JPH0348998Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a siding board (hereinafter simply referred to as a board) that is useful for forming horizontal and vertical walls inside and outside buildings and structures. ) regarding. [Prior art] This type of board that has been used in the past includes Tokoku No. 51-29339, Utility Model No. 51-11882,
There is Jikko No. 54-26649. however,
There were various problems with the above board. In other words, if rainwater is blown by the wind on a board (cladding board), the rainwater will leak to the back side because it is simply a connecting structure between flat plates, corroding the edges and pillars, and adding moisture to the room and closet. There was a drawback. In addition, since the length of the sloped part of the lower edge to the rising part of the board is long, it is weak in tensile force and has the disadvantage that only an exterior without joints can be formed. Moreover, although the exterior was originally without joints, due to the skill of the builder, the exterior was made up of joints of varying widths, some with no joints, some with joints, and there was a risk of injury at the rising parts during construction. In addition, the board has a complicated side shape, making it difficult and expensive to mold.Furthermore, there are no reinforcing ribs on the flat part, so warping, twisting, etc. appear on the decorative surface and spoil the aesthetic appearance. There were flaws. In addition, since all boards have no backing material and the wall base and surface material come into direct contact, condensation forms on the back of the decorative surface, leading to rust and corrosion of the wall base, and the insulation of the wall itself. Fireproof,
It lacks soundproofing properties, cannot prevent deformation of the decorative surface, and has the drawbacks that the board itself is easily deformed and lacks connecting force. Additionally, these boards had the drawback of lacking a three-dimensional effect. [Purpose of the invention] In order to eliminate the above-mentioned drawbacks, the present invention has the following objectives:
At least one decorative groove with a triangular cross-section formed from the side wall and the inclined side wall is provided in the decorative surface part formed at both ends of the side wall and the inclined side wall to divide it into a plurality of horizontal decorative pieces. By increasing the proportion of the bead to the bead, the specular reflection becomes diffused, making the bead stand out and enhance the three-dimensional effect, and the bead's twisting,
It prevents bending and warping, and improves economy and latheability by making the board wider. Also, a male connecting part with an insertion edge and an engaging groove is formed on the edge of the inclined side wall of the decorative surface part. A female connecting portion having a fitting groove is formed on the edge of the side wall, and the connecting structure of the board is engaged as a double layer of the insertion edge and the fitting groove, and the engaging groove and the lower edge of the fitting groove. The resultant force and waterproofness are improved, and in addition, a recessed groove is formed along the longitudinal direction on the upper side of the insertion edge, and a waterproof groove is provided at the innermost part of the upper edge of the fitting groove.
In addition to doubly preventing capillary action and further strengthening waterproofness, the board is a drop-in type that can be easily installed by one person, and it also proposes a board that can be used vertically. It is. [Structure of the invention] Representative embodiments of the board according to the invention will be described in detail below with reference to the drawings. That is,
FIG. 1 is a perspective view showing the board A, which includes surface-treated steel sheets, zinc-nickel alloy plated steel plates, aluminum-zinc alloy plated steel plates (product names: GALF-AN, Galvalume steel plate, Superging), aluminum plates, and aluminum alloy plates. , a surface material 1 made of a metal plate (including flat plate and embossed plate) made of one type of copper plate, clad steel plate, vibration damping steel plate, etc., or a synthetic resin plate by one type of roll, press, or extrusion molding. , a core material 23 filled in the back surface of the surface material 1 , and a sheet-like back material 24 covering the back surface of the core material 23.
To explain further, the surface material 1 is composed of a decorative surface part 2 , a male connecting part 9 , and a female connecting part 17 , as shown in FIG. To explain further, the decorative surface section 2 has a substantially gutter-like cross section formed by an inclined side wall 3 bent at θ ₁ at one end and a side wall 4 bent at θ ₂ at the other end. Since this inclined side wall 3 has θ ₁ <90°, it improves the flow of rainwater and prevents rainwater from accumulating in the joints. 1:5～
It is formed to have a ratio of 0.2, and is useful for strengthening the three-dimensional appearance of the joint area through specular reflection and diffused reflection, and increasing the working width. The side walls 4 cast shadows on the joints and enhance the three-dimensional appearance of the wall. Further, at least one cosmetic groove 5 is formed along the longitudinal direction in the decorative surface portion 2 , and a plurality of horizontal decorative pieces 2a, 2b are formed by the decorative groove 5. This decorative groove 5 has a side surface 6 that intersects with the decorative piece _2a at least at an angle θ ₃ corresponding to the angle θ 2 described above.
