The present invention relates to a metal roofing material (member) that is disposed together with other metal roofing members on a roof base, and to a roofing structure and a roofing method that utilize the metal roofing member.
Conventionally, this type of metal roofing member is considered and disclosed. For example, the following structure is disclosed in Patent Document 1. That is, the conventional metal roofing member includes a front substrate in which a metal sheet is formed into a box shape. Roofing of a house is carried out by arranging side by side, on a roof base, a plurality of metal roofing members, while abutting respective side surfaces of the front substrates against each other.
Patent Document 1: Japanese Patent Application Publication No. 2003-74147 A
The front substrate in such a conventional metal roofing member is box-shaped, and thus causes the following problems for practical use. That is, the box-shaped front substrate has a constant thickness in order to ensure functionality as a roofing member. Abutting of the entire side surfaces of the front substrates having such a constant thickness against each other will result in a pool of a significant amount of water such as rainwater between the metal roofing members, which will cause corrosion of the metal roofing members and the roof base.
It is also conceivable that flanges are projected from side portions of the front substrate and the flanges are abutted against each other over the entire side portion of each metal roofing member. The flanges also contribute to improvement of strength of the metal roofing member. However, with such a configuration, a space is formed in the upper portion of the flange, so that water may enter the ridge side through this space as a passage.
The present invention has been made to solve the above problems. An object of the present invention is to provide a metal roofing member, and a roofing structure and roofing method that utilize the metal roofing member, which can reduce water pooled between the metal roofing members and can also reduce water entering the ridge side of the metal roofing member, thereby improving the strength of the metal roofing members.
The present invention relates to a metal roofing member that is arranged on a roof base together with other metal roofing members, the metal roofing member comprising: a front substrate made of a metal sheet, the front substrate comprising a body portion formed in a box shape; a back substrate arranged on a back side of the front substrate, the back substrate being configured to cover an opening of the body portion; and a core material filled between the body portion and the back substrate; wherein the body portion comprises: first side surfaces; and second side surfaces, each of the second side surfaces being adapted so as to be located on the ridge side of each of the first side surfaces when the metal roofing member is placed on the roof base, each of the second side surfaces being arranged at a position protruding to the outer side along a width direction of the body portion than the first side surface; wherein each of the first side surfaces comprises a side flange, the side flange being formed by folding back the metal sheet toward the back side of the front substrate such that the metal sheet wraps around the back substrate, the metal sheet extending from the lower end of the first side surface toward the outer side along the width direction; wherein the side flange comprising a back end that will be in contact with the roof base; wherein a distance between the back end of the side flange and the back surface of the back substrate is 1 mm or more and 4 mm or less; wherein a protruding width of the side flange from the first side surface is equal to or less than a protruding width of the second side surface from the first side surface; and wherein the metal roofing member is configured to be arranged on the roof base while abutting at least the second side surface against a second side surface of the other metal roofing member.
The present invention relates to a roofing structure comprising a plurality of metal roofing members, each comprising: a front substrate made of a metal sheet, the front substrate comprising a body portion formed in a box shape; a back substrate arranged on the back side of the front substrate, the back substrate being configured to cover an opening of the body portion; and a core material filled between the front substrate and the back substrate; wherein the body portion comprises: first side surfaces; and second side surface, each of the second side surfaces being adapted so as to be located on the ridge side of each of the first side surfaces when the metal roofing member is placed on a roof base, each of the second side surfaces being arranged at a position protruding toward the outer side along the width direction of the body portion than the first side surface; wherein each of the first side surfaces comprises a side flange, the side flange being formed by folding back the metal sheet toward the back side of the front substrate such that the metal sheet extending from the lower end of the first side surface toward the outer side along the width direction wraps around the back substrate; wherein the side flange comprises a back end, the back end being in contact with the roof base; wherein a distance between the back end of the side flange and the back surface of the back substrate is 1 mm or more and 4 mm or less; wherein a protruding width of the side flange from the first side surface is equal to or less than a protruding width of the second side surface from the first side surface; and wherein the plurality of metal roofing members are arranged on the roof base while abutting at least the second side surfaces against each other.
