Why Fiber Cement Cladding?
Fiber cement panel, a.k.a fibre cement cladding, is a building material used to cover the exterior of a building in both commercial and residential applications. It can be used with or without insulation materials when applying to the building’s exterior. Wallshell® fiber cement panel is a composite material made of cement reinforced with cellulose fibers.
Fiber cement siding has several benefits since it is resistant to termites, does not rot, is impact resistant, and has fireproof properties.
Why Rock Wool Insulation?
Its high thermal efficiency reduces energy bills for heating and cooling in residential buildings due to the outstanding thermal resistance of the rock wool. The thermal resistance of a construction material is measured by what’s known as the R-value, with a higher number indicating that a substance can better resist thermal transfer. According to the U.S Department of Energy, fiberglass offers an R-value of 2.2 to 2.7 per inch, while rock wool has an R-value of 3.0 to 4.0 per inch.
Rock wool offers noise insulation due to its innovative materials that have higher densities and random fibre standard orientation that trap sound waves and deadens vibration time. For this reason it is perfect choice for spaces where the occupants are looking to minimise noise such as offices, bedrooms, meeting rooms or accommodation close to busy roads.
Rock wool offers fire protection to the building and improved safety because of its rock fire resistant property.
Rock wool is a breathable material allowing moisture to escape from the construction. This reduces the risk of mould and bacterial growth on the inside of the property.
Rock wool constitutes a compression-resistant material that can be used as bonded panels. So it is ideal for thermal applications on domestic buildings such as extensions and loft conversions.
It offers quick and easy installation providing airtightness to the building envelope.
It has minimum environmental impact because it reduces carbon footprint due to its natural origin and hazardous-free classifications that offer minimum embodied carbon. Additionally, it reduces the use of non-renewable energy sources such as gas and electricity contributing to air pollution reduction.
Rock wool itself is sourced from naturally raw materials and perhaps more importantly it can be completely recycled when the building is no longer in use without producing waste.
What is Powder Coating?
Powder coating is a type of coating that is applied as a free-flowing, dry powder. The main difference between a conventional liquid paint and a powder coating is that the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a "skin". The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as household appliances, aluminum extrusions, and automobile bodies. However, it is also used in construction materials, such as fiber cement and glass fiber reinforced concrete. Newer technologies allow other materials, such as high-density fiber cement board,, to be powder coated using different methods.
How To Determine the Correct Insulation?
With insulation & continuous insulation (CI) requirements being enforced, you need to make sure you’re installing the correct types and amounts of insulation to meet regulations.
To simplify these requirements, follow three steps:
Refer to the requirements for each building envelope area for your region;
Determine the R value compliance requirements;
Select insulation types and determine the thickness of the materials per required R values;
What is Correlation of Wind Speed and Wind Pressure?
Equivalency between wind speed and pressure is not linear. Wind pressure increases faster than wind speed. See details in the correlation diagram of wind speed and wind pressure that shows the pressure ranges for types of window and cladding tests.
How to Compute Insulation R-values?
In building and construction, the R-value is a measure of how well an object, per unit of its exposed area, resists conductive flow of heat: the greater the R-value, the greater the resistance, and so the better the thermal insulating properties of the object. R-values are used in describing effectiveness of insulation and in analysis of heat flow across assemblies (such as walls, roofs, and windows) under steady-state conditions. Heat flow through an object is driven by temperature difference between two sides of the object, and the R-value quantifies how effectively the object resists this drive: divided by the R-value and then multiplied by the surface area of the object's side gives the total rate of heat flow through the object (as measured in Watts or in BTUs per hour). Moreover, as long as the materials involved are dense solids in direct mutual contact, R-values are additive; for example, the total R-value of an object composed of several layers of material is the sum of the R-values of the individual layers. Note that the R-value is the building industry term for what is in other contexts called ″thermal resistance per unit area.″ It is sometimes denoted RSI-value if the SI (metric) units are used. see R-Values.
An R-value can be given for a material (e.g. for polyethylene foam), or for an assembly of materials (e.g. a wall or a window). In the case of materials, it is often expressed in terms of R-value per unit length (e.g. per inch of thickness). The latter can be misleading in the case of low-density building thermal insulations, for which R-values are not additive: their R-value per inch is not constant as the material gets thicker, but rather usually decreases.
