JP2018141369A - Metallic roof material and manufacturing method thereof, and roofing structure and roofing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic roof material capable of improving wind pressure resistance performance.SOLUTION: A metallic roof material 1 is arranged side by side together with other metallic roof materials on a roof substrate. The metallic roof material 1 has a box-shaped front base material 10 including a metal plate made of a steel plate, a rear base material 11 arranged at the rear side of the front base material 10 so as to close an opening of the front base material 10, and a core material 12 made of resin foam filled up between the front base material 10 and the rear base material 11. The front base material 10 includes a side wall part continuing in a circumferential direction. Vickers hardness in whole of the side wall part is enhanced from 1.4 times to 1.6 times than that of the metal plate by work-hardening.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a metal roof material arranged side by side with other metal roof materials on a roof base.

  As this kind of metal roofing material used conventionally, the structure shown by the following patent documents 1-3 etc. can be mentioned, for example. That is, in the conventional metal roofing material, a metal plate having a shape as shown in FIG. 5 is bent to form a box-shaped surface base material. Concrete, a synthetic resin foam, a synthetic resin sheet, or the like is filled or sandwiched in the void portion of the front substrate.

JP 2003-74147 A JP-A-52-97228 JP-A-2-190553

  The conventional metal roof material as described above has a certain thickness in order to ensure the function as the roof material. However, since it is a roof material that is simply bent and box-shaped, the following problems arise. That is, in recent years, the mounting of solar cell modules on the roof has increased rapidly. This solar cell module is generally arranged side by side on the roof base via fastening metal fittings, etc., but from the viewpoint of structural constraints and design, and further downsizing of the module fastening member, the roof material is more Thinning is required. However, in the conventional metal roofing material by bending, there is a problem that the wind-resistant performance decreases when it is thinned.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a metal roof material capable of improving the wind pressure resistance, a manufacturing method thereof, a roofing structure, and a roofing method. It is to be.

  The metal roof material according to the present invention is a metal roof material arranged side by side with other metal roof materials on the roof base, and a box-shaped surface base material made of a metal plate made of a steel plate, and a surface base A back substrate disposed on the back side of the front substrate so as to close the opening of the material, and a core material made of foamed resin filled between the front substrate and the back substrate, The whole side wall part has a Vickers hardness 1.4 to 1.6 times higher than that of the metal plate by work hardening.

  Moreover, the manufacturing method of the metal roofing material according to the present invention includes a box-shaped front substrate made of a metal plate made of a steel plate, and a back disposed on the back side of the front substrate so as to close the opening of the front substrate. A method for producing a metal roofing material comprising a base material and a core material made of foamed resin filled between a front base material and a back base material, wherein the metal plate is subjected to drawing processing or overhanging processing, Including the formation of a front substrate having a side wall portion that is continuous in the direction, the Vickers hardness of the entire side wall portion is increased by 1.4 to 1.6 times that of the metal plate by work hardening.

  Further, the roofing structure according to the present invention includes a box-shaped front substrate made of a metal plate made of a steel plate, and a back substrate disposed on the back side of the front substrate so as to close the opening of the front substrate. And a core material made of foamed resin filled between the front base material and the back base material, the front base material has a side wall portion continuous in the circumferential direction, and the entire side wall portion is processed. A plurality of metal roofing materials whose Vickers hardness is increased by 1.4 to 1.6 times than the metal plate by curing are provided, and the plurality of metal roofing materials are arranged side by side on the roof base.

  Further, the roofing method according to the present invention includes a box-shaped front substrate made of a metal plate made of a steel plate, and a back substrate disposed on the back side of the front substrate so as to close the opening of the front substrate. And a core material made of foamed resin filled between the front base material and the back base material, the front base material has a side wall portion continuous in the circumferential direction, and the entire side wall portion is processed. Using a plurality of metal roofing materials whose Vickers hardness is increased by 1.4 to 1.6 times that of the metal plate by curing, and arranging the plurality of metal roofing materials side by side on the roof base.

  According to the metal roofing material, the manufacturing method thereof, the roofing structure, and the roofing method of the present invention, the front substrate has a side wall portion that is continuous in the circumferential direction, and the entire side wall portion is Vickers than the metal plate by work hardening. Since the hardness is increased by 1.4 to 1.6 times, the wind pressure resistance can be improved.