The present invention relates to a roofing method using a plurality of metal roofing members, each of the metal roofing members comprising: a front substrate made of a metal sheet, the front substrate comprising a body portion formed in a box shape; a back substrate arranged on the back side of the front substrate, the back substrate being configured to cover an opening of the body portion; and a core material filled between the front substrate and the back substrate; the body portion comprising: first side surfaces and second side surfaces, each of the second side surfaces being adapted so as to be located on the ridge side of each of the first side surfaces when placed on a roof base, each of the second side surfaces being arranged at a position protruding to the outer side along the width direction of the body portion than the first side surface; each of the first side surface comprising a side flange, the side flange being formed by folding back the metal sheet toward the back side of the front substrate such that the metal sheet wraps around the back substrate the metal sheet extending from the lower end of the first side surface toward the outer side along the width direction; the side flange comprising a back end, the back end being in contact with the roof base; a distance between the back end of the side flange and the back surface of the back substrate being 1 mm or more and 4 mm or less; and a protruding width of the side flange from the first side surface being equal to or less than a protruding width of the second side surface from the first side surface; wherein the method comprises arranging the plurality of metal roofing members on the roof base while abutting at least the second side surfaces against each other.
According to the metal roofing member, and the roofing structure and roofing method that employ the metal roofing member of the present invention, the metal roofing members are configured to be arranged on the roof base while abutting the second side surface against a second side surface of other metal roofing member, thereby allowing reduction of water pooled between the metal roofing members, and also allowing reduction of water entering the ridge side of the metal roofing member. Further, each of the first side surfaces is provided with the side flange, so that the strength of the metal roofing members can be improved.
Embodiments for carrying out the present invention will be described with reference to the drawings.
The metal roofing member 1 as shown in
As particularly shown in
The front substrate 10 is made of a metal sheet and appears on the outer surface of the roof as the metal roofing material 1 is placed on the roof base. The metal sheet making up the front substrate 10 that can be used includes a hot-dip Zn-based plated steel sheet, a hot-dip Al plated steel sheet, a hot-dip Zn-based plated stainless steel sheet, a hot-dip Al plated stainless steel sheet, a stainless steel sheet, an Al sheet, a Ti sheet, a coated hot-dip Zn-based plated steel sheet, a coated hot-dip Al plated steel sheet, a coated hot-dip Zn-based plated stainless steel sheet, a coated hot-dip Al plated stainless steel sheet, a coated stainless steel sheet, a coated Al sheet or a coated Ti sheet.
Preferably, the thickness of the metal sheet is 0.27 mm or more and 0.5 mm or less. An increasing thickness of the metal sheet will result in increased strength, but increased weight. The thickness of the metal sheet of 0.27 mm or more can ensure strength required for the roofing member, and sufficiently provide wind pressure resistance performance and tread-down properties. The wind pressure resistance performance refers to performance for which the metal roofing member 1 can withstand strong wind without buckling of the metal roofing member 1. The thickness of the metal sheet of 0.5 mm or less can prevent the weight of the metal roofing member 1 from becoming excessive, thereby keeping down the total weight of the roof when equipment such as a solar cell module, a solar water heater, an outdoor unit of an air conditioner and snow melting equipment is provided on the roof.
The front substrate 10 includes a box-shaped body portion 100 having a top plate 101 and peripheral wall portion 102. The body portion 100 is preferably formed by performing drawing or bulging processing on a metal sheet. By forming the box-shaped body portion 100 by performing the drawing or bulging processing, each of the side wall portion 102 can have a wall surface that is continuous in the circumferential direction of the front substrate 10, and any likelihood that water enters the inside of the body portion 100 can be reduced. However, it is also possible to bend the metal sheet having a shape as shown in
When the steel sheet (the hot-dip Zn-based plated steel sheet, the hot-dip Al plated steel sheet, the hot-dip Zn-based plated stainless steel sheet, the hot-dip Al plated stainless steel sheet, the stainless steel sheet, the Al sheet, the Ti sheet, the coated hot-dip Zn-based plated steel sheet, the coated hot-dip Al plated steel sheet, the coated hot-dip Zn-based plated stainless steel sheet, the coated hot-dip Al plated stainless steel sheet or the coated stainless steel sheet) is used as the metal sheet of the front substrate 10 and when the body portion 100 is formed by the drawing or bulging processing, the hardness of the peripheral wall portion 102 are increased by work hardening. More particularly, the Vickers hardness of the peripheral wall portion 102 can be increased to about 1.4 to 1.6 times the hardness before the working. The wind pressure resistance performance of the metal roofing member 1 is significantly improved by virtue of the fact that the peripheral wall portion 102 has the wall surface that is continuous in the circumferential direction of the front substrate 10, as described above, and by virtue of the fact that the hardness of the peripheral wall portion 102 is increased by work hardening.
