 3-7, it allows water to actively move through the wall and rapidly evaporate helping it to dry out faster and more easily.
- Having a high alkaline pH value, the board inhibits mould growth
- Euro fire classification A1 non-combustible product. Easy to comply with Part B Fire safety requirements of the building regulations
- The low-emission manufacturing process for Redstone Pura Core boards made solely from natural raw materials results in less environmental impact
Questions
There are currently no questions and answers published for this product
Technical Details
Key Technical Data
Installation Guide
For the best outcome, please ensure all the necessary precautions have been observed, and the wall is appropriately prepared for Internal Wall Insulation before commencing with the installation. You can read our guide here: “How to prepare traditional solid walls for IWI Installation” to ensure you achieve the best results.
If the wall is uneven, use a lime-based plaster or Diathonite Thermactive.037 (installation guide can be found here) to level it before installing Pura Core.
Once the wall surface is level and free of any obstructions, it may need to be pre-wetted depending on the absorption of the surface in advance of the installation. To prevent draughts around windows and door frames and at floor or ceiling junctions, use Pro Clima Fiden Exo (an expanding gap-filling tape) to ensure all small gaps and cracks at the edges of boards are filled and made airtight.
For walls that are to be used for hanging heavy components, there are two options available:
- Option A: mount components by securing the fixings through the insulation back to the supporting substrate with appropriate mechanical fixings suited to the background.
- Option B: prepare for the heavy component in advance, fixing position by placing mounting grounds onto the substrate using a strong block of structural insulation Warmotech Phonotherm for thermal continuity.
Once the necessary preparation is complete, glue the boards into position by combing Pura Light adhesive onto the board surface using a notched (10mm notch depth or greater) trowel. Ensure that the entire board has been ‘buttered` with the Pura Light adhesive to achieve full contact between the system and the wall surface. Work by applying adhesive to one board at a time, patting the board into position against the wall surface before using the next board.
Add an application of Redstone Pura Light and embed Redstone Clima Redboard Pro Reinforcing Mesh to increase impact resistance and reduce the risk of micro-cracking. The next day, add a further application of Pura Light which will give a grainy finish. If a smoother finish is desired then instead of adding a second coat of Pura Light, add a coat of Redstone Clima Redboard Pro Smooth Finishing Plaster (Luno).
Once dry finish by painting with a breathable paint such as Auro.
To keep your interior insulation working properly by allowing moisture to pass through, avoid using any paint, wall coverings, or treatments that don’t let air or moisture through. This means you shouldn’t use plastic-based paints, oil-based paints, or any waterproof wallpapers or coatings on the finished walls. The function of the capillary-active and vapour-permeable Pura Core interior insulation panels is also limited by the application of tiles, so where necessary, try to plan for free wall space above or beside necessary tiling so that breathability may be maximised in all cases.
Please note that – if tiles are to be installed anyway – the Pura Core interior insulation panels may need to be fastened also for additional support.
Fastening/anchoring When attaching loads (e.g. shelves, curtain rods, etc.), it is important to ensure that fastening elements of appropriate length that reach into the load-bearing walls are used.
Redstone Pura Core: Ceramic Tiling on top of Pura Core
If you wish to use ceramic tiles on the wall, at least one-third of the area insulated with Pura Core must be left un-tiled so the system can continue to work effectively. Wallpaper is not suitable for use over Pura Core boards.
In bathrooms/wet rooms on walls outside shower area:
Apply first layer of Luno Kalkglätte (Luno Smooth Finishing Plaster) with the Reinforcing Mesh
Then apply 4 insulation fixings per m2 to ensure the boards are bonded and mechanically fastened to the wall. Redstone recommend the Fischer TermoZ CN 8 or similar approved.
Then apply the second layer of Luno Kalkglätte (Luno Smooth Finishing Plaster)
Following this the tile adhesive and tiles may be applied.
In bathrooms/wet rooms on walls inside an enclosed shower/bath area:
Once the Pura Core boards have been installed, apply the first layer of Pura Light with the Reinforcing Mesh.
Next, apply 4 insulation fixings per square meter to ensure the boards are both bonded and mechanically fastened to the wall. Redstone recommends the Fischer TermoZ CN 8.
Then apply the second layer of Pura Light.
Apply the first coat of Diasen Watstop epoxy cement-based waterproof tanking plaster on the surface where the tiles will be installed, making sure to follow the manufacturer’s installation guidance.
Install Diasen Polites 80 reinforcement mesh while the first coat of Watstop is still tacky/fresh (before it has completely dried out, approximately within 12 hours at 23°C and 50% R.H.).
Apply a second coat of Diasen Watstop
The tiles can now be applied directly to the Diasen Watstop
Note: For detailed application instructions for Diasen Watstop, specifiers and installers must refer to the manufacturer's technical datasheet.
Hints & Tips
To make the job very neat with as little cutting as possible, ensure the first horizontal row of boards that are applied are aligned with a laser level tool in case the floor surface is not perfectly level, which can throw off the application as the installation progresses later on, higher up the wall surface.