It is a top view which shows the metal roof material by Embodiment 1 of this invention. It is sectional drawing which follows the line II-II of FIG. It is explanatory drawing which shows the roofing structure and roofing method using the metal roof material of FIG.1 and FIG.2. It is explanatory drawing which shows the relationship of the two metal roof materials arrange | positioned shifting in the eaves-ridge direction of FIG. It is explanatory drawing which shows the structure of the conventional metal roof material.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a plan view showing a metal roof material 1 according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  The metal roofing material 1 shown in FIG.1 and FIG.2 is arrange | positioned along with another metal roofing material on the roof base | substrate of buildings, such as a house. As particularly shown in FIG. 2, the metal roof material 1 has a front base material 10, a back base material 11, and a core material 12.

  The front substrate 10 is made of a metal plate, and is a member that appears on the outer surface of the roof when the metal roofing material 1 is placed on the roof base.

  The metal plate that is the material of the front substrate 10 includes a hot-dip Zn-plated steel plate, hot-dip Al-plated steel plate, hot-dip Zn-plated stainless steel plate, hot-dip Al-plated stainless steel plate, stainless steel plate, painted hot-melt Zn-plated steel plate, and paint-melted Al. A plated steel plate, a coated hot-dip Zn-plated stainless steel plate, a painted hot-Al plated stainless steel plate, a painted hot-Al-Zn-plated steel plate, a painted stainless steel plate, a painted Al plate, or a painted Ti plate can be used.

  The thickness of the metal plate is preferably 0.27 mm or more and 0.5 mm or less. As the thickness of the metal plate increases, the strength of the roofing material increases but the weight also increases. By setting the thickness of the metal plate to 0.27 mm or more, sufficient strength required as a roofing material can be secured, and wind pressure resistance and tread resistance can be sufficiently obtained. By setting the thickness of the metal plate to 0.5 mm or less, it is possible to avoid the weight of the metal roofing material 1 from becoming too large, and to cover equipment such as solar cell modules, solar water heaters, air conditioner outdoor units, snow melting related equipment, etc. The total weight of the roof when placed on top can be reduced.

  The front substrate 10 is formed in a box shape having a top plate portion 101 and a side wall portion 102. The front substrate 10 is formed by drawing or projecting a metal plate. Thereby, the side wall 102 is a wall surface continuous in the circumferential direction of the front substrate 10. By making the side wall part 102 into the wall surface which continued in the circumferential direction, the stress added to the surface base material 10 can be received in the whole side wall part 102, and the wind-resistant performance of the metal roof material 1 can be improved. The wind pressure resistance is the performance that the metal roofing material 1 can withstand without buckling against strong wind.

  In particular, steel plates (hot Zn-plated steel plates, hot-dip Al-plated steel plates, hot-dip Zn-plated stainless steel plates, hot-dip Al-plated stainless steel plates, stainless steel plates, Al plates, Ti plates, painted hot-dip Zn-based plating as the metal plate of the front substrate 10 Steel plate, painted hot-dip Al-plated steel plate, painted hot-dip Zn-plated stainless steel plate, painted hot-plated Al-plated stainless steel plate, painted hot-Al-Zn-plated stainless steel plate, painted stainless steel plate) When 10 is formed, the hardness of the side wall 102 is increased by work hardening. Specifically, the Vickers hardness of the side wall 102 is increased by about 1.4 to 1.6 times compared to before processing. As described above, the side wall 102 is a wall surface continuous in the circumferential direction, and the hardness of the side wall 102 is increased by work hardening, so that the wind pressure resistance of the metal roofing material 1 is remarkably improved.

  In addition, when the metal plate is bent to form a box shape as in the conventional configuration shown in FIG. 5, a break is generated between the side wall portions. The side wall portions independent by the cuts individually receive the stress applied to the front substrate. For this reason, compared with the structure of this Embodiment in which the side wall part 102 is made into the wall surface continued in the circumferential direction, a metal roof material will buckle also with a weaker wind. Moreover, work hardening does not arise in the whole side wall part only by bending a metal plate.

  The back substrate 11 is a member arranged on the back side of the front substrate 10 so as to close the opening of the front substrate 10. As the back substrate 11, a lightweight material such as aluminum foil, aluminum vapor-deposited paper, aluminum hydroxide paper, calcium carbonate paper, resin film or glass fiber paper can be used. By using these lightweight materials for the back substrate 11, it is possible to avoid an increase in the weight of the metal roofing material 1.