The back substrate 11 is a member that is arranged on the back side of the front substrate 10 so as to covert an opening of the body portion 100. The back substrate 11 that can be used include lightweight materials such as an aluminum foil, aluminum vapor deposited paper, aluminum hydroxide paper, calcium carbonate paper, resin films or glass fiber paper and the like. The use of these lightweight materials for the back substrate 10 allows prevention of an increase in the weight of the metal roofing material 1.
The core material 12 is made of, for example a foamed resin or the like, and is filled between the body portion 100 of the front substrate 10 and the back substrate 11. The filling of the core material 12 between the body portion 100 of the front substrate 10 and the back substrate 3 can lead to a stronger adhesion of the core material 12 to the inside of the body portion 100 as compared with an embodiment where a backing material such as a resin sheet or the like is attached onto the back side of the front substrate 11, so that the performance required for the roofing materials, such as rainfall noise reduction, heat insulation and tread-down properties, can be improved.
The material of the core material 12 includes, but not limited to, for example, urethane, phenol and cyanurate resins. For roofing materials, however, certified noncombustible materials must be used. The test for certification of noncombustible material is conducted by a heat release test according to the cone calorimeter test method defined in ISO 5660-1. If the foamed resin for forming the core material 12 is urethane having a higher calorific value or the like, the thickness of the core material 12 may be decreased, or inorganic expandable particles may be incorporated into the foamed resin.
A height h of the body portion 100 filled with the core material 12 is preferably 4 mm or more and 8 mm or less. The height h of the body portion 100 of 4 mm or more enables sufficiently higher strength of the body portion 100, and improved wind pressure resistance. The height h of 4 mm or more can also provide improved heat insulation properties. The height h of the body portion 100 of 8 mm or less can prevent the organic mass of the core material 12 from becoming excessive, and can allow certification of noncombustible material to be more reliably obtained.
Returning to
The peripheral wall portion 102 of the body portion 100 is provided with first side surfaces 105, second side surfaces 106, a ridge-side end surface 107, and an eave-side end surface 108.
The first and second side surfaces 105, 106 are provided on both sides of the body portion 100 along the width direction 100a, respectively. The second side surface 106 is adapted to be positioned on the ridge side relative to the first side surface 105 when the metal roofing member 1 is placed on the roof base. As particularly shown in
The first side surface 105 is provided with a side flange 105a. The side flange 105a is comprised of a metal sheet extending from the lower end of the first side surface 105 toward the outer side along the width direction 100a, and is formed by folding back the metal sheet toward the back side of the front substrate 10 such that the metal sheet wraps around the back substrate 11. The providing of the side flange 105a integrally with the body portion 100 leads to improved durability (wind pressure resistance performance) of the metal roofing member 1 against an external force that will act to warp the metal roofing member 1 to the front side or the back side along a straight line along the width direction 100a.
A protruding width W1 of the side flange 105a from the first side surface 105 is less than or equal to a protruding width W2 of the second side surface 106 from the first side surface 105 (W1≤W2). Further, the protruding width W1 of the side flange 105a from the first side surface 105 is preferably 2 mm or more and 5 mm or less. The protruding width W1 of 2 mm or more can provide the side flange 105a with sufficient strength and reliably prevent warping of the front substrate 10. The protruding width W1 of 5 mm or less can avoid decreased strength of the side flange 105a due to an increase in the protruding width W1 and maintain good design properties of the metal roofing member 1. In this embodiment, the total width of the metal roofing member 1 is about 908 mm, the protruding width W1 is about 4.5 mm, and the protruding width W2 is about 5.0 mm.
The second side surface 106 is not provided with the flange, because a flange extending from the second side surface 106 is cut off after forming the box-shaped body portion 100.
Returning to
As particularly shown in
Each of the inclined portions 107b of the ridge-side end surface 170 is not provided with the flange, because the flange extending from each inclined portion 107 is cut off after forming the box-shaped body portion 100, as in the second side surface 106 as described above. However, each of the inclined portions 107b may be provided with a flange similar to the ridge-side flange 107c.
The eave-side end surface 108 is located at the other end along the depth direction 100b and is adapted to be located on the eave side when the metal roofing member 1 is placed on the roof base. In the metal roofing member 1 according to this embodiment, the eave-side end surface 108 is structured only by a straight portion extending along the width direction 100a. However, the eave-side end surface 108 may have any other shape.
The eave-side flange 108 is comprised of a metal sheet extending outward along the depth direction 100b from the lower end of the eave-side end surface 108 and is formed by folding back the metal sheet toward the back side of the front substrate 10 such that the metal sheet wraps around the back substrate 11. As with the side flange 105a and the ridge-side flange 107c described above, a protruding width of the eave-side flange 108a from the eave-side end surface 108 is preferably 2 mm or more and 5 mm or less.
The ridge-side flange 107c and the eave-side flange 108a extend along the width direction 100a and prevent warping of the metal roofing member 1 along the direction crossing the width direction 100a.
Hereinafter, the three flanges of the side flange 105a, the ridge-side flange 107c and the eave-side flange 108a are collectively referred to simply as a flange. As can be seen from
The folded-back portion of the flange is provided with a back end 109b that will be in contact with the roof base. A distance D1 (see
The shape of the folded-back portion of the flange may be just one single folding through bending at 180° with constant curvature, as illustrated in
Next,
As shown in
As described above, the first side surface 105 is provided with the side flange 105a. By providing the side flange 105a, the strength of the metal roofing member 1 is improved. As described with reference to
When the side portions of the metal roofing materials 1 are abutted against each other, a space extending along the depth direction 100b is formed on the side of the first side surface 105 of each metal roofing material 1 and above the side flange 105a. However, since the second side surfaces 106 of the respective metal roofing materials 1 are abutted against each other, this space is closed by the abutting portion of the second side surfaces 106. Therefore, it is possible to reduce the amount of water entering the ridge side of the metal roofing material 1 through this space.
Water may enter the ridge side of the metal roofing member 1 due to strong wind or the like. However, since the ridge-side end surface 107 is provided with the inclined portions 107b, water entering the ridge side is guided by the inclined portion 107b to the abutted portion of the second side surfaces 106, and the water can be gradually discharged to the eave side through the butted portion.
A plurality of metal roofing members 1 are arranged on the roof base while the metal roofing member 1 on the ridge side is superposed on the metal roofing member 1 on the eave side, in the eave-ridge direction 3.
In this case, the metal roofing member 1 on the ridge side is overlapped with the metal roofing member 1 on the eave side such that the eave-side end portion (the side end 109a of the eave-side flange 108a) of the metal roofing member 1 on the ridge side is positioned above the first side surface 105 and the side flange 105a of the eave-side metal roofing member 1. When the metal roofing member 1 on the ridge side is overlapped with the metal roofing member 1 on the eave side, for example, an external force such as strong wind will act to warp the metal roofing member 1 on the eave side, starting at the eave-side end portion of the metal roofing material 1 on the ridge side. By overlapping the metal roofing materials 1 as described above, the external force can be withstood by the side flange 105a having relatively higher strength, so that the warping of the metal roofing member 1 on the eave side can be suppressed. That is, the wind pressure resistance performance is improved by the arrangement of the metal roofing members 1 as described above.
Further, the metal roofing member 1 on the ridge side is overlapped with the metal roofing member 1 on the eave side such that the second side surface 106 of the metal roofing member on the ridge side is placed above the ridge-side end portion (the side edge 109a of the ridge-side flange 107c) of the metal roofing substrate 1 on the eave side. The overlap of the metal roofing members 1 in such a way reduces any risk of water entering the ridge side of the metal roofing member 1 on the eave side through the gap between the metal roofing members 1 on the ridge side.
Examples are now illustrated. The inventors experimentally produced test members of the metal roofing member 1 under conditions given below.
A coated hot-dip Zn-55% Al plated steel sheet, a coated hot-dip Zn-6% Al-3% Mg plated steel sheet or a coated hot-dip Al plated steel sheet, which has a size of 0.20 mm to 0.6 mm, was used as the material of the front substrate 10.
Glass fiber paper having a size of 0.2 mm, Al metallized paper having a size of 0.2 mm, a PE resin film having a size of 0.2 mm, an Al foil having a size of 0.1 mm or a coated hot-dip Zn-based plated steel sheet having a size of 0.27 mm was used as the back substrate 11.
A two-liquid mixture type foam resin was used as the core material 12. The mixing ratio of a polyol component and isocyanate, phenol or cyanurate component was 1:1, in ratio by weight.
The front substrate 10 was processed to have a predetermined thickness and shape of the roofing member. The back substrate 11 was then disposed on the back side of the front substrate 10 so as to cover the opening of the body portion 100, and the foam resin was injected into the gap between the body portion 100 of the front substrate 10 and the back substrate 11, using a commercially available high-pressure injection machine. Foaming of the resin was accomplished by maintaining the resin for 2 minutes in a mold at which the temperature was adjusted to 70° C. by circulating hot water; subsequently, the roofing member was removed from the mold, and was allowed to stand for 5 minutes at room temperature of 20° C., to complete foaming of the resin.
After complete of the foaming of the resin, the metal sheet extending from a lower edge of the body portion 100 toward the outer direction of the body portion 100 was cut such that the protruding width of the flange (the side flange 105a, the ridge-side flange 107c and the eave-side flange 108a) was 5 mm, and the cut metal sheet was subjected to a bending process by means of a bender to have a predetermined shape. The dimensions of the final metal roofing member 1 were 414 mm×910 mm. The thickness of the final roofing member was in the range of from 3 mm to 8 mm.
For comparison, a specimen of a metal roofing member (conventional structure) was produced by subjecting a 0.3 mm coated hot-dip Zn-55% Al alloy plated steel sheet as the front substrate to inward 90°-bending of the four sides of the steel sheet to have a box shape using a bender, and injecting the foam resin in accordance with the method as described above. Glass fiber paper having a size of 0.2 mm was used as the back substrate of this metal roofing member. The thickness of the roofing member was 6 mm, while other conditions were the same as those described above.
For comparison, the following metal roofing members were also tested: a metal roofing member with no foam resin injected; a roofing member obtained by bonding a commercially available 0.3 mm thermally-insulating polyethylene sheet to a processed front substrate using an adhesive; a concrete roofing tile having a thickness of 6 mm; a clay roof tile having a thickness of 16 mm; and a metal roofing member of mating type that utilized a coated hot-dip Zn-55% Al alloy plated steel sheet (without backing material) having a thickness of 0.35 mm.
Using the above test members, the inventors evaluated: (1) the weight of the roofing member, (2) the bending strength of the roofing member, (3) rainwater pooling, (4) corrosion resistance, (5) heat insulation properties and (6) the amount of rainwater entering the ridge side from the abutted portion. The results are given in the table below.
(1) Evaluation Criteria of Roofing Member Weight
The unit weight of each roofing member was measured and evaluated in accordance with the following criteria. It should be noted that the evaluation was made based on an assumption that a standard 130 N/m2 solar cell module was placed on the roof, using the following evaluation criteria based on the total weight of the entire roof including the roofing member.
(2) Measurement and Evaluation Criteria of Bending Strength of Roofing Member
The roofing member was placed on a pair of rod-like members disposed spaced apart from each other by 450 mm, such that the extension direction of the rod-like members was the short direction of the roofing member, and a maximum load was measured using an Autograph, in which case the positions of the rod-like members acted as supporting points and the intermediate position between the rod-like members acted as a force point.
The bending strength of the roofing member was evaluated in accordance with the following criteria.
(3) Evaluation Method and Evaluation Criteria of Rainwater Pooling
A commercially available waterproof sheet was affixed to a surface of a roofing board (a thickness of 12 mm), and four tiers of roofing members were roofed at an inclination angle of 30° by the overlap roofing illustrated in
The dry state was evaluated in accordance with the following criteria:
(4) Evaluation Method and Evaluation Criteria of Corrosion Resistance
To simulate the roof obtained by the overlap roofing, three tiers of roofing members were roofed by the overlap roofing illustrated in
Corrosion resistance was evaluated in accordance with the following criteria:
(5) Evaluation Method and Evaluation Criteria of Heat Insulation Properties
Thermocouples were attached to the surface of the front substrate and the back surface of the roofing board of the simulated roof in which rainwater pooling had been evaluated. Twelve lamps (100/110 V, 150 W) were equidistantly arranged at positions of 180 mm from the surface of the simulated roof. The temperature of the back side of the roofing board after 1 hour of irradiation at a lamp output of 60% was measured by the thermocouples, to evaluate heat insulation properties.
