Renovation methods and renovated roofs

Abstract

The challenge is to prevent deterioration of the exterior walls and roof caused by the ventilation layer between the exterior cladding and the exterior wall. [Solution] A method for renovating an existing lean-to roof 11 that extends diagonally downward outward from the exterior wall 2, below the lower end of the exterior material 5 that is attached to the exterior wall 2 with a ventilation layer 6 in between, and having an existing roofing material 16 on its upper surface, includes the steps of: cutting off the lower end of the exterior material 5; laying a waterproof sheet 30 on top of the existing roofing material 16 and inserting the waterproof sheet 30 between the existing flashing 18 provided at the junction of the existing lean-to roof 11 and the exterior wall 2 and the existing roofing material 16; inserting a second roofing material 40 between the lower end of the exterior material 5 and the existing flashing 18 so as to bring it closer to the exterior wall 2, and laying the second roofing material 40 on top of the waterproof sheet 30 and the existing flashing 18; and moving the new flashing 50 away from the lower end of the exterior material 5 after cutting, and attaching the new flashing 50 to the junction of the second roofing material 40 and the exterior wall 2.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a method for renovating an existing basement and a renovated roof renovated by the method.

Background Art

[0002] Patent Document 1 discloses a renovation technology for a basement by the overlapping roofing method. Specifically, a newly installed roofing is laid on the existing roof material, and a plurality of purlins are fixed from above the newly installed roofing to the existing roof material so as to extend in the left-right direction, and the newly installed roof material is laid on the newly installed roofing and fixed on the purlins. The first member of the support member is fixed on the existing rain pressing member between the existing roof material and the exterior material, the second member of the support member is fixed on the first member, and the second member projects from the first member toward the existing roof material, and the projecting portion is supported on the existing roof material. A newly installed rain pressing material is installed at the joint of the newly installed roof material and the exterior material so as to cover the support member from above.

[0003] In the technology of Patent Document 1, the lower end of the gap between the exterior material and the building body is blocked by the first member of the support member and the existing rain pressing member. Therefore, air is trapped in the gap between the exterior material and the building body, and condensation occurs in the gap. The water generated by the condensation becomes a factor for deteriorating the outer wall. The water generated by the condensation flows down to the existing rain pressing member, and the water is blocked by the first member of the support member. The water deteriorates the support member and the existing rain pressing member. There is a risk that the deterioration spreads from the support member and the existing rain pressing member to the building body, the existing basement, the newly installed roofing, and the newly installed roof material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem that the technology disclosed herein seeks to solve is to prevent deterioration of exterior walls and roofs caused by the ventilation layer between the exterior material and the exterior wall. [Means for solving the problem]

[0006] To address the above issues, this specification discloses the following repair method and repaired roof. The symbols indicated in parentheses below are referenced in Figures 1 to 3.

[0007] (Section 1) In a method for renovating an existing lean-to (11) that extends diagonally downward outward from the exterior wall (2) below the lower end of the exterior cladding (5) that is applied to the exterior wall (2) with a ventilation layer (6) in between, and having an existing roofing material (16) on its upper surface, The process of cutting off the lower end of the exterior material (5), The process involves laying the waterproof sheet (30) on top of the existing roofing material (16), and inserting and sandwiching the waterproof sheet (30) between the existing flashing (18) provided at the junction of the existing lean-to (11) and the exterior wall (2) and the existing roofing material (16), The process involves inserting the second roofing material (40) between the lower end of the exterior material (5) and the existing flashing (18) so that it is close to the exterior wall (2), and then laying the second roofing material (40) on top of the waterproof sheet (30) and the existing flashing (18). The process involves separating the newly installed flashing (50) from the lower end of the exterior material (5) after cutting, and attaching the newly installed flashing (50) to the joint between the second roof material (40) and the exterior wall (2), Renovation methods including those mentioned.

[0008] According to paragraph 1, cutting off the lower end of the exterior material (5) helps to secure space for the installation of the new flashing (50) and the second roofing material (40). Furthermore, cutting off the lower end of the exterior material (5) allows the new flashing (50) to be installed at a distance below the lower end of the exterior material (5) after it has been cut. By positioning the newly installed flashing (50) away from the lower end of the cut exterior material (5) and attaching it to the joint between the second roofing material (40) and the exterior wall (2), ventilation from the outside to the ventilation layer (6) is ensured. As a result, moisture generated from the exterior wall (2) does not accumulate in the ventilation layer (6) but is discharged from the ventilation layer (6). Therefore, condensation is less likely to occur in the ventilation layer (6), and deterioration of the exterior wall (2) and the renovated roof (10) caused by the ventilation layer (6) is prevented. Even if condensation does occur in the ventilation layer (6), the water flows down and is discharged onto the second roofing material (40) along the surface of the newly installed flashing (50). Because the waterproof sheet (30) is sandwiched between the existing flashing (18) and the existing roofing material (16), even if water such as rainwater penetrates under the second roofing material (40), the water will not seep under the waterproof sheet (30). As a result, the existing lean-to roof (11) is protected and its deterioration is suppressed. Installing the second roofing material (40) without removing the existing roofing material (16) contributes to the realization of a simple renovation of the existing lower roof (11). The double-layer structure of the existing roofing material (16) and the second roofing material (40) contributes to improving the heat shielding and insulation properties of the renovated roof (10).

[0009] (Section 2) A step of attaching the cover (80) to the outer surface of the exterior material (5) such that the cover (80) hangs down below the lower end of the exterior material (5) after cutting, and the cover (80) is positioned away from the newly installed rain flashing (50). The modification method described in paragraph 1, including the above.

[0010] According to paragraph 2, attaching the cover (80) to the outer surface of the exterior material (5) so that it hangs down below the lower end of the exterior material (5) after cutting will conceal the joint between the exterior wall (2) and the second roof material (40), and the cut area at the lower end of the exterior material (5). Therefore, the cover (80) contributes to improving the aesthetic appearance of the renovated roof (10). Attaching the cover (80) to the outer surface of the exterior material (5) so that it is separated above the newly installed rain flashing (50) helps to ensure ventilation from the outside to the ventilation layer (6). Therefore, condensation in the ventilation layer (6) is prevented.

[0011] (Section 3) An existing lean-to (11) extends diagonally downward outward from the exterior wall (2) below the lower end of the exterior cladding (5) that is applied to the exterior wall (2) with a ventilation layer (6) in between, and has an existing roofing material (16) laid on its upper surface. A waterproof sheet (30) is laid on top of the existing roofing material (16) and is inserted and sandwiched between the existing flashing (18) provided at the junction of the existing lean-to (11) and the exterior wall (2) and the existing roofing material (16), A second roofing material (40) is laid on top of the aforementioned waterproof sheet (30) and inserted between the lower end of the exterior material (5) and the existing flashing (18) so as to be closer to the exterior wall (2), The aforementioned Exterior wall (2) A new flashing (50) is attached to the joint of the second roofing material (40) and is located below the lower end of the exterior material (5), A refurbished roof (10) equipped with [a specific feature].

[0012] According to paragraph 3, the fact that the newly installed flashing (50) is positioned away from the lower end of the cut exterior material (5) and attached to the joint between the second roofing material (40) and the exterior wall (2) ensures ventilation from the outside to the ventilation layer (6). As a result, moisture generated from the exterior wall (2) does not accumulate in the ventilation layer (6) but is discharged from the ventilation layer (6). Therefore, condensation is less likely to occur in the ventilation layer (6), and deterioration of the exterior wall (2) and the renovated roof (10) caused by the ventilation layer (6) is prevented. Even if condensation does occur in the ventilation layer (6), the water flows down and is discharged onto the second roofing material (40) along the surface of the newly installed flashing (50). Since the waterproof sheet (30) is sandwiched between the existing rain retainer (18) and the existing roofing material (16), even if water such as rainwater penetrates under the second roofing material (40), the water will not flow under the waterproof sheet (30). Therefore, the existing attic (11) is protected and deterioration of the existing attic (11) is suppressed. The fact that the second roofing material (40) is installed without removing the existing roofing material (16) contributes to the realization of simple renovation of the existing attic (11). The double structure of the existing roofing material (16) and the second roofing material (40) contributes to improvement of the heat insulation and heat retention properties of the renovated roof (10).

