Mineral Wool Insulation Research Articles

Determining Moisture Condition of External Thermal Insulation Composite System (ETICS) of an Existing Building

ETICS is a popular external wall insulation system, which is not without possible defects and damages. A frequent cause, direct or indirect, of damage to buildings is the impact of water (moisture). This article presents, among others, the results of tests of the moisture content of ETICS layers, the water absorption and capillary absorption of the render by means of the Karsten tube method, numerical thermo-moisture simulations, and tests of interlayer adhesion, in sample residential buildings. Mass moisture content testing of the wall substrate showed acceptable moisture levels (1–4%m) within masonry walls made of silicate blocks, as well as locally elevated moisture levels (4–8%m) in the case of reinforced concrete walls. Moisture testing of the insulation samples showed a predominantly dry condition, and testing of the reinforcement layer showed an acceptable level of moisture. Severe moisture was found in the sample taken in the ground-floor zone at the interface between mineral wool and EPS-P insulation underneath the reinforced layer. Capillary water absorption tests helped classify silicone render as an impermeable and surface hydrophobic coating. Tests of the water absorption of the facade plaster showed that the value declared by the manufacturer (<0.5 kg/m2) was mostly met (not in the ground-floor zone). The simulation calculations gave information that there was no continuous increase in condensation during the assumed analysis time (the influence of interstitial condensation on the observed anomalies was excluded). The tests carried out indicated the occurrence of numerous errors in the implementation of insulation works affecting the moisture content and durability of external partitions.

Detection and characterization of chloride induced stress corrosion cracking on SS304 under thermal insulation using acoustic emission technique

This study investigates the detection of chloride-induced stress corrosion cracking (CI-SCC) in SS304 stainless steel using the acoustic emission technique (AET). Test samples in as-received (AR) and sensitized (SE) conditions were bent into a U-shape according to ASTM G30. These samples were placed on a hot pipe-spool at 90 °C and insulated with mineral wool. Over 28 days, the insulated samples were intermittently wetted with a 3.5 wt% sodium chloride (NaCl) solution using a drip test apparatus in line with ASTM C692. CI-SCC detection was performed by connecting AET to the U-bend samples. Post-test analysis revealed that acoustic emission (AE) signals, such as energy, RA (rise time/amplitude), counts, and average frequency, varied significantly during different SCC stages. Microscopic examination confirmed SCC in both sample types. In SE sample, cracks initiated from corrosion pits and propagated toward neighbouring pits due to compromised integrity from heat sensitization, producing low-energy AE signals. In contrast, AR sample exhibited high-energy emissions, indicating structural differences. Additionally, mineral wool insulation showed a higher water absorption rate as per EN13472, contributing to a corrosive environment. This study can help to estimate AET’s potential in assessing damage severity and preventing failures in thermally insulated systems.

Comparison of the Position of the Maximum Humidification Zone when Using the Methods of Stationary and Non-Stationary Heat and Humidity Regime

The basic formulas for mathematical modeling of the heat and moisture regime of building envelopes in stationary and non-stationary settings are given. It is noted that the mathematical model uses third kind boundary conditions. Objective of the study: to check whether the moisture maximum plane position in the thickness of building envelopes is confirmed assessing non-stationary moisture conditions. Two methods for verification are used: the graphical method for determining the plane of maximum moisture and the method for assessing the non-stationary moisture regime, based on the Gagarin and Kozlov moisture potential. It was found that the maximum moisture is confirmed both for facade systems with mineral wool insulation and for facade systems with expanded polystyrene insulation. In the case of mineral wool, the maximum moisture is located outside the insulation layer. For expanded polystyrene insulation, the maximum moisture is determined inside the insulation layer. Thus, it was confirmed that the maximum moisture in the thickness of the enclosing structure, determined by the graphical method, is confirmed by mathematical modeling of a non-stationary heat and moisture regime.