, an inclined surface 7 that intersects with the decorative piece 2b at an angle θ ₄ corresponding to the angle θ ₁ , and a recess 8 formed between the side surface 6 and the inclined surface 7 . Furthermore, the cosmetic groove 5 is provided one in the center of the decorative surface part 2 , one in the center of the decorative surface part 2 , or a plurality of grooves (same shape, irregular shape) so as to divide the decorative surface part 2 into 3 to 5 parts. It mainly prevents warping, twisting, and unevenness of the decorative surface portion 2 , and also prevents the decorative surface portion 2 from being bent.
Together with the inclined side wall 3, the ratio is about 1:5 to 0.2,
The so-called makeup piece 2a, which creates a large shadow different from the conventional makeup groove and enhances the three-dimensional effect of the makeup surface part 2 ,
2b, the inclined side wall 3, and the decorative groove 5, the contrast of specular reflection and diffused reflection creates a sense of unevenness, and the cross section of the joint shown in FIG. 3 and the cross section of the decorative groove 5 are almost the same or similar. The joints between the boards A are made into decorative grooves to improve the design of the wall. The size of θ ₃ may be an acute angle, an obtuse angle, or a right angle; however, in the case of an acute angle, it becomes clear due to the step and is effective for emphasizing the angle using the inclined surface 7. In addition, the recess 8 makes the division between the side surface 6 and the sloped surface 7 clear, and also makes the appearance closely resemble the contact area between the side wall 4 and the sloped side wall 3 at the joint shown in FIG. This creates a horizontal line consisting of repeated grooves 5 and improves the design. The male connecting portion 9 has an insertion edge 10 protruding outward from the tip of the inclined side wall 3 substantially parallel to the decorative pieces 2a and 2b, and the tip of the insertion edge 10 is bent inward.
Next, the engagement groove 13 is bent outward to form a substantially U-shaped cross section, the extension portion 15 is formed by extending the lower edge 14 of the engagement groove 13 outward, and the tip of the extension portion 15 is formed as required. The tongue piece 16 bent into a seam shape and the insertion edge 10
It is formed from a groove portion 11 provided on the upper side and a reinforcing rib (pipe-shaped in the figure) 12. To explain further, the insertion edge 10 is a female connecting portion 17 which will be described later.
The engagement groove 13 engages the lower edge 19 of the engagement groove 20 to double the connection structure of the board A, thereby strengthening waterproofness, engagement force, and packing performance. , the board A can be used both horizontally and vertically. Furthermore, the groove portion 11 forms a void within the connecting structure of the board A to prevent capillary phenomenon. In addition, the reinforcing rib 12 functions as a rain cover, reinforces the tip of the insertion edge 10, and closes the opening of a waterproof groove 21, which will be described later, so that the gap for preventing capillary phenomenon is replaced by the gap formed by the groove 11. This is to make the gap formed by the waterproof groove part 21 double. Note that it is also possible to interpose a core material 28 between the upper and lower surfaces of the insertion edge 10. In addition, the extension part 15
is the part where board A is fixed to the wall base using fixing tools such as nails at a location where rainwater will not directly infiltrate. Further, the tongue piece 16 prevents the tip of the extension part 15 from waving, and also prevents injuries caused by the edge of the extension part 16 during operation. Although not shown, caulking material is applied to a portion of the groove 11.
It is also possible to install packing material to further strengthen waterproofness. In addition, the tongue piece 16 is formed in the shape of a seam,
It is also possible to pinch the edges of the back material 24.
The female connecting portion 17 bends the end edge of the side wall 4 inward to form an upper edge 18, then outwards to form a lower edge 19, and has a cross section that is approximately U-shaped from the upper edge 18 and the lower edge 19. It consists of a fitting groove 20 formed in a shape, a waterproof groove 21 provided at the innermost part of the upper edge 18, and a tongue piece 22 bent at the tip of the lower edge 19 into a seam shape.
This fitting groove 20 fits the insertion edge 10, and the lower edge 19 engages with the fitting groove 13. Further, as shown in FIG. 3, the opening of the waterproof groove 21 is closed by a reinforcing rib 12, and there are two gaps in the connecting structure: one by the groove 11 and the other by the waterproof groove 21.