[0013] (Item 4) The exterior material (5) has a cut surface at its lower end The renovated roof (10) according to claim 3.

[0014] According to item 4, by cutting off the lower end of the exterior material (5) before cutting, the exterior material (5) has a cut surface at its lower end. Cutting off the lower end of the exterior material (5) leads to securing the installation space for the new rain retainer (50) and the second roofing material (40).

[0015] (Item 5) A cover (80) attached to the outer surface of the exterior material (5), hanging down below the lower end of the exterior material (5), and spaced upward from the new rain retainer (50) The renovated roof (10) according to claim 3 or 4, further comprising the cover (80).

[0016] According to item 5, the fact that the cover (80) attached to the outer surface of the exterior material (5) hangs down below the lower end of the exterior material (5) leads to hiding the engagement between the outer wall (2) and the second roofing material (40) and hiding the cutting portion at the lower end of the exterior material (5). Therefore, the cover (80) contributes to improving the aesthetic appearance of the renovated roof (10). The fact that the cover (80) is spaced upward from the new rain retainer (50) leads to securing ventilation and air exchange from the outdoors to the ventilation layer (6). Thus, condensation in the ventilation layer (6) is prevented.

[0017] (Item 6) The seal (83) provided at the upper end of the cover (80) The renovated roof (10) according to claim 5, further comprising the seal (83).

[0018] According to claim 6, the seal (83) prevents water from entering between the cover (80) and the exterior material (5).

Effect of the Invention

[0019] Deterioration of the outer wall and the renovated roof due to the ventilation layer between the exterior material and the outer wall is prevented.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a vertical cross-sectional view showing the engagement between the renovated roof and the outer wall. [Figure 2] FIG. 2 is a vertical cross-sectional view showing the engagement between the existing roof and the outer wall during renovation. [Figure 3] FIG. 3 is a vertical cross-sectional view showing the engagement between the existing roof and the outer wall during renovation.

Modes for Carrying Out the Invention

[0021] Hereinafter, embodiments will be described with reference to the drawings. The features and technical effects of the embodiments will be understood from the following detailed description and the drawings. However, the scope of the present invention is not limited to the embodiments disclosed below. Since the drawings are provided for illustrative purposes only, the scope of the present invention is not limited to the illustrations in the drawings.

[0022] <1. Renovated Roof> FIG. 1 is a cross-sectional view of the renovated roof 10. This renovated roof 10 is a renovation of the existing lean-to roof 11 using the overlay roofing method. The existing lean-to roof 11 is a lean-to roof of an existing wooden house. In the example shown in Figure 1, the existing wooden house is a wall-type structure building constructed using the panel construction method, particularly the wood panel adhesive construction method. The existing wooden house may also be a wall-type structure building constructed using the framed wall construction method. The existing wooden house may also be a framed structure building constructed using the post-and-beam construction method. In the following description, a wood panel such as a wood wall panel or wood roof panel has a rectangular frame body made of four wooden frame members assembled into a rectangular frame shape, and wooden facing material attached to one or both sides of the rectangular frame body. If necessary, auxiliary battens may be assembled inside the rectangular frame body. If necessary, insulation material may be packed inside the rectangular frame body.

[0023] <2. Existing lean-to roof, exterior walls, exterior cladding, and ventilation layer> The existing lean-to roof 11 is a single-slope roof that extends from the upper part of the exterior wall 2 of the wooden house and covers the lower part of the wooden house. The ridge of the lean-to roof 11 is attached to the exterior wall 2. The lean-to roof 11 slopes downward from the ridge towards the eaves of the lean-to roof 11.

