JP7601541B2 - Waterproofing construction and its construction method - Google Patents

Description

The present invention relates to a waterproofing structure for renovating existing waterproof layers in waterproofing structures for rooftops, roofs, verandas, etc., and a construction method for the same.

Conventionally, waterproofing work has been carried out using waterproof sheets as a waterproof layer to waterproof the framework of verandas, balconies, flat roofs, etc. However, there are concerns that these waterproof sheets will deteriorate over time and lose their waterproofing properties, so existing waterproof sheets are repaired at appropriate times.

When repairing such existing waterproof sheets using a waterproof sheet, the mechanical fixing method is often used. In repair methods using the mechanical fixing method, the waterproof sheet for repair is laid on top of the existing waterproof sheet, and the waterproof sheet for repair is fixed to the base using a fixing disk that is fixed to the base with screws.

Patent Document 1 discloses a waterproof sheet for renovation that is used to lay from above an existing waterproof sheet laid on a base for the purpose of repairing it, and that the waterproof sheet is made of rubber and has a thermoplastic resin film laminated and integrated onto at least the underside of the main waterproof sheet body, and that a fixing plate is anchored onto the existing waterproof sheet in advance, and the waterproof sheet for renovation is laid and fixed by heat fusing to the fixing plate.

JP 2006-125182 A

However, when repairs are made using the mechanical fixing method, screws must be driven into the base to fix the fixing disk, which creates problems such as noise and vibration. Therefore, an adhesive method can be used to fix the new waterproof sheet for repairs using adhesive.
When repairs are carried out using adhesive construction methods, there is a concern that the movement of the base will cause the deteriorated joints between adjacent existing waterproof sheets to tear or move, causing the new waterproof sheet that is laid and fixed on top of the joints to tear or wrinkle.

In other words, the purpose of the present invention is to prevent the generation of noise and vibration when renovating an existing waterproof sheet, and to reduce the risk of the new waterproof sheet being torn or wrinkled due to the joints of the existing waterproof sheet being torn or moved.

The method used to solve the problem involves laying and fixing a new waterproof layer on top of the existing waterproof sheet using adhesive, and then applying adhesive to the joints of the existing waterproof sheet.
Specifically, the waterproofing structure is a repaired waterproofing structure comprising an adhesive layer applied with adhesive so as to continuously cover the joints of an existing waterproof sheet laid and fixed on a base, and a sheet-like new waterproof layer laid and fixed on the existing waterproof layer by the adhesive layer, the joints being the overlapping parts of adjacent existing waterproof sheets, the new waterproof layer having a buffer sheet adhered to the adhesive layer and a new waterproof sheet laminated and integrated with the buffer sheet in advance, the buffer sheet being made of a foam sheet. Also , a single buffer sheet may be laid to cover the joints, or the buffer sheet may further have a reinforcing layer. Also, the joints of the existing waterproof sheet and the joints of the new waterproof sheet may be arranged so as not to overlap.
Furthermore, as a construction method, a construction method for a renovated waterproof structure can be used which includes the steps of applying adhesive so as to continuously cover the joints of multiple existing waterproof sheets laid and fixed on a base to form an adhesive layer, and laying and fixing a new waterproof layer on top of the adhesive layer , wherein the joints are overlapping portions of adjacent existing waterproof sheets, the new waterproof layer has a buffer sheet which is adhered to the adhesive layer and a new waterproof sheet which has been pre-laminated and integrated with the buffer sheet, and the buffer sheet is composed of a foam sheet.

According to the present invention, by fixing the new waterproof layer with adhesive, it is possible to prevent noise and vibrations during renovation. In addition, by applying adhesive across the joints of the existing waterproof sheet and laying and fixing the new waterproof layer, the deteriorated joints are repaired while the new waterproof layer is formed. This reduces the risk of the joints of the existing waterproof layer breaking or moving, and also provides a renovation waterproof structure and construction method that can reduce breaking or wrinkling of the new waterproof layer.