  The core material 12 is made of a foamed resin filled between the front substrate 10 and the back substrate 11. By filling the foamed resin between the front base material 10 and the back base material 11, the core inside the front base material 10 can be used instead of an aspect in which a backing material such as a resin sheet is attached to the back side of the front base material 10. The material 12 can be firmly adhered, and the performance required for the roofing material such as rain sound property, heat insulating property, and tread resistance can be improved.

  In addition, in the structure in which the cut is formed between the side wall portions as in the conventional configuration, an operation of sealing the cut is required to avoid leakage of the foamed resin from the cut. On the other hand, such a work is not required because the side wall 102 is a wall surface continuous in the circumferential direction as in the configuration of the present embodiment.

  There is no restriction | limiting in particular as a raw material of the core material 12, Urethane, phenol, a nurate resin etc. can be used. However, it is essential to use incombustible certified materials for roofing materials. In the incombustible material qualification test, an exothermic test based on the ISO 5660-1 cone calorimeter test method is performed. When the foamed resin to be the core material 12 is urethane having a large calorific value, the thickness of the front substrate 100 can be reduced, or the foamed resin can contain inorganic foam particles.

  The height h of the front substrate 10 filled with the core material 12 is 4 mm or more and 8 mm or less. By setting the height h of the front substrate 100 to 4 mm or more, the strength of the front substrate 10 can be increased and the wind pressure resistance can be improved. Further, by setting the height h of the front substrate 10 to 8 mm or less, the organic material of the core material 12 is avoided from being excessively increased, and the incombustible material certification can be obtained more reliably.

  Next, FIG. 3 is an explanatory view showing a roofing structure and a roofing method using the metal roofing material 1 of FIGS. 1 and 2, and FIG. 4 is arranged 2 shifted in the eaves-ridge direction 3 of FIG. 3. It is explanatory drawing which shows the relationship of the two metal roofing materials.

  As shown in FIG. 3, the metal roof material 1 is arranged on the roof base while the side edge of the front base material 10 is abutted with the side edge of the front base material 10 of the other metal roof material 1. More specifically, the plurality of metal roofing materials 1 are arranged side by side on the roof base while the side ends of the front base materials 10 are abutted against each other in the direction 2 parallel to the eaves. Each metal roofing material 1 is fixed to the roof base by a stop member 4 such as a nail. In FIG. 3, in order to avoid complication of the drawing, the stop member 4 is shown for only one metal roof material 1, and the illustration of the stop member 4 for the other metal roof material 1 is omitted.

  When the side ends of the front base material 10 are abutted, the side ends of the adjacent front base materials 10 are brought into contact with each other, or the side ends of the front base materials 10 of the adjacent metal roofing materials 1 are close to each other. Means. The metal roofing materials 1 arranged side by side have the same configuration. However, other metal roofing materials can be used at different conditions such as the edge of the roof.

  Further, the plurality of metal roofing materials 1 are arranged on the roof base while the eaves side end of the metal roofing material 1 on the ridge side is superimposed on the ridge side end of the metal roofing material 1 on the eave side with respect to the eaves building direction 3. Placed in. At least one part of the stop member 4 is struck so as to penetrate both the eaves-side metal roofing material 1 and the ridge-side metal roofing material 1. In this way, the stop member 4 is struck so as to penetrate both the eaves-side metal roofing material 1 and the ridge-side metal roofing material 1, so that the ridge-side metal roofing material 1 is It can arrange | position substantially parallel to the metal roofing material 1 of the eaves side, and it can reduce that the eaves side edge part of the metal roofing material 1 of the ridge side floats up. The watertightness of the roof can be improved by reducing the lifting of the eaves side end of the metal roofing material 1 on the ridge side.

  As shown in FIG. 3, the length L <b> 2 where the metal roofing material 1 overlaps in the eaves building direction 3 is larger than the length L <b> 1 where the building-side metal roofing material 1 does not overlap with the eaves-side metal roofing material 1 ( L2> L1). Thereby, the stop member 4 can be struck so that it may penetrate both the eaves-side metal roofing material 1 and the ridge-side metal roofing material 1 in a wider area.

  Next, an example is given. The inventor made a prototype of the metal roofing material 1 as a test material under the following conditions.

The material of the front substrate 10 was a 0.20 to 0.8 mm coated hot-melt Zn-55% Al-plated steel plate, a paint-hot Zn-6% Al-3% Mg-plated steel plate or a painted hot-Al-plated steel plate.
As the back substrate 11, 0.2 mm glass fiber paper, 0.2 mm Al vapor-deposited paper, 0.2 mm PE resin film, and 0.1 mm Al foil were used.
As the core material 12, a two-component mixed type foamed resin was used. The mixing ratio of the polyol component and the isocyanate, phenol or nurate component was 1: 1 by weight.
For comparison, concrete and synthetic resin sheets were also used.

  The front substrate 10 was processed to have a predetermined roof material thickness and shape. The processing was performed by drawing or overhanging with a press machine. The mold clearance, molding speed, surface lubricity, and material temperature during processing were adjusted so that the Vickers hardness of the side wall after processing was 1.4 to 1.6 times that before processing. For comparison, a box-shaped roof material was also created by bending 90 ° by a vendor.

  The processed front base material 10 has a back base material 11 disposed on the back side of the front base material 10 so as to close the opening of the front base material 10, and the front base material 10 and the back base material 11 are separated by a commercially available high-pressure injector. A foamed resin was injected into the space between them. The foamed resin is kept in a mold whose temperature is adjusted to 70 ° C. by circulating hot water for 2 minutes, and then the roofing material is taken out of the mold and left at room temperature of 20 ° C. for 5 minutes to complete the foaming of the resin. It was.

  After completing the foaming of the resin, the flange portion was cut and bent by a bender. The final size of the metal roofing material 1 was 414 mm × 910 mm. The final roof material thickness was in the range of 4 mm to 8 mm.

  In addition, for comparison, a metal in which 0.3 mm-painted Zn-55% Al alloy-plated steel sheet is used as a surface base material to be bent into a box shape by bending four sides inward by 90 ° using a bender, and foamed resin is injected by the above-described method. The roof material was also prototyped (conventional configuration).

A 0.2 mm glass fiber paper was used for the backing substrate. In addition, the dimension of the roofing material was 6 mm in thickness, and other conditions were the same as those described above.
For comparison, a metal roof material not injected with foamed resin and a roof material obtained by bonding a commercially available 0.3 mm heat-insulating polyethylene sheet to a surface base material processed with an adhesive were also used for the test.

  The present inventor uses the above-described test materials to (1) evaluate the wind pressure resistance of the roof material, (2) evaluate the weight of the roof material, (3) evaluate the stepping property of the roof material, and (4) heat insulation. Was evaluated. The results are shown in the following table.

(1) Certification of evaluation criteria for roof material wind pressure resistance The wind pressure resistance test was conducted in accordance with Japanese Industrial Standard A1515. That is, using a dynamic wind pressure test apparatus, the presence or absence of destruction of the specimen when pressurized in the pressurization process was observed. Evaluation of resistance to wind pressure resistance were evaluated by breaking pressure when leading to destruction, destruction pressure is negative pressure 6,000N / m ² or more ◎, the negative pressure 5,000 N / m ² or more 6,000N / m less than ² ○ , less than the negative pressure 2250 over 5000N / m ² △, was × less than the negative pressure 2250N / m ^2.

(2) Evaluation Criteria for Roof Material Weight The weight of the roof material was measured and evaluated according to the following criteria. In addition, this evaluation criteria assumed that a standard 130 N / m ² solar cell module was mounted on the roof, and evaluated according to the following evaluation criteria from the weight of the entire roof including the roofing material.
○: The weight of the roofing material is less than 250 N / m ² ×: The weight of the roofing material is 250 N / m ² or more

(3) Crushability of roofing material A person with a weight of 65-75 kg stands on one foot in the center of the roofing material, and after adding the total weight to the roofing material, the deformation of the roofing material under no load is visually evaluated. did. The case where there was a significant deformation was indicated as x, the case where there was a slight deformation, Δ, and the case where there was no deformation, ○.

