Drywall Systems Research Articles

Performance Evaluation of Low Thermal Bridging Drywall System with Separating Clips for C-Studs

Drywall systems comprising gypsum boards and steel C-studs are widely used due to their lightweight structure, rapid construction, and ease of installation. These systems must meet the required thermal insulation performance for their specific applications. However, metal C-studs penetrate the insulation layer at intervals, leading to additional heat loss, reduced thermal insulation performance, and lower indoor surface temperatures, which can result in condensation and mold growth. To address these issues, this study proposes a drywall system with low thermal bridging studs made up of two small-sized studs and four or five separating clips made of reinforced plastic. These clips separate the studs to minimize heat transfer through metal elements, maintain structural stability despite the spacing between them, and facilitate easy assembly. The results from mock-up tests showed that the proposed system’s thermal transmittance was 0.370 W/m2K, which is 28.8% lower than the 0.52 W/m2K observed with conventional C-studs. The proposed drywall system also met Korean regulations for acoustic insulation level 3 and the 2 h fire resistance criteria, similar to existing drywall systems with conventional C-studs. Moreover, the maximum and residual displacements were within an acceptable range for a horizontal load of 3000 N applied vertically to the non-load-bearing wall. Building energy analysis indicated that using the proposed drywall adjacent to unconditioned spaces could reduce the annual heating and cooling load by 2.5–3.0%, despite a 1.5–1.9% increase in the annual cooling load. The annual heating load decreased by 4.8–5.9% under infiltration rates of 0.5 to 1.5 air changes per hour for adjacent unconditioned spaces, making this drywall system’s improved insulation quality crucial for achieving heating-dominant zero-energy buildings.

Insulation performance improvement for drywall using highly insulated steel studs with slots

Drywall systems are a highly constructible technology with short construction times that allow the recycling and reuse of materials. However, steel studs used to anchor the insulation can cause thermal bridging owing to their high thermal conductivity, which can reduce the insulation performance and thermal comfort of occupants. This study proposes a new design method for drywall systems that can overcome the shortcomings and contribute to building energy conservation. Studs with slots applied in the web area are proposed, and the thermal performance and optimal slot size were determined by thermal analysis simulations. Through sensitivity and regression analysis, a design method for drywall was proposed. The developed studs showed an increase in insulation performance of approximately 22.1 % compared with conventional studs. The error rate between the simulation results and the regression model was 0.4 %. An experiment was conducted to verify the insulation performance of the studs. The results of this study can contribute to expanding the application of drywall technology in the building field by solving the problem of thermal bridging and providing a unique perspective on the drywall.

Fire resistance of gypsum drywall partitions with polyurethane foam filling

AbstractGypsum drywall systems have gained their popularity, among other reasons, due to the excellent fire‐resistant properties. The use of different variants of the structures filled with insulating material (most often mineral wool) makes it possible to shape the parameters of fire resistance according to the requirements. The use of polyurethane foam for filling spaces inside drywall systems has become increasingly popular. This is especially applicable to the performance of thermal insulation of wooden roof slopes. The advantages of polyurethane foams over mineral wool include good adhesion to the substrate, lower specific weight, lower thermal conductivity and shorter time to make a tight filling layer. Its undoubted disadvantage is lower fire resistance. The paper presents a research on the fire resistance of gypsum drywall systems with self‐extinguishing polyurethane foam filling. The fire resistance time of the structures was measured in accordance with EN1363‐1 using a standard temperature‐time curve. The tests simulated a fire on the outside of a service shaft with a layer of polyurethane foam on its interior side, and a fire in an attic room with self‐extinguishing polyurethane foam thermal insulation between wooden rafters, and an interior enclosure made of two layers of gypsum board on a steel frame. The tests made it possible to determine the times of meeting the fire resistance criteria of partitions with polyurethane filling.