FIG. 2 is a partial cross-sectional view of a renovated waterproof structure according to an embodiment of the present invention. FIG. 2 is a partial plan view showing an example of the arrangement of an existing waterproof sheet and an adhesive layer according to the present invention. FIG. 2 is a partial plan view showing an example of the arrangement of an existing waterproof sheet and a new waterproof layer according to the present invention. FIG. 2 is a partial plan view showing an example of the arrangement of an existing waterproof sheet and a new waterproof layer according to the present invention. FIG. 3 is a partial plan view showing a state in which an adhesive is applied to an adhesive layer according to the present invention. FIG. 4 is a partial plan view showing an applied state of an adhesive. FIG. 2 is a partial plan view showing an example of the arrangement of a new waterproof layer according to the present invention.

The following describes an embodiment of the present invention with reference to the drawings.

The present invention will be described with reference to Fig. 1. An existing waterproof sheet P is laid and fixed on a base S, and an adhesive layer A is provided on the existing waterproof sheet P with an adhesive. Here, the adhesive layer A is formed by continuously applying it across the joints M of the existing waterproof sheet. Then, a new waterproof layer 3 is laid and fixed on the adhesive layer A. The new waterproof layer 3 has a buffer sheet 1 and a new waterproof sheet 2, and the buffer sheet 1 and the new waterproof sheet 2 are laminated and integrated in advance before construction. The buffer sheet 1 is fixed to the adhesive layer A, and the new waterproof sheet 2 is placed on the front side.
Here, the joint portion M is approximately the overlapping portion between the existing waterproof sheet P1 and the existing waterproof sheet P2.

Here, the existing waterproof sheet P and the new waterproof layer 3 are sheets. Therefore, the shorter side of the sheet is the width, and the side that is perpendicular to the width and longer than the width is the length. The width side may be referred to as the width direction, and the length side as the length direction.

As shown in FIG. 2, the joints M of the existing waterproof sheet P include joints M2 parallel to the longitudinal direction of the existing waterproof sheet P and joints M1 arranged in the width direction, and adhesive is applied to these joints M1 and M2 so as to continuously cover each of the joints M to provide an adhesive layer A. Although an adhesive layer may be provided across either one of the joints, it is preferable to form an adhesive layer A that covers both joints M1 and M2, as this is preferable because it reduces the occurrence of cuts and wrinkles in the new waterproof layer 3 in both the longitudinal and width directions.

When applying the adhesive that forms the adhesive layer A, if the adhesive is applied to match the existing waterproof sheet P, it will be divided into sections for each joint of the existing waterproof sheet P, and the adhesive will not be applied to the entire joint, which is not preferable. Also, when applying the adhesive using a toothed trowel, if the teeth J of the adhesive are arranged in parallel with the joint M as shown in Figure 6, the adhesive will not be applied continuously to cover the joint M, which is not preferable.

On the other hand, when applying the adhesive using a comb trowel as shown in Fig. 5, it is preferable to form the teeth of the adhesive in an arc shape, because the adhesive is applied in a comb shape to cover the entire joint portion M. Also, when applying the adhesive using a roller, it is preferable to position the roller so as to straddle the joint portion so that the adhesive is applied to the entire joint portion M.
In this way, forming a continuous adhesive layer A to cover the joint portion M does not require that the adhesive be applied so as to completely cover the joint portion M, but rather that the adhesive be applied in the form of comb-like streaks that cross the joint portion M to cover the joint portion M.

The new waterproof layer 3 is formed by laminating and integrating a buffer sheet 1 and a new waterproof sheet 2. When the existing waterproof sheet P moves in accordance with the movement of the substrate, the buffer sheet 1 prevents the movement from being directly transmitted to the new waterproof sheet 2, thereby preventing the new waterproof sheet 2 from tearing or wrinkling. By laminating and integrating the buffer sheet 1 and the new waterproof sheet 2, the process of joining the buffer sheet 1 and the new waterproof sheet 2 can be eliminated.
The buffer sheet is also fixed to the joints M of the existing waterproof sheet P via the adhesive layer A, and the adhesive and buffer sheet repair the joints M, especially the deteriorated joints M.