[0024] On the lower roof 11, a waterproof and breathable sheet 3 is attached to the outer surface of the exterior wall 2. The exterior wall 2 has multiple wooden wall panels. These wooden wall panels are erected and arranged in the periphery direction, and adjacent wooden wall panels are joined to each other. Note that the exterior wall 2 is not limited to those constructed by the wooden panel adhesive method. That is, for example, the exterior wall 2 may have multiple columns, multiple studs, multiple braces and multiple structural sheathing materials constructed by the post-and-beam method. The exterior wall 2 may also have multiple wall frames and multiple structural sheathing materials constructed by the framed wall method.

[0025] The exterior cladding 5 is attached to the exterior wall 2 via furring strips. The furring strips are attached to the exterior wall 2 from the outside of the waterproof and breathable sheet 3, and the waterproof and breathable sheet 3 is sandwiched between the exterior wall 2 and the furring strips. The exterior cladding 5 is fixed to the furring strips, which ensure a gap between the exterior cladding 5 and the exterior wall 2, and a hollow ventilation layer 6 is formed between the exterior cladding 5 and the exterior wall 2. The ventilation layer 6 opens downwards at the lower end of the exterior cladding 5. The waterproof and breathable sheet 3, the furring strips, and the exterior cladding 5 may be attached to the exterior wall 2 in advance before the renovation of the existing lean-to 11, or they may be attached during the renovation of the existing lean-to 11. The lower end of the exterior cladding 5 is cut off. Therefore, the exterior cladding 5 has a cut surface at its lower end. The cutting of the lower end of the exterior cladding 5 is done to secure space for the installation of the new flashing 50, underlayment 48, and roofing material 40 below the exterior cladding 5. In the drawing, the dashed line represents the exterior cladding 5 before cutting. In the following explanation, unless otherwise specified, the lower end of exterior material 5 refers to the lower end after cutting.

[0026] The lower roof 11 has a roof body 12, a waterproof sheet 14, a reinforcing sheet 15, roofing material 16, a base 17, and a flashing 18. The roof body 12, waterproof sheet 14, reinforcing sheet 15, roofing material 16, base 17, and flashing 18 were already installed before the renovation of the lower roof 11. The roof body 12, waterproof sheet 14, reinforcing sheet 15, roofing material 16, base 17, or flashing 18 may be repaired during the renovation of the lower roof 11.

[0027] The roof structure 12 has multiple wooden roof panels that are arranged and installed above the lower floor. These wooden roof panels are installed above the lower floor with a downward slope from the ridge to the eaves. The facing material 12a of the wooden roof panels can also be called roof sheathing. The roof structure 12 is not limited to those constructed by the wooden panel adhesive method. That is, for example, the roof structure 12 may have multiple rafters installed above the lower floor with a downward slope from the ridge to the eaves, and roof sheathing attached to these rafters.

[0028] The waterproof sheet 14 is an underlayment such as an asphalt roofing sheet, a modified asphalt roofing sheet, or a nonwoven fabric roofing sheet. The waterproof sheet 14 is laid on top of the roof body 12 and fastened to the roof body 12 with adhesive or staples. The waterproof sheet 14 extends from the roof body 12 to the exterior wall 2 and covers the lower part of the outer surface of the exterior wall 2.

[0029] The reinforcing sheet 15 covers the joint between the roof body 12 and the exterior wall 2, over the waterproof sheet 14. The reinforcing sheet 15 is waterproof. The reinforcing sheet 15 may also be water-resistant.

[0030] The roofing material 16 is laid on the roof body 12 over the waterproof sheet 14 and the reinforcing sheet 15. The roofing material 16 is a slate roofing material.