Heat insulation properties were evaluated according to the following criteria:
(6) Measurement Method and Evaluation Criteria of Amount of Rainwater Entering Ridge Side from Abutted Portion of Side Flanges
A simulated roof was produced in the same method as that of the above item (3). For the simulated roof, water responsive paper 104 available from Syngenta (Switzerland) was inserted between the roofing material on the eave side and the waterproof sheet, as shown in
For the degree of rainwater entering, water was sprayed for 7 minutes under an environment of a wind speed of 30 m/s on the simulated roof to simulate the situation where the roof was exposed to storm. The amount of rainwater at this time was 4,000 mL/min per 1 m2.
In the case of Nos. 13 and 16 in Table 1, in which the distance D1 between the back end 109b of the flange and the back surface of the back substrate 11 was less than 1 mm, rainwater was pooled in the gap portion between the back substrate 11 and the roof base, so that the corrosion resistance of the front substrate positioned underneath was impaired. In the case of No. 14 where the distance D1 was more than 4 mm, the bending strength was decreased, and rainwater was pooled in the gap portion between the roofing members abutted against each other, so that the corrosion resistance was impaired. These results demonstrated that it was advantageous to set the distance D1 between the back end 109b of the flange and the back surface of the back substrate 11 to be 1 mm or more and 4 mm or less.
In each of Nos. 9 and 10, the protruding width W1 of the flange was less than 2 mm, so that the bending strength was insufficient. In No. 11 the protruding width W1 was more than 5 mm, so that the bending strength was decreased. These results demonstrated that it was advantageous to set the protruding width W1 of the flange to be 2 mm or more and 5 mm or less.
In each of Nos. 12 and 15, the protruding width W1 of the side flange 105a was more than or equal to the protruding width W2 of the second side surface 106, so that the second side surfaces were not abutted against each other and the gap was thus formed, and as result, rainwater entered the ridge direction from the opening of the abutted portion of the first side surfaces. These results demonstrated that it was advantageous to set the protruding width W1 to be more than or equal to W2 to allow the second side surfaces to closely adhere to each other, thereby suppressing rainwater entering the eave side from the opening portion generated at the first side surface portion due to a wind storm.
In each of Nos. 8 and 13, the thickness of the front substrate was less than 0.27 mm, so that the bending strength was insufficient. In No. 9, the thickness of the front substrate was more than 0.5 mm, so that the evaluation of the roofing member weight was poor (×). These results demonstrated that it was advantageous to set the thickness of the metal sheet making up the front substrate 10 to be 0.27 mm or more and 0.5 mm or less.
In the case of each of Nos. 13 and 16 where the curvature radius was less than 0.5 mm, the front substrate 10 was made of the coated hot-dip Al plated steel sheet, so that cracks were generated in the coated film and the plated layer, and as a result, corrosion was generated at the abutted portion between the roofing members and the evaluation rating of corrosion resistance was poor. These results demonstrated that it was advantageous to set the curvature radius of the bent portion of the metal sheet to be 0.5 mm or more when using the metal sheet having the coated film and/or the plated layer.
In No. 6, the thickness of the body portion 100 (roofing member) was less than 4 mm, so that the evaluation of the bending strength was poor (×). The heat insulating performance was slightly lowered and evaluated as (Δ). These results demonstrated that it was advantageous to set the height of the body portion 100 to be 4 mm or higher. Although not particularly shown in Table 1, the organic mass of the core material 12 can be prevented from becoming excessive by setting the height of the body portion 100 to be 8 mm or lower, thereby allowing certification of noncombustible material to be more reliably obtained.