Adjacent new waterproof layers 3 are required to overlap adjacent new waterproof sheets 2 to increase waterproofing. For this reason, it is preferable for the new waterproof layer 3 to have a joining piece 4, as shown in Figure 1. The buffer sheet 1 is set to be shorter in width than the new waterproof sheet 2, the buffer sheet 1 is not laminated to the new waterproof layer 3, and the part formed by the new waterproof sheet 2 becomes the joining piece 4. In other words, the joining piece 4 is formed by the new waterproof sheet 2.

Next, the joining using the joining piece 4 will be described with reference to Fig. 1. Note that the first new waterproof layer, the second new waterproof layer, and the third new waterproof layer are new waterproof layers, and the first new waterproof sheet and the second new waterproof sheet are new waterproof sheets.
The joining piece 42 of the second new waterproof layer 32 is placed on top of the first new waterproof sheet 21, and the joining piece 42 and the first new waterproof sheet 21 are joined together. Therefore, the joint portion N between the first new waterproof layer 31 and the second new waterproof layer 32 is overlapped by the joining piece 42, which is part of the second new waterproof sheet of the second new waterproof layer.

Here, if the joint portion M of the existing waterproof sheet P is torn or moved, and there is a joint portion N of the new waterproof layer 3 above the joint portion M, there is a concern that the upper joint portion N may also be torn. Therefore, as shown in Figure 1, it is preferable to prevent the joint portion M of the existing waterproof sheet P from overlapping with the joint portion N of the new waterproof layer 3, as this further reduces the risk of the joint portion N being torn. In other words, it is preferable to lay and fix the new waterproof layer 3 while covering the joint portion M of the existing waterproof sheet P. Here, if the buffer sheet 1 covers the joint portion M, the new waterproof layer 3 will cover the joint portion M.
3 and 4 are partial plan views showing the arrangement of an existing waterproof sheet P and a new waterproof layer 3. The area surrounded by a dotted line indicates one existing waterproof sheet P, and the dotted line indicates a joint portion M. Similarly, the area surrounded by a solid line indicates one new waterproof layer 3, and the solid line indicates a joint portion N.
3, it is preferable to lay the new waterproof layer 3 so as to cover both the longitudinal joint M2 and the lateral joint M1 of the existing waterproof sheet P. Also, due to restrictions on the arrangement of the existing waterproof sheet P and the new waterproof layer 3, the new waterproof layer 3 may be laid and fixed so as to cover only one of the joints.

The new waterproof layer 3 may be laid so that the longitudinal direction of the existing waterproof sheet P and the longitudinal direction of the new waterproof layer 3 are approximately parallel, as shown in Figure 3, or the new waterproof layer 3 may be arranged so that it is approximately perpendicular to the longitudinal direction of the existing waterproof sheet P, as shown in Figure 4.

Here, if the width of the existing waterproof sheet P and the width of the new waterproof layer 3 are approximately the same, arranging the existing waterproof sheet P and the new waterproof layer 3 in parallel as in Figure 3 will tend to cause the joints M of the existing waterproof sheet P and the joints N of the new waterproof layer to overlap vertically. In such a case, it is preferable to arrange the existing waterproof sheet P and the new waterproof layer 3 approximately perpendicularly as in Figure 4, so that the joints M of the existing waterproof sheet P and the joints N of the new waterproof layer 3 do not overlap and the new waterproof layer 3 can be arranged to cover at least the joints M1 in the width direction of the existing waterproof sheet P.

FIG. 7 is a partial plan view showing the layout of the new waterproof layers 3, and six new waterproof layers 3 are arranged in FIG.
When multiple new waterproof layers 3 are laid on an existing waterproof sheet P, the joints of the new waterproof layers 3 are formed with a widthwise joint N1 and a lengthwise joint N2 as shown in Fig. 7. Here, the new waterproof layer 3 has a joint piece 4, and when the joint piece 4 is provided in the lengthwise direction of the new waterproof layer 3, the joints N2 between the adjacent first new waterproof layer 31 and second new waterproof layer 32 are joined and fixed by overlapping the joint piece 42 of the second new waterproof layer 32 on the first new waterproof sheet 21 of the first new waterproof layer 31.

