TEST SERIES TO EVALUATE THE STRUCTURAL BEHAVIOUR OF ISOBOARD OVER RAFTER SYSTEM

TEST SERIES TO EVALUATE THE STRUCTURAL BEHAVIOUR OF ISOBOARD OVER RAFTER SYSTEM J A Wium Institute of Structural Engineering 19 November 2007 ISI2007-3

TEST SERIES TO EVALUATE THE STRUCTURAL BEHAVIOUR OF ISOBOARD OVER RAFTER SYSTEM TABLE OF CONTENTS 1. Introduction 2. Description of the investigation 3. Theoretical calculations : 4. Test series 4.1 Compressive strength tests 4.2 Deformation under screw forces 4.3 Lateral endurance tests and pull out capacity 4.3.1 Screws 4.3.2 Nails 4.4 Lateral strength and stiffness tests 5. Theoretical analysis to investigate lateral connection stiffness. 5.1 An 8m long 50 x 225 SA Pine rafter 5.2 A 6m long 36 x 150 SA Pine truss top chord member 6 Evaluation and interpretation of results 6.1 Pull out capacity 6.2 Compressive bearing pressures 6.3 Lateral restraint to truss chords and rafters 6.4 Construction 7. Conclusions and recommendations 8. References ANNEXURE A : ANNEXURE B : ANNEXURE C : ANNEXURE D : ANNEXURE E : ANNEXURE F : COMPRESSIVE STRENGTH TEST DEFORMATION UNDER SCREW LOAD SCREW PULL OUT CAPACITY LATERAL STIFFNESS AND STRENGTH TESTS Theoretical evaluation of lateral restraint provided by battens when ISOBOARD is used in an over rafter application. BRACING SYTEMS 1

TEST SERIES TO EVALUATE THE STRUCTURAL BEHAVIOUR OF ISOBOARD OVER RAFTER SYSTEM 1. Introduction An investigation was carried out by the Institute of Structural Engineering at the University of Stellenbosch to evaluate the structural performance of the ISOBOARD system in an over rafter and over truss application. This document describes the investigation which includes a described of the tests performed, and a presentation and interpretation of results. Finally, recommendations are made for the use of ISOBOARD in an over rafter and over truss application. (Definitions : For purpose of this investigation, a rafter is defined as a simply supported single span timber beam with its ends prevented from lateral movement and its ends prevented from torsional rotation about its longitudinal axis. A truss is defined as a built up structural assembly consisting of top and bottom chords, as well as vertical and/or diagonal web elements.) 2. Description of the investigation The investigation consisted of the following parts : - A desk top study was performed to determine the expected loads on the system. The structural strength and stability criteria as defined by Agrément South Africa were used for the assessment of the system. Loads were calculated using SABS 0160 (1989) to determine wind loading on roofs. - In support of the desk top study, a series of tests were performed in the laboratory. The testing was performed to determine certain material and system behaviour characteristics. The following tests were performed : Measurement of deformation of ISOBOARD under screw loads (fixation loads) (refer to Section 4.2) Compressive stiffness tests on ISOBOARD cut-outs (refer to Section 4.1) Repetitive lateral tests on batten and rafter systems with ISOBOARD installed in an over rafter application to simulate the movement in roofs due to long term thermal behaviour (refer to Section 4.3) Pull out tests on fasteners after completion of the repetitive loads on the batten and rafter systems (refer to Section 4.3) Lateral strength-stiffness tests on battens fixed to rafters through ISOBOARD (refer to Section 4.4) - A further desk top study was performed to study the capability of batten connections to provide lateral resistance to top chord members and rafters in bending. The study uses the information obtained in the strength-stiffness tests (Section 4.4). This evaluation is described in Section 5. 2

SCREW/NAIL ISOBOARD BATTEN (PURLIN) Rafter FIGURE 1 : ISOBOARD over rafter system The extent of the investigation included : - The thickness of ISOBOARD panels considered in the test series were as follows : o 25mm, 30mm and 40 mm panels were tested. - The following fasteners were used in the tests : o Screws : 150mm long below the head, 4.4mm diameter on the shaft above the thread, 5.3mm diameter measured over the thread. o Nails : 135 mm long, 5mm diameter 3. Theoretical calculations : The theoretical evaluation was performed based on the Agrément South Africa wind specifications which are summarized as follows : - Terrain Category 3 : i.e. suburbs, towns, wooded areas, industrial areas. - Altitude approximately at sea level - 25 year return period - No remarkable geographical features - Less than 5m from the ground - Ultimate load factor for wind load is 1.3 and for opposing self weight 0.9. From the above assumptions, it follows that the ultimate design pressures on the roof is 0.77 kpa upwards (local effects on eaves overhangs 1.01 kpa upwards). Based on different spacing of battens and rafters, the wind uplift on a connector (screw or nail) at a batten-rafter junction is given in Table 1a below. The values in the table are based on an assumed own weight of the roof material of 6kg/m 2. Similar wind uplift force on a connector (screw or nail) are shown in Table 1b for an eaves overhang of 600mm. Table 1a : Ultimate wind uplift forces on connectors at batten-rafter interface System Rafter x battens Nominal Own weight Nominal Wind uplift Resultant force (ULS)* = 0.9 DL + 1.3 WL 600 x 600 0.020 kn down 0.277 kn up 0.257 kn up 750 x 600 0.024 kn down 0.347 kn up 0.323 kn up 600 x 1500 0.049 kn down 0.693 kn up 0.644 kn up 750 x 1500 0.061 kn down 0.866 kn up 0.805 kn up * ULS = Ultimate limit state; DL = dead load; WL = wind load 3

Table 1b : Ultimate wind uplift forces on connectors at batten-rafter interface at eaves overhang System Rafter x battens Nominal Own weight Nominal Wind uplift Resultant force (ULS)* = 0.9 DL + 1.3 WL 600 x 600 0.020 kn down 0.320 kn up 0.398 kn up 750 x 600 0.024 kn down 0.401 kn up 0.500 kn up 600 x 1500 0.049 kn down 0.801 kn up 0.997 kn up 750 x 1500 0.061 kn down 1.000 kn up 1.245 kn up * ULS = Ultimate limit state; DL = dead load; WL = wind load 4. Test series 4.1 Compressive strength tests A series of tests was performed to determine the compressive strength of the ISOBOARD panels. Tests were performed on ten 50mm x 50mm samples of ISOBOARD panels, each with a thickness of 25mm, 30mm and 50mm. This test focused primarily on obtaining the panel compressive strength and force-deformation characteristics. The tests were performed according to SANS 1508 1990. The Zwig testing machine in the structural laboratory with a capacity of 250 kn was used. Loading rate is shown in Table A1 for each of the tests. The results of the tests are summarized in Annexure A. Results are presented in Tables A1 and A2. A graphical presentation of the test results are presented in Figures A1 to A4. An image of a typical test specimen in the Zwig testing machine is shown in Figure A5. The method to determine yield stress can be seen in Figures A2 to A4. From the results in table A1 and A2 it can be seen that yield was reached for all specimens before a deformation of 10% of the specimen. 4.2 Deformation under screw forces The specimens prepared for the lateral endurance tests (see Section 4.3) were used to measure deformations (indent) of the ISOBOARD panel under screw forces (refer to Figure B1). Panels of 25mm, 30mm and 40 mm were measured. Four fixings were measured for each ISOBOARD panel thickness. The purpose of the measurements was to determine the extracting force which the ISOBOARD exerts on the screw. The maximum values are shown in bold in the table for each ISOBOARD thickness. 4.3 Lateral endurance tests and pull out capacity 4.3.1 Screws The lateral displacement of the screw and panel arrangement was tested to investigate the behaviour under repetitive loads. The thickness of ISOBOARDs panels to be tested was 25mm, 30mm and 40mm. Tests were performed with and without ISOBOARD in place. Frames were made up consisting of four connections each, screw fixing two purlins to two rafters. The assembly was then placed in a testing frame where an imposed deformation was acting on the purlins. 4

