R-Wall ICF Formwork Options and achievable U-Values
R-Boards come in lengths of 2500mm and heights of 298mm and are available in varying thicknesses. The thickness of the R-Boards (insulation) determines the energy efficiency of the wall. The more the insulation the better U-Value that will be achieved. The various R-Board options are shown below, and any combination of these can be used to achieve the desired U-Value or wall thickness. Architects will occasionally vary the insulation board in accordance with external cladding choices to achieve a flush finish to the wall eg. Stone to render. External insulation can also be thickened to further enhance the qualities' of thermal mass. The most popular systems are the Standard system (75mm/concrete core/75mm), which is building regs compliant with an achievable U-Value of 0.18, and the Supreme (100mm/concrete core/100mm), with an achievable U-Value of 0.14 just below passive house. The Eco system (50mm/concrete core/50mm) is generally used for non domestic walls. R-WALL can achieve U-Values as low as 0.09.
The table below displays the full range of available R-WALL systems, their achievable U-Values and wall thickness prior to finishings. Building Regulation compliance for new builds is currently a U-Value of 0.18 and Passive house below 0.15.
Please note these U-Values are a guide and will vary dependant on the finishes applied to the wall.
The above table assumes the standard 159mm or 6" R-Tie. The R-Tie is selected to vary the thickness of the concrete core. The options available are as follows;
Our most popular R-Tie is the 159mm or 6", used for most standard domestic wall applications. The 105mm or 4" is designed for use with internal walls. R-WALL is structural engineer specified. However as a general guide the 212mm (8") wall is often used for retaining wall type elements up to around up to 3m, 262mm (10") R-Tie is often utilised for walls 3m - 6m walls and the 313mm 6m +. The size of the core can be altered as required. For example if a retaining wall is at the rear in a 8", the side walls could be 6". Equally if a basement in specified in the 10" as soon as the build is above ground the core can convert back to the 6". Saving costs and space. ​​​​​​
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R-WALL is structural engineer specified but as standard R-WALL does not require steel reinforcement, only above openings to form intel's or areas requiring additional strengthening, for example retaining walls. The R-Ties feature convenient notches for placement of rebar ensuring correct concrete cover options (40mm and 50mm).
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The R-Tie has been specifically designed to allow flow of concrete. The cavity is unobstructed and ensures not only a good fill effciency but also puts less strain on the formwork during pour. The video below demonstrates how well concrete flows into the R-WALL formwork.
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It's simple - Alter the R-Tie length to select the concrete core.
Alter the R-Board thickness to achieve the desired Energy efficiency.
The thicker the insulation the more energy efficient the building!
Advantages of R-WALL
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01
Limitless Design options - create the dream!
R-WALL's non modular design makes designing easy. Therefore there is no need for specialist ICF Architects! R-WALL's versatility offers the freedom to design around the vision not the build system! Any angle of corner, degree of curve, height or size of opening can be achieved, Cantilever's, basements, pools. You name it and R-WALL can build it!
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An R-WALL construction will have more strength than a timber frame or standard construction. Just think you use a 7.5 Newton block in standard construction and you place 35 Newton concrete in R-WALL! Its strength results in more design scope. For example, retaining walls can also form the wall of the home, space and cost saving. Steel can be placed into the formwork, overcoming thermal bridging and allowing construction of elements such as cantilevers.
R-WALL with its four components allows the easy formation of any angle of corner and any degree of curve, without the requirement of any specialist additions. Reducing costs and again, increasing its versatility.
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Unlike many ICFs the core thickness can be altered at any point by simply changing the tie length. For example, if a basement is retaining in say a 8 inch core, R-WALL can convert to the 6 inch as it comes out of ground and no longer requires the strength aspect, space and cost saving. The below picture demonstrates a change horizontally through the wall;
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02
Quick Build Speed - labour saving
R-WALL is a very quick build method, resulting in obvious labour costs and making R-WALL the perfect choice for those time critical projects! So why is it so fast? There are many ways R-WALL increases the speed, both in the initial construction stages, but also in first fix. For example: R-Boards come in 2.5m lengths, laying 2 blocks and placing in your R-Rail system is equivalent to laying 14 concrete blocks in one go! The equivalent of half a pack of blocks can be placed on your shoulder and walked around the site with ease. Have you ever considered the time it takes to unload and move heavy concrete blocks around a site? With R-WALL movement of material is very quick and easy, reducing onsite requirement for heavy lifting equipment, and significantly reducing the associated labour and health and safety implications. There are no messy processes such as mixing of mortar and the washing down. Builders say with R-WALL, unlike other build systems, they are building as soon as they arrive, until the minute they leave!
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Once the formwork is constructed and poured, this is your finished wall ready for plasterboard and finishings. This is unlike other build methods, which require various stages to reach that same construction point. For example, timber frames initially appear to fly up, but constructing the timber aspect is far from your finished wall. Unfortunately, you still have the undulous process of insulating, air taping and blocking the outside before you reach the same construction point as R-WALL.