On the other hand, when the first new waterproof layer 31 and the third new waterproof layer 33 are in contact at their widthwise edge portions, i.e., when adjacent new waterproof layers 3 are adjacent in areas where there is no joining piece 4, the widthwise joint portion N2 can also be overlapped with the adjacent new waterproof layers 3 and joined with an adhesive or the like.
It is also preferable to arrange the adjacent first new waterproof layer 31 and third new waterproof layer 33 with their widthwise edge portions butted together, and to join the joint portion N1 formed by the butting together with the same type of joint portion sheet T as the new waterproof sheet 2 so as to cover the joint portion N1. In this way, by joining the joint portion N1 of the new waterproof layer 3 with the same type of joint portion sheet T as the new waterproof sheet 2, the joint strength and stability of the joint portion N1 are increased, which is preferable as it provides a higher waterproof performance.
Moreover, as shown in FIG. 7, by covering and joining a plurality of widthwise joints N1 with a single joint sheet T, workability is simplified and waterproofing is improved, which is more preferable.

Furthermore, in the embodiment of the present invention, it is preferable that the repair be performed on the entire surface of the existing waterproof sheet P. Not only is waterproofing improved by performing a full repair rather than a partial repair, but the embodiment of the present invention is suitable for performing a full repair. Even in the case of a full repair, depending on the parapet or other structure, the surrounding area may be a different construction structure, and it is preferable to repair the roughly flat part of the base of the roof, etc., using the embodiment of the present invention.

In this way, it is preferable to renovate almost the entire surface of the existing waterproof sheet P with a new waterproof layer 3, since this creates a double waterproof layer consisting of the existing waterproof sheet P and the new waterproof layer 3. In this case, it is preferable to inspect the existing waterproof sheet P and carry out repairs to ensure waterproofing.

The base S may be of any material or structure that is used in conventional waterproof structures such as reinforced concrete, ALC, wood, steel, or metal corrugated roofs.

The new waterproof layer 3 is formed by laminating and integrating a buffer sheet 1 and a new waterproof sheet 2. As the new waterproof sheet 2, any of the common new waterproof sheets such as polyvinyl chloride resin-based, vulcanized rubber-based, non-vulcanized rubber-based, thermoplastic elastomer-based, olefin-based, and ethylene vinyl acetate resin-based can be used.
The novel waterproof sheet 2 may be a single layer of thermoplastic resin, but is preferably a multi-layer product in which a base layer such as glass cloth, glass nonwoven fabric, polyester cloth, or polyester nonwoven fabric is laminated, because of its excellent dimensional stability and tensile strength. The base layer may be provided as the bottom layer, or may be provided between the thermoplastic resin layers. The thermoplastic resin layer may be a single layer or multiple layers, and each layer may have a different composition.
In addition, the existing waterproof sheet P may be constructed in the same manner as the new waterproof sheet 2.

Here, it is preferable that the new waterproof sheet 2 be a polyvinyl chloride resin-based sheet, as this sheet has excellent flexibility and bonding properties. If a polyvinyl chloride resin-based waterproof sheet or an olefin-based waterproof sheet is used as the existing new waterproof sheet P, it is preferable that the new waterproof sheet 2 of the new waterproof layer 3 be a polyvinyl chloride resin-based waterproof sheet.

The buffer sheet 1 used for the new waterproof layer 3 may be any material that reduces the transmission of the movement of the substrate to the new waterproof layer 3 and prevents the new waterproof layer 3 from tearing or wrinkling. Therefore, a sheet-like material with a certain degree of flexibility is preferable, and a foam sheet or the like is preferably used. As the foam sheet, polyolefins such as polyethylene, styrenes, and polyurethanes can be used. In addition, the buffer sheet 1 is bonded to the existing waterproof sheet P with an adhesive, and is also laminated with the new waterproof sheet 2. Therefore, the other surface of the buffer sheet 1 that is laminated with the new waterproof sheet 2 is bonded to the existing waterproof sheet P with an adhesive. The adhesive part with the existing waterproof sheet P is firmly bonded, and it is preferable that a reinforcing layer such as nonwoven fabric, woven fabric, or paper is provided so that the foam sheet that constitutes the buffer sheet 1 does not easily break.