The imposed deformation was 3mm in each direction, which represents a 20 change in temperature for a 10m long steel sheet (temperature coefficient of expansion taken to be 12 x10-6 m/m/ C.): o = 10 x 20 x 12 x10-6 = 2.4 mm, say 3mm. o Number of repetitions : 350 days x 30 years = 10500 o Period of application : 24 hours. The test pieces were placed in the testing assembly with a 0.5 mm clearance of movement in each direction. The number of repetitions was applied over a period of 24 hours. The test frame, test set-up and pull out tests are shown in Figures C1 to C5. Upon completion of the repetitive load testing, the pull out capacity of the screws was obtained through pull out tests performed in the Zwig testing machine (capacity 250 kn). A pull-out rate of 3mm/min. was applied as per ASTM D-1761-06 (Figure C6). Pull-out capacities for screws with and without repetition loads are summarized in Table C1. It can be seen that the repetition loads had negligible influence of the pull-out capacity. 4.3.2 Nails Tests were performed on similar assemblies as for connections with screws. Nail lengths of 150mm and 120mm were used together with ISOBOARD thickness of 30mm. The tests were performed for comparison with the screw connection tests. Frames were made up consisting of four connections each, nailing two battens to two rafters. The assembly was then placed in a testing frame where an imposed deformation was acting on the purlins. The imposed deformation was 3mm in each direction, which represents a 20 change in temperature for a 10m long steel sheet (temperature coefficient of expansion taken to be 12 x10-6 m/m/ C.): o = 10 x 20 x 12 x10-6 = 2.4 mm, say 3mm. o Number of repetitions : 350 days x 30 years = 10500 o Period of application : 24 hours. The test pieces were placed in the testing assembly with a 0.5 mm clearance of movement in each direction. The number of repetitions was applied over a period of 24 hours. An additional arrangement was prepared and similarly tested without ISOBOARD, using four connection points for 125 mm nails. Upon completion of the repetition loads, pull out tests were performed at a rate of 3mm/min as per ASTM D-1761-06, using the Zwig testing machine. The pull out capacities for different nail lengths in battens with and without ISOBOARD, are presented in Table C2. The nail pull out capacities are significantly less than those of the screws. The influence of nail length can also be seen from the table. 4.4 Lateral strength and stiffness tests A series of tests was performed to determine the lateral strength and stiffness of screw connections through ISOBOARD panels. The purpose of the tests was to determine the capacity of the connections to provide effective lateral restraint. This is of importance in roof members where the battens or purlins provide lateral restraint for sections under compression or bending. The lateral load capacity of the following connections was evaluated : o Four connection points using 145 mm screws (4.5 mm diameter) connecting a batten with a rafter through 40 mm ISOBOARD 5

o o Four connection points using 165 mm nails connecting a batten with a rafter through 40 mm ISOBOARD Four connection points using 125 mm nails connecting a batten with a rafter (without ISOBOARD). All battens used were 50 x 76 mm. The connections were tested by application of a lateral load to a batten on a rafter. An arrangement was used where the rotation of the batten could be limited under lateral load, in order to simulate a continuous batten supported on more than one rafter. The test arrangement can be seen in Figure D1 and D2. Short sections of batten were tested by applying a lateral load from the Zwig machine. The results of the tests are presented in Annexure D. Table D1 shows the range of tests performed which includes the following basic variables : o connections with screws and ISOBOARD, o connections with nails and ISOBOARD, o connections with nails without ISOBOARD (standard construction). The choice of variable enables a comparison between standard construction and the effect of ISOBOARD on the connection. The results of the tests are presented in graphical format in Figure D3. The figure shows that connections with nails and no ISOBOARD have a significantly higher lateral capacity and stiffness than those using ISOBOARD. An approximate lateral stiffness of 500 kn/m was obtained for the specimen without ISOBOARD. An approximate stiffness of 50 kn/m was obtained for specimens with ISOBOARD. 5. Theoretical analysis to investigate lateral connection stiffness. One of the roles of battens in roof systems is to provide lateral restraint to compression members in trusses, and to provide lateral restraint to compression edges of rafters in bending. Since a much lower lateral stiffness was obtained during the test series for systems with ISOBOARD, an analysis was performed to investigate the effects of the lower connection stiffness on the ability of the connection to provide lateral restraint. This evaluation is described in this Section. Analyses were performed using the PROKON commercial software package. For the purpose of evaluation the following two structural configurations were considered : - An 8m long 50 x 225 SA Pine Grade 6 timber beam, considered to be acting as a rafter supporting battens. - A 6m long 36 x 150 Pine Grade 4 timber section, considered to act as a top chord truss member Second order analyses were performed on all the structural configurations. The purpose was to determine if lateral buckling occurs under axial compression (truss chord) or compression in bending (rafter). The analyses for these configurations are described in the following sections. 5.1 An 8m long 50 x 225 SA Pine rafter The following values were first calculated by hand for the 50 x 225 rafter : 6