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When you move to first fix, this also moves faster - plasterboard screws straight to the horizontal rail systems - no dot and dabbing! No missing of fixings (unlike modular ICFS with imperial and vertical fixings),electrics can be chased straight into the insulation and run through conduit - easy quick and time saving! A quick video of electrical installation is demonstrated below;
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03
Increased Build Versatility and formwork strength
R-WALL non-modularity increases build versatility on site which in turn increases speed of build. Timber and standard construction have always offered versatility and the ability to adapt around construction obstacles. However, older modular ICF systems, or EPS based blocks were often formed in courses with undulations, much like children's lego blocks. Whilst the preformed blocked seemed appealing on paper, the reality is on site the inability to alter the block, fixed webs or ties and the requirement for the to "stack" and "connect" aspects, raised challenges during builds. Lets imagine, for example, starter bars on a slab - modular blocks need to be placed in exact locations to connect to the next modular block, but what if a web or connector tie is located where a starter bar rises from the slab? This poses issues for modular blocks, but not R-WALL - just slide the R-Tie along! Simple! What if that slab, footing or block and beam is out of level? Let's be honest its rare to find a perfectly level slab! No problem for R-WALL, the 2.5 meter boards naturally sail over and level small discrepancies, but if the levels are seriously out, the R-Boards can be trimmed to accommodate and the R-Rail grove reinserted with simple tools (steel saw/ bench saw/multi tool) and off you go. This is not possible with modular blocks - imagine trimming off the undulations on a lego block, they simply wouldn't connect as you have removed the connective aspects! Another consideration is securing the formwork to the Slab or footing, how is this achieved with a large block? Screws are simply not long enough to screw down through! Unfortunately, this results in the requirement for additional measures which cost in time, money and resources. R-WALL however has a starter pack system included within the formwork cost which is screwed and secured as shown in the picture adjacent. Adequate connection to the slab, footing or block and beam is of great importance, ensuring correct layout, preventing movement during build and providing crucial strength and preventing uplift during concrete pour. These are just a few examples of the buildability of R-WALL which results in the homeowner achieving the build process quicker and easier.
04
Can be constructed in all weathers - helping to meet build schedules. Materials unaffected by wet
We all know that building in the UK is nearly always hampered by wet weather, particularly standard construction and timber frame creating delays in build, and can in most cases become detrimental to the associated materials (insulation saturation, unprotected wood saturation and onset of rot). R-WALL with its closed cell insulation can be built in all weathers because all component's of R-WALL are unaffected by water or damp. This offers a wealth of advantages to the homeowner, including maintenance of thermal conductivity and performance of materials, longevity of build and helping ensure build schedules are met.
05
Open cavity - better fill effciencies
R-WALLs R-Tie and R-Rail system provide an unobstructed cavity, and unlike many ICF systems as standard they do not need steels to maintain straightness. This creates a much more open cavity where concrete can flow effortlessly into the cavity, resulting in creating full and complete fill efficiency's, a critical requirement for achieving the performance of the building. This is demonstrated in the video below;
06
Longevity
R-WALL buildings are built to last and have very little aftercare. The environment for curing concrete within R-WALL is perfect. Protected from external temperatures, the formwork retains the heat from the chemical reaction further enhancing the curing process. The closed cell insulation prevents loss of water, and all theses things combine to ensure a full and complete curing process. The concrete is then protected by the R-WALL throughout the buildings lifetime. The BBA state 60 years plus for longevity, but this is the maximum expectation they will place on any building. The reality is, unprotected concrete has been around for 100s of years and so should R-WALL!
07
Air Tightness
R-WALL is naturally air tight, and unlike other construction methods, doesn't require the process of air taping. Air tightness is incredibly important to the energy efficiency of the building and the comfort of the living environment. It is almost pointless insulating your home to a high standard and then simply allowing cold air to infiltrate through gaps in the superstructure. R-Boards are closed cell, preventing movement of air, and the very nature of building with R-WALL to withhold concrete during pour, ensures a full and complete insulation layer is formed. The cavity is then filled with concrete creating another air barrier. To date the lowest recording of airtightness has been 0.24 (the build was not complete but roof on and windows in, no finishing which will of course further improve the recording). This reading is well below Passive house standards ( below 0.6) and well within building regulations (below 5). Airtightness is often the area of failure in those trying to achieve passive house standard with other construction methods. Because R-WALL is naturally airtight there is no need for air taping as required in timber frames and standard construction, which costs in resources and labour. Not to mention the potential of fail of such tapes over time, particularly in timber frames which warp and move.
08
Any choice of Finish
R-WALLs choice of finishes are virtually limitless Wood, Render, Stone, Brick, Steel. Renders are applied directly onto R-WALL, and other finishes are applied via battens secured to the R-Rails, and occasional fixings to the concrete core for heavier claddings. Any doors and windows can be incorporated either using straps or straight through into the concrete core. The insulation that wraps the entire window opening can be rasped as required, so windows can be ordered and fitted snuggly into the opening rather than under sizing, requiring filling.
