Roof Deck Research Articles

Sealing of roof penetrations during building construction

For new building construction, roofs typically have a large number of penetrations that are blocked out before the roof deck is poured. After the roof is poured, these penetrations need to be sealed temporarily to prevent rainwater entering the building. Unfortunately, it is all too common that the ad-hoc approach to sealing these openings results in penetrations left open to the elements. This results in water pouring into the building every time it rains. This paper shows examples of unsealed roof penetrations and of the subsequent damage caused. The penetrations relate to the work of several different trades, who may not place any priority on this issue. It is therefore suggested that this is a problem that the construction management team has to take charge of. At the very least, the roof should be inspected before impending rain events.

Building Roof Covering Materials for Residential and Commercial: Comparison and Best Choices

Choosing the right roofing material is an important aspect of building design and construction. Both residential and commercial buildings have roof-related needs. But basically, the selection of roofing materials is not only for protection from but also based on energy efficiency, aesthetics, and longevity of the building. In addition, the design of roof shape selection must be done carefully because the wrong selection can cause rainwater seepage or leakage on the roof and high repair costs. This research aims to explore by comparing the characteristics of roof covering materials and provide the best choice based on needs. The research method used is a qualitative research method with the stages carried out, namely data collection techniques, sample determination, data analysis and research conclusions. Based on the analysis, it is concluded that for residential houses, tile roofs and concrete deck roofs are the best choice because they offer an optimal combination of aesthetics, durability, energy efficiency, and cost that is suitable for the Indonesian climate. While for commercial buildings, metal tile roof is an excellent choice due to its durability, energy efficiency, and modern aesthetics that suit the needs of commercial buildings.

Energy consumption, power generation and performance analysis of solar photovoltaic module based building roof

Building energy intensity (BEI) of typical office buildings in Malaysia ranges from 200 to 250 kWh/m2/year, wherein a substantial portion is due to the cooling system. This study evaluates of the performance and suitability of double-laminated monocrystalline solar photovoltaic (PV) glass in comparison to traditional solar PV systems installed on roofs in Malaysian conditions. To address this aim, simulation studies have been conducted to examine the efficacy of Building Attached Photovoltaic (BAPV) and Building Integrated Photovoltaic (BIPV) systems. Key parameters such as heat transfer across the building envelope, cooling demand, daylight utilization, and solar irradiance were analyzed. Additionally, an evaluation of economic viability, including Return on Investment (ROI) and payback period (PBP), was undertaken. Analysis showed that more heat was transferred through the roof on the BIPV building as the U-value of the solar PV glass was higher than the metal deck roof on the BAPV building. The lighting energy in the BIPV building can be saved by up to 80 % as sufficient daylight was entering the building. More than 30 % of the building area had a daylight factor of 1.0 %–3.5 %. From economic viewpoint, the double-laminated monocrystalline solar PV glass had a longer payback period as the initial capital cost was much higher even though the one-off savings and annual savings in the BIPV building were more than the BAPV building.

THE STUDY OF SBS IN BUILDINGS – IMPACT ON HEALTH AND TECHNOLOGICAL SOLUTION

Sick Building Syndrome is a condition whereby occupants of a building experience sicknesses that can be linked to the amount spent in that particular building. The end users experience unhealthy mild or sometimes severe symptoms or fall sick with such conditions as allergies as well as irritations of the throat, eyes, nose and also lethargy and sometimes dizziness Mølhave (1989). Unlike Building-related illnesses (BRI), SBS has no identifiable cause. In 1984, the World Health Organization (WHO) estimated that 30% of new and remodelled buildings worldwide may have SBS. This study will analyze the severity of SBS in North Cyprus based on different building elements and how they support the development of SBS in a building. Part of the outcome of this work is to develop a framework to test the level of SBS in a residential building by testing how occupants react to the building and demonstrating that building design elements such as orientation, roofing insulation systems, roof installations, and thermal floor masses alter the SBS effect on occupants. The goal is to develop "SBS TEST SOFTWARE" to assist professionals in assessing the SBS level in a building utilizing direct interview software, which can readily identify SBS-prone structures in Cyprus and worldwide. Cyprus’ SBS difficulties can be attributed to several design flaws in building elements, improper ventilation, uneven or inadequate heat distribution, and a lack of moisture-proofing of roof decks, walls, and foundations Obi (2016).