- The maximum bending resistance for a 8m long beam was determined without lateral top flange restraint. A value of M r = 0.93 knm was calculated (SABS 0163-1:1994) - The maximum bending resistance was determined for a beam with lateral support of the top flange. A value of 3.42 knm was calculated (SABS 0163-1:1994). If the resistance factor (Ф) and the multiplication of the γ i factors are both taken as unity, then this value is 5.61 knm. The rafter was then modeled in the PROKON analysis by using shell elements. 4 elements were used in the depth of the rafter, and 52 along the length of the rafter. The top of the rafter was given an initial central lateral displacement of 10mm perpendicular to the rafter longitudinal axis. The top of the rafter followed a parabolic shape with zero lateral displacement at the supports, and 10mm in the centre. The bottom of the rafter had no initial lateral displacement. This initial lateral displacement initiated a lateral buckling behaviour in the second order analyses. The following cases were considered : - Case 1 : An application of equal vertical point loads at 307mm spacing on the top of the rafter to develop a bending moment of 0.93 knm in the rafter. No lateral restraint was provided at the top of the rafter. This was the maximum load that could be applied. With an increase of 5% of the forces which generated this bending moment value, the analysis was terminated by the program to due instability. - Case 2 : An application of equal vertical point loads at 307mm spacing on the top of the rafter to develop a bending moment of 0.93 knm in the rafter. Lateral restraint was provided at the top of the rafter using spring elements at a spacing of 307mm and each with a stiffness of 50 kn/m (screw connection with ISOBOARD). The lateral displacement was 0.07mm. - Case 3 : An application of equal vertical point loads at 307mm spacing on the top of the rafter to develop a bending moment of 5.61 knm in the rafter. Lateral restraint was provided at the top of the rafter using spring elements at a spacing of 614 mm with a stiffness of 500 kn/m (nail connection without ISOBOARD). The system was stable and it shows that nails and battens provide adequate restraint to the rafter. - Case 4 : An application of equal vertical point loads at 307mm spacing on the top of the rafter to develop a bending moment of 5.61 knm. Lateral restraint was provided at the top of the rafter using spring elements at a spacing of 614 mm with a stiffness of 50 kn/m (screw connection with ISOBOARD). The system was stable and it shows that screws through ISOBOARD and and battens provide adequate restraint to the rafter. - Case 5 : An application of equal vertical point loads at 307mm spacing on the top of the rafter to develop a bending moment of 5.61 knm in the rafter. Lateral restraint was provided at the top of the rafter using spring elements at a spacing of 307mm with a stiffness of 500 kn/m (nail connection without ISOBOARD). The system was stable and it shows that nails and battens provide adequate restraint to the rafter. - Case 6 : An application of equal vertical point loads at 307mm spacing on the top of the rafter to develop a bending moment of 5.61 knm in the rafter. Lateral restraint was provided at the top of the rafter using spring elements at a spacing of 307mm with a stiffness of 50 kn/m (screw connection with ISOBOARD). The system was stable and it shows that screws through ISOBOARD and and battens provide adequate restraint to the rafter. For each case the stability of the rafter was calculated applying a second order analysis. All rafter configurations were stable, i.e. no lateral torsional buckling occurred. The only case where no additional load could be applied is Case 1 (no top of rafter restraint).. An increase of 5% of the applied load resulted in an instability. This is similar to the result from the hand calculation based on the design code (SABS 0163-1:1994) The lateral displacement of the rafter was calculated for each case and is summarized in Table E1. The unrestrained rafter has by far the largest lateral displacement. Although the connections with 7