Water transport and corrosion under insulation: Experimental investigations of drying in mineral wool

Corrosion under insulation (CUI) is a major risk factor for the material integrity of insulated equipment that is encountered i.a. in the chemical process industries. Undetected CUI has been the root cause for major accidents, including loss-of-site, loss-of-life, prolonged plant shutdown, and environmental pollution. Reducing CUI risk via labour-intensive inspection routines is associated with billions of dollars of annual maintenance costs worldwide. CUI is caused by water bypassing a weather shield, migrating through the insulation and contacting the equipment surface. The resulting corrosion rates are very high and the process is hidden from view. Surprisingly, the fundamental mechanisms that drive water migration through insulation have been largely unexplored. In this work we present novel experimental investigations of the evaporation and drying dynamics for a heated vertical pipe with preformed mineral wool insulation and metal cladding. Relative humidity and temperature sensors provide measurements of how the water evaporates and travels through the system during controlled water ingress experiments. The experimental data shows that the drying time of the insulation material is proportional to the amount of water added. We find that the drying process proceeds in two stages, where the length of the first drying regime is directly related to the diffusion-limited evaporation from the bulk liquid water, while the second drying time is influenced also by other factors such as the adsorption and desorption of water on the insulation material fibres. The findings have implications for how time of wetness, used in CUI risk-based inspection methods, can be obtained from humidity sensor data. The new insights into water transport in insulation enables a paradigm shift towards predictive CUI maintenance using humidity spot sensors.

Hygrothermal Properties and Performance of Bio-Based Insulation Materials Locally Sourced in Sweden.

In recent years, there has been a paradigm shift in the building sector towards more sustainable, resource efficient, and renewable materials. Bio-based insulation derived from renewable resources, such as plant or animal fibres, is one promising group of such materials. Compared to mineral wool and polystyrene-based insulation materials, these bio-based insulation materials generally have a slightly higher thermal conductivity, and they are significantly more hygroscopic, two factors that need to be considered when using these bio-based insulation materials. This study assesses the hygrothermal properties of three bio-based insulation materials: eelgrass, grass, and wood fibre. All three have the potential to be locally sourced in Sweden. Mineral wool (stone wool) was used as a reference material. Hygrothermal material properties were measured with dynamic vapour sorption (DVS), transient plane source (TPS), and sorption calorimetry. Moisture buffering of the insulation materials was assessed, and their thermal insulation capacity was tested on a building component level in a hot box that exposed the materials to a steady-state climate, simulating in-use conditions in, e.g., an external wall. The tested bio-based insulation materials have significantly different sorption properties to stone wool and have higher thermal conductivity than what the manufacturers declared. The hot-box experiments showed that the insulating capacity of the bio-based insulators cannot be reliably calculated from the measured thermal conductivity alone. The results of this study could be used as input data for numerical simulations and analyses of the thermal and hygroscopic behaviour of these bio-based insulation materials.

Optimizing thermal insulation in subtropical monsoon climate religious buildings: material selection and thickness assessment

Purpose Determining the suitable material and accurate thickness of the thermal insulation layer used in exterior walls during the design phase of a building can be challenging. This study aims to determine suitable material and optimum thickness for the insulation layer considering both operational and embodied factors by a comprehensive assessment of the energy, economic and environmental (3E) parameters. Design/methodology/approach First, the energy model of an existing building was created by using Autodesk Revit software according to the as-built floor layout to evaluate the impact of five alternative insulating materials in varying thickness values. Second, using the results derived from the model, a thorough evaluation was conducted to ascertain the optimal insulation material and thickness through individual analysis of 3E factors, followed by a comprehensive analysis considering the three aforementioned factors simultaneously. Findings The findings indicated that polyurethane with 13 cm thickness, rockwool with 10 cm thickness and EPS with 20 cm thickness were the best states based on energy consumption, cost and environmental footprint, respectively. After completing the 3E investigation, the 15-cm-thick mineral wool insulation was presented as the ideal state. Practical implications This study explores how suitable material and thickness of insulating material can be determined in advance during the design phase of a building, which is a lot more accurate and cost-effective than applying insulating materials by assumed thickness in the construction phase. Originality/value To the best of the authors’ knowledge, this paper is unique in investigating the advantages of using thermally insulating materials in the context of a mosque structure, taking into account its distinctive attributes that deviate from those of typical buildings. Furthermore, there has been no prior analysis of the cost and sustainability implications of these materials concerning the characteristics of subtropical monsoon climate.