(4) Evaluation method and evaluation standard of heat insulation A thermocouple was attached to the front base material surface of the simulated roof and the back surface of the field plate which evaluated the staying state of rainwater. 12 lamps (100 / 110V, 150W) are evenly arranged at a position of 180mm from the surface of the simulated roof, and the temperature at the back of the baseboard after 1 hour of irradiation is measured with a thermocouple at a lamp output of 60%. Insulation was evaluated.
The heat insulation was evaluated according to the following criteria.
○: The temperature of the back of the base plate is less than 50 ° C.
(Triangle | delta): A baseplate back temperature is 50-55 degreeC.
X: The baseplate back temperature is 55 ° C or higher.

  In Table 1, no. 10-12, the wind pressure resistance evaluation was x. This is no. It is considered that 10 to 12 surface base materials are formed by bending as in the conventional configuration. On the other hand, in other test materials, since the surface base material was formed by drawing or overhanging, the wind pressure resistance was evaluated as Δ, ○, or ◎. Thereby, the superiority of forming the front substrate by drawing or overhanging was confirmed.

  No. Nos. 9 and 13 were evaluated as Δ in wind resistance resistance. This is no. In No. 9, the core material 12 is omitted. No. 13 is considered because the height h of the front substrate is lower than 4 mm. For this reason, in the structure which forms a surface base material by a drawing process or an overhang | projection process, while providing the core material 12, it was confirmed that the height h of a surface base material shall be 4 mm or more. In addition, although a test result etc. are not shown especially in Table 1, it avoids that the organic mass of the core material 12 increases too much by making the height of the table | surface base material 8 or less, and more reliably nonflammable. Material certification can be obtained.

  In No. 13, the thickness of the front substrate is less than 0.27 mm, which is considered to cause a decrease in wind pressure resistance. Moreover, the thickness of the surface base material of No. 14 exceeded 0.5 mm, and the roofing material weight became evaluation of x. From this result, it was confirmed that the thickness of the metal plate constituting the surface base material 10 is 0.27 mm or more and 0.5 mm or less.

  No. In No. 8, the evaluation of wind pressure resistance was ○. Thereby, it was confirmed that even with a metal other than a steel plate such as Al, it is possible to improve the favorable wind pressure resistance by forming the front substrate by drawing or overhanging.

  No. In Nos. 1 to 7, the wind pressure resistance was evaluated as ◎. Thus, it was confirmed that by performing drawing or overhanging on the steel sheet, the hardness of the side wall portion 102 is increased by work hardening, and the wind pressure resistance performance of the metal roofing material 1 is remarkably improved.

  In addition, although test results etc. are not particularly shown in Table 1, the weight of the metal roofing material 1 is reduced by using a lightweight material such as glass fiber paper, Al vapor-deposited paper, PE resin negative film, and Al foil as the back substrate. It can avoid becoming too large. When a metal plate such as a front substrate is applied to the back substrate, the weight of the roof material becomes large, causing a problem.

  According to such a metal roofing material 1 and a manufacturing method thereof, a roofing structure and a roofing method, the front base material 10 has the side wall part 102 which continues in the circumferential direction, and the entire side wall part 102 is made of metal by work hardening. Since the Vickers hardness is increased by 1.4 to 1.6 times compared to the plate, the wind pressure resistance can be improved. Thereby, the roof material thinner than the conventional configuration can be provided while maintaining the wind pressure resistance.

  Moreover, the metal plate which is the raw material of the surface base material 10 is a hot-dip Zn-plated steel plate, hot-dip Al-plated steel plate, hot-dip Zn-plated stainless steel plate, hot-dip Al-plated stainless steel plate, stainless steel plate, painted hot-melt Zn-plated steel plate, paint melt Since it is made of an Al-plated steel sheet, a coated hot-dip Zn-plated stainless steel sheet, a painted hot-Al-plated stainless steel sheet, a painted hot-Al-Zn-plated stainless steel sheet, or a painted stainless steel sheet, the hardness of the side wall 102 can be improved by drawing or overhanging. Wind resistance performance can be further improved.

  Moreover, since the plate | board thickness of the metal plate which comprises the surface base material 10 is 0.27 mm or more and 0.5 mm or less, the increase in a weight can be suppressed, ensuring a wind-resistant performance.

  Furthermore, since the back base material 11 consists of aluminum foil, aluminum vapor deposition paper, aluminum hydroxide paper, calcium carbonate paper, a resin film, or glass fiber paper, it can avoid that the weight of the metal roofing material 1 becomes too large.