It forms two voids and double prevents capillary action.
This strengthens waterproofness. Further, the tongue piece 22 prevents the edge of the lower edge 19 from waving, makes it easier to insert the lower edge 19 into the engagement groove 13, and prevents injury caused by the edge of the lower edge 19.
Note that the tongue piece 22 is formed into an upper seam shape as shown in the figure to sandwich the edge of the back material 24, thereby strengthening the integration of the surface material 1 , the core material 23, and the back material 24, and also It is also possible to prevent leakage from around the female type connecting portion 17 , or to form a bottom groove (not shown). The core material 23 is filled in at least a gutter-shaped part surrounded by the decorative surface part 2 , the male connecting part 9 , and the female connecting part 17 on the back side of the surface material 1 , and mainly provides insulation to the board A. It is made of one or more materials that have secondary functions such as adhesives, noncombustible materials, cushioning materials, and soundproofing materials. Specifically, synthetic resin foam, rock wool,
glass wool, sheathing board, gypsum board,
It is made of wood wool cement board, etc., and is made of raw material that is discharged, molded, hardened, and self-adhesive, or it is made of a molded body. In addition, when a molded body is used as the core material 23, an adhesive (not shown) is required between the core material 23, the surface material 1 , and the back material 24. To explain further, the core material 23 is mainly made of synthetic resin foam, such as resin for polyurethane foam, resin for phenol foam, resin for polyisocyanurate foam, polystyrene foam, etc.
Phenol foam resin is coated around pearlite and foamed by heating and pressurizing it, and these are combined with flame retardants and flame retardant aids (borax, sodium metaborate, antimony trioxide, calcium carbonate, aluminum hydroxide). , bentonite,
It is made by adding one or more of the following: pearlite grains, shirasu balloons). A recessed portion 23a is formed in the vicinity of the female connecting portion 17 of the core member 23, and in combination with the extension portion 15 at the connecting portion of the board A, looseness is removed and the fit of the board A is improved. Further, although not shown, the core material 23 may be provided to bulge downward from the back surface of the extension portion 15 to further improve heat insulation and fire protection. 2
4 is a backing material that covers at least the backside of the core material 23 to give the board A a sandwich structure, which improves the mechanical strength of the board A itself, as well as a noncombustible sheet, a waterproof membrane, a heat shielding sheet, a water absorbing sheet, a soundproofing sheet, and a packing material. For example, asbestos paper, kraft paper, asphalt felt, metal foil (Al, Fe, Pb, Cu), synthetic resin sheet, rubber sheet, cloth sheet, gypsum paper, aluminum hydroxide paper, glass. Type 1 or 2 of fiber non-woven fabric etc.
It is made of a laminate of seeds or more, or a sheet that has been treated with waterproofing or flame retardant treatment. Note that both ends of the backing material 24 may be held between the tongue pieces 16 and 22, or placed between the surface material 1 and the core material 23, or placed outward from the edge of the male connecting portion 9 . It is also possible to stand out. Here, the sizes of each of the above parts will be explained. As shown in FIGS. 1 and 2, cosmetic pieces 2a, 2
The lengths of b are L ₁ and L ₂ , the range of the inclined side wall 3 is W ₁ , the range of the inclined surface 7 is W ₂ , the distance from the edge of the inclined side wall 3 to the tip of the insertion edge 10 is l ₁ , The width of the upper surface of the reinforcing rib 12 is l ₂ , the distance from the innermost part of the engagement groove 13 to the tip of the insertion edge 10 is l ₃ , and the distance from the innermost part of the engagement groove 13 to the tip of the extension part 15 is l ₄ , side wall 4
The distance from the lower end of the fitting groove 20 to the innermost part of the fitting groove 20 is l ₅ , the opening width of the waterproof groove part 21 is l ₆ , the distance from the innermost part of the fitting groove 20 to the tip of the lower edge 19 is l ₇ , and the recessed part 23a