Effect of insolation heating of roof coverings on their performance reliability

Introduction. The article addresses the issues of ensuring the performance reliability of warm roofs in terms of condensation moisture accumulating in their structures, which causes leaks on the upper floors of buildings. Such problems are often revealed when buildings are inspected during repair and reconstruction works. Leaks in the ceilings of buildings with warm roofs were detected in dry, sunny weather with significant heating of the roof covering due to solar radiation.Aim. To examine the effect of the insolation heating of a roof covering on the formation of condensate in the warm roof of a building in summer, taking into account its design solution.Materials and methods. Materials are presented on inspection of buildings in the Moscow region for repair and reconstruction needs; they reveal the problem of leak formation in the warm roofs of buildings on dry, sunny summer days. The process of moisture transfer through the exterior covering was analyzed through analytical calculations using the roof design solution in the considered structure as an example.Results. The calculation of moisture transfer yielded vapor transmission resistance, conventional true and maximum partial pressures of water vapor, as well as temperatures at the layer boundaries in the studied structures. Changes in these parameters across the thickness of structures were revealed via a graphical method, which showed where the dew point indicating possible condensation in the covering is formed. For a comparative analysis, moisture transfer was calculated for a similar design in which mineral wool insulation was replaced by extruded polystyrene.Conclusions. 1. The calculations of moisture transfer in the examined covering designs confirmed the formation of condensate due to the insolation heating of the roof in summer. 2. The choice of a covering design solution in the design of buildings should be based on accurate heat and moisture calculations taking into account climatic conditions in the construction area, including for the summer season.

Experimental Study of the Charring of I-Joists and Recession of Combustible Insulation in Light Timber Frame Assemblies with Comparison to Eurocode 5

Design models are commonly used in fire safety design of light timber frame assemblies. Parameters for use in the models are available for rectangular members with mineral wool, wood fibre or cellulose insulation and for assemblies with I-joists and mineral wool. For assemblies where I-joists and combustible insulations are combined, design parameters are missing. Five fire experiments with two I-joist types and four combustible insulation products have been conducted. The aim was to study charring of I-joist flanges and recession rates of combustible insulations and in addition, to compare their behaviour to the new and existing models of Eurocode 5. Charring rates for the flanges were 0.40–0.76 mm/min and 0.54–1.72 mm/min for the protected and post-protected phase, respectively. Rates decreased with increasing flange size. Charring rates for flanges of solid wood and LVL were comparable. The results show that lateral charring of I-joist flanges can be significant in the protected phase. The tested insulation products showed a lower recession rate than values reported for glass wool insulation, with a more pronounced difference for wood fibre and cellulose insulations. The low recession rates compared to previously reported generic values can possibly be explained by better product-specific properties, negligible shrinking and slightly different test set-up. The insulation stayed well in place after gypsum board fall-off and best-practice for keeping the insulation in place is given. The results, completed with future loaded full-scale tests, can give basis for further development of design models for assemblies with I-joists and combustible insulations.

Characterization of hygrothermal properties of two wood species- the impact of anisotropy on their thermal and moisture behaviors

Wood is an anisotropic material that has non-identical properties in different structural directions. Due to its particularly biological characteristics, wood is susceptible to moisture degradation. To better understand the hygrothermal performance of wooden products in buildings and reduce moisture-induced deteriorations, a complete hygrothermal measurement of oak and spruce in three structural directions is carried out. The oriented-dependent moisture transport characteristics are acquired from water vapor transmission, drying, and water absorption tests. The anisotropic properties of both wood species are characterized, and their impacts are further investigated by studying the thermal and moisture behaviors of spruce and oak beams embedded in the wall assemblies interiorly insulated by the calcium silicate and mineral wool insulation systems. Hygrothermal simulations performed by the 2D and 3D models with the isotropic property are compared with those of the 3D models with the anisotropic property. The results show that the 3D hygrothermal models with the anisotropic property can properly represent the heat and moisture conditions of wooden beams. The longitudinal property yields a similar hygrothermal performance of the wooden beam to the anisotropic property. For simplification, the longitudinal property can replace the anisotropic property of wood in the 3D model of the wall assemblies to assess the moisture deterioration risk with sufficient accuracy.

Performance of a Volatile Corrosion Inhibitor for Mitigating Corrosion Under Insulation

This study evaluated the efficacy of a commercial volatile corrosion inhibitor (VCI) in mitigating the corrosion of carbon steel insulated with mineral wool insulation, especially as a retrofitted solution to corrosion under insulation (CUI) management. When VCI was added in dry insulation before the test solution was introduced, the severity of CUI was reduced after 14 d of exposure. However, when the exposure time was extended to 90 d, no significant mitigation effect was observed. Furthermore, VCI was ineffective when added to precorroded insulated systems, indicating that it could not be used as a retrofitted solution to alleviate CUI problems. A separate set of tests with bare steel samples exposed to 10 mL VCI in closed jars showed that VCI was adsorbed on the corrosion products but could not effectively impede the propagation of localized corrosion. The possible influences of insulation jacketing, insulation properties, VCI dosages, and dosing methods were also discussed, suggesting the need for further investigations.