In No. 12, the back substrate 11 was the coated hot-dip Zn-based plated steel sheet which was not lightweight, so that the evaluation of roofing member weight was poor. This result demonstrated that it was advantageous to use a lightweight material such as aluminum foil, aluminum metallized paper, aluminum hydroxide paper, calcium carbonate paper, a resin film or glass fiber paper as the back substrate 11.
In No. 17 having no core material, the bending strength was insufficient and the evaluation of warp was poor, as well as the heat insulation properties were significantly deteriorated.
The inventors carried out a wind pressure resistance test on the roofing members in accordance with Japanese Industrial Standard A 1515. That is, the presence or absence of breakage in a test member when pressed in a pressing process was evaluated using a dynamic wind pressure tester.
A coated hot-dip Zn-55% Al plated steel sheet having a thickness of 0.27 mm and an aluminum sheet having a thickness of 0.5 mm were used as the material of the front substrate 10. These materials were subjected to bulging processing to produce the body portion 100. Glass fiber paper as the back substrate 11 was disposed on the back side of the front substrate 10 so as to cover the opening of the body portion 100, and a cyanurate resin was injected into the gap between the front substrate 10 and the back substrate 11, using a commercially available injection machine. Foaming of the resin was accomplished by holding the resin for 2 minutes in a mold at which the temperature was adjusted to 70° C. by circulating hot water; subsequently, the roofing member was removed from the mold, and was allowed to stand for 5 minutes under conditions of temperature of 20° C., to complete the foaming of the resin. The thickness of the roofing member was 5 mm. The metal sheet extending from a lower edge of the body portion 100 toward the outer direction of the body portion 100 was cut such that the width of the flange was 5 mm, and the metal sheet was processed to the bent shape of
Wind pressure resistance was evaluated on the basis of a breaking pressure at the time of induced breakage. When the coated hot-dip Zn-55% Al plated steel sheet having a thickness of 0.27 mm was used as the material of the front substrate 10, the breaking pressure was a negative pressure of 6,000 N/m2 or more, whereas when the aluminum sheet having a thickness of 0.5 mm was used as the material of the front substrate 10, the breaking pressure was a negative pressure of 5,000 N/m2 or more and less than 6,000 N/m2. That is, it was found that improved wind pressure resistance can be achieved even if an aluminum sheet is used, and that further improved wind pressure resistance can also be achieved when a steel sheet is used. Work hardening of the peripheral wall portion 102 derived from bulging is more notably presented in the steel sheet than in the aluminum sheet; it is believed that this difference in hardness of the peripheral wall portion 102 brings about the difference in evaluation results in the wind pressure resistance test.
According to such a metal roofing member 1, and the roofing structure and roofing method that utilize the metal roofing member 1, the metal roofing member 1 is configured to be arranged on the roof base while abutting the second side surface 106 of the metal roofing member 1 against a second side surface 106 of other metal roofing member 1. Therefore, this can allow reduction of water pooled between the metal roofing members, and also allow reduction of water entering the ridge side of the metal roofing member 1. Further, since the first side surface 105 is provided with the side flange 105a, the strength of the metal roofing member 1 can be improved.
Further, the ridge-side end surface 107 includes the inclined portions 107b which are provided on both sides of the straight portion 107a so as to connect the straight portion 107a and the second side surface 106, and which each extends so as to be inclined to the straight portion 107a such that each inclined portion 107 is directed to the eave side as it approaches the second side surface 106. Therefore, water entering the ridge side can be guided to the abutted portion of the second side surfaces 106 by the inclined portions 107b, and the water can be gradually discharged to the eave side through the abutted portion.
Furthermore, since the straight portion 107a of the ridge-side end surface 107 is provided with the ridge-side flange 107c, warping of the metal roofing member 1 along the direction crossing the width direction 100a can be reduced.
Moreover, since the eave side end surface 108 is provided with the eave-side flange 108a, warping of the metal roofing member 1 along the direction crossing the width direction 100a can be reduced. Also, the flange 108a provided on the straight portion of the eave-side end surface 108 will be a portion where a wind pressure is applied. This portion will tend to generate partial warpage due to strong wind and to generate a gap between the upper and lower roofing members. However, the flange 108a suppresses generation of the gap and improves durability (wind pressure resistance performance).