Residential Wind Loss Mitigation Case Study: An Analysis of Insurance Claim Data for Hurricane Michael

This study analyzes insurance claim data from an 11-county area in the Florida Panhandle following the landfall of Hurricane Michael. The data includes 1467 non-mobile home structures, with 902 (61.5%) storm-damaged structures in Bay County. The analysis focuses on Wind Mitigation form 1802. Specifically, building design variables were analyzed via linear regression as to their influence on the percent claim loss. The building design variables included total square footage, dwelling construction type, age of the building, roof type, roof cover type, roof deck attachment type, roof to wall attachment, the presence of secondary water resistance (or sealed roof deck), opening protection type, and roof shape. Results show that building design variables for insurance claims have a high predictive value relative to a Category 5 hurricane event. However, the predictive values of building design variables are also dependent on the dwelling’s proximity to the coast, its location relative to the strong or weak side of the storm, the diameter of the storm, and other wind field variables.

Building energy and exergy analysis of the light-weight roofs compared with the traditional ones in different climates

A significant research gap exists concerning the thermal properties of lightweight roofs, as extensive investigations have predominantly focused on their mechanical characteristics. However, there is a notable dearth of studies addressing the thermal behavior of lightweight roof systems. The comprehension of thermal properties in lightweight roofs is of paramount importance, as it enables the promotion of energy-efficient design practices. The absence of comprehensive research in this domain constrains the optimization of thermal insulation mechanisms within lightweight roof constructions. Consequently, this hinders developments aimed at reducing energy consumption in buildings. To bridge this research gap, this study investigates the thermal performance of two lightweight roofs called waffle slab and bubble deck in three different climates, and compare them with conventional cement block roofs. Results revealed that Valencia had the lowest heating load due to its moderate climate, while Denver showed the minimum cooling load due to colder temperatures. The bubble deck roof outperformed other roofs in terms of heat loss reduction, achieving an average of 76% in winter and 41% in summer. Additionally, the bubble deck roof demonstrated the best overall efficiency (72% on average) and improved thermal comfort during summer, with lower energy consumption. Exergy analysis showed that the bubble deck roof significantly reduced input and output exergy, indicating its superior energy conservation capabilities compared to waffle slab and cement block roofs. These findings emphasize the potential benefits of lightweight roofs, particularly the bubble deck, in enhancing energy efficiency and occupant comfort.

Forensic Analysis of Roof Deterioration Due to Condensation

Corrosion of the structural steel roof deck of large warehouses resulted in several invasive forensic investigations to determine the cause and mechanism of the corrosion. The warehouse roof investigation presented in this paper is one of many similar warehouses located near the Gulf of Mexico and along the Southern Atlantic Seaboard experiencing corroded roof decks when constructed using fiberboard roof insulation made from sugarcane fiber called bagasse. Consensus exists among individuals studying this phenomenon that the fiberboard became saturated with water, which dissolved formic and acetic acid from the fiberboard. The steel deck corroded when it came in contact with the acidic solution. There was little consensus regarding the mechanism by which water intruded into the roof assembly. Invasive investigation of the low-slope roofs of buildings with various types of insulation (including bagasse fiberboard) and observation of physical commonalities between the instances led to the following conclusion: Water in the roof assemblies did not result from leaks through a compromised roof membrane but rather from humid air infiltrating the roof assembly and condensing on the underside of the roof membrane.

Development of an indoor solar simulator for the evaluation of the thermal roof performance for commercial buildings in Malaysia

Past researchers have expressed the difficulty in assessing the empirical thermal performance of an entire roof assembly in terms of thermal resistance (RSI value) under hot conditions. This research discussed the development of an indoor solar simulator to assess the thermal performance of commercial building roofs under steady-state conditions. The indoor solar simulator has 40 halogen lamps to simulate solar radiation. Thermocouples and heat flux transducers are mounted at various points across the roof assembly to measure the heat transfer through the roof assembly. From the error analysis, the RSI values obtained experimentally using the indoor solar simulator and ASHRAE Standard agree with a MAPE value of 6.13%. This paper compares the thermal performance of radiant barriers, bubble foil reflective insulation, polyurethane (PU) foam, and mineral glass wool in a roof assembly. The measurement results showed that the radiant barrier and bubble foil reflective insulation has high RSI values ranging from 1.22 m2K/W to 2.19 m2K/W for enclosed air gap thicknesses from 25 mm to 125 mm. In contrast, the metal deck roof with PU metal resulted in RSI values from 0.55 m2K/W to 1.62 m2K/W for PU thicknesses from 20 mm to 50 mm. The combination of radiant barrier and glass mineral wool of 50 mm and 100 mm resulted in RSI values of 0.83 m2K/W and 1.60 m2K/W, respectively. The results from this research can be used to identify the optimum insulation for different roof configurations commonly used in the Malaysian building industry.

Structural Behavior of Reinforced Concrete Hollow Beams under Partial Uniformly Distributed Load

A Longitudinal opening is used to construct hollow core beam is a cast in site or precast or pre stressed concrete member with continuous voids provided to reduce weight, cost and, as a side benefit, to use for concealed electrical or mechanical runs. Primarily is used as floor beams or roof deck systems. This study investigate the behavior of six beams (solid or with opening) of dimension (length 1000 x height 180 x width120mm) simply support under partial uniformly distributed load, four of these beam contain long opening of varied section (40x40mm) or (80x40mm). The effect of vertical steel reinforcing, opening size and orientations are investigated to evaluate the response of beams. The experimental behavior based on load-deflection measured at central and quarter of tension zones. The experimental test result shows the presence of Hollow decrease the load carrying capacity by about (37.14% to 58.33%) and increased the deflections by about (71.6% for (Hollow ratio 7.4%) to 75.5% for (Hollow ratio 14.8%)) for same applied loadcompared with solid beams with the same properties. The increase shear steel reinforcing will decrease all the deformations at all stages of loading, but particularly after initial cracking and give enhancement in ultimate load capacity of beams by about 31.5% with increasing the amount of shear steel reinforcing by about 50%. Finally, ductility is increased in all cases under partial uniformly distributed load when hollow ratio decreased by about 50% or increased in shear steel reinforcing by about 50%

Performance of asphalt shingles under simulated hurricane winds and evaluation of current installation practices

This paper investigates the wind resistance of asphalt shingles, evaluates the efficiency of their current installation methods, and addresses the lack of a system-level resistance metric from a wind engineering standpoint. The study examined the wind performance of asphalt shingles considering three installation practices recommended in high-velocity wind areas and three nailing non-conformities due to workmanship issues by conducting full-scale failure assessment tests at the NHERI Wall of Wind Experimental Facility. Roofing Application Standard (RAS) No. 115 and FEMA's recommended practices, with and without modifications, were used as recommended practices; while missing nails, over-driven nailing, and high-nailing cases were simulated as installation deviations or errors. Monoslope, gable, and hip roof decks were also used to study the contribution of roofing geometries. The results showed that asphalt shingles installed using methods recommended by the current guidelines may be vulnerable to wind flows from critical directions. Asphalt shingles, tested in the current work, experienced failure at wind speeds below their design level, especially due to cavity pressurization. Nailing non-conformities were also observed to compromise shingles' performance. Additionally, asphalt shingle failure modes, extents, and areas varied with roof geometries and the employed installation methods.

Experimental investigations on innovative built-up lattice steel beams

Spatial truss beams are an extremely efficient typological solution for covering large spans, especially in the cases where members do not have lateral restraints capable of preventing flexural–torsional buckling phenomena In this study the structural behaviour of innovative steel 3D lattice beams in combination with structural glass slabs, used as roof decks, is investigated for protection of historical assets and archaeological sites. After a brief description of the novel structural system, the attention is focused on the experimental activities carried out for the mechanical characterization of both material and structure. In particular, four-point bending tests are carried out on full-scale prototypes in order to both validate the design procedure and calibrate numerical models useful to extend the achieved results through Geometrically and Materially Nonlinear Analysis with Imperfections (GMNIA analysis).