The range is l ₈ , the height of the side surface 6 of the decorative groove 5 is h ₁ , the height of the side wall 4 is h ₂ , the height from the upper edge 18 to the lower edge 19 is h ₃ , from the upper side of the reinforcing rib 12 Assuming that the height to the _surface of the extension part 15 is _h4 , and the heights from the decorative pieces 2a and 2b to the back surface of the core material 23 are _h5 and _h6 , respectively, _l1≈l5 , _l2 ≧ _l6 , l ₃ ≒ l ₇ , l ₄ ≒ l ₈ , h ₁ ≒ h ₂ , h ₃
≒h ₄ , h ₅ ≒h ₆ , and W ₁ :L ₁ =1:5~
0.2, W ₂ :L ₂ =1:5 to 0.2. In other words, the above relationship means that when the boards A are connected, the decorative grooves 5 and the joints have a very similar appearance, creating unified lines in the wall, forming a wall with rich design, and also making the sloped surface 7, the slope This is to improve the three-dimensional effect of the wall due to specular reflection and diffused reflection between the side wall 3 and the decorative pieces 2a and 2b. Further, due to the relationship l ₂ ≧ l ₆ , as shown in FIG. 3, the opening of the waterproof groove 21 is closed by the waterproof rib 12, creating a double structure that prevents capillary action and strengthens the waterproof property. It is. Note that L ₁ and L ₂ and W ₁ and W ₂ are L ₁ ≒ L ₂ and W ₁ ≒ W ₂ as shown in the figure, and L ₁ :W ₁ ≒
L ₂ : W ₂ is preferred, but if necessary
L ₁ <L ₂ , or L ₁ >L ₂ , W ₁ <W ₂ , or W ₁ >
It is also possible to take a relationship such as W ₂ , that is, L ₁ :W ₁ ≠L ₂ :W ₂ . [Example of Turning] Now, it is assumed that board A as shown in FIG. 1 is laid horizontally as shown in FIG. 3 to form a wall. In addition, the boards A ₁ and A ₂ use a 0.27 mm thick color steel plate for the surface material 1 , aluminum kraft paper is used for the back material 24, and the core material 23 is made of the surface material 1 and the back material 2.
4, raw materials for polyisocyanurate foam were discharged, reacted and foamed, and then cured and integrated. Therefore, the nth board is placed on the wall base consisting of main pillars, studs, waterproof sheets, etc. (the figure shows the wall base when no waterproof sheets are used).
The extension part 15 of _A1 is fixed via the nail β. Next, the fitting groove 20 of the female connecting portion 17 of the n+1th board A ₂ is combined with the insertion edge 10 of the board A ₁ to achieve waterproofness, engagement force, and packing as shown in FIG. 3. It forms a joint area with rich characteristics. In addition, in order to form the entire wall, the steps described above may be performed from the base to the girder. Although not shown, it is necessary to use a starter for the base, jointer and caulking for the vertical joints, and caulking and accessories for the exit and entry corners. Although not shown, the board A can also be used vertically as described above. [Other Embodiments] What has been described above is only one embodiment of the board A according to the present invention, and it can also be formed as shown in FIGS. 4 to 9. That is, FIGS. 4A to 4L show modified examples of the decorative groove 5, where FIG. 4A shows the decorative groove 5 with θ ₃ formed at an acute angle, FIG _. Figures 5 and 6 show a decorative groove 5 in which a chamfered surface 5a is formed between the decorative piece 2a and the side surface 6, or between the side surface 6 and the recessed part 8, and Figures e to h show the recessed part 8 having a modified shape to strengthen the step function. Cosmetic groove 5, figure i is cosmetic piece 2
The decorative groove 5 has a decorative protrusion 5b provided between the side surface 6 and the side surface 6, and the decorative groove 5, k, and l are shown in FIG.
The figure shows a decorative groove 5 in which the inclined surface 7 is a curved surface. Fifth
Figures a to q show modified examples of the male type connecting part 9. Figure a shows the male type connecting part 9 in which the tongue piece 16 is formed in the shape of an upper seam, and b
Figures 1 to d show a male connecting part 9 in which one or more protrusions 15a and grooves 15b are provided in the middle of the extension 15 or on the lower edge 14, and figure e shows the upper edge 13 of the engagement groove 13.