ИНСТРУМЕНТАЛЬНОЕ ТЕПЛОТЕХНИЧЕСКОЕ ОБСЛЕДОВАНИЕ ОГРАЖДАЮЩИХ КОНСТРУКЦИЙ ЗДАНИЙ ПЕРЕД ПРОВЕДЕНИЕМ КАПИТАЛЬНОГО РЕМОНТА

The analysis of the results of the instrumental thermal engineering survey of 22 multi-apartment residential buildings built of silicate and ceramic bricks or reinforced concrete panels, with a service life of buildings of more than 40–50 years, carried out before major repairs is given. Thermal calculations to determine the savings in energy resources showed an average value of savings in thermal energy after insulation of 28 %. Typical defects of enclosing structures identified during thermal imaging examination are presented and systematized. An external examination by infrared thermography is carried out with a thermal imager, followed by processing of thermograms. The absence of influence of the results of thermal imaging examination on the parameters of the insulation is shown. The results of measurements of resistance to heat transfer are presented. The measurements are made using ten-channel heat flux density and temperature meters. The actual measured heat transfer resistance deviated from the design resistance by an average of 16 per cent to 33 per cent. The heat transfer resistance of the wall before insulation is much less than the value of the heat transfer resistance of the insulation and the final resistance of the multilayer wall structure. The error in determining the thermal resistance of the insulated wall does not affect the required thickness of the insulation. It is concluded that the instrumental examination of the enclosing structures of buildings before a major overhaul seems to be redundant. It is recommended to use a typical thickness of insulation during the overhaul of Soviet-built residential buildings, which for the climatic conditions of the Belgorod Region will be 10 cm of mineral wool insulation.

Constraining industrial ammonia emissions using hyperspectral infrared imaging

Atmospheric emissions of reactive nitrogen in the form of nitrogen dioxide (NO2) and ammonia (NH3) worsen air quality and upon deposition, dramatically affect the environment. Recent infrared satellite measurements have revealed that NH3 emitted by industries are an important and underestimated emission source. Yet, to assess these emissions, current satellite sounders are severely limited by their spatial resolution. In this paper, we analyse measurement data recorded in a series of imaging surveys that were conducted over industries in the Greater Berlin area (Germany). On board the aircraft were the Telops Hyper-Cam LW, targeting NH3 measurements in the longwave infrared at a resolution of 4 m and the SWING+ spectrometer targeting NO2 measurements in the UV–Vis at a resolution of 180 m.Two flights were carried out over German’s largest production facility of synthetic NH3, urea and other fertilizers. In both cases, a large NH3 plume was observed originating from the factory. Using a Gaussian plume model to take into account plume rise and dispersion, coupled with well-established radiative transfer and inverse methods, we retrieve vertical column densities. From these, we calculate NH3 emission fluxes using the integrated mass enhancement and cross-sectional flux methods, yielding consistent emissions of the order of 2200 t yr−1 for both flights, assuming constant fluxes across the year. These estimates are about five times larger than those reported in the European Pollutant Release and Transfer Register (E-PRTR) for this plant. In the second campaign, a co-emitted NO2 plume was measured, likely related to the production of nitric acid at the plant.A third flight was carried out over an area comprising the cities of Staßfurt and Bernburg. Several small NH3 plumes were seen, one over a production facility of mineral wool insulation, one over a sugar factory and two over the soda ash plants in Staßfurt and Bernburg. A fifth and much larger plume was seen to originate from the sedimentation basins associated with the soda ash plant in Staßfurt, indicating rapid volatilization of ammonium rich effluents. We use the different measurement campaigns to simulate measurements of Nitrosat, a potential future satellite sounder dedicated to the sounding of reactive nitrogen at a resolution of 500 m. We demonstrate that such measurements would allow accurately constraining emissions in a single overpass, overcoming a number of important drawbacks of current satellite sounders.