C-스터드 이격용 클립을 적용한 석고보드 건식벽체 시스템의 단열 및 구조성능 평가

Purpose: Dry-wall systems, which use gypsum boards and steel C-studs, are widely used because they have many advantages. They are lightweight and have a faster construction period and easy construction. Dry-wall systems should achieved thermal-insulation performance according to their applications, such as a wall indirectly or directly adjacent to the outdoors. In this case, the proper thickness of the thermal insulation is determined in the design stage. However, steel C-studs, which penetrate the insulation layer repeatedly at 450㎜ or 600㎜ for installation of insulation materials and finishing boards, lead to additional heat loss. They also reduce the thermal insulation performance in the field. Thus, in this study, C-studs with separating clips were proposed to reduce the additional heat loss due to C-studs, and their structural and thermal insulation performance was evaluated. Method: To compare typical C-studs and proposed C-stud with separating clips, certified thermal-transmittance tests, according to the KS F 2277 - determination of steady-state thermal transmission properties, were conducted. The first test specimen used typical C-studs and the second used the proposed C-studs. The linear thermal transmittances of each stud were calculated and compared. In addition, a structural analysis of the proposed C-studs was conducted to evaluate the structural stability and find the proper fixing interval of the separating clips. Result: The thermal transmittance of the proposed C-stud dry-wall system is 0.37W/㎡K, which is 28.8% less than that of the typical C-stud dry-wall system, 0.52W/㎡K. The linear thermal transmittances of the typical and proposed studs were 0.117 and 0.061W/mK, respectively.

Seismic fragility assessment of non-structural drywall partitions with screw and adhesive fixing through multi-axis cyclic testing

Drywall partitions are the most common type of non-structural walls used in modern multi-story buildings. Damage investigation of these walls during the past earthquakes has shown their vulnerability under small to moderate inter-story drifts leading to significant economic losses. To propose innovative solutions to this problem, accurate damage assessment must be conducted using the data obtained from realistic experiments. In this study, the classic performance-based earthquake engineering framework is used as a method for performing a probabilistic estimation of damage progression in the drywall partitions in a limited-ductility reinforced-concrete building. The Multi-Axis Substructure Testing system at Swinburne University of Technology is used to conduct large-scale three-dimensional cyclic tests on two assemblies of drywall partitions. The assemblies included two types of fixings, namely, screw fixing as a common construction method, and adhesive fixing recently developed for mitigating the creaking noise under serviceability wind loads. The results of the experiments are used to define three levels of damage states to produce fragility curves of drywall systems given the building inter-story drifts. Vulnerability curves are then developed to account for the uncertainties in the building response due to record-to-record variability, and the factors controlling the progression of damage in partition walls such as the variability in material and construction quality.

An Insight into the Reasons Behind the Unpopularity of Drywall Systems in the Iranian Construction Industry

An Insight into the Reasons Behind the Unpopularity of Drywall Systems in the Iranian Construction Industry

Coupled thermo-mechanical simulation for the performance-based fire design of CFS drywall systems

In the present study, a fully coupled thermo-mechanical simulation methodology is presented, capable of estimating the response of cold-formed steel drywall systems exposed to fire and evaluating whether or not compliance with the performance-based fire safety requirements is achieved, in terms of the load-bearing capacity (R), integrity (E) and insulation (I) criteria. The proposed nonlinear coupled thermo-mechanical approach, accounting for geometry, material and contact nonlinearities, is validated against full-scale furnace test results of typical, commercially available, load-bearing drywall systems, achieving a very good qualitative and quantitative agreement; maximum discrepancies between the predicted and measured fire-resistance ratings do not exceed 2%. Several parametric studies are carried out, concerning the magnitude of the imposed load on the bearing walls and the effect of the cavity insulation placement on the overall fire performance of drywall systems. It is found that installation of thermal insulation inside the drywall cavity may decrease the system's fire-resistance rating, depending on the employed configuration. The proposed numerical approach can be effectively used to estimate the fire-resistance rating of load-bearing lightweight steel drywall systems in support of performance-based fire design standards.

Thermal and Mechanical Computational Study of Load-Bearing Cold-Formed Steel Drywall Systems Exposed to Fire

The structural fire behavior of typical load-bearing drywall systems, consisting of light cold-formed steel (CFS) studs, sheathed with single or double layers of gypsum plasterboards and air cavity or mineral wool insulation, is investigated. For that purpose, an efficient numerical modeling approach with satisfying accuracy is developed and validated against experimental and numerical results available in the literature. Heat transfer and structural analyses of the investigated drywall assemblies are carried out, employing the computational tools ANSYS CFX and ADINA, respectively. Transient heat transfer analyses provide the spatial and temporal temperature variation over the drywall assembly, which is assumed to be exposed to the standard ISO 834 fire curve from one side. Thermal simulation results are then introduced in the subsequent structural analyses, where the load-bearing capacity of the CFS studs under fire conditions is estimated, by means of Geometry and Material Nonlinear Analyses accounting for Imperfections (GMNIA). The load-bearing capacity assuming uniform cross-sectional temperature distributions is also evaluated and compared to the respective predictions under non-uniform temperature profiles. Results obtained by varying the imposed load or the applied temperature (fire duration), are compared to predictions of existing and literature-proposed fire design guidelines. EN 1993-1-2 provisions lead to average underestimation of the load-bearing capacity by approximately 20%, while the literature-proposed methods are found to underestimate the load-bearing capacity by 5% to 15%. The limitation of using a critical temperature of 350°C for the structural fire design of thin-walled sections is found to be rather conservative, since the investigated CFS studs are able to exhibit satisfying fire performance also under higher temperature conditions.

Experimental investigation of the fire resistance of multi-layer drywall systems incorporating Vacuum Insulation Panels and Phase Change Materials

This paper studies the fire resistance of innovative high thermally insulated multilayer drywall assemblies incorporating conventional insulation materials, Phase Change Materials (PCMs) and Vacuum Insulation Panels (VIPs). An experimental study was developed and implemented into two directions. In the first direction, four different multilayer drywall configurations were subjected to fire temperatures up to 900°C from one side, while the other side was at ambient conditions. Each configuration consisted of a gypsum board with PCMs (PCM-GB), a standard gypsum board (S-GB), an Expanded Polystyrene (EPS) layer, a thermal insulation render containing EPS (TIR) and an insulation layer located between the PCM-GB and the S-GB. A different insulation layer was used for each configuration: cavity (no insulation), EPS, mineral wool (MW) (both conventional insulation materials) and Vacuum Insulation Panels (VIP) (super insulation material). In the second direction, Differential Scanning Calorimetry (DSC) measurements, at inert (nitrogen) and oxidized (air) environments, were performed for all the utilized materials.DSC results indicated that at temperatures up to 200°C, the gypsum boards (both PCM-GB and S-GB) act as fire retardants because of the dehydration process. The paraffin and PMMA components of the PCM started to evaporate and oxidize at temperatures higher than 200°C and up to 500°C. The resin binder of the mineral wool started to volatilize and oxidize at 265°C, while at 500°C the mineral wool started to melt. The volatilization of the EPS started at 275°C, while the full volatilization and oxidation took place at the temperature range between 420°C and 550°C. The chemically bound water of the TIR dehydrated at the temperature range between 50°C and 200°C, while the EPS contained in the TIR behaved similar as the EPS sample. Finally, the cellulose fibers contained in the VIP volatilized and oxidized at the temperature range between 320°C and 480°C.Furnace results confirmed the fire resistance behavior of the gypsum boards indicated by the dehydration “plateau”. The wall assembly with the EPS layer found to behave similar to the assembly with the cavity due to the fact that the EPS melted at temperatures near 200°C. The wall assembly with the mineral wool delayed the temperature rise until 500°C where it started to melt. The VIP layer found to significantly delay the penetration of the heat through the drywall configuration when compared to the other configurations. According to the failure criteria regarding excessive temperature rise on the ambient facing side of the wall, the VIP layer was found to increase the time-to-failure by approximately 68%, with respect to the assembly with the cavity. On the other hand, the respective time increase for the conventional insulation materials was 2% and 19% for the EPS and the MW, respectively.