A male connecting portion 9 with a protrusion 13b or a groove (not shown) formed on a to strengthen engagement force and waterproofness;
Figure f shows a male type connecting part 9 in which a protrusion 12a is provided on the upper side of the reinforcing rib 12, Figure g shows a male type connecting part 9 in which the upper edge 13a of the engagement groove 13 is inclined at an angle θ ₅ with respect to the lower edge 14,
Figure h shows the male connecting part 9 with the lower edge 14 slanted, i, j
The figure shows a male connecting part 9 with a step formed in the extension part 15,
Figure K shows a male connecting part 9 formed with l ₃ > l ₁ , Figure L shows a male connecting part 9 having a triangular groove 11, m,
Figure n shows a male connecting part 9 in which a raised surface 9a is provided between the inclined side wall 3 and the insertion edge 10 to prevent rainwater from entering at the connecting part, and figure o shows the inclined side wall 3 and the groove part 1.
1, a male type connecting part 9 with a horizontal piece 9b provided in the middle with 1;
Figures p and q show a male connecting part 9 with a curved side wall 3.
It is. Figures 6a to 6k are examples of the female type connecting part 17 , and Figure a shows the female type connecting part 1 in which θ ₂ is formed at an acute angle.
Figure 7, b shows a female connecting part 17 with θ ₂ formed at an obtuse angle.
Figures c and d show a female connecting part 17 with a chamfered surface 4a provided between the side wall 4 and the upper edge 18, or between the side wall 4 and the decorative piece 2b to further improve the three-dimensional effect, and figure e shows the side wall 4.
A decorative protrusion 4b is provided between the and the decorative piece 2b to further enhance the design and waterproofness of the female connecting portion 17 , f.
The figure shows a female connecting part 1 with a tongue piece 22 formed in the shape of a bottom seam.
7. Figure g shows a female type connecting part 17 with a protrusion 19a or a groove (not shown) formed on the lower edge 19, Figure h shows a female type connecting part 17 with a protrusion 18a formed on the upper edge 18 ,
Figure i shows the female connecting part 17 formed so that _l5 < _l7 , and figure j shows the tip of the lower edge 19 bent inward and then extended as it is to form the core material holding piece 22a, and the core material 23 The female type connecting part 17 is designed to strengthen the integration of the surface material 1 and the surface material 1, and to prevent leakage of the core material 23 from around the female type connecting part 17. This is the connecting portion 17 . In addition, in FIGS. 4 to 6, only the surface material 1 is shown, and the plate thickness is omitted. Furthermore, FIGS. 7a to 7k are explanatory diagrams showing how the backing material 24 is attached to the male connecting portion 9 , and FIG.
Figure b shows the state in which the backing material 24 is glued together, the end of the backing material 24 is held between the tongue pieces 16, and FIG.
Figures d to j show core material 2 protruding outward from 5.
Back material 2 when 3 is expanded downward from the extension part 15
4, the installed state in figure K shows the state in which the end of the back material 24 is disposed between the engagement groove 13 and the core material 23,
b, d, f, h, j, k are used to prevent liquid leakage when the core material 23 is discharged as a raw material or used as a mold release material; c is used to improve waterproofness;
The figure shows that by sandwiching the backing material 24, the board A
This is the installed state to improve mechanical strength and prevent deformation. Moreover, FIGS. 8a to 8d show the state in which the back material 24 is attached on the female type connecting portion 17 side, and the purpose, function, and effect are the same as those in FIG. 7. In addition, in FIG. 7 and FIG. 8, the front surface material 1 is shown with a two-dot chain line, and the back surface material 24 is shown with a solid line. Furthermore, FIGS. 9a to 9k are explanatory diagrams showing deformation of the core material 23 and the decorative surface portion 2 , and FIGS.