Building Analysis of the Lill Hajj Wall Umrah Building Based on Functionality of the Building for Umrah and Hajj Pilgrims

PT Lill Hajj Wall Umrah is targeted to get 5,226 consumers per year or equivalent to 436 people per month by 2030. The old office in the form of a shophouse with a building area of 119.75 m² for a capacity of 99 people is considered inadequate to serve 436 consumers per month, so PT Lill Hajj Wall Umrah needs a new office with a meeting room of at least 523.2 m². A new office will be planned based on SNI 2847-2019, SNI 1726-2019, SNI 1727-2020, and PBI 1983. The planning results are in the form of an analysis of the new office structure with building dimensions of 28.30 x 23.35m, four floors with a building area of 4,503 m². The material specifications of the building structure are concrete quality (fc') 41.5 MPa, melted reinforcing steel quality (fy) 400 MPa (BJTS), and 280 MPa (BJTP). Basement floor column dimensions 0.6 x 0.6 m, first to fourth floor columns 0.5 x 0.6 m, rooftop columns 0.4 x 0.4 m, main beam dimensions 0.25 x 0.35 m, child beams 0.25x0.5 m, stair beams 0.25 x 0.35 m, roof deck beams 0.25 x 0.3 m and 0.3 x 0.4 m, concrete slab thickness 0.15 m. The results of structural modeling using the Etabs application showed that there was no over-strength (O/S) in the column and beam structure elements. The results of the design of the new office building Lill Hajj Wall Umrah in the form of a basement floor equipped with prayer room facilities covering an area of 14 m2, a generator room covering an area of 15.28 m2, a pump room covering an area of 15.28 m2, parking covering an area of 781.53 m2. The first floor is equipped with VIP room facilities covering an area of 33.33 m2, a prayer room covering an area of 25.87 m2, a toilet covering an area of 44.93 m2, and a boutique room covering an area of 55.22 m2, and a warehouse covering an area of 12.3 m2. The second floor is equipped with a meeting room covering an area of 47.9 m2, a manager's room covering an area of 36.7 m2, a toilet covering an area of 30.9 m2, a prayer room covering an area of 16.08 m2, a boardroom covering an area of 80.59 m2 and a waiting room covering an area of 45 m2. The third and fourth floors are equipped with toilets covering an area of 25.75 m2, a prayer room covering an area of 23.95 m2, and a ballroom of 383.75 m2. The estimated budget for the construction of lill Hajj Wall Umrah's new office is Rp 7.612.645.721.- and takes 406 working days for construction.

Finite element analysis of TPO membrane- retrofitted metal roof system subjected to wind loads

Metal roofing is a common system for low-slope and flat roofing systems such as those used in industrial and storage facilities. Despite its longevity, a metal roof will require a retrofitting when it displays a functional deficiency or reaches to the end of its service life. One of the common retrofitting methods is to use a thermoplastic polyolefin single ply membrane due to its ease of installation, economic efficiency, and lightweight. A single ply membrane typically relies on the existing metal deck system as a structural deck and provides insulation and protection against wind uplift. This paper presents a high-fidelity finite element model to investigate the behavior of a single ply membrane retrofitting metal deck roof under wind uplift. The developed finite element models (FEMs) were validated with experimental results of three full-scale retrofitted metal deck systems using Thermoplastic Polyolefin (TPO) membrane. Parametric study was carried out to investigate the effect of different fastener patterns, transverse and longitudinal fastener spacing, and membrane strength.

The analysis of web opening configuration on cold-formed steel hat purlin under torsion behaviour

PurposeCold-formed steel has been used extensively as secondary elements such as purlins and girts in building frames. Purlin is critical to the structure of the roof because it supports the weight of the roof deck and aids to make the entire roof structure more rigid. Furthermore, cold-formed steel purlin is a replacement for wood purlin because steel purlins are light weight and more economical. Hence, the purpose of this study to investigate the effect of opening due to torsion behaviour.Design/methodology/approachThis analysis used cold-formed steel hat purlin with and without openings (WOs) under different opening shape, location and spacing by using finite element LUSAS software.FindingsThe finite element results showed that purlin with openings had higher angle of rotation than section WO, with a percentage difference of not more than 6%. When the opening was located at mid-span, the angle of rotation reduced. Angle of rotation increased when the opening spacing increased. Number of openings also affected the torsional behaviour of the purlin. Five opening shapes, which were circle, diamond, C-hexagon, square and elongated circle, were studied. Among all the shapes, purlin with diamond opening was more resistance to torsion.Originality/valueThe use of cold-formed steel section with web openings (rectangular or circular) is a practical solution when it is required to pass service ducts through the structural member. However, the presence of opening gives minor effect on the structural behaviour of cold-formed steel hat purlin.

A Study on the Evaluation Methods of Nitrogen Oxide Removal Performance of Photocatalytic Concrete for Outdoor Applications

In Korea, the issue of particulate matter pollution is growing, and many solutions are being developed to deal with it. Photocatalytic technology has been found to be helpful in removing precursors such as nitrogen oxides that cause particulate matter. In a microcosm setup, ISO 22197-1 has been successfully used to quantify the removal of nitrogen oxides from the specimen to which the photocatalyst is applied. However, owing to a lack of suitable tools, on-site measurement of real-scale efficacy is difficult. Depending on the substrate and surrounding circumstances at the application location, the photocatalyst may function at varying levels. Additionally, the expected photocatalytic effect may differ depending on the ambient air quality and sunlight irradiation intensity. This article describes two approaches for studying outdoor concrete photocatalysis. Standard gas measurement and dual-reactor measurement are the recommended evaluation approaches. The standard gas measurement method was found useful for assessing the applied photocatalyst itself as an outcome of field assessment. The performance of photocatalysts at different sites was found to be mutually exclusive and comparable. Over 180 min, on a building roof deck, the NO removal by the standard gas method was 0.68 ppm, whereas, at two shaded locations, the removal amount was 0.51 ppm (side wall) and 0.24 ppm (underpass) for 300 min. The dual reactor measurement approach, on the other hand, was discovered to be one of the most suitable methods for assessing how much of an improvement there has been in the air quality in areas where photocatalysts have been placed.

Study some Mechanical and Thermal Properties of reinforced Perlite Concrete

Expanded perlite as an aggregate in concrete may make insulating concrete and fire-resistant suitable for roof decks and other purposes. Expanded perlite aggregate (EPA) may be used with gypsum plasters and Portland cement to protect columns, beams, and external applications. Other building uses are chimney linings, under-floor insulation, ceiling tiles, gypsum boards, and roof insulation boards. The primary goal of this research is to learn more about the effects of employing perlite aggregate (EPA) as a partial or complete substitute for sand on various characteristics of expanded perlite concrete (EPC) at 7 and 28 days. Air-dry density, compressive strength, water absorption, flexural strength, and thermal conductivity are all investigated in this research. EPA replacement by volume of sand was used to create five EPC mixes with 0%, 25 %, 50 %, %, and 100%. The effects of introducing 0.5% polypropylene fiber on the characteristics of EPC mixes were investigated. To increase the EPC workability, superplasticizer was utilized, particularly at the higher EPA replacement levels. The test outcomes reveal that the measured mechanical and physical properties of EPC decrease when increasing the EPA content. Thermal insulation of EPC increases with increasing the percentage of perlite aggregate replacement. In addition, using polypropylene fibers in the EPC specimens cause a slight reduction in density, compressive strength, and thermal conductivity compared to unreinforced specimens. Polypropylene fibers significantly increase in modulus of rupture reach 29% at 28 days, and increase in water absorption compared with unreinforced specimens.

Rainfall noise simulation and mitigation

A newly constructed and otherwise well-regarded building suffered from excessive rain noise in open areas where the roof deck was exposed. A single major rain event was used to characterize the existing condition, making use of a handheld sound level meter, mobile phone recordings, and weather radar data and corresponding rainfall rates. Several retrofit options were evaluated using a "homebuilt" rainfall simulator fashioned after that described in ISO 140-18. Measured data allowed each treatment's benefit to be compared to a speech interference criterion. Because the actual practical criterion was Owner satisfaction, an audio presentation using filtered recordings was planned rather than presentation of engineering data. However the simulator was constructed so that changes could be rapidly made, so that an Owner representative was able to personally experience and approve the changes prior to installation.