[0031] The underlayment 17 is provided in the shape of a strip. The underlayment 17 is laid on top of the roofing material 16 on the ridge side along the boundary between the exterior wall 2 and the roof body 12. The underlayment 17 may be fastened to the roof body 12 or the roofing material 16 on the ridge side by fasteners, etc. The underlayment 17 is made of wood, wood-based material, resin, or rubber. Wood-based material refers to wood board, which means medium-density fiberboard (MDF), hard fiberboard (hardboard), or soft fiberboard (insulation board).

[0032] The flashing 18 is a sheet metal material. The flashing 18 covers the substrate 17 and is laid on top of the substrate 17. The flashing 18 extends from the substrate 17 towards the eaves and covers the roofing material 16 on the ridge side. The flashing 18 is bent upward at the junction of the substrate 17 and the exterior wall 2 and covers the exterior wall 2 as well. The portion of the flashing 18 that covers the exterior wall 2 is fixed to the exterior wall 2, for example, with screws. Part of the reinforcing sheet 15 and the waterproof sheet 14 is sandwiched between the exterior wall 2 and the flashing 18. The overlap of the waterproof sheet 14, the reinforcing sheet 15 and the flashing 18 enters the ventilation layer 6 from below the lower end of the exterior material 5. The flashing 18 has a return 18a at the tip on the eaves side. In the example shown in Figure 1, the return 18a is bent upward and folded back towards the exterior wall 2. In contrast, the return 18a may be bent downwards and folded back toward the exterior wall 2. The flashing 18 has a return 18b at its upper end on the side facing the exterior wall 2. The return 18b is bent toward the eaves and folded back downwards. On the back side of the exterior material 5, the flashing 18, reinforcing sheet 15 and waterproof sheet 14 are covered by the waterproof sheet 14.

[0033] The flashing 18 prevents water from entering between the substrate 17 and the exterior wall 2, between the ridge end of the roofing material 16 and the exterior wall 2, and between the roof body 12 and the exterior wall 2. This water intrusion prevention effect is achieved by (i) to (iv) below. (i) The flashing 18 is fixed to the exterior wall 2, and the reinforcing sheet 15 and the waterproof sheet 14 are sandwiched between the flashing 18 and the exterior wall 2. (ii) The flashing 18 is positioned underneath the gap between the exterior material 5 and the exterior wall 2. (iii) The return 18b is formed at the upper end of the rain cover 18. (iv) The flashing 18, the reinforcing sheet 15, and the waterproof sheet 14 are covered by the waterproof breathable sheet 3.

[0034] <3. Newly installed waterproofing sheets, waterproof adhesive sheets, roofing materials, flashing, lower roof covers and seals> The renovated roof 10 includes, in addition to the existing lean-to roof 11 as described above, a new waterproof sheet 30, a new waterproof adhesive sheet 31, a new roofing material 40, a new flashing 50, a new underlayment 48, a new lean-to roof cover 80, and a new seal 83.

[0035] The waterproof sheet 30 is an underlayment such as an asphalt roofing sheet, a modified asphalt roofing sheet, or a nonwoven fabric roofing sheet. The waterproof sheet 30 is laid on top of the existing lean-to roof 11. In other words, the waterproof sheet 30 is laid on top of the roofing material 16. The waterproof sheet 30 is fastened to the roofing material 16 by adhesive or staples.

[0036] The waterproof sheet 30 is inserted between the flashing 18 and the roofing material 16, sandwiched between them. This helps prevent water from seeping between the waterproof sheet 30 and the roofing material 16. The waterproof adhesive sheet 31 is attached to the rain flashing 18 by covering the overlapping portion of the rain flashing 18 and the waterproof sheet 30 from above the return 18a of the rain flashing 18. The waterproof adhesive sheet 31 extends beyond the rain flashing 18 onto the waterproof sheet 30 and is attached to the waterproof sheet 30. The waterproof adhesive sheet 31 prevents water from entering between the rain flashing 18 and the waterproof sheet 30.