Evaluation of epoxy-based coating degradation under thermal insulation at elevated temperatures on different steel substrates

Corrosion under insulation (CUI) remains one of the most critical issues in the petrochemical industry. In a typical CUI system, protective coatings (organic or metallic) are used primarily as the last barrier to prevent the rapid corrosion of the metallic substrate. However, organic coatings exposed to high operating temperatures and thermal cycling conditions are susceptible to failure and thus require coating performance evaluations under representative thermal insulation conditions. This study presents experimental designs to investigate the degradation of an organic polyamine-cured epoxy coating under accelerated laboratory test conditions. Additionally, a systematic CUI evaluation protocol for high-temperature organic coating performance is presented. The method involved specially designed apparatus to simulate CUI systems and characterisation techniques, such as visual inspection, adhesion test, peel-off test, scanning electron microscopy, electrochemical impedance spectroscopy, and chemical analysis using Fourier-transform infrared spectroscopy, and differential scanning calorimetry. The results showed that polyamine-based epoxy coating experienced thermal degradation starting at temperatures above 130 °C under mineral wool insulation in accelerated and cyclic CUI tests. Chemical degradation was the primary mode of degradation, with the formation of carbonyl functional groups and increased glass transition temperature observed at higher exposure temperatures. The proposed combination of electrochemical, spectroscopic, mechanical, and microscopy techniques allows quantifying coating performance under insulation and subsequently provides insights into predicting coatings' service lifetime.

Optimal supply chain networks for waste materials used in alkali-activated concrete fostering circular economy

Global objectives to mitigate climate change stimulate transformations within construction sector. Alternative binders to carbon-intensive cement are being researched, including alkali-activated materials. However, barriers preventing adaptation of developed solutions include the absence of supply chains and lack of collaborations between waste producers and concrete manufacturers. We propose a methodological framework that combines geospatial analysis and life cycle assessment with linear optimization model to identify the most optimal supply chain networks for waste materials, focusing on transportation between the actors. Two types of waste generated in Switzerland were examined as case studies, one with distributed source locations, such as ashes produced at municipal waste incinerators, and another with scattered source locations, such as mineral wool insulation waste from construction and demolition activities. Results show that direct symbiosis between waste producers and concrete manufacturers results in 68% and 63% lower CO2 emissions and costs of transportation for ashes and mineral wool waste respectively, compared to cement transportation for conventional concrete production. However, considering investment costs, decision-makers might support the centralized supply chain network design.

Hygrothermal Performance Evaluation of Internally Insulated Historic Stone Building in a Cold Climate

In most cases, internal insulation is the only solution to improve the energy efficiency of historic buildings. However, it is one of the most challenging and complex energy efficiency measures due to changes in boundary conditions and hygrothermal behavior of the wall, particularly in cold climates. This study presents the long-term monitoring of the hygrothermal performance of an internally insulated historic stone wall building. The study aimed to assess the hygrothermal behavior of the dolomite wall if mineral wool insulation is applied internally on the north-east wall in the rooms with and without high internal moisture load. The measurements included temperature, relative humidity, water content, and heat flux. Monitoring results are compared with 1D hygrothermal simulations and a building energy consumption simulation. The in situ measurement results and hygrothermal assessment shows energy consumption decreased by 55% with relative humidity under the insulation staying belove 60% for most of the time, with short periods of increase over 80%. Energy consumption simulation shows an energy saving potential of up to 72% in the case of proper energy management.

Sustainable bio & waste resources for thermal insulation of buildings

A growing awareness of the environmental impact of construction materials is leading to development of more sustainable building products, with particular attention focussed on bio-based resources and circularity. In recent years the market share of bio-based building products has grown significantly, supported by research on materials such as wood fibre, hemp, and straw bale. At the same time there has been growing awareness of the potential for greater circularity in construction, prolonging the life of existing products and materials, thus minimising embodied carbon emissions of future projects, as well as reducing reliance on primary resources and impact on landfill. This paper presents results of an investigation into the thermal and hygric characteristics of three novel insulation prototypes developed from bio-based or waste-stream materials. The experimental development and characterisation of insulation using maize pith, recycled bedding (polyester duvet) materials, and wheat straw insulating prototypes are presented. Hygric and thermal performance are compared to a mineral wool insulation product. As part of this work a series of large-scale thermal conductivity and hygric investigations were also conducted in which the performance of each insulation product with a timber framed wall was studied under steady state and variable environmental conditions. This work was part of a larger international research project aimed at developing insulating materials from bio-based and waste streams and will support market development of novel materials and products into mainstream construction.