In particular, the surface rigidity can be increased by providing the flanges 107a, 108b and 105a which surround the four sides of the roofing member. As a force applied to the lower roof pressed by the tightened upper roofing member is increased, neither the upper roof nor the lower roof is easily deformed. As a result, the durability (wind pressure resistance performance) is improved. In addition, the flanges 107a, 108b and 105a which surround the four sides of the roof member have effects of improving the flatness of the roofing member itself and of suppressing initial warping and twist, and the gaps between the upper and lower roofing members generated due to the warping and twist.
Further, since the body portion 100 includes the peripheral wall portion 102 comprised of a wall surface that is continuous in the circumferential direction of the front substrate 10, any the possibility of water entering the body portion 100 can be reduced.
Further, the protruding width W1 of the flange (the side flange 105a, the ridge-side flange 107c and the eave-side flange 108a) is 2 mm or more and 5 mm or less, and hence the flange can be imparted with sufficient strength, and the design properties of the metal roofing member 1 can be maintained satisfactorily.
The metal sheet as the material of the front substrate 10 is made of the hot-dip Zn-based plated steel sheet, the hot-dip Al plated steel sheet, the hot-dip Zn-based plated stainless steel sheet, the hot-dip Al plated stainless steel sheet, the stainless steel sheet, the Al sheet, the Ti sheet, the coated hot-dip Zn-based plated steel sheet, the coated hot-dip Al plated steel sheet, the coated hot-dip Zn-based plated stainless steel sheet, the coated hot-dip Al plated stainless steel sheet, the coated stainless steel sheet, the coated Al sheet or the coated Ti sheet. Therefore, the concern of corrosion of the metal roofing member can be more reliably reduced.
Further, since the the metal sheet making up the front substrate 10 has a thickness of 0.27 mm or more and 0.5 mm or less, the strength required for the roofing member can be sufficiently ensured, and the weight of the metal roofing member 1 can be prevented from becoming excessively large. Such a configuration is particularly useful when equipment such as a solar cell module, a solar water heater, an air conditioner outdoor unit or snow melting equipment is provided on the roof.
Further, the bent portion of the metal sheet included in the flange has a curvature radius of 0.5 mm or more. Therefore, it is possible to avoid the generation of cracks in the coated film and the plated layer of the metal sheet due to bending, so that corrosion of the metal sheet can be more reliably avoided.
Furthermore, the body portion 100 has a height h of 4 mm or more and 8 mm or less, the certification of noncombustible material can be more surely obtained while maintaining the heat insulating properties and strength.
Further, the body portion 100 is formed by subjecting the metal sheet to drawing or bulging processing, and is made of the hot-dip Zn-based plated steel sheet, the hot-dip Al plated steel sheet, the hot-dip Zn-based plated stainless steel sheet, the hot-dip Al plated stainless steel sheet, the stainless steel sheet, the Al sheet, the Ti sheet, the coated hot-dip Zn-based plated steel sheet, the coated hot-dip Al plated steel sheet, the coated hot-dip Zn-based plated stainless steel sheet, the coated hot-dip Al plated stainless steel sheet or the coated stainless steel sheet. Therefore, the hardness of the peripheral wall portion 102 can be improved by work hardening, and better wind pressure resistance performance can be achieved.
Moreover, the weight of the metal roofing member 1 can be prevented from being excessively large, because the back substrate 11 comprises or comprised of the aluminum foil, aluminum metallized paper, aluminum hydroxide paper, calcium carbonate paper, the resin film or glass fiber paper.
Furthermore, the metal roofing member 1 on the ridge side is arranged by overlapping with the metal roofing member 1 on the eave side such that the eave-side end portion of the metal roofing member 1 on the ridge side is positioned above the first side surface 105 and the side flange 105a of the metal roofing member 1 on the eave side. Therefore, it is possible to withstand an external force by the side flange 105a having relatively higher strength, so that warping of the metal roofing member 1 on the eave side can be suppressed.
In addition, the second side surface 106 of the metal roofing member 1 on the ridge side is positioned above the ridge-side end portion of the metal roofing member 1 on the eave side. Therefore, it is possible to reduce any risk that water enters the ridge side of the metal roofing member 1 on the eave side through the gap between the metal roofing members 1 on the ridge side.
Number | Date | Country | Kind |
---|---|---|---|
2015-231569 | Nov 2015 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2016/059384 | 3/24/2016 | WO | 00 |