[0037] The roofing material 40 is laid on top of the waterproof sheet 30 on the roofing material 16. The roofing material 16 is a slate roofing material. The ridge portion of the roofing material 40 is inserted between the lower end of the exterior material 5 and the flashing 18, and is positioned closer to the exterior wall 2. The ridge portion of the roofing material 40 covers the existing flashing 18 from above the flashing 18.

[0038] The underlayment 48 is provided in the shape of a strip. The underlayment 48 is inserted between the lower end of the exterior material 5 and the ridge-side roofing material 40, and is positioned closer to the exterior wall 2. Below the lower end of the exterior material 5, the underlayment 48 is laid on top of the ridge-side roofing material 40 along the boundary between the exterior wall 2 and the roofing material 40. The underlayment 48 may be fastened to the ridge-side roofing material 40 or the exterior wall 2 by fasteners or the like. The underlayment 48 is made of wood, wood-based material, resin, or rubber. Wood-based material refers to wood-based boards, which include medium-density fiberboard, hard fiberboard, or soft fiberboard.

[0039] The flashing 50 is a metal material made from sheet metal. The flashing 50 is inserted between the lower end of the exterior material 5 and the roofing material 40 on the ridge side, and is positioned closer to the exterior wall 2. Below the lower end of the exterior material 5, the flashing 50 covers the substrate 48 and is laid on top of the substrate 48. The flashing 50 extends from the substrate 48 towards the eaves and covers the roofing material 40 on the ridge side. The flashing 50 is bent upward at the junction of the substrate 48 and the exterior wall 2, and also covers the exterior wall 2. Part of the reinforcing sheet 15, the waterproof sheet 14, and the waterproof breathable sheet 3 is sandwiched between the exterior wall 2 and the flashing 50. In addition to the reinforcing sheet 15, the waterproof sheet 14, and the waterproof breathable sheet 3, the upper part of the existing flashing 18 may also be sandwiched between the exterior wall 2 and the flashing 50. The upper part of the existing flashing 18 does not have to be sandwiched between the exterior wall 2 and the flashing 50. The overlap of the waterproof sheet 14, the reinforcing sheet 15, and the flashing 50 may extend from below the lower end of the exterior material 5 into the ventilation layer 6. The flashing 50 has a return 50a at its tip on the eaves side. In the example shown in Figure 1, the return 50a is bent downwards and folded back toward the exterior wall 2. Alternatively, the return 50a may be bent upwards and folded back toward the exterior wall 2. The flashing 50 has a return 50b at its upper end on the exterior wall 2 side. The return 50b is bent toward the eaves and folded back downwards.

[0040] The lower roof cover 80 is attached to the outer surface of the exterior material 5. The lower roof cover 80 extends outward from the outer surface of the exterior material 5 and hangs down below the lower end of the exterior material 5. The lower roof cover 80 covers the gap between the lower end of the exterior material 5 and the flashing 50 from the outside. The lower end of the lower roof cover 80 is set above the flashing 50, ensuring ventilation from the outside to the ventilation layer 6.

[0041] The seal 83 is located in the inner corner between the return 82, which is the upper end of the lower roof cover 80, and the exterior material 5.

[0042] <4. Renovation Method> Next, I will explain the method for renovating the lower roof 11. As shown in Figure 2, the lower end of the exterior material 5 is cut off before cutting. Cutting off the lower end of the exterior material 5 secures workspace, making subsequent processes easier.

[0043] As shown in Figure 3, the waterproof sheet 30 is laid on top of the existing roofing material 16. At this time, without removing the flashing 18 from the exterior wall 2, the flashing 18 is lifted away from the roofing material 16, and the waterproof sheet 30 is inserted between the flashing 18 and the roofing material 16, as indicated by the arrow in Figure 3. After that, when the flashing 18 is released, the flashing 18 returns to its original position due to its elastic force, and the waterproof sheet 30 is sandwiched between the flashing 18 and the roofing material 16. The exterior material 5 does not interfere with these operations because the lower end of the exterior material 5 was cut off as described above before cutting.