When the buffer sheet 1 has a reinforcing layer, the fibers used for the nonwoven fabric and woven fabric can be natural fibers such as cotton, wool, hemp, pulp, silk, and mineral fibers, and chemical fibers such as rayon (regenerated fiber), nylon, polyester, polypropylene, acrylic fiber, vinylon, and aramid fiber.

Here, since the new waterproof layer 3 is bonded and fixed to the adhesive layer A via the buffer sheet 1, in order to make the new waterproof layer 3 less likely to peel off due to wind pressure, it is preferable that the peel strength between the foam sheet and the reinforcing layer such as nonwoven fabric in the buffer sheet 1 is greater than the peel strength between the reinforcing layer and the existing waterproof sheet P. It is also preferable that the peel strength between the foam sheet of the buffer sheet 1 and the new waterproof sheet 2 is greater than the peel strength between the reinforcing layer such as nonwoven fabric and the existing waterproof sheet P. Therefore, when the new waterproof layer 3 is fixed onto the existing waterproof sheet P via the adhesive layer A by adhesive, it is preferable that the adhesive undergoes cohesive failure, or that the foam sheet of the buffer sheet 1 undergoes material failure.

The adhesive that constitutes the adhesive layer A can be one that can adequately bond the existing waterproof sheet P and the buffer sheet 1 of the new waterproof layer 3, and examples of such adhesives include epoxy-based, NBR (nitrile rubber)-based, SBR (styrene-butadiene rubber)-based, urethane-based, and acrylic-based adhesives.

It is preferable to select an adhesive depending on the existing waterproof sheet and the new waterproof layer. When a polyvinyl chloride resin-based waterproof sheet is used for the existing waterproof sheet P, it is preferable to use an NBR-based adhesive as the adhesive, as this provides sufficient bonding strength. Also, when an olefin-based waterproof sheet is used for the existing waterproof sheet P, it is preferable to use an SBR-based adhesive as the adhesive, as this provides sufficient bonding strength.

In such a case, an NBR-based adhesive or an SBR-based adhesive can be applied to the existing waterproof sheet P, and an adhesive may also be applied to the new waterproof layer 3. In particular, when a polyvinyl chloride resin-based waterproof sheet is used for the existing waterproof sheet P, an NBR-based adhesive can be applied to both sides of the existing waterproof sheet P and the new waterproof layer 3 to achieve a stronger bond.

When the existing waterproof sheet P is a polyvinyl chloride resin-based waterproof sheet or an olefin-based waterproof sheet, the method of joining the existing waterproof sheet P to the base may be a mechanical fixing method using fixing screws and fixing disks, or an adhesive method using an adhesive.
When using a polyvinyl chloride resin-based waterproof sheet as the existing new waterproof sheet P and using a mechanical fixing method, the polyvinyl chloride resin-based waterproof sheet may be laid on top of the base S, a fixing disk may be placed on top of it, and fixing screws may be driven in to fix the polyvinyl chloride resin-based waterproof sheet with the fixing disk, or a fixing disk may be placed on top of the base and fixed to the base with fixing screws, the polyvinyl chloride resin-based waterproof sheet may be laid on top of the fixing disk, and the polyvinyl chloride resin-based waterproof sheet and the fixing disk may be fixed together with an adhesive applied to the top surface of the fixing disk.
In addition, when using a polyvinyl chloride resin-based waterproof sheet as the existing new waterproof sheet P and using an adhesive construction method, NBR-based adhesive can be applied to both sides of the base and the polyvinyl chloride resin-based waterproof sheet, and the polyvinyl chloride resin-based waterproof sheet can be laid and fixed to the base.
When using a polyolefin-based waterproof sheet as the existing waterproof sheet P and employing an adhesive construction method, an SBR-based adhesive can be applied to the base, and the polyolefin-based waterproof sheet can be laid and fixed onto the base.
In FIG. 1, an existing waterproof sheet P is fixed to a base S by an adhesive (not shown).

The joint sheet T can be of the same type as the new waterproof sheet 2. If the new waterproof sheet 2 of the new waterproof layer 3 is a polyvinyl chloride resin-based waterproof sheet, it is preferable to use a polyvinyl chloride resin-based waterproof sheet for the joining sheet as well.