screws have a much lower stiffness than that of the nails, the lateral displacement is still very small. A print out of the final displaced rafter is presented for each case in Figures E1 to E6. 5.2 A 6m long 36 x 150 SA Pine truss top chord member The following values were used for the analysis of the top chord truss member : - An axial compression load of 50 kn (9.3 MPa < Ф x f cp = 10.8 MPa) - Vertical batten loads of 0.28 kn spaced at approximately 800 mm. The top chord was modeled in the PROKON analysis to be made up of beam elements. 64 elements were used along the length of the chord. The chord was given an initial central lateral displacement of 5mm perpendicular to the chord longitudinal axis. This initial lateral displacement initiated a lateral buckling behaviour in a second order analyses. The following cases were considered : - Case 1 : Two intermediate vertical supports at 2.25m spacing. Lateral restraint at 0.75m with a stiffness of 500 kn/m (nails) : o Maximum lateral displacement = 14.5mm (too high) - Case 2 : Two intermediate vertical supports at 2.25m spacing. Lateral restraint at 0.375m with a stiffness of 50 kn/m (screws). o UNSTABLE Although the condition of combined axial compression and bending is not considered in the evaluation above, it is clear that a truss with a top chord member restrained by battens, fixed with screws through ISOBOARD, is not sufficiently restrained to prevent instability. 6 Evaluation and interpretation of results The test series and theoretical analyses allow an evaluation of the following three basic aspects of the system where ISOBOARD is used in an over rafter application : - pull out capacity of the connection : this is, the ability of the connection to resist uplift forces from wind - bearing capacity : this is the ability of the ISOBOARD panels to resist compressive bearing pressures at batten-rafter connections - lateral restraint provided to rafter and truss members in compression (or bending). These three aspects plus construction aspects are evaluated in the following sections. 6.1 Pull out capacity The maximum wind uplift force at a connection between batten and rafter (or truss chord) is shown in Table 1a to be 0.805 kn (750 x 1500mm spacings) on the roof, and 1.245 kn (750 x 1500 spacing) for a 600mm eaves overhang. The maximum uplift force due to the resistance of the ISOBOARD after tightening a screw at a connection between batten and rafter (or truss chord), is given as 0.56 kn (Table B1). The smallest pull out capacity achieved for a connection with screws is 3.477 kn (Tabel C1). The smallest pull out capacity achieved for a nail is 0.44 kn (Table C2) (ignoring the smallest results of 0.028 kn) Thus the ratio between pull out capacity and uplift force is as follows : 8

3.477/(0.805 + 0.56) = 2.54 (Screw) : Roof 3.477/(1.245 + 0.56) = 1.93 (Screw) : Overhang 0.44/(0.805 + 0.56) = 0.32 (nail) : Roof 0.44/(1.245 + 0.56) = 0.244 (nail ) : Overhang The screw is considered to provide adequate resistance to uplift. The nail is inadequate. 6.2 Compressive bearing pressures The maximum force before yielding during the compressive force tests is taken to be 450 N. This is equivalent to 180 kpa on the 50 x 50 mm specimens. If ISOBOARD panels are to be limited to this compressive stress, then typical limits for spacing of rafters and battens can be calculated. The limits presented here are based on the following : - Assuming a material factor of 1.15 (strength reduction factor) on the compressive strength (i.e. limit = 450/1.15 = 390N) - Roof tiles with mass of 60 kg/m 2 - Roof sheeting with mass 10 kg/m 2 - Imposed load of 0.5 kpa - Imposed load factor 1.6 - Dead load factor 1.2. The calculated limits for rafter and batten spacing are presented in Tables 2 and3 for sheeted and tiled roofs. Table 2 : Spacing limits for battens and rafters of tiled roofs Member sizes Battens on rafter (mm on mm) Maximum allowed Supporting area (m 2 ) Examples of limits Batten x rafter (mm x mm) 38 x 50 0.195 310 x 629 38 x 75 0.293 310 x 945 50 x 50 0.257 350 x 735 50 x 75 0.385 350 x 1100 Table 3 : Spacing limits for battens and rafters of sheeted roofs Member sizes Battens on rafter (mm on mm) Maximum allowed Supporting area (m 2 ) Examples of spacing limits Batten x rafter (mm x mm) 38 x 50 0.323 600 x 535 38 x 75 0.484 600 x 806 50 x 50 0.425 600 x 705 705 x 600 50 x 75 0.635 1000 x 635 800 x 790 1050 x 600 6.3 Lateral restraint to truss chords and rafters The lateral strength and stiffness tests enabled the analyses to be performed as described under Section 5 above. 9