[0044] Next, the waterproof adhesive sheet 31 is placed over the boundary between the flashing 18 and the waterproof sheet 30, covering the flashing 18 and the waterproof sheet 30, and the waterproof adhesive sheet 31 is attached to the flashing 18 and the waterproof sheet 30. Next, the roofing material 40 is laid on top of the waterproof sheet 30 and the existing flashing 18. When laying the roofing material 40 on the ridge side, the roofing material 40 is inserted between the lower end of the exterior material 5 and the flashing 18 so that the ridge-side end of the roofing material 40 is brought towards the exterior wall 2.

[0045] Next, the underlayment 48 is positioned close to the exterior wall 2 so that it can be inserted between the lower end of the exterior material 5 and the ridge-side roofing material 40, and the underlayment 48 is laid on top of the ridge-side roofing material 40 along the boundary between the exterior wall 2 and the roofing material 40. The underlayment 48 may also be fastened to the ridge-side roofing material 40 or both to the exterior wall 2 using fasteners or the like.

[0046] Next, insert the flashing 50 between the lower end of the exterior material 5 and the roofing material 40 on the ridge side, so that it is separated from the lower end of the exterior material 5. Cover the flashing 50 with the base 48 and make contact with the base 48, the roofing material 40 and the exterior wall 2. Secure the flashing 50 to the roofing material 40 with screws with waterproof gaskets or the like. Secure the flashing 50 to the base 48 with screws with waterproof gaskets or the like. Secure the flashing 50 to the exterior wall 2 with screws with waterproof gaskets or the like.

[0047] Next, the lower roof cover 80 is placed on top of the flashing 50 and pressed against the lower edge of the outer surface of the exterior material 5, so that the lower roof cover 80 hangs down below the lower edge of the exterior material 5, and the lower edge of the lower roof cover 80 is separated from the flashing 50, so that the gap between the lower edge of the exterior material 5 and the flashing 50 is covered by the lower roof cover 80 from the front. The lower roof cover 80 is then fixed to the exterior material 5 with screws with waterproof gaskets or the like.

[0048] Next, the seal 83 is placed in the inner corner between the return 82 and the exterior material 5.

[0049] <5. Summary> (1) By cutting off the lower end of the exterior material 5 before cutting, the exterior material 5 has a cut surface at its lower end. Cutting off the lower end of the exterior material 5 helps to secure space for the installation of the new flashing 50 and the second roofing material, and also helps to secure work space. Furthermore, cutting off the lower end of the exterior material 5 allows the new flashing 50 to be installed at a distance below the lower end of the exterior material 5 after cutting.

[0050] (2) By installing the new flashing 50 away from the lower end of the exterior material 5 after cutting, and attaching the new flashing 50 to the joint between the second roofing material 40 and the exterior wall 2, ventilation from the outside to the ventilation layer 6 is ensured. As a result, moisture generated from the exterior wall 2 does not accumulate in the ventilation layer 6 but is discharged from the ventilation layer 6. Thus, condensation is less likely to occur in the ventilation layer 6, and deterioration of the exterior wall 2 and the renovated roof 10 caused by the ventilation layer 6 is prevented. Even if condensation does occur in the ventilation layer 6, the water flows down and is discharged onto the second roofing material 40 along the surface of the new flashing 50.

[0051] (3) Because the waterproof sheet 30 is sandwiched between the existing flashing 18 and the existing roofing material 16, even if water such as rainwater penetrates under the second roofing material 40, the water will not seep under the waterproof sheet 30. As a result, the existing lean-to roof 11 is protected and its deterioration is suppressed.

[0052] (4) The fact that the existing roofing material 16 is laid on the second roofing material (40) without being removed contributes to the realization of a simple renovation of the existing lower roof 11. The double structure of the existing roofing material 16 and the second roofing material 40 contributes to the improvement of the heat shielding and insulation properties of the renovated roof 10.