Here, the joining between the new waterproof sheets 2 of adjacent new waterproof layers 3 is preferably performed by welding with a solvent or by fusion bonding with heat, and such joining by fusion bonding is preferable because it has superior stability of the joining strength over time compared to adhesion via an adhesive. If the new waterproof sheet 2 is a polyvinyl chloride resin-based waterproof sheet, the joining piece 4 of the new waterproof layer 3 is also composed of a polyvinyl chloride resin-based waterproof sheet. Therefore, since the joining piece 4 and the new waterproof sheet 2 overlapping with the joining piece 4 are composed of a polyvinyl chloride resin-based waterproof sheet, the joining piece 4 and the new waterproof sheet 2 can be joined by fusion bonding. Also, by using the same polyvinyl chloride resin-based waterproof sheet as the new waterproof sheet 2 for the joint sheet T, the new waterproof sheet 2 and the joint sheet T can be joined by fusion bonding.
The solvent used in the solvent welding is preferably a good solvent for the resin constituting the novel waterproof sheet 2. For example, when the novel waterproof sheet 2 is a polyvinyl chloride resin-based waterproof sheet, it is preferable to use THF as the main component.

Here, if the strength of the existing waterproof sheet P to the base S is insufficient, it is possible to repair the existing waterproof sheet P. If the existing waterproof sheet P is joined by an adhesive method, the portion where the joining strength is insufficient is cut open, adhesive is applied to the base, and the cut existing waterproof sheet P is rejoined, or a new waterproof sheet for repair is laid and fixed to the cut portion.
In addition, if the existing waterproof sheet P is fixed by mechanical fixing, repairs may be made to the parts that are not sufficiently fixed by using a fixing disk, a fixing disk.

Next, the construction method for the repaired waterproof structure will be explained using Figures 1 and 2. An adhesive is applied to the existing waterproof sheet P to form adhesive layer A, and a new waterproof layer 3 is laid and fixed on top of adhesive layer A. Here, adhesive is applied to the joints M of the existing waterproof sheet P.

More specifically, an existing waterproof sheet P is laid on a base S, and an adhesive is applied to the existing waterproof sheet P to form an adhesive layer A. A new waterproof layer 3, in which a buffer sheet 1 and a new waterproof sheet 2 are laminated and integrated, is laid on the adhesive layer A. An adhesive is applied to the joint portion M of the existing waterproof sheet P. At this time, the new waterproof layer 3 has a joint piece 4, and a second new waterproof layer is laid and fixed parallel to the longitudinal direction of the first new waterproof layer 31, and the joint piece 42 of the second new waterproof layer is placed on the first new waterproof sheet of the first new waterproof layer and joined by solvent welding. The joining of the joint piece 4 may also be performed by heat fusion. Then, a third new waterproof layer is laid and fixed so as to be adjacent to the edge portion in the width direction of the first new waterproof layer. A strip-shaped joint portion sheet T is fused to cover the joint portion N1 of the first new waterproof layer and the third new waterproof layer. Here, the joint portion tape T is composed of the same type of waterproof sheet as the new waterproof sheet 2.

An embodiment of the present invention will be described below mainly with reference to FIGS.
"Example 1"
In FIG. 1, an NBR adhesive is applied on a polyvinyl chloride resin-based waterproof sheet, which is an existing waterproof sheet P. The adhesive is applied continuously to cover the joint M, with the adhesive comb-like pattern formed in an arc shape. As a result, an adhesive layer A is formed in which the adhesive comb-like pattern crosses the joint M and the adhesive is covered in stripes at the joint M. The new waterproof layer 3 (31, 32) is formed by laminating and integrating a buffer sheet 1 onto the new waterproof sheet 2 (21, 22). The new waterproof sheet 2 (21, 22) is made of a polyvinyl chloride resin-based waterproof sheet, and the buffer sheet 1 is made of a polyethylene foam sheet laminated with a polyester nonwoven fabric. The new waterproof layer 3 (31, 32) is laid and fixed on the existing waterproof sheet P, with the back side of the new waterproof layer 3 (31, 32), i.e., the polyester nonwoven fabric side of the buffer sheet 1 in contact. At this time, an NBR adhesive is also applied to the polyester nonwoven fabric side as a reinforcing layer of the buffer sheet 1.

In FIG. 7, the second new waterproof layer 32 is laid and fixed adjacent to the first new waterproof layer 31 at its longitudinal edge. The second new waterproof layer 32 has a joint piece 42 provided along the longitudinal direction. Here, since the new waterproof sheet 2 (21, 22) is made of a polyvinyl chloride resin-based waterproof sheet, this joint piece 4 (42) is also made of a polyvinyl chloride resin-based waterproof sheet. The joint piece 42 is superimposed on the first new waterproof sheet 21 of the first new waterproof layer 31, and the joint piece 42 and the first new waterproof sheet 21 are joined by solvent welding. The joint piece 42 and the first new waterproof sheet 21 may also be joined by heat fusion. Furthermore, a sealer (not shown) is applied to the edge of the joint piece 42 and the first new waterproof sheet 21.

Furthermore, in FIG. 7, the third new waterproof layer 33 adjacent to the first new waterproof layer 31 at the edge in the width direction is also laid and fixed using an NBR-based adhesive. The third new waterproof layer 33 is fixed in the same manner as the new waterproof layer 3 (31, 32) shown in FIG. 1, and the adhesive is applied continuously to cover the joint M1 by forming an arc-shaped comb of adhesive at the joint M1. The joint N1 between the first new waterproof layer 31 and the third new waterproof layer 33 is formed by butting. No joint piece is provided at the edge in the width direction of the new waterproof layer 3. A joint sheet T narrower than the new waterproof sheet 2 of the new waterproof layer is laid to cover the joint N1, and the new waterproof sheets 31, 33 and the joint sheet T are joined by liquid welding using a solvent. The new waterproof sheets 31, 33 and the joint sheet T may be joined by heat fusion. Furthermore, a sealer (not shown) is applied to the edge portions of the new waterproof sheets 31, 33 and the joint sheet T. The joint sheet T has the same structure and composition as the new waterproof sheet 2.
Here, if multiple new waterproof layers are to be laid, the example shown in Example 1 can be repeated as many times as necessary, and a similar repair structure can be achieved over the entire planar portion of the existing waterproof sheet P.

"Example 2"
The existing waterproof sheet P is made of an olefin-based waterproof sheet. In the first embodiment, the adhesive is changed from NBR-based to SBR-based, and the adhesive is applied only to the top surface of the existing waterproof sheet, thereby making it possible to obtain a similarly improved waterproof structure.

"Example 3"
The construction method of Example 1 is shown. In Fig. 1, NBR adhesive is applied using a comb trowel on a polyvinyl chloride resin-based waterproof sheet, which is an existing waterproof sheet P. At this time, the adhesive is applied continuously over the joints M so that the adhesive combs are formed in an arc shape at the joints M. As a result, the adhesive combs cross the joints M, and an adhesive layer A is formed in which the adhesive is covered in stripes at the joints M. Here, the new waterproof layer 3 is formed by laminating and integrating a new waterproof sheet 2 with a buffer sheet 1. The new waterproof sheet 2 is made of a polyvinyl chloride resin-based waterproof sheet, and the buffer sheet 1 is made of a polyethylene foam sheet with a polyester nonwoven fabric laminated thereon.
Then, NBR -based adhesive is applied to the back surface of the new waterproof layer 3, i.e., the polyester nonwoven fabric surface of the buffer sheet 1, and the new waterproof layer 3 is laid on top of the adhesive layer A on the existing waterproof sheet P so that the polyester nonwoven fabric surface is in contact with the adhesive layer A, and fixed in place with the NBR-based adhesive.

In FIG. 7, the second new waterproof layer (32) has a joint piece 4 along its length. Here, since the new waterproof sheets 2 (21, 22) are made of polyvinyl chloride resin-based waterproof sheets, the joint piece 4 is also made of polyvinyl chloride resin-based waterproof sheets. The second new waterproof layer 32 is laid and fixed adjacent to the first new waterproof layer 31 and its longitudinal edge. Then, the joint piece 42 of the second new waterproof layer 32 is laid on top of the first new waterproof sheet 21 of the first new waterproof layer 31, and the joint piece 42 and the first new waterproof sheet 21 are joined by solvent welding. The joint piece 42 and the first new waterproof sheet 21 may also be joined by heat fusion. Furthermore, a sealer (not shown) is applied to the edge of the joint piece 42 and the first new waterproof sheet 21.

Further, in FIG. 7, the third new waterproof layer 33 is laid and fixed adjacent to the widthwise edge of the first new waterproof layer 31 using an NBR-based adhesive. The third new waterproof layer 33 is fixed in the same manner as the new waterproof layer 3 (31, 32) shown in FIG. 1, and the adhesive is continuously applied so that the adhesive comb is formed in an arc shape at the joint M1 and covers the joint M1, similar to the joint M2. Here, since no joint piece is provided at the widthwise edge of the new waterproof layer 3, the first new waterproof layer 31 and the third new waterproof layer 33 are laid in abutment. Then, a joint sheet T narrower than the new waterproof sheet 2 of the new waterproof layer 3 is laid so as to cover the joint N1 formed by the first new waterproof layer 31 and the third new waterproof layer 33. The new waterproof sheets 31 and 33 are joined to the joint sheet T by liquid welding using a solvent. The new waterproof sheets 31, 33 may be joined to the joint sheet T by thermal fusion. Furthermore, a sealer (not shown) is applied to the edge portions of the new waterproof sheets 31, 33 and the joint sheet T. The joint sheet T has the same structure and composition as the new waterproof sheet 2.
Here, if multiple new waterproof layers are to be laid, the example shown in Example 3 can be repeated the necessary number of times, and the same repair structure can be constructed over the entire planar portion of the existing waterproof sheet P.

"Example 4"
If the existing waterproof sheet P is composed of an olefin-based waterproof sheet, in Example 3, the adhesive can be changed from NBR-based to SBR-based and the adhesive application can be changed to a one-sided application only to the top surface of the existing waterproof sheet, thereby creating a similar construction method for a renovated waterproof structure.

According to the present invention, it is possible to provide an adhesive construction method that prevents the generation of noise and vibration during renovation when replacing an existing waterproof sheet that has deteriorated over time with a new waterproof sheet. In addition, by reducing the risk of the joints of the existing waterproof sheet tearing or moving, the present invention can be used in a waterproof construction and construction method for renovation that can reduce tearing and wrinkling of the new waterproof sheet.

S Base P Existing waterproof sheet A Adhesive layer 1 Buffer sheet 2 New waterproof sheet 3 New waterproof layer 4 Joint piece M Joint part of existing waterproof sheet N Joint part of new waterproof layer T Joint part sheet

Claims (5)

An adhesive layer is provided by applying an adhesive so as to continuously cover the joints of the existing waterproof sheet laid and fixed on the base;
A sheet-like new waterproof layer is laid and fixed to the existing waterproof sheet by the adhesive layer,
The joint portion is an overlapping portion of adjacent existing waterproof sheets,
The novel waterproof layer has a buffer sheet that is bonded to the adhesive layer, and a novel waterproof sheet that is laminated and integrated with the buffer sheet in advance,
A renovated waterproof structure in which the cushioning sheet is made of a foam sheet. The waterproofing structure of claim 1, in which one of the buffer sheets is laid to cover the joints. The improved waterproof structure according to claim 1 or 2, wherein the buffer sheet further has a reinforcing layer. The waterproofing structure of claim 1, in which the joints of the existing waterproof sheet and the joints of the new waterproof sheet are arranged so as not to overlap. A step of applying an adhesive to continuously cover the joints of a plurality of existing waterproof sheets laid and fixed on a base to form an adhesive layer;
and a step of laying and fixing a new waterproof layer on the adhesive layer.
The joint portion is an overlapping portion of adjacent existing waterproof sheets,
A construction method for a renovated waterproof structure comprising a new waterproof layer, a buffer sheet which is adhered to the adhesive layer, and a new waterproof sheet which has been pre-laminated and integrated with the buffer sheet, the buffer sheet being composed of a foam sheet.