Top chords in trusses : From the analyses it is clear that when battens are fixed to top chord members in trusses using screws (or nails), the connection does not provide inadequate lateral support to the member. Battens used in conjunction with ISOBOARD panels in an over truss application as studied in this report can therefore not be relied upon to provide lateral restraint to top chord members in trusses. Rafters : A maximum span of 8m was investigated using a rafter of 50 x 225mm. It is found that screw connections with ISOBOARD panels in an over rafter application can provide adequate lateral restraint in bending to the top of the rafter under gravity loads. This is valid for battens at a maximum spacing of 600mm. Rafters with a maximum size of 50 x 255mm and a maximum span of 8m are therefore considered to be adequately retrained laterally by the screw connection for bending under gravity loads. Sketches are shown in Annexure F to explain the above concepts of systems which may or may not be sufficiently braced against lateral buckling. 6.4 Construction The tests in this series were performed with material prepared and fixed in laboratory conditions. It is however important to realize that construction conditions on site may be significantly different. For this reason, it is imperative that the following be taken into account when ISOBOARD panels are used in an over rafter application : - Contractors need to have a suitable method to ensure that screws can be fixed through battens and ISOBOARD panels into rafters in such a manner that adequate edge distances are maintained in both batten and rafter. Pre-drilling of screw guide holes is considered to be the only manner suitable. - Contractors need to have well monitored quality procedures in place to ensure that the method statements are correctly followed. Recommendations for battens to provide adequate restraint is based on the assumption that battens are fixed in such a manner elsewhere that they are prevented form lateral movement themselves. 7. Conclusions and recommendations An investigation was carried out to evaluate the structural performance of the ISOBOARD system in an over rafter and an over truss application. The investigation consisted of a series of tests to determine strength and stiffness properties of ISOBOARD panels and of typical connections. Furthermore, theoretical analyses were performed to study lateral restraint provided by the batten connections to top chord members and for rafters. The range of ISOBOARD panel thickness and connector sizes (screw and nail) which were investigated are described in the report. The following recommendations are presented for ISOBOARD used in an over TRUSS application: - Guide holes must be pre drilled in truss members and battens before fixing of screws. - Nails are not considered an adequate method of fixing battens to the truss.. - ISOBOARD panels and timber battens fixed with either nails or screws in an over chord application, do not provide sufficient lateral restraint to top chord members in trusses. The 10

limitation is due to the fact that connection does not possess sufficient lateral stiffness between the batten and the top chord truss member. Other means are necessary to provide lateral restraint to top chords in trusses if ISOBOARD is used in an over truss application. - If other elements are provided in a roof system to provide lateral restraint to the top chord of trusses, then ISOBOARD panels can be used in an over truss application. In such a case, there is a limitation on the spacing of battens and trusses which needs to be adhered to, and which is a function of the roof material type, being either roof sheets or roof tiles. These limitations are provided in Tables 2 and 3. - Battens and truss top chord members shall be SA Pine Grade 4 or better. - Contractors must have a well prepared method statement to ensure correct placement and fixing of battens over trusses to ensure that screws will be placed within SABS 1200 tolerance specifications. - Contractors must have an approved quality control procedure to monitor the correct placement of ISOBOARD panels and screws. The following recommendations are presented for ISOBOARD used in an over RAFTER application: - When used in an over rafter application, ISOBOARD panels must be fixed between the rafter and batten using 150mm screws with a diameter of 4.4mm tying the battens to timber rafters. - Timber rafters shall have a minimum width of 50mm - Guide holes must be pre drilled in rafters and battens before fixing of screws. - Nails are not considered an adequate method of fixing battens to rafters. - Screw connections fixing battens to rafters with ISOBOARD panels in an over rafter application can be considered to provide sufficient lateral restraint to the top of the timber beam under gravity load with the following limitations : o Maximum rafter span length is 8m (longer span lengths were not investigated). o Maximum spacing between battens is 600mm. o o Maximum rafter size 75 x 225mm (larger rafters were not investigated) Maximum imposed (live) load on the roof is 0.5 kpa (higher loads were not investigated). - The above limitations can be exceeded if other elements are provided in a roof system to provide lateral restraint to the top of rafters. - There is a limitation on the spacing of battens and rafters which needs to be adhered to, and which is a function of the roof material type, being either roof sheets or roof tiles. These limitations are provided in Tables 2 and 3. - Battens and rafters shall be SA Pine Grade 4 or better. - Contractors must have a well prepared method statement to ensure correct placement and fixing of battens over rafters to ensure that screws will be placed within SABS 1200 tolerance specifications. - Contractors must have an approved quality control procedure to monitor the correct placement of ISOBOARD panels and screws. 8. References ASTM D-1761-06. : Standard test methods for mechanical fasteners in word. ASTM Standards, Philadelphia, USA. 2006. SABS 0160 (1989) : The general procedures and loadings to be adopted in the design of buildings. South African Bureau of Standards, Pretoria. As amended 1990. SABS 0163-1:1994 : The structural use of timber Part 1 : Limit-states design. South African Bureau of Standards, Pretoria. As amended 1997. SABS 1508-1990 : Expanded polystyrene thermal insulation boards. South African Bureau of Standards, Pretoria. 1990. 11