[0053] (5) The cover 80 is attached to the outer surface of the exterior material 5 such that it hangs down below the lower end of the exterior material 5 after it has been cut, which helps to conceal the joint between the exterior wall 2 and the second roof material 40, and also conceals the cut area at the lower end of the exterior material 5. Therefore, the cover 80 contributes to improving the aesthetic appearance of the renovated roof 10.

[0054] (6) Attaching the cover 80 to the outer surface of the exterior material 5 such that the cover 80 is separated from the newly installed rain flashing 50 helps to ensure ventilation from the outside to the ventilation layer 6. Thus, condensation in the ventilation layer 6 is prevented, as is deterioration of the exterior wall 2 and the renovated roof 10 caused by the ventilation layer 6.

[0055] (7) The seal 83 prevents water from entering between the cover 80 and the exterior material 5.

[0056] (8) The renovated roof 10, which has been refurbished by the installation of the waterproof sheet 30, roofing material 40, flashing 50, lower roof cover 80 and seal 83, will have a longer lifespan than the lower roof 11 before the renovation, and the lifespan of the building equipped with such a refurbished roof 10 will be extended. The waterproof sheet 30, roofing material 40, flashing 50, lower roof cover 80 and seal 83 will contribute to achieving goals such as "making cities and livable" and "SDGs (Sustainable Development Goals)" by extending the lifespan of the building and the lower roof 11.

[0057] (9) The embodiments disclosed herein are for illustrative purposes only and are not intended to limit the scope of the invention. The scope of the invention should be interpreted by the terms of the claims. [Explanation of Symbols]

[0058] 2. Exterior walls 5. Exterior materials 6. Ventilation layer 10. Roof renovation 11 Existing lean-to 16 Existing roofing materials 18 Existing rain flashing 30 Waterproof Sheets 40 Second roofing material 50 Newly installed rain gutter 80 Roof Cover 83 Seals

Claims

1. In a method for renovating an existing lean-to that extends diagonally downward outward from the exterior wall, below the lower end of the exterior cladding material that is applied to the exterior wall of a building with a ventilation layer in between, and having an existing roofing material installed on its upper surface, The process of cutting off the lower end of the exterior material, The process involves laying a waterproof sheet on top of the existing roofing material, and inserting and sandwiching the waterproof sheet between the existing flashing installed at the junction of the existing lean-to and the exterior wall and the existing roofing material, The process involves inserting the second roofing material between the lower end of the exterior material and the existing flashing so that it is close to the exterior wall, and then laying the second roofing material on top of the waterproof sheet and the existing flashing. The process involves separating the newly installed flashing from the lower end of the exterior material after cutting, and attaching the newly installed flashing to the joint between the second roofing material and the exterior wall. Renovation methods including those mentioned.

2. A step of attaching the cover to the outer surface of the exterior material such that the cover hangs down below the lower end of the exterior material after cutting, and the cover is positioned above the newly installed rain flashing. The modification method according to claim 1, including the following:

3. An existing lean-to has a ventilation layer between the exterior wall of the building and the exterior material that is applied to the exterior wall, extending diagonally downward outward from the exterior wall, with the existing roofing material laid on its upper surface, below the lower end of the exterior material that is applied to the exterior wall, A waterproof sheet is laid on top of the existing roofing material and inserted and sandwiched between the existing flashing, which is installed at the junction of the existing lean-to and the exterior wall, and the existing roofing material. A second roofing material is laid on top of the aforementioned waterproof sheet and inserted between the lower end of the exterior material and the existing flashing so as to be close to the exterior wall, A newly installed flashing is provided at the junction of the exterior wall and the second roofing material, A refurbished roof equipped with [features].

4. The exterior material has a cut surface at its lower end. The refurbished roof according to claim 3.

5. A cover attached to the outer surface of the exterior material, hanging below the lower end of the exterior material and away from the newly installed rain flashing. The refurbished roof according to claim 3 or 4, further comprising:

6. A seal provided at the upper end of the cover The refurbished roof according to claim 5, further comprising:

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