An Inquiry into the Life Cycle of Systems of Inner Walls: Comparison of Masonry and Drywall

Life Cycle Assessment is a methodology that investigates impacts linked to a product or service during its entire life cycle. Life Cycle Assessment studies investigate processes and sub-processes in a fragmented way to ascertain their inputs, outputs and emissions and get an overview of the generating sources of their environmental loads. The lifecycle concept involves all direct and indirect processes of the studied object. This article aims to model the material flows in the masonry and drywall systems and internal walls in a Brazilian scenario, and calculate the climate change impacts generated by the transport of the component materials of the systems. Internal walls of a residential dwelling in Rio de Janeiro are analyzed from a qualitative inventory of all life cycles with an analysis of material flows, based on technical and academic literature. All Life Cycle Impact Assessment of the systems is carried out with international data from the database, and using the IPCC2013 method for climate change impacts. This study disregards the refurbishment and possible extensions within the use phase. Thus, the inventory identifies weaknesses of the systems while the impact assessment validates the results. This study allows us a complete understanding about the inner walls systems in the Brazilian scenario, evidencing its main weaknesses and subsidizes decision-making for the industry and for planning of the new buildings.

Multiple-criteria Analysis of Plasterboard Systems

Multiple-criteria analysis methods are a useful tool for decision making support in everyday engineering practice. They turn out to be especially helpful when one considers numerous variants described by many parameters, such as commercially available drywall systems - plasterboard partition walls, claddings and suspended ceilings. In this study four methods of multiple-criteria analysis are investigated (weighted sum, weighted product, ideal point and PROMETHEE II) and 7 normalization algorithms (vector, Manhattan, maximum, Weitendorf linear, Jüttler-Korth linear, Peldschus nonlinear, Zavadskas and Turskis logarithmic) and their influence on the rankings obtained for 5 groups of products: plasterboard partition walls without fire resistance, EI30 partition walls, hard partition walls, suspended ceilings and ceiling claddings. The study shows high sensitivity of the commonly used methods to input data normalization algorithms and indicates the need for a cautious approach to the results obtained by them.

Experimental thermal characterization of a Mediterranean residential building with PCM gypsum board walls

A two-storey typical family house was built in the mid-western part of Greece, comprising a load bearing steel skeleton and dry wall systems. Its walls consist of multiple layers of insulation materials and gypsum plasterboard panels containing Phase Change Materials (PCMs) for thermal energy storage purposes. A detailed matrix of sensors was installed in different locations of all external walls of the house, as well as indoors, in order to provide detailed temperature measurements and thus lead to a thorough depiction of the house's thermal behaviour. In this work, experimental data obtained during the first year of monitoring (2011) are presented. Throughout this particular monitoring period the house purposely remained closed, unoccupied and no energy systems were installed. Hence the presented analysis focuses on the thermal characterization of the house's walling system. Average monthly temperature, decrement factor and time lag values are presented for each room–wall and are discussed with respect to their orientation and exposure to the external weather conditions. Furthermore, measurements conducted on different layers of the living room's east wall aim to examine the influence of PCMs in the wall's thermal response. It is shown that within the adopted conditions (unoccupied house/no energy systems), the thermal mass of the walling system is enhanced during late spring, early summer and autumn, due to the PCM implementation, resulting also in a decrease of the decrement factor by a further 30–40% and an increase on the time lag of approximately 100 min.

Enhanced laminated composite phase change material for energy storage

This paper summarises studies undertaken towards the development of a laminated composite aluminium/hexadecane phase change material (PCM) drywall based on previous analytical work. The study also covered the selection and testing of various types of adhesive materials and identified Polyvinyl acetate (PVA) material as a suitable bonding material. For the purpose of comparison pure hexadecane and composite aluminium/hexadecane samples were developed and tested. The test results revealed faster thermal response by the aluminium/hexadecane sample regarding the rate of heat flux and also achieved about 10% and 15% heat transfer enhancements during the charging and discharging periods respectively. Its measured effective thermal conductivity also increased remarkably to 1.25 W/mK as compared with 0.15 W/mK for pure hexadecane. However there was about 5% less total cumulative thermal energy discharged at the end of the test which indicates that its effective thermal capacity was reduced by the presence of the aluminium particles. The study has shown that some of the scientific and technical barriers associated with the development of laminated composite PCM drywall systems can be overcome but further investigations of effects of adhesive materials are needed.

06/00760 Dynamics of energy storage in phase change drywall systems: Darkwa, K. and Kim, J.-S. International Journal of Energy Research, 2005, 29, (4), 335–343.

06/00760 Dynamics of energy storage in phase change drywall systems: Darkwa, K. and Kim, J.-S. International Journal of Energy Research, 2005, 29, (4), 335–343.

Dynamics of energy storage in phase change drywall systems

Experimental evaluations of manufactured samples of laminated and randomly mixed phase change material (PCM) drywalls have been carried out and compared with numerical results. The analysis showed that the laminated PCM drywall performed thermally better. Even though there was a maximum 3% deviation of the average experimental result from the numerical values, the laminated PCM board achieved about 55% of the phase change process as against 48% for the randomly distributed drywall sample. The laminated board sample also released about 27% more latent heat than the randomly distributed type at the optimum time of 90 min thus validating previous simulation study. Given the experimental conditions and assumptions the experiment has proved that it is feasible to develop the laminated PCM technique for enhancing and minimising multi-dimensional heat transfers in drywall systems. Further practical developments are however encouraged to improve the overall level of heat transfer. Copyright © 2005 John Wiley & Sons, Ltd.

Thermal Analysis of Composite Phase Change Drywall Systems

The main barriers affecting the performance of phase change materials (PCM) wallboard system during energy recovery mode are identified as inadequate heat transfer and overall reduction in thermal conductivities. In order to assess the extent of these barriers, two integrated PCM drywall systems (i.e., randomly mixed and laminated PCM systems) have been evaluated numerically. The results showed a great advantage of the laminated PCM-wallboard system over the randomly mixed PCM type in terms of enhanced thermal performance and rapid heat transfer rates under narrow temperature swing. For instance, the maximum instantaneous enhancement in heat flux obtained was between 20% and 50% higher during the phase change process and up to about 18% more heat storage and release capacity. Experimental evaluation is, however, required towards validation and development of the laminated system.

Heat transfer in neuron composite laminated phase-change drywall

Inadequate heat transfer and overall reduction in thermal conductivities during energy recovery are identified as the main barriers affecting the performance of a phase-change material (PCM) wallboard system. Two integrated PCM drywall systems have been evaluated numerically, and the results showed a great advantage of the laminated PCM wallboard system over the randomly mixed PCM type in terms of enhanced thermal performance and rapid heat transfer rates under a narrow temperature swing. For instance, the maximum instantaneous enhancement in heat flux obtained was between 20 and 50 per cent higher during the phase change process, with up to about 18 per cent more heat storage and release capacity. However, experimental evaluation is required for validation and development.

Sound transmission through concrete blocks with attached drywall

The furring system for attaching drywall to concrete block walls must be chosen with care if sound transmission is not to be increased at low frequencies. Once drywall is attached to a normal-weight block wall, sound transmission loss is increased above a frequency fx given by fx=K/(Md)1/2 . (M is the surface mass of the drywall, kg/m2, and d is the depth of the cavity behind it, m. K is 108 for an empty cavity and 60 for a cavity filled with fibrous sound-absorbing material.) Sound transmission loss data measured for a number of 190-mm normal-weight concrete block wall systems are presented to support the above result. Walls were measured with drywall systems mounted on different furring types on one side and on both sides. The cavities behind the drywall were either empty or filled with glass fiber. A simple, limited prediction scheme that can be used to recreate the data is described. The measurements in this paper present a consistent picture of the influence of the depth of the air space between the drywall and the block, and the presence of sound-absorbing material in the cavity.