ANNEXURE A : COMPRESSIVE STRENGTH TEST TABLE A1. Compressive strength tests force at yield Specimen thickness (mm) Force at yield (N) Stress at yield (kpa) Deformation at yield 25 455-510 182-204 0.032-0.036 30 455-507 182-203 0.026-0.029 40 420-530 168-212 0.016-0.033 TABLE A2 Compressive strength tests force at 90% of original thickness Specimen number Thickness Loading rate Force at 90% of thickness mm mm/min N Thickness 40mm 1 39.5 3.95 577 2 40 4 558 3 39 3.9 609 4 39.5 3.95 568 5 39.5 3.95 660 6 39.5 3.95 642 7 39.5 3.95 555 8 40 4 594 9 39.5 3.95 580 10 40 4 575 average 591.8 Thickness 30mm 11 30 3 603 12 30 3 556 13 30 3 622 14 30 3 590 15 30 3 567 16 30 3 582 17 30 3 570 18 30 3 587 19 29.5 2.95 590 20 29.5 2.95 556 average 582.3 Thickness 25mm 21 25 2.5 525 22 26 2.6 569 23 26 2.6 546 24 26 2.6 519 25 26 2.6 539 26 26 2.6 553 27 25.5 2.55 543 28 25.5 2.55 536 29 25.5 2.55 535 30 25.5 2.55 527 average 539.2 12

Compressive Graphs 6000 5000 Force (N) 4000 3000 2000 25mm Thickness 30mm Thickness 40mm Thickness 1000 0 0 5 10 15 20 25 30 35 40 Displacement (mm) FIGURE A1 : Force vs displacement behaviour of ISOBOARD specimens. 25 mm 700 600 500 Force [N] 400 300 200 100 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Displacement [mm] FIGURE A2 : Force vs displacement behaviour of ISOBOARD specimens (25 mm) 13

30mm ISOBOARD 700 600 500 Force [N] 400 300 200 100 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Displacement [mm] FIGURE A3 : Force vs displacement behaviour of ISOBOARD specimens (30 mm) 40mm ISOBOARD 700 600 500 Force [N] 400 300 200 100 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Displacement [mm] FIGURE A4 : Force vs displacement behaviour of ISOBOARD specimens (40 mm) 14

FIGURE A5 : ISOBOARD specimen in Zwig testing machine for compressive strength test 15

ANNEXURE B : DEFORMATION UNDER SCREW LOAD SCREW/NAIL ISOBOARD BATTEN (PURLIN) Rafter INDENT MEASURED (Table B1) FIGURE B1 : Measurement of indent TABLE B1: Deformation under screw tightening loads ISO Board Thickness Thickness before (mm) Thickness after (mm) Deformation Equivalent force (from Fig. A2- A4) mm mm mm mm N 25 25 24.5 0.5 232 25 26.4 24.4 2 511 25 24.2 23.8 0.4 148 25 24.4 24.2 0.2 15.7 30 29.55 28.5 1.05 500 30 29.8 28 1.8 560 30 29.8 28 1.8 560 30 29.8 28.6 1.2 513 40 39 37.8 1.2 454 40 40.2 37.7 2.5 524 40 39 36 3 541 40 40 38.2 1.8 489 16

ANNEXURE C : SCREW PULL OUT CAPACITY A SCREW/NAIL ISOBOARD BATTEN (PURLIN) Rafter A 0.5 mm gap SCREW/NAIL ISOBOARD BATTEN (PURLIN) Angle irons Moved 7 mm Rafter (fixed against movement) SECTION A-A FIGURE C1 : Set-up for repetition loads 17

FIGURE C2: Test frame for repetition loads FIGURE C3: Specimen in test frame for repetition loads 18

FIGURE C4: Specimen in test frame for repetition loads FIGURE C5: Specimen in test frame for repetition loads 19