Figure c shows the core material 23 bulging out below the extension part 15,
Board A is designed to improve heat insulation and fire resistance. Figure d shows board A in which the core material 23 is made of multiple materials (same or different). Figures e to g have a flow groove 25 formed on the back side and Board A with an air cycle effect added to the board A, Figure h is board A with caulking material 26 implanted in at least one of the positions indicated by hatching in the male connecting portion 9 and female connecting portion 17 , and the caulking material 26 is This is a board made of hot melt adhesive, molded packing material, or a material in which a non-adhesive packing material is planted with hot melt adhesive after the adhesive has been applied, and is designed to improve waterproofness. In Figures A and i, an end wall 27 is formed on both edges or one edge of the decorative surface section 2 in the short direction, so that waterproofing of the vertical joints when the boards A are joined in the longitudinal direction is easily performed. 1 is a board A in which intermediate decorative grooves 2c and 2d are formed in the decorative pieces 2a and 2b, and FIG. Of course, it is also possible to create a board A that is a combination of each of FIGS. 4 to 9. [Effects of the invention] As mentioned above, according to the board according to the invention,
Since the male and female joints have the above-mentioned drop-in structure, it can be easily carried out by one person, and the joint width can be kept constant. Since at least one decorative groove is formed in the decorative surface part, the strength is sufficiently reinforced, the decorative surface part can be prevented from warping, twisting, and flattening, and the decorative surface part does not become mountain-like. Since the decorative grooves and the joints have almost the same cross-sectional shape, the entire wall has no joints and is made up of only the so-called decorative grooves, making it possible to form a wall that is both beautiful and rich in design. The decorative surface portion is formed as follows: inclined side wall - decorative piece - side surface of the decorative groove - inclined surface of the decorative groove - decorative piece - side wall, and the ratio of decorative piece: inclined side wall, decorative piece: inclined surface is 1:5.
By increasing the width of the sloped side walls and slopes as shown in ~0.2, we effectively utilized diffused reflection and specular reflection to create a bulge in the decorative piece, and on top of that, we created a decorative groove similar to the joint to reduce the level difference. It is possible to create a wall with a three-dimensional effect by making it clearer and making the decorative pieces stand out. The board has a sanderch structure, which greatly improves mechanical strength. Since the board can be made wide, it is easy to install, and the width of the material can be used effectively, making it highly economical. The board can be stretched vertically or horizontally. Flatness of the entire wall can be easily obtained.
Since the connecting structure of the boards is double, the engagement force,
Packing properties are improved. In the connection structure of the board, there is a gap formed by the groove on the insertion edge of the male connection part and a gap formed by the waterproof groove in the fitting groove of the female connection part, which double prevents capillary phenomenon and makes it waterproof. Excellent. It has the following characteristics.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the siding board according to the present invention, Fig. 2 is an explanatory drawing explaining the surface material, and Fig. 3 is an example of the joint part of a wall formed using the above board. Explanatory diagrams shown in Figure 4 a to l,
FIGS. 5 a-q, FIGS. 6 a-k, FIGS. 7 a-k, FIGS. 8 a-d, and FIGS. 9 a-k are explanatory diagrams showing other embodiments. A... Siding board, 1 ... Surface material, 2 ... Decorative surface portion, 2a, 2b... Decorative piece, 3
... Sloped side wall, 5 ... Decorative groove, 7 ... Sloped surface, 8
... recessed part, 9 ... male type connecting part, 10 ... insertion edge,
DESCRIPTION OF SYMBOLS 11...Groove part, 13...Engaging groove, 17 ...Female connecting part, 20...Fitting groove, 21...Waterproof groove part, 23
... Core material, 24 ... Back material.

Claims (1)

[Scope of utility model registration request] A horizontally long metal plate or a synthetic resin plate is used as the surface material, and a side wall and an inclined side wall are provided on the longitudinal edge of the surface material to form a substantially gutter-like cross section to form a decorative surface part. is provided with at least one decorative groove having a substantially triangular cross section from the side surface and the inclined surface to divide the decorative surface portion into a plurality of decorative pieces, and a male connecting portion is provided at the edge of the inclined side wall of the decorative surface portion. , a female connecting portion is provided at the edge of the side wall, and
In a siding board in which the back surface of the surface material is integrally filled with a core material and the back surface of the core material is covered with a sheet-like back material, the shape of the male connecting portion is adjusted so that the edge of the inclined side wall is directed outward. A protruding insertion edge, an engagement groove in which the tip of the insertion edge is folded inward and then bent outward to form a substantially U-shaped cross section, and the lower edge of the engagement groove is bent outward. It consists of an extension part extending in the direction, a groove part recessed in the upper side of the insertion edge parallel to the longitudinal direction, and a reinforcing rib provided at the tip, and a female connecting part with the lower end of the side wall facing inward. It consists of a fitting groove which is bent inward and then bent outward to form a substantially U-shaped cross section, and a waterproof groove provided at the innermost part of the upper edge of the fitting groove, and the decorative groove. A recess is formed between the side surface and the sloped surface, and the ratio of the sloped side wall of the decorative surface part to the decorative piece and the sloped surface of the decorative groove to the decorative piece is 1:5 to 0.2. A siding board that is characterized by: