Leave Waterproofing Work in Aoba-ku, Yokohama to Kakeru Koumuten Co., Ltd.!
If you are looking for a waterproofing contractor in Aoba-ku, Yokohama,
please contact Kakeru Koumuten.
Kakeru Koumuten is a company specializing in exterior renovations based in Aoba-ku, Yokohama.
We receive many requests for waterproofing work for both single-family homes and apartment buildings in Aoba-ku.
“Reasons why Kakeru Koumuten is chosen in Aoba-ku”
“About the costs of waterproofing work”
“How to choose a waterproofing contractor”
“About grants and subsidies applicable to waterproofing work in Aoba-ku”
We will explain the above four points!
This will definitely be helpful for customers considering waterproofing work in Aoba-ku, Yokohama, so
please take a look!
Reasons why Kakeru Koumuten is chosen for waterproofing work in Aoba-ku, Yokohama
The reasons why our company can be entrusted with waterproofing work by customers in Aoba-ku, Yokohama include
one reason being that Kakeru Koumuten’s headquarters is in Aoba-ku,
“Our strengths in waterproofing work that cannot be imitated by other companies”, which have received high praise from many customers.
We have absolute confidence in “cost,” “quality,” and “plans,” so
we would be grateful if you could compare our estimates with those of other companies.
Because we are confident, we welcome competitive estimates!
1.Facilities Specialized in Exterior Renovation
Kakeru Koumuten Co., Ltd. has prepared the following warehouses and material storage areas to provide exterior renovations such as waterproofing at lower costs and faster.
We have established 5 bases centered around Aoba-ku, Yokohama for material storage and showrooms.
In-House Scaffolding Materials


We own the scaffolding materials necessary for temporary scaffolding required for waterproofing work, allowing us to assemble temporary scaffolding in-house.
By conducting scaffolding work with our own scaffolding team instead of outsourcing, we can also reduce the costs associated with scaffolding work.
Since everything is handled in-house, we can significantly reduce costs by shortening the construction period!
We have enough scaffolding materials for approximately 50 single-family homes!
Storage of materials in our large in-house warehouse

We store roofing materials and waterproofing components.
By ordering a large quantity of materials at once, we can purchase materials at a lower cost!
Additionally, we always have waterproofing components in stock, allowing us to respond quickly to emergency waterproofing work!
In-house sorting of waste materials
In waterproofing work, various waste materials are generated.
Most contractors dispose of them all together, but by sorting and recycling waste materials, significant cost savings on waste disposal can be achieved.
Exterior Renovation Dedicated Showroom


In our showroom, not only can you have meetings, but you can also
directly check the actual structure and color variations.
2.Complete In-House Construction
One of Kakeru Koumuten’s major strengths is complete in-house construction.
From inquiry to project completion, everything is handled by Kakeru Koumuten Co., Ltd. This allows us to keep costs down while providing high-quality waterproofing work.
Additionally, one representative will assist you from the estimate to the completion of the project.
Since the same person will handle sales and construction management, smooth communication is possible.
We are confident in our construction plans and costs, so we welcome competitive estimates!
3. Various Permits and Skilled Workers

We have obtained construction industry permits and permits for industrial waste collection and transportation!
We also have qualified personnel on staff, and we are confident in our construction techniques.
We are capable of handling large-scale waterproofing projects such as those for factories!
4. Warranty and Aftercare
Waterproofing work comes with a guarantee!
Depending on the type of waterproofing work, we provide a 5 to 10-year leak guarantee.
If you have any questions about the guarantee, please click on the image above!
In the unlikely event that leaks are not resolved after the waterproofing work, we will take responsibility and respond accordingly!
Additionally, aftercare maintenance is available every year, and we will send you a DM reminder for aftercare maintenance each year.
During aftercare maintenance, we will check the entire waterproofing system and assess the condition of any deterioration.
5. Flexible and Prompt Response
Our company is equipped to handle various troubles and situations.
If we cannot access the rooftop for waterproofing checks, we will utilize drones to assess the condition.
We can also conduct investigations using thermal imaging cameras during leak investigations.
We will respond according to your wishes.
We also accept emergency measures for sudden leaks!
Since our sales and construction management are not separated, one dedicated representative will handle everything from the estimate to the completion of the work!
Changing representatives frequently can lead to miscommunication regarding the details and precautions of the work, which could cause problems, so we have a system in place to keep the same representative throughout the process.
6. Human Resource Development
To enhance our skills, we create various building models and conduct practical training.
We regularly provide technical training so that each staff member can handle various types of buildings.
Subsidies and Grants That May Apply to Waterproofing Work in Aoba-ku, Yokohama
If damage from natural disasters is recognized, it may be covered by fire insurance.
In terms of waterproofing, potential damage from natural disasters could include “holes in waterproof sheets caused by flying objects or falling debris due to wind disasters.”
If you are unsure whether it is covered by fire insurance, please feel free to contact us!
Property Tax Reduction System for Condominiums with Major Repairs (Condominium Longevity Promotion Tax System)
To promote the longevity of condominiums, for those that meet certain requirements, if major repairs contributing to longevity are carried out between April 1, 2023, and March 31, 2027, and necessary documents are submitted to the Tax Division of the Ward Office within three months of the completion of the work, there is a system that reduces the property tax for the following fiscal year by half for the relevant condominium.
Condominium Longevity Promotion Tax System
Yokohama City Official Website
About the Costs of Waterproofing Work
⇧Construction Menu|For information on waterproofing costs, click here
Examples of Waterproofing Work
| Construction Details |
| Urethane waterproofing ventilation buffer method / High-strength urethane type Existing waterproofing: PVC sheet waterproofing |
| Materials Used |
| Waterproofing: AGC polymer building materials / Saracene A (high-strength urethane) Ventilation sheet: QV sheet Vent pipe: Stainless steel Replaced with renovation drain |
| Price Range |
| 700,000 to 800,000 yen |
| Construction Period |
| Approximately 2 weeks |
| Completion Month |
| May 2024 |
| Inquiry Details |
| We have received the following inquiries from our customer: ・There are wrinkles and bulges in the waterproof sheet on the rooftop, so we are worried about leaks. ・We would like an estimate for a complete waterproof renovation, not just partial repairs or a top coat. ・We learned that urethane waterproofing has high waterproofing properties, so we would like an estimate for urethane waterproofing. ・Since this is our first waterproofing project, we would like to compare estimates. |
Our Proposal
Since you expressed a desire to renovate using a long-lasting method rather than just protective agents like top coats, we proposed a complete “urethane waterproofing project” for the rooftop.
If urethane waterproofing is applied using the adhesion method, air rising from the building can cause bulges in the waterproof layer, so we proposed the “urethane waterproofing ventilation buffer method.”
The ventilation buffer method involves applying a ventilation buffer sheet across the entire area before installing the urethane waterproofing.
By applying the ventilation buffer sheet first, the air rising from the building is suppressed by the ventilation sheet and expelled through the “ventilation tube.”
This can prevent the most common problem with waterproofing: bulging of the waterproof layer!
After explaining the materials and methods, we were entrusted with the project among four competing estimates!
Timing for Waterproofing Work
Leaks Have Already Occurred
If leaks have already occurred, it is necessary to address the issue promptly before the damage spreads.
If left unattended, it can negatively impact the interior and underlying structures, so it is crucial to stop the leaks quickly.
Bulging or Cracking of the Waterproof Layer
If the waterproof area is cracked, it can lead to rainwater intrusion.
If the waterproof layer is bulging, it indicates that moisture is accumulating within the layer.
Bulging can lead to cracks, which can result in leaks, so early detection and action are necessary.
Moss or Mold Growth
Moss or mold can develop due to the accumulation of moisture or rainwater.
This can be caused by inadequate drainage or sinking of the waterproof layer due to aging.
Exceeding the Durability Period
Generