Aluminum Furring and Hat Channels for Wall Cladding and Rainscreens

In the modern construction industry, the performance and aesthetics of the building façade is more and more important, the rainscreen system as a core component to protect the building structure and enhance the quality of the building, has become a standard for commercial buildings, residential buildings and all kinds of special facilities.
Aluminum alloy metal rainscreen keel bar, as the “skeleton” of the rainscreen system, bears the key role of connecting the building structure wall with the facade panel, its material advantages and application flexibility, so that it stands out among the many keel materials, and has become the first choice of the rainscreen system in modern buildings.
In this article, we will analyze the core value, application scenarios and related key knowledge of aluminum alloy metal rain curtain keel bars, which will help building practitioners, designers and project parties to comprehensively understand the application points, and make selection more accurate and construction more efficient.

Basic Knowledge of Rainscreen System

Rainscreen is a kind of building facade protection structure, by separating the facade finish layer from the building structure wall, forming an air cavity between the two and building a “double protection barrier”, the core role is to resist external rain, wind, temperature fluctuations, and other environmental factors on the erosion of the building structure.

Rainwater can penetrate into the building wall through capillary action, gravity, wind momentum, etc., and the rain curtain system through scientific structural design, not only can block most of the rainwater directly in contact with the structure of the wall, but also allows a small amount of rainwater infiltration through the drainage channel, while realizing the air circulation, so that the building “breathing”, to solve the root cause of wall moisture, mildew, structural aging, etc. The problems of dampness, mold, structural aging, etc. are fundamentally solved.

After more than a century of development, the rainscreen system has been upgraded from a traditional protective structure to a comprehensive system with multiple functions such as protection, energy saving, aesthetics, etc., and is now widely used in various types of buildings, especially in line with the development trend of modern construction “green, energy-saving, durable”, which not only enhances the service life of the building but also reduces the cost of late maintenance. Rainscreen system

Structure of a Rainscreen

A complete rainscreen system is not a single component, but by a number of core parts work together, in which the aluminum alloy rainscreen keel is the key to connect the components, its structure mainly includes the following parts:

Exterior Finish Layer: As the first protective barrier, the use of durable, non-porous panel materials, such as aluminum alloy, stone, glass, terra cotta, etc., allows rainwater to flow in both directions on its surface, blocking most of the external environmental erosion.

Open joints and vents: Gaps are set up for ventilation, and labyrinth interlocking dry joints are designed to effectively control the momentum, surface tension, gravity, and capillary action of rainwater, and wet sealing materials such as sealant can be used behind the veneer panels to enhance the protective effect, if necessary.

Pressure equalization chamber: The main wall of the building is divided into several independent airtight chambers, the size of each chamber is precisely calculated to ensure airtightness, and the size of the chamber determines the size of the vents, the bigger the chamber the bigger the vent is needed to achieve equalization of pressure inside and outside the chamber.

Chamber baffle: As the side wall of the pressure equalization chamber, it needs to have certain airtightness and wind pressure resistance, which can be in the form of structural connectors, snaps, etc., and at the same time play the role of supporting the exterior panel.

Air and moisture barriers: form an airtight barrier between the chamber and the interior of the building, and need to have sufficient strength to resist external wind and pressure, and some of the materials can have the dual function of air and water barriers to enhance the sealing effect.

Drip eaves, flood panels and drainage channels: to guide the rainwater inside the chamber out of the building to avoid rainwater accumulation, some rainscreen panels will also be designed with a special drainage channel to channel the water on the surface and back of the panel.

Waterproof and thermal insulation layer: set up according to the project requirements, mainly used to enhance the building’s thermal insulation performance, reduce energy loss, usually installed on the outside of the structural wall.

Internal structural wall: as the load-bearing foundation of the rainscreen system, it can be made of concrete, wood, bricks, etc. It should have enough strength to support the weight of the rainscreen system and the exterior panels.

Aluminum alloy rainscreen keel bar: Throughout the entire rainscreen system, fixed on the structural wall, used to support the exterior panels, fixed thermal insulation and moisture barrier, while separating the air cavity, is to ensure the stability of the rainscreen system and functionality of the core skeleton.

Definition of Rainscreen Furring Channel

Rainscreen keel bar is a strip-like component used for leveling the wall surface and supporting the exterior finish layer in the construction of buildings, which is widely used in the rainscreen system, wall and ceiling projects. Traditional keel strips are mostly made of galvanized steel and wood, while aluminum alloy keel strips have gradually become the first choice for rainscreen systems due to their superior performance.

The core function of the aluminum alloy metal rain curtain keel bar is to “build bridges and lead wires”: on the one hand, it is fixed on the wall of the building structure, leveling the irregular parts of the wall, providing a stable installation base for the exterior panels;

On the other hand, it separates the uniform air cavity to ensure the ventilation and drainage function of the rainscreen system, and at the same time, it supports the heat preservation layer and moisture-proof barrier to ensure that the whole rainscreen system works in concert and plays the multiple roles of protection, energy saving and aesthetics.

Key Characteristics of Aluminum Furring Strips

In the choice of materials for rain curtain keel bars, the reason why aluminum alloy can replace traditional galvanized steel and wood as the industry’s first choice lies in the core of its unique material characteristics, which are perfectly adapted to the working environment and functional requirements of the rain curtain system, as follows:

Light Weight and High Strength

Aluminum alloy density is much lower than steel, so aluminum alloy rain curtain keel is lighter than galvanized steel keel, whether it is transport, handling or overhead installation, can significantly reduce the labor intensity of the construction workers, improve construction efficiency. At the same time, the strength of aluminum alloy fully meets the support needs of the rain curtain system, can effectively support the weight of the exterior panels, insulation and other components, and will not increase the structural load of the building, reducing the design pressure of the building foundation, especially suitable for high-rise buildings, high-altitude operation and other scenes.

Excellent Corrosion Resistance

Aluminum alloy surface will naturally form a layer of dense oxidation protective film, without additional galvanizing treatment, it can effectively resist the erosion of rain, moisture, salt spray, industrial pollutants, etc., and will not rust, corrosion and other problems. This feature makes it especially suitable for coastal, humid, industrial and other complex environments, can maintain long-term structural stability, to avoid corrosion of the keel leading to the loosening of the rainscreen system, fall off, to extend the service life of the rainscreen system.

Compliance with Safety Standards

Aluminum alloy rainscreen keel bar has the characteristics of non-conductivity and non-combustibility, which is suitable for hospitals, laboratories and other places with special requirements for electromagnetic environment, and also meets the building fire code, especially in high-rise buildings and crowded places, which can effectively improve the fire safety level of the building to avoid fire hazards, and meets the safety standards of modern buildings.

Strong Processability

Aluminum alloy has good processability, and can be easily cut, drilled, bent, stamped and other processing according to the project design requirements, and can be adapted to different sizes and shapes of the rainscreen system, whether it is a conventional vertical installation, or complex curved, shaped structure, can be accurately matched. At the same time, the on-site processing is convenient and can be adjusted according to the actual situation of the construction, which reduces the construction error and improves the construction efficiency.

Fitting in with Sustainable Development

Aluminum alloy is 100% recyclable, and there is no loss of material properties in the recycling process, so the recycling rate is high. Compared with steel, wood and other materials, its carbon emissions during the production process are lower, which effectively reduces the carbon footprint of the construction project, fits the development concept of “green, low-carbon and sustainable” in modern construction, and helps the construction project obtain the Green building certification.

Beautiful Surface

Aluminum alloy rainscreen keel bars usually adopt smooth or anodic oxidation surface treatment, which has a clean appearance and outstanding texture, and even if some areas are exposed, they can be perfectly integrated with the exterior panels, thus enhancing the aesthetics of the building façade. At the same time, aluminum alloy keel bars do not require frequent maintenance, only need to regularly clean the surface of the dust, debris, can maintain its performance and appearance, significantly reducing the maintenance costs.

Thermal Conductivity

It should be noted that the thermal conductivity of aluminum alloy is higher than that of steel, which may produce a thermal bridge effect in the rainscreen system, affecting the building’s thermal insulation effect. Therefore, in the construction process, the thermal bridge effect can be effectively mitigated by setting heat-insulating spacers between the keel and the structural wall, optimizing the keel spacing, etc., to ensure that the building’s heat preservation and insulation performance is not affected.

Primary Applications of Aluminum Rainscreen Furring Strips

With its superior performance, aluminum alloy rainscreen keel bars are suitable for a variety of building types and environments, and are widely used in commercial buildings, residential buildings, special facilities and extreme environment projects, the specific application scenarios are as follows:

Commercial Building Applications

Commercial buildings have high requirements for the beauty, durability and energy saving of the building facade, which is the core application scenario of aluminum alloy rainscreen keel bars:

Office buildings, office parks: exterior panels are mostly made of aluminum alloy, glass and other materials, in pursuit of modern simplicity, high-end atmospheric appearance, aluminum alloy rainscreen keel bars are lightweight and high-strength, which can support large-area panels and achieve good thermal insulation and energy-saving effects at the same time, which is in line with the operational needs of commercial buildings.

Shopping malls, complexes: the building facade shape is diverse, aluminum alloy rainscreen keel bars can be processed into shaped structures, adapting to the complex design needs, while its corrosion resistance, easy maintenance characteristics, can reduce the maintenance costs of commercial buildings in the later stages, to keep the facade clean and beautiful.

High-rise buildings: Aluminum alloy keel bars are lightweight and can reduce the structural load of the building, and at the same time can resist strong winds at high altitude to ensure the stability of the rainscreen system, such as the Denver 50 Building, Loyola University, Monroe Hall and other commercial buildings, are using aluminum alloy rainscreen keel bars to support the rainscreen system, taking into account the aesthetics and performance.

Residential Building Applications

With the improvement of the quality of residential buildings, the rainscreen system has been gradually applied to high-rise residential and villa projects, and the advantages of aluminum alloy rainscreen keel bars are especially prominent in such scenarios:

High-rise apartments: need to take into account the heat preservation, moisture-proof, aesthetics, aluminum alloy rainscreen keel bar can effectively improve the building’s moisture management ability, to avoid the wall from moisture mold, while its lightweight design will not increase the building load, suitable for high-rise residential structure needs.

Coastal and humid areas: the corrosion resistance of aluminum alloy rainscreen keel bars can effectively resist the erosion of salt spray and humidity, avoiding rust and corrosion of the keel, prolonging the life of the rainscreen system, and guaranteeing the safety and comfort of the residence.

Residential renovation projects: aluminum alloy rainscreen keel bars are highly processable and can be adapted to the wall structure of old buildings, which is convenient for the renovation construction, and at the same time can improve the heat preservation and moisture-proof performance of old buildings, so as to give new vitality to old buildings.

Application of Special Facilities

All kinds of special facilities have special requirements for building protection, safety and aesthetics, and aluminum alloy rainscreen keel bars are widely used in the following scenarios due to their flexible adaptability:

Educational facilities: taking into account the cost, durability and heat preservation performance, aluminum alloy rainscreen keel bars are cost-effective, easy to maintain, and can meet the long-term use of campus buildings, while its environmental characteristics fit the campus green building concept.

Medical facilities: high requirements for dry and sterile indoor environment, aluminum alloy rainscreen keel bar’s moisture management ability can effectively avoid the wall from moisture and mildew, at the same time, its non-combustible, easy to clean the characteristics, in line with the health standards of medical facilities.

Hotels, resorts: focusing on the aesthetics and uniqueness of the building appearance, aluminum alloy rainscreen keel bars can be adapted to a variety of exterior panels and modeling design, to create a high-end facade in line with the positioning of the hotel, while its durability and low maintenance costs, can reduce the operating costs of the hotel.

Culture, public facilities: need to take into account the aesthetics and durability, aluminum alloy rainscreen keel bars can support stone, glass and other high-end panels, to create a sense of art facade, while its long-term stability to protect the long-term use of cultural facilities.

Extreme Environmental Applications

In some projects with harsh environments, the advantages of aluminum alloy rainscreen keel bars are more obvious, and can effectively deal with the challenges of extreme environments:

Coastal areas: salt spray, humid environments require high corrosion resistance of the keel material, aluminum alloy rainscreen keel bars do not need to be galvanized to resist salt spray erosion, avoid rust, and protect the stability of the rainscreen system.

Industrial areas: industrial emissions, pollutants, the corrosion resistance of aluminum alloy rainscreen keel bars can effectively resist the erosion of chemical substances, prolonging the service life, while its easy-to-clean characteristics, can keep the building facade clean.

Strong wind area: aluminum alloy rainscreen keel bars have high strength and good rigidity, and with the vertical frame support system, it can effectively resist strong wind loads, avoiding the shedding of exterior panels, and guaranteeing the safety of the building.

Other Auxiliary Application Scenarios

In addition to the core application of the rainscreen system, aluminum alloy rainscreen keel bars can also be used for wall, ceiling and other auxiliary scenes:

Wall system: used for leveling irregular wall surfaces such as concrete, masonry, etc., to provide a stable installation base for gypsum boards, decorative panels, etc., and at the same time, it can be used with soundproofing materials to enhance the soundproofing performance of the wall.

Ceiling system: It is used for hanging ceiling panels, tiles, etc., which can reduce the transmission of noise, and at the same time provide installation space for electrical lines, HVAC equipment, etc., which is suitable for the ceiling needs of various types of buildings, such as commercial and residential buildings.

Fire-resistant building: aluminum alloy rainscreen keel bars are non-combustible and can be used for the construction of fire-resistant walls, which, together with fire-resistant materials, meets the building fire code and improves the fire safety level of the building.

Integration with Rainscreen System Components

The application effect of aluminum alloy rain curtain keel bar not only depends on its own performance, but also depends on the adaptability with other components of the rain curtain system, only the components work together to give full play to the multiple functions of the rain curtain system.

Adaptability with the Exterior Panel

Rainscreen system of the exterior panel materials, aluminum alloy rainscreen keel bars can be perfectly adapted to various types of panels, the specific points of adaptation are as follows:

Aluminum alloy panel: the same material as the aluminum alloy keel bar, strong compatibility, seamless connection can be achieved, not only the appearance of unity, but also enhance the overall stability and durability of the system, while facilitating processing and installation.

Stone, glass, terra cotta panels: these panels are heavier, aluminum alloy rainscreen keel bar needs to be based on the weight of the panel, the reasonable design of the spacing and thickness, to ensure that the support is stable, and at the same time can be through the special connector, to achieve a solid fixation of the panel, to avoid falling off.

Fiber cement, wood panels: these panels focus on moisture, ventilation, aluminum alloy rainscreen keel bar separated from the air cavity, can effectively promote ventilation, to avoid deformation of the panel moisture, while the corrosion resistance of the keel bar can avoid contact with wood, fiber cement corrosion.

Adaptability with Heat Preservation and Moisture-Proof Components

Thermal insulation and moisture-proof is one of the core functions of the rainscreen system, aluminum alloy rainscreen keel bar and thermal insulation, moisture-proof components adaptability, directly affecting the system’s energy saving and moisture-proof effect:

Thermal insulation materials: aluminum alloy rainscreen keel bar can be easily adapted to various types of thermal insulation materials such as foam board, rock wool board, closed-cell spray foam, etc. The design of keel spacing needs to be matched with the dimensions of the thermal insulation materials to ensure that the thermal insulation layer is laid flat and without gaps, and at the same time through the thermal spacer, to alleviate the thermal bridging effect, and to enhance the effect of thermal insulation.

Moisture barrier: aluminum alloy rainscreen keel bar can support moisture-proof film, moisture-proof boards and other moisture-proof components to ensure that the installation of moisture barrier is smooth and airtight, to avoid gaps that lead to moisture infiltration, while the corrosion-resistant performance of the keel bar can avoid chemical reactions with the contact of moisture-proof materials to safeguard the moisture-proof effect.

Adaptability to Installation and Fixing Method

Aluminum alloy rainscreen keel bar installation and fixing methods, according to the type of rainscreen system, exterior panel materials and other flexible choice, common fixing methods include:

Concealed fastening: suitable for projects pursuing simple appearance, fasteners are hidden behind the panel, no visible hardware, aluminum alloy rainscreen keel bars need to be matched with special concealed fastening connectors to ensure that the panel is firmly installed, while keeping the façade neat and clean.

Penetrating fixing: traditional fixing method, fasteners penetrate the panel fixed on the keel bar, easy to install, strong rigidity, suitable for the appearance of the requirements are not high, the panel weight of the project, the aluminum alloy keel bar needs to have enough strength to withstand the fixing force of the fasteners.

Vertical frame support fixing: as the”pillar” of the rain curtain system, the vertical frame and aluminum alloy rain curtain keel bar work together to provide strong wind resistance, suitable for high-rise buildings, strong winds in the region, to ensure the stability and reliability of the entire rain curtain system.

Complete Guide to Installing a Rainscreen

The installation quality of aluminum alloy rainscreen keel bar directly determines the stability and service life of the rainscreen system, which needs to strictly follow the installation specifications and pay attention to the following points to ensure the construction quality.

Preparation before Installation

Specification verification: check the local building code and manufacturer’s installation guide before installation to ensure that the installation process, keel specifications, etc. meet the requirements to avoid illegal construction.

Wall inspection: check the flatness and strength of the building structure wall, clean up dust and debris on the wall surface, and level the uneven parts to ensure that the keel is firmly installed.

Keel selection: according to the material, weight and environmental conditions of the exterior panel, select the aluminum alloy rainscreen keel bars with appropriate specifications and thickness to ensure that their strength and bearing capacity meet the demand.

Material preparation: Prepare aluminum alloy keel bars, fasteners, connectors, heat-insulating gaskets and other materials in advance, check the quality of the materials and avoid using damaged or deformed materials.

Standard Installation Steps

Installation of moisture-proof barrier: lay the moisture-proof membrane or moisture-proof board on the surface of the structural wall to ensure that the laying is smooth, airtight and without gaps, laying the foundation for the subsequent thermal insulation and keel installation.

Installation of thermal insulation layer: lay the thermal insulation material on the moisture-proof barrier to ensure that it is laid flat and without gaps, and the thickness of the thermal insulation layer is determined in accordance with the energy-saving requirements of the project, while reserving the keel installation position.

Fixed aluminum alloy keel bar: using stainless steel fasteners, fix the keel bar vertically on the structural wall to ensure that the keel is installed smoothly and firmly, with the spacing controlled at about 0.3 meters, and at the same time set up thermal insulation gaskets between the keel and the wall to alleviate the thermal bridge effect.

Installation of connectors: According to the type of exterior panel, install special connectors and buckles on the keel strip to ensure that the connectors are firmly installed and the position is accurate, so as to prepare for the panel installation.

Installation of exterior panels: fix the exterior panels on the connectors, adjust the panel position to ensure that the panel installation is smooth and the gap is even, and at the same time do a good job of sealing the panel seams.

Finishing: clean up the debris generated during the installation process, check the fixing of keel, panel and connectors, reinforce the loose parts, and install the drainage components such as drip eaves and flashing boards to ensure smooth drainage.

Installation Precautions

Expansion and Reservation: Aluminum alloy has the characteristic of thermal expansion and contraction, so it is necessary to reserve a certain expansion and contraction gap during installation to avoid deformation of the keel and cracking of the panel caused by temperature change.

Cutting and processing: When cutting aluminum alloy keel bars, it is recommended to use high-quality carbide saw blades, and when drilling holes, use special drills to ensure that the cuts and apertures are smooth to avoid damaging the structure of the keel and affecting the strength.

End sealing: For the cut keel ends, sealing treatment is required to prevent moisture from seeping in from the ends, resulting in corrosion of the keel.

Fastener selection: use stainless steel and other corrosion-resistant fasteners, avoid the use of ordinary carbon steel fasteners to prevent fasteners from rusting, affecting the effect of keel fixing.

Weather requirements: avoid construction in rainy days, gusty winds and other inclement weather to prevent rainwater from penetrating into the wall, affecting the effect of moisture-proofing and heat preservation, and at the same time ensure construction safety.

Maintenance and Long-Term Performance Guarantee

Although aluminum alloy rainscreen keel bars are durable and easy to maintain, they are exposed to the external environment for a long time and still need regular maintenance to ensure stable performance and prolong the service life, as well as to guarantee the normal operation of the rainscreen system.

The Importance of Maintenance

Guarantee structural stability: regular maintenance can be found in a timely manner loose keel, connectors fall off and other issues, to avoid potential safety hazards of the rainscreen system, to ensure that the exterior panels are firmly fixed.

Extend the service life: timely cleaning of the keel surface dust, pollutants, can avoid its surface oxidation, corrosion, while timely treatment of damaged parts, can effectively extend the service life of the keel and rainscreen system.

Comply with warranty requirements: regular maintenance can ensure that the aluminum alloy rainscreen keel bars comply with the manufacturer’s warranty conditions, to avoid voiding the warranty due to failure to comply with the maintenance requirements.

Recommended Maintenance Methods

Daily inspection: every 3-6 months on the aluminum alloy rainscreen keel bar for a comprehensive inspection, focusing on checking whether the keel is loose, deformation, whether the connectors are off, whether there is corrosion, damage to the surface and so on.

Cleaning and maintenance: according to the environment, regularly clean the surface of the keel, coastal, industrial areas every 6-12 months cleaning, inland protected areas can be cleaned every 1-2 years. Use warm water with neutral detergent when cleaning, wipe with soft cloth, sponge or non-abrasive brush, avoid using corrosive detergent, high pressure water gun close rinsing to prevent damage to the keel surface.

Timely repair: find loose keel, timely reinforcement of fasteners; find keel surface corrosion, damage, timely repair or replacement; find connectors fall off, timely reinstallation, to ensure system stability.

Initial maintenance after installation: after the installation is completed, clean up the construction residual cement, sealant and other debris in a timely manner to avoid its long-term attachment to the keel surface, resulting in surface corrosion and staining.

Comparison of Aluminum alloy Rainscreen Furring Strips and Other Materials Furring Strips

Currently on the market rain curtain keel bar materials are mainly aluminum alloy, galvanized steel, wood, zinc, copper, etc., of which the aluminum alloy keel bar has become the preferred choice for most of the projects by virtue of its comprehensive advantages, the specific comparisons are as follows:

Aluminum Alloy vs Galvanized Steel

In the rainscreen keel material, galvanized steel keel is the traditional material used for a long time, by virtue of high structural strength, was widely used in all kinds of low-end construction projects. However, as the construction industry’s requirements for construction efficiency, durability and design flexibility have increased, its inherent disadvantages have gradually come to the fore, and the gap with aluminum alloy keel bars has become more and more obvious.

Specifically, the core disadvantages of galvanized steel keel is focused on three points: First, the weight is large, the weight of each meter of galvanized steel keel is about 2-3 times the weight of aluminum alloy keel, not only increase the transportation cost and handling difficulties, but also bring additional load to the building structure, especially in high-rise building construction, the high altitude of handling and installation of labor intensity increased significantly, slowing down the construction progress;

Secondly, the anti-corrosion performance depends on post-processing, galvanized steel needs to be hot-dip galvanized or cold galvanized process to achieve anti-corrosion, but if the construction process of galvanized layer breakage, or long-term exposure to coastal salt spray, industrial corrosive environments, the galvanized layer is easy to fall off, aging, which leads to rust and corrosion of the keel, which seriously affects the stability of the rainscreen system, shortening the service life;

Third, poor processability, galvanized steel is hard, cutting, bending, drilling and other processing with the help of professional heavy equipment, it is difficult to adapt to arcs, shapes and other complex architectural shapes, limiting the degree of freedom of design.

In contrast, aluminum alloy rainscreen keel bar perfectly circumvents the above shortcomings: its lightweight and high-strength characteristics, not only to meet the support needs of the rainscreen system, but also significantly reduce the transportation and construction costs, especially suitable for high-rise buildings, high-altitude work and other scenes, which can significantly improve the construction efficiency; the surface of the aluminum alloy will naturally form a layer of dense oxidation protective film, without additional galvanization treatment, it can resist the erosion of rain, salt spray, industrial pollutants, etc., corrosion resistance, corrosion resistance. The surface of aluminum alloy will naturally form a dense oxidized protective film, which can resist the erosion of rain, salt spray, industrial pollutants, etc. without additional galvanizing treatment, and the anticorrosion performance is more stable and long-lasting;

At the same time, aluminum alloy is highly processable, and it can be easily processed by conventional tools, such as cutting, bending, stamping, etc., and it can be accurately matched with all kinds of complex design shapes to meet the aesthetic demands of modern architecture. Although the initial unit price of aluminum alloy keel bar is slightly higher than galvanized steel keel, but from the perspective of long-term use, it does not require frequent maintenance, replacement, service life of galvanized steel keel can be 1.5-2 times, the comprehensive cost-effective, especially for high-rise buildings, coastal environment, and other projects that require high performance of the keel.

Aluminum vs Wood

Timber keel with natural texture, has been used in some of the pursuit of natural style of construction, especially for low-rise housing, villas and other low load requirements of the project. However, the natural characteristics of timber determine its limitations in the rainscreen system, compared with aluminum alloy keel bars, there are obvious shortcomings in durability, practicality and other aspects.

Timber keel’s core shortcomings are poor adaptability to the environment: First, it is susceptible to moisture, wood itself is hygroscopic, long-term exposure to the outdoor or humid environment, it is very easy to moisture, mildew, insects, etc., which will not only lead to deformation of the keel, strength loss, but also may breed mold, affecting the health of indoor environments, and its service life is usually only 5-8 years, much lower than the aluminum alloy keel;

Secondly, the construction and maintenance costs are high, timber keel weight is large, the construction process requires additional reinforcement fixed, and in order to enhance its anticorrosion, insect resistance, the need for professional anticorrosion treatment, and later need to be regularly repainted with anticorrosive coatings, the maintenance costs remain high;

Third, the fire performance is insufficient, wood is a flammable material, can not meet the fire code of high-rise buildings, densely populated places, there are serious safety hazards, which also limits its application in medium and high-rise buildings.

Aluminum alloy rainscreen furring strips is very good to make up for the shortcomings of the timber keel: its moisture-proof, anti-corrosion, anti-insect performance is excellent, without any additional treatment, can be in the outdoors for a long time in the humid environment to maintain the stability of the structure, the service life of up to 20 years or more; at the same time, the aluminum alloy keel bar is lightweight, easy to construct, no need for complex anticorrosive treatment, and the later need to clean up the surface dust on a regular basis, the cost of maintenance is very low; in addition, aluminum alloy is a non-combustible material, and it is completely safe.

In addition, aluminum alloy is a non-combustible material, fully compliant with the building fire code, can be widely used in all kinds of high-rise buildings, crowded places. Although the aluminum alloy keel lacks the natural texture of wood, it can present various colors and textures through anodic oxidation, powder coating and other surface treatment processes, and can be perfectly adapted to various types of exterior panels such as aluminum alloy, stone, glass, etc., to create a simple, modern, high-end and atmospheric architectural facade, which is suitable for most of the architectural scenarios.

Aluminum Alloy vs. Other Metals

In addition to galvanized steel, wood, zinc, copper and other metals can also be used as rain curtain keel material, both have a certain degree of durability, but due to the material characteristics and cost, the scope of application is relatively narrow, compared with the aluminum alloy keel bars, the comprehensive suitability of the obvious gap.

The core advantage of zinc keel is better durability, the surface will form a layer of zinc oxide film, can resist a certain degree of corrosion, but there are obvious limitations in its application scenarios: the appearance of zinc keel texture is relatively single, most of the silver gray, less decorative, and the material is softer, the strength of the material is insufficient, it is difficult to support a large area, the weight of the exterior decorative panels, and therefore more applied to agricultural buildings, low-rise buildings, and so on. For the appearance and strength of the lower requirements of the project, in modern commercial buildings, high-rise buildings in the application of less.

Copper keel by virtue of the unique metal texture and excellent durability, occasionally used in some high-end buildings, but there are two fatal shortcomings: First, the cost is very high, the market price of copper is much higher than aluminum alloy, the use of copper keel will significantly increase the initial investment in the project, the cost-effective is extremely low;

The second is the processing difficulty, copper material is hard and toughness, cutting, bending, drilling and other processing with the help of professional equipment and technology, construction efficiency is low, and difficult to adapt to complex architectural shapes, the scope of application is very narrow.

Aluminum alloy rain curtain keel bar is to achieve a perfect balance between cost-effectiveness and performance: its durability can be comparable with zinc, copper keel, and the appearance can be optimized through a variety of surface treatment processes, more decorative; processing difficulty is low, construction is convenient, and can be adapted to various types of complex shapes and different weights of the exterior panels; at the same time, the unit price is much lower than the copper keel, and does not require complex post-maintenance, the comprehensive cost is more advantageous, can meet the At the same time, its unit price is much lower than copper keel, and no complicated post maintenance, the comprehensive cost is more advantageous, not only can meet the quality requirements of high-end buildings, but also can be adapted to the needs of ordinary commercial and residential buildings, the scope of application is more extensive.

Cost-Benefit Analysis

For construction projects, the choice of keel material should not only consider the initial investment, but also take into account the long-term cost of use, in order to maximize the overall benefits. From the point of view of cost composition, the difference between aluminum alloy rainscreen keel bars and traditional materials is mainly reflected in the initial investment, construction costs, maintenance costs and service life of four aspects, a comprehensive comparison, aluminum alloy keel bars have more advantages in the long-term benefits.

From the initial investment point of view, aluminum alloy rain curtain keel bar unit price is indeed higher than galvanized steel, wood and other traditional materials, aluminum alloy keel price per meter is about 1.2-1.5 times the galvanized steel keel, wood keel 1.5-2 times, which is part of the project will be preferred to choose the traditional materials at the beginning of the main reason.

But from the long-term use, the advantages of aluminum alloy keel bar gradually highlight: First, the construction cost is lower, aluminum alloy keel bar is light, transportation, handling, installation of higher efficiency, can reduce labor costs and equipment investment, especially in high-rise buildings, this advantage is more obvious, can significantly shorten the construction cycle;

Secondly, the maintenance cost is very low, aluminum alloy keel bar without anticorrosion treatment, no need to regularly replenish the coating, only need to regularly clean up the surface dust, debris, the maintenance cost of galvanized steel keel 1/3, 1/5 of the timber keel;

Thirdly, the service life is longer, the service life of aluminum alloy keel bar can be up to 20-30 years, while the service life of galvanized steel keel is about 10-15 years, and the service life of timber keel is only 5-8 years, so the long-term use of the keel can reduce the cost of replacement and manpower investment.In addition, the lightweight design of aluminum alloy keel bars can reduce the load of the building structure, reduce the design and construction costs of the building foundation, especially suitable for high-rise buildings, large-span buildings and other projects with strict requirements on structural loads.

From a comprehensive point of view, although the initial investment of aluminum alloy rainscreen keel bars is slightly higher, with the advantages of convenient construction, easy maintenance and long service life, its long-term comprehensive cost is much lower than that of traditional materials, which is especially suitable for long-term use and construction projects with high quality and durability requirements, and it is a more cost-effective choice.

Conclusion

Aluminum alloy metal rain curtain keel bar as the core skeleton of the rain curtain system, by virtue of light weight and high strength, corrosion resistance, strong processability, green and environmental protection and other advantages, has become the first choice of material for modern building rain curtain system, and its application covers a variety of scenarios, such as commercial buildings, residential buildings, special facilities, etc., which can not only guarantee the protection, energy saving and beautiful function of the rain curtain system, but also reduce the maintenance cost of the building in the later stage, which is in line with the modern architecture. “Green, energy-saving, durable” development trend.

When choosing aluminum alloy rainscreen keel bars, you need to combine the project’s environment, design needs, exterior panel materials, etc., reasonable selection, standardized installation, and good regular maintenance, in order to give full play to its advantages, to ensure the long-term stable operation of the rainscreen system. If you have questions about the selection, installation, maintenance and other aspects of the aluminum alloy rain curtain keel bar, it is recommended that you consult a professional aluminum alloy profile manufacturers or technical experts to obtain targeted solutions to ensure the smooth progress of the project.