Acoustical aspects of replacing traditional materials in building elements with renewable and recycled ones

Building elements, especially partitions, floors and external walls significantly affect indoor acoustic comfort. Their ability to reduce noise transmission from neighbouring rooms or from outdoors depends on the element composition and the building materials used. In Central Europe, the heavyweight masonry or concrete walls and slabs are typical elements both for family and residential buildings. However, increasing popularity of lightweight multi-layered structures is noticeable. This creates new opportunities for the gradual replacement of traditional materials with renewable and recycled ones, both for load-bearing components and for fillings and other layers of building elements. This paper introduces such design changes in relation to acoustics, particularly airborne sound insulation. The greatest attention is paid to the replacement of masonry and mineral wool insulation with timber and wood fibres. The overview is supplemented by examples of low-energy house external wall and timber wall with recycled infill whose sound insulation has been determined by measurements in the acoustic laboratory.

Thermal insulating walls based on Ti3C2TX as energy storage panels for future smart house

Sustainable decentralized energy generation and storage in the cities are critical for a sustainable future. Here we design a smart energy storage device based on thermal insulation and MXene (Ti3C2Tx) for powered future smart homes. The modified surface of a common thermal insulation wall (TIW) using Ti3C2Tx and polyaniline (PANI) by in situ chemical oxidative polymerization of aniline monomer serves as an energy storage device in the wall and, at the same time, maintains the temperature inside the house. The as-fabricated PANI@Ti3C2Tx-TIW-based supercapacitor exhibited high specific capacitance with outstanding rate capability, cyclic stability, mechanical stability, and power density, and functions in extreme temperatures (−15 °C to 45 °C). Further, the device was integrated into real rock mineral wool insulation to develop a future house energy storage system that can store electricity in the house wall and supply power to operate emergency evacuation and alert devices in the event of a disaster.

An experimental study on a cylindrical-conical cavity receiver for the parabolic dish collector.

Solar thermal energy is a promising solution to the environmental and energy demands issues which the world is faced with them. Among all the solar thermal collectors and solar towers used in this field, parabolic dish collectors are one of the preferable options for researchers due to their high working temperature range and high thermal performance. It has been proved that cavity receivers in solar dish collectors are the best way to achieve the best thermal performance. The main concern in the cavity receivers is their thermal efficiency enhancement by employing different geometries. The hybrid geometry of cylindrical-conical can be used to achieve the high pressure drop and low thermal efficiency of conventional cylindrical and conical cavity receivers, respectively. Furthermore, using proper insulation for the cavity receiver helps to performance enhancement of the dish collector. Ceramic fiber insulation can be suitable for this purpose due to its good thermal properties and fewer environmental issues. Hence, in this study, the objective of efficiency enhancement of parabolic dish collector is followed by utilizing a cylindrical-conical cavity receiver equipped with the fiber ceramic insulation. The results show that ceramic fiber is better insulation than the common mineral wool insulation and can enhance thermal performance by 5.03% on average. In addition, the maximum, average, and minimum thermal efficiencies of the cylindrical-conical cavity receiver by using the ceramic fiber insulation and water as the working fluid were obtained up to 38.77%, 35.19%, and 32.66%, respectively.

Experimental Investigation of Concrete Sandwich Walls with Glass-Fiber-Composite Connectors Exposed to Fire and Mechanical Loading

Precast concrete sandwich panels (PCSPs) are known for their good thermal, acoustic and structural properties. Severe environmental demands can be met by PCSPs due to their use of highly thermally insulating materials and non-metallic connectors. One of the main issues limiting the wider use of sandwich walls in construction is their unknown fire resistance. Furthermore, the actual behaviour of connectors and insulation in fire in terms of their mechanical performance and their impact on fire spread and the fire resistance of walls is not fully understood. This paper presents an experimental investigation on the structural and thermal behaviour of PCSPs with mineral-wool insulation and glass-fiber-reinforced polymeric bar connectors coupling two concrete wythes. Three full-size walls were tested following the REI certification test procedure for fire walls under fire and vertical eccentric and post-fire mechanical impact load. The three test configurations were adopted for the assessment of the connectors’ fire behaviour and its impact on the general fire resistance of the walls. All the specimens met the REI 120-M criteria. The connectors did not contribute to the fire’s spread and the integrity of the walls was maintained throughout the testing time. This was also confirmed in the most unfavourable test configuration, in which some of the connectors in the inner area of the wall were significantly damaged, and yet the structural connection of the concrete wythes was maintained. The walls experienced heavy heat-induced thermal bowing. The significant contribution of connectors to the stiffness of the wall during fire was observed and discussed.