Performance of green roof installed on highly insulated roof deck and the plants’ effect: An experimental study

Extensive green roof system is widely used due to its lightweight, thin growing media, limited or no maintenance, low cost, and high potential application for use over the new or existing lightweight structures. This study is focused on the energy performance and rainwater retention performance of extensive green roofs when coupled with highly insulated roof deck. In this experimental study, three roof systems: conventional roof (CR) and two extensive green roofs with plants (GR) and with no plants (GM) are constructed, instrumented and their responses to real environmental conditions are monitored for over a year and analyzed. The experimental results suggest that during wet period, the rainwater retention potential of green roof is only about 21%, while in the summer the rainwater retention capacity increases as high as 100%. Plants play an important role in rainwater interception, growing media wetness, rain runoff and the green roof's thermal performance by modifying short- and long-wave radiation and as well as convective heat exchanges. Installation of green roofs on highly insulated roof decks yields a mixed performance in a mild and wet climate. The heat loss through the green roof during the heating months is about 2% higher than a similar roof without green roof. Whereas during the cooling months the green roof is able to reduce the heat gain by 66%. This substantial heat gain reduction can help to reduce overheating problems in highly insulated buildings.

Rainwater Harvesting System Integrated With Sensors for Attic Temperature Reduction

This cool roof system focuses on utilization of rainwater harvesting systems by integrating the smart sensor to cool the roof and attic temperatures for the improvement of comfort level of building occupants. An ideal cool roof technology system is basically made up of these three components: (1) moving-air-cavity (MAC) ventilation, (2) solar-powered fan and (3) rainwater harvesting system. These three main components integrate to perform and control the cool roof system. Four small-scale cool roof models were designed and constructed to inspect the performance of the rooftop and attic temperatures. The experimental work was carried out indoors by employing the halogen lamp as the replacement for solar irradiation, while the ambient temperature is monitored to be around 29.8 °C throughout the test. The temperatures of the rooftop surface, MAC aluminum tube, and attic region were measured by K-type thermocouples to evaluate the performance of the cool roof designs. The solar-powered fans were incorporated into the MAC, which accelerated the airflow rate within the cavity and rejected the hot air out before transferring it to the attic region. Meanwhile, an innovative rainwater harvesting system was executed to cool the rooftop temperature rapidly by reducing the rate of heat transfer to the attic region. The result of this inventive cool roof system (Design Z) has successfully reduced the attic temperature by 10.8 °C compared to the normal metal deck roof model (Design W). The findings of the project revealed that the integrated cool roofing technology system comprises the ability to enhance the comfortability of building occupants toward a long-term sustainable development for a better world.

Integration of Lightweight Foam Concrete Roof, Moving-Air-Cavity, and Solar-Powered Fans for Attic Temperature Reduction

This paper presents a novel cool roof technology system that promotes both passive and active cooling methods in reducing the attic temperature of the building. The project aimed to evaluate the effect of various roof model designs on the heating load to establish the capacity of a cooling roof system by maintaining the thermal comfort level for occupants in the buildings. There are four main components in constructing the cool roof models: 1) metal deck roof, 2) lightweight foam concrete roof, 3) moving-air-cavity (MAC) ventilation, and 4) solar-powered fan. Four small-scale cool roof models were built to evaluate the performance of each cool roof design. The performances of the roof surface and attic temperatures of each designed cool roof models were compared with the conventional metal deck roof. The roof models were conducted indoors by using halogen spotlights. The result of the Roof Design IV with the integration of lightweight foam concrete, MAC, and solar-powered fans has effectively reduced the attic temperature by 6.0°C compared with the normal roof model (Roof Design I). As a result, this integrated cool roof design comprises the ability to enhance the comfortability of occupants toward long-term sustainable development with the utilization of renewable energy to protect the natural environment.