FIGURE C6: Pull-out test after repetitive loads 20

TABLE C1 : Pull out capacity of SCREWS without load repetition and after load repetition. Frame Connection nr ISO Board Thickness Purlin Thickness Pullout capacity without repetition Purlin Thickness Pullout capacity after repetition mm mm N mm N Screws 1 25 47.8 9470 46.8 4750 2 25 47.8 4329 46.7 4910 3 25 47.6 8233 49 4414 4 25 47.9 4059 49 5072 Screws 5 30 47.2 3323 47.2 5094 6 30 47.9 3422 47 5648 7 30 47.6 4060 47.6 4764 8 30 47.5 4012 47.4 5618 Screws 9 40 47.4 2814 47.7 3809 10 40 47.4 3273 47.8 4367 11 40 48.4 2974 47 3477 12 40 47.4 2734 47 4754 21

TABLE C2 : Pull out capacity of NAILS with load repetition. Frame Connection nr ISO Board Nail Purlin Pullout Thickness length Thickness capacity mm mm mm N Nails 1 30 150 47.8 1087.1 2 30 150 47.2 851.1 3 30 150 48 973.89 4 30 150 47.4 894.06 Nails 9 30 120 46.2 736.41 10 30 120 47.1 28.47 11 30 120 47.6 438.96 12 30 120 47.8 719.41 Nails 13 no Isoboard 125 47.6 1373.81-14 no Isoboard 125 47.8 781.03-15 no Isoboard 125 47.6 1124.37-16 no Isoboard 125 47.6 955.67 22

ANNEXURE D : LATERAL STIFFNESS AND STRENGTH TESTS TABLE D1 : Range of tests performed with lateral strength values Fmax Screw Length Nail Length ISO board thickness N mm mm mm Screw1 1588 140-40 Screw2 1579 140-40 Screw3 1427 140-40 Nail1 719-150 40 Nail2 1009-150 40 Nail3 1057-150 40 Nail4 851 - Nail5 3074-120 - Nail6 3162-120 - Nail7 2447-120 - FIGURE D1 : Lateral stiffness test on specimen with ISOBOARD 23

FIGURE D2 : Lateral stiffness test on specimen without ISOBOARD Lateral Stiffness Graphs 3500 3000 Force (N) 2500 2000 1500 1000 Nail150mmISO40mm#1 Nail150mmISO40mm#2 Nail150mmISO40mm#3 Nail150mmISO40mm#3 Nails120mm#1 Nails120mm#2 Nails120mm#3 Screws140mmISO40mm#1 Screws140mmISO40mm#2 Screws140mmISO40mm#3 500 0 0 5 10 15 20 25 30 35 40 45 Displacement (mm) FIGURE D3 : Results of tests to determine lateral stiffness of connections 24

ANNEXURE E : THEORETICAL EVALUATION OF LATERAL RESTRAINT PROVIDED BY BATTENS WHEN ISOBOARD IS USED IN AN OVER RAFTER APPLICATION. Table E1 : Lateral displacement of rafter under various restraint conditions Case Bending moment Restraint at top of rafter Displacement (mm) 1 0.93 knm No restraint 376 2 0.93 knm Screw + ISOBOARD at 307mm 0.07 3 5.61 knm Nails at 614 mm 0.18 4 5.61 knm Screw + ISOBOARD at 614mm 1.21 5 5.61 knm Nails at 307 mm 0.15 6 5.61 knm Screw + ISOBOARD at 307mm 0.57 FIGURE E1 : Case 1 : Rafter with no lateral restraint (M = 0.93 knm) 25

FIGURE E2 : Case 2 : Rafter with battens fixed with screws at 307mm (M =0.93 knm) FIGURE E3 : Case 3 : Rafter with battens NAILED on at 614mm (M =5.61 knm) 26

FIGURE E4 : Case 4 : Rafter with battens fixed with screws at 614mm (M =5.61 knm) FIGURE E5 : Case 5 : Rafter with battens fixed with nails at 307mm (M =5.61 knm) 27

FIGURE E6 : Case 6 : Rafter with battens fixed with screws at 307mm (M =5.61 knm) FIGURE E7 : Truss top chord with battens fixed with nails at 750mm 28

FIGURE E8 : Truss top chord with battens fixed with screws at 375mm 29

ANNEXURE F : BRACING SYTEMS 30

31

32