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Internally plasterboard is applied directly to the insulation, no need for dot and dabbing, no need to battening off walls. With our horizontal fixings, plasterboard can be applied in full sheets without the need for cutting to meet fixing points. Increasing speed, saving money and decreasing waste.
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R-WALL has been designed with horizontal fixing points, unlike many of its competitors which have vertical. The advantage means you will never miss a fixing. This results in cost savings and, of course, increased build speed.​
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Electrics are easily chased into the polystyrene with a multitool or hot knife. R-WALL's insulation does not contain plastic webbing and therefore this process is extremely quick and easy.
10
Designed for the UK!
R-WALL, unlike most other ICF systems, was designed and manufactured for the UK, to UK standards. Fixing points in the formwork align perfectly for our metric building products e.g. plasterboard. Fixings run every 298mm horizontally, identifiable by the course joint line. Most EPS based ICF's have vertical fixings to imperial measurements, which can be problematic and costly later in the build.
09
Zero Cold bridging & building regulation compliance with market leading Psi Values
R-WALL provides a full and complete Thermal envelope eliminating any cold bridging (also known as Thermal bridging) issues. Cold bridging is areas or materials in a building which allow heat to transfer through the building more easily. For example - where there are gaps in insulation layers, or perhaps where a joist penetrates through the construction, There are a number of reasons why thermal bridges should be avoided, firstly heat loss - it has been estimated that around 30% of the total loss of heat from a building can be attributed to thermal bridging, increasing the energy consumption and therefore cost of running the building. Furthermore thermal bridges create mould growth and unhealthy living environment's.
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New building regulations stipulate that construction types must now have a set of unique Psi values for every detail of the envelope. Psi values are a measure of thermal performance and therefore identification of Thermal bridging. These Psi values are used to contribute to building regulation compliance. Failure to meet these standard's could result in the buildings not being signed off and issues with obtaining a mortgage and insurance.
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R-WALL has a full set of market leading Psi values and associated certificates. Please contact R-WALL to obtain copies, referencing the associated build and quotation.
12
Future proof, Low carbon & Environmentally friendly
R-WALL offers the building industry a low carbon environmentally friendly choice of construction. Keeping carbon footprints to a minimum is essential. R-WALL has tackled this in a number of ways;
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93% of R-WALL plastics are recycled plastic!
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The R-Board is BREEAM A rated! (Breeam is a detailed assessment of the sustainability & performance of products - looking at raw materials, production, lifetime and use of the product to recyclability)
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R-Board is made from a revolutionary new science of insulation manufacture, using waste C02 and manufactured using wind energy. This results in a Global Warming potential of less than 5 and a Ozone Depletion Potential (ODP) of zero.
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R-WALL is totally UK based and UK manufactured, nothing is imported saving huge Carbon footprints!
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Flat packed! As R-WALL is non modular it means less transportation, resulting in cost and carbon savings!
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Re-Use - Re-Cycle. As all elements of R-WALL are individual it means that every aspect is recyclable. Being non-modular means any off cuts are re-usable back into the wall! Keeping waste to a minimum and saving on those skip costs!
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R-WALL creates Eco homes which are energy efficient and require very little heating. They say the largest proportion of the carbon footprint of any home is its lifetime running. Therefore it is imperative we make our homes as energy efficient as we possibly can. This is not only good for the environment, keeping Carbon footprints to a minimum, but also financially in terms of running costs.
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R-WALL longevity means that the build envelope should be around for much longer. The longer the longevity of a building the less its carbon footprint. You imagine building a timber frame compared to an R-WALL. A quick internet search will tell you the average soft wood timber frame longevity is placed at approximately 30 years. R-WALL would be expected to last at least 2 to 3 times this length. So if you had to rebuild that timber frame in its entirety 3 times to the once with R-WALL, you can see the carbon footprint saving is immense!
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R-WALL uses concrete which uses locally sourced aggregates, then shipped straight to site. With standard construction/timber frame the aggregate for concrete blocks are first transported to the factory for formation, and then to merchants before arriving at site. Again, increasing the carbon footprint. Also, concrete is now being used with reduced carbon methods, making use of recycled or waste material like furnace slag. The use of such "replacements" has been found to increase the standards of the concrete whilst also being environmentally friendly! This is great news for the future of construction. Hansons have supplied the majority of low carbon concrete used in R-WALL, details of which can be found here Sustainable Low Carbon Concrete | Heidelberg Materials UK
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Designing in R-WALL is building sustainably for our future generations.
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Fantastic on site training and support
Building yourself? Have a builder you trust but with no experience building R-WALL? - No problem! R-WALL offers all its clients a fully comprehensive onsite training and support package. As standard any client or builder commencing construction with R-WALL will receive a 2 day training package. This package includes firstly demonstrating on the clients site of setting out, building courses, corners, lintels and bracing of walls, as well as progress checks (equivalent to 1 working day) and attending the first pour (2nd day). Clients are supplied with installation guides and access to an unlimited technical helpline. This support can be extended as required and as requested.
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Have a look at our google reviews, we are 5 star for our customer satisfaction!
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If you don't want to build it yourself check out our list of trained installers Useful contacts page below;
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