The units of an R-value are usually not explicitly stated, and so it is important to decide from context which units are being used: an R-value expressed in I-P (inch-pound) units is about 5.68 times larger than when expressed in SI units, so that, for example, a window that is R-2 in I-P units has an RSI of 0.35 (since 2/5.68=0.35).
The more a material is intrinsically able to conduct heat, as given by its thermal conductivity, the lower its R-value. On the other hand, the thicker the material, the higher its R-value. Sometimes heat transfer processes other than conduction (namely, convection and radiation) significantly contribute to heat transfer within the material. In such cases, it is useful to introduce an ″apparent thermal conductivity″, which captures the effects of all three kinds of processes, and to define the R-value in general as “thickness of specimen divided by apparent thermal conductivity”. This comes at a price, however: R-values that include non-conductive processes may no longer be additive and may have significant temperature dependence. In particular, for a loose or porous material, the R-value per inch generally depends on the thickness, almost always so that it decreases with increasing thickness (polyisocyanurate being an exception; its R-value/inch increases with thickness). For similar reasons, the R-value per inch also depends on the temperature of the material, usually increasing with decreasing temperature (polyso again being an exception); a nominally R-13 fiberglass batt may be R-14 at -12° C (10° F) and R-12 at +43° C (110° F). Nevertheless, in construction it is common to treat R-values as independent of temperature.
What is Wet Cladding?
In the WET cladding system, exterior cladding is directly adhered to the perimeter wall to form the building envelope. There are different ways to achieve this fixing, most common ones being – Direct adhesion, Spot bonding, Combined system (adhesion along with mechanical systems).
In Direct Adhesion method, a thin layer of mortar is applied to the surface of the structure and the cladding panel is simply placed on it (See Fig. 1). This is the simplest method of wet fixing and does not require any drilling. This method is well suited for small sizes and thin cladding panels and very short structures. Some of the key challenges associated with this fixing method are – Mortar shrinkage, Water absorption and Bond failure between panel-mortar interface.
In Spot Bonding method, an epoxy adhesive is applied in a spotted manner on the surface to which the cladding panels adheres to. Unlike direct adhesion method in which complete surface must be covered with mortar, only limited surface is covered in spot bonding method. This results in air pockets between the cladding panels and the wall. In this method also, the panels can fall due to bond failure between panel-mortar interfaces.
In the Combined method, anchors along with special clamps are used to supplement the adhesion using mortar. This system requires holes to be drilled or groves to be carved in the cladding panels for inserting the clamp or tie. The drilling or cutting operation must be carefully executed to avoid splitting of panels. This is typically used in case of large and heavy panels. It is not suited for thin panels. This system and installation is complex.
What is Dry Cladding?
In this system, the cladding panel is fixed using a attachment system to the perimeter wall. Though the installation process is more complex than direct adhesion, there is less likelihood of cladding panel breakage and collapse. There are different ways to achieve this fixing, most common ones are – Clamp systems, Mixed systems (MS fame along with clamp) and Aluminum channel systems. Usually a gap of roughly 10 mm is left between panels due to fixing method and needs to be filled with jointing compound.
In a clamp system, the clamp is anchored directly to the perimeter wall (see Fig. 3). A hole is drilled into the cladding panel to accommodate clamp as per requirement. The panel is then mounted on the clamp, which is in turn anchored to the perimeter wall. This dry panel fixing method is elaborately discussed in Volume 1 of CPWD specifications (2009). This system is not suited for thin panels.
In mixed system, the supporting sub-structure made of MS is fixed to the building using anchors. Cladding panel is then fixed to MS frame using clamps and nut/bolts. The clamp is either welded or screwed to the MS frame. This system is not suited for thin panels. In aluminum channel system, grooves are cut throughout the length of panel at top and bottom edges. The aluminum channel is fixed to the MS fame as per panel size. The panels are then slid onto aluminum channel. This system is not suitable for thin panel.
What is Fluorocarbon Coating?
Fluorocarbon Coating (PTFE, Xylan, Teflon, Emralon )
Fluorocarbon Coating is an organic coating consisting of solid lubricant dispersed in an organic binder and dissolved in a specially formulated mixture of solvents. It is also corrosion-resistant due to the use of a thermally cured thermosetting synthetic binding material. When applied to the substrates it resists galling, seizure and fretting and offers corrosion resistance.
Fluorocarbon Coating has the following characteristics:
- It is a lustrous coating.
- It has excellent adhesion.
- The effective optimum film thickness is 15-25 microns.
- Load bearing capacity: 1000 bar
- Corrosion resistance: Between 100 to 400 hours salt spray (depending upon the thickness) as per ASTM B117
- Working range: 200 °C (continuous), 250 °C short bursts
Fluorocarbon Coating may be applied by dip, spray or any one of the conventional painting methods. Prior surface preparation has a marked bearing upon the quality of Fluorocarbon Coating. Fluorocarbon Coating can be given on any metal or alloy surface, which can be suitably pretreated by phosphating, blasting, anodizing or Soft Nitriding/Nitrocarburising.
Fluorocarbon Coating performs well under a number of extreme environmental conditions. Its lubricating ability from room temperature up to 200 °C in air and even higher temperatures in non-oxidizing atmospheres makes it attractive for aerospace applications. Fluorocarbon Coating is administered in machine parts exposed to corrosion and where lubrication is needed. For example,
- Parts working in corrosive atmosphere
- Where operating pressure exceeds the load bearing capacity of ordinary oils and greases
- Where clean operation is desired - such as textile or pharmaceutical industries.
- Where easy release is desired such as in nuts, screws, etc. (as dust and debris do not adhere to the coated surface of PTFE as in the case of oil and grease)
- Sliding surfaces like cams, gears, bushes, wire ropes, chains, cutting tools, roller bearings
- Agricultural implements like mowers and door hinges
What is Powder Coating on Fiber Cement?
The primer is the first coat to be applied. The primer serves several purposes.
It serves as a leveler, which is important since the wall often has marks and other forms of surface defect after being manufactured in the factory. A smoother surface is created by leveling out these defects and therefore a better final product.
It protects the fiber cement panels from moisture, storms, heat differences, material impacts, UV-light, etc.
It improves ease of application by making it easier for paints to stick to the surface. Using a primer, a more varied range of paints can be used.
The base coat is applied after the primer coat. This coat contains the visual properties of color and effects, and is usually the one referred to as the paint. Base coat used in fiber cement applications is commonly divided into three categories: solid, metallic, and pearlescent pigments.
Solid paints have no sparkle effects except the color. This is the easiest type of paint to apply, and the most common type of paint for heavy traffic areas. It is also widely for contemporary color schemes for aesthetic of the buildings. Clear coat was not used on solid colors until the early 1990s.
Metallic paints contain aluminum flakes to create a sparkling and grainy effect, generally referred to as a metallic look. This paint is harder to manage than solid paints because of the extra dimensions to consider. Metallic and pearlescent paints must be applied evenly to ensure a consistent looking finish without light and dark spots which are often called "mottling". Metallic basic oats are formulated so that the aluminum flake is parallel to the substrate. This maximizes the "flop". This is the difference in the brightness between looking perpendicularly at the paint and that at an acute angle. The "flop" is maximized if the base coat increases in viscosity shortly after application so that the aluminum flake which is in a random orientation after spraying is locked into this position while there is still much solvent (or water) in the coating. Subsequent evaporation of the solvent (or water), leads to a reduction in the film thickness of the drying coating, causing the aluminum flake to be dragged into an orientation parallel to the substrate. This orientation then needs to be unaffected by the application of the clear coat solvents. The formulation of the clear coat needs to be carefully chosen so that it will not "re-dissolve" the base coat and thus affect the orientation of the metallic flake but will still exhibit enough adhesion between the coatings so as to avoid delaminating of the clear coat.
Pearlescent paints contain special iridescent pigments commonly referred to as "pearls". A similar mode of action occurs with pearlescent pigmented base coats. Pearl pigments impart a colored sparkle to the finish which works to create depth of color. Pearlescent paints can be two stage in nature (pearl base color + clear) or 3 stage in nature (base coat + pearl mid-coat + clear-coat).