DESCRIPTION OF SYMBOLS 1 Metal roofing material 10 Front base material 11 Back base material 11a Back surface 12 Core material

Claims (13)

A metal roofing material arranged side by side with other metal roofing materials on the roof base,
A box-shaped surface base material made of a metal plate made of a steel plate; and
A back substrate disposed on the back side of the front substrate so as to close the opening of the front substrate;
A core material made of foamed resin filled between the front base material and the back base material,
The front substrate has a side wall portion continuous in the circumferential direction,
The metal roofing material, wherein the entire side wall portion has a Vickers hardness of 1.4 to 1.6 times higher than that of the metal plate by work hardening. The metal plate, which is the material of the front substrate, is a molten Zn-based plated steel sheet, a molten Al-plated steel sheet, a molten Zn-based plated stainless steel sheet, a molten Al-plated stainless steel sheet, a stainless steel sheet, a painted molten Zn-based plated steel sheet, and a coated molten Al sheet. The metal roofing material according to claim 1, wherein the metal roofing material is made of a plated steel plate, a coated hot-dip Zn-plated stainless steel plate, a painted hot-Al-plated stainless steel plate, a painted hot-Al—Zn-plated steel plate, or a painted stainless steel plate. The metal roofing material according to claim 1 or 2, wherein a thickness of the metal plate constituting the front substrate is 0.27 mm or more and 0.5 mm or less. The said back base material consists of aluminum foil, aluminum vapor-deposited paper, aluminum hydroxide paper, calcium carbonate paper, a resin film, or glass fiber paper. The said any one of Claim 1 to 3 characterized by the above-mentioned. Metal roofing material. The height of the surface base material is 4 mm or more and 8 mm or less. The metal roof material according to any one of claims 1 to 4, wherein the height is 4 mm or less and 8 mm or less. A box-shaped front substrate made of a metal plate made of a steel plate, a back substrate arranged on the back side of the front substrate so as to close the opening of the front substrate, the front substrate and the back substrate A method for producing a metal roofing material comprising a core material made of foamed resin filled between the materials,
Including subjecting the metal plate to drawing or overhanging to form the front substrate having a side wall portion continuous in the circumferential direction,
The method for producing a metal roof material, wherein the entire side wall portion has a Vickers hardness of 1.4 to 1.6 times higher than that of the metal plate by work hardening. The height of the front substrate is 4 mm or more and 8 mm or less. The method for producing a metal roof material according to claim 6. A box-shaped surface base material made of a metal plate made of a steel plate; and
A back substrate disposed on the back side of the front substrate so as to close the opening of the front substrate;
Each having a core made of a foamed resin filled between the front substrate and the back substrate,
The front substrate has a side wall portion continuous in the circumferential direction,
The entire side wall includes a plurality of metal roofing materials whose Vickers hardness is increased by 1.4 to 1.6 times than the metal plate by work hardening,
The roofing structure, wherein the plurality of metal roof materials are arranged side by side on a roof base. The roofing structure according to claim 8, wherein a height of the front base material is 4 mm or more and 8 mm or less. The plurality of metal roofing materials are arranged side by side in a direction parallel to the roof eaves, and the ridge side metal roofing material is placed on the ridge side end of the eaves side metal roofing material with respect to the roof eaves direction. The roofing structure according to claim 8 or 9, wherein the eaves side end portions are arranged while being overlapped. A box-shaped surface base material made of a metal plate made of a steel plate; and
A back substrate disposed on the back side of the front substrate so as to close the opening of the front substrate;
Each having a core made of a foamed resin filled between the front substrate and the back substrate,
The front substrate has a side wall portion continuous in the circumferential direction,
The entire side wall portion uses a plurality of metal roofing materials whose Vickers hardness is increased by 1.4 to 1.6 times than the metal plate by work hardening,
Arranging the plurality of metal roofing materials side by side on a roof base. The roofing method according to claim 11, wherein a height of the front base material is 4 mm or more and 8 mm or less. The plurality of metal roofing materials are arranged side by side in a direction parallel to the roof eaves, and the ridge side metal roofing material is placed on the ridge side end of the eaves side metal roofing material with respect to the roof eaves direction. The roofing method according to claim 11 or 12, wherein the eaves side end portions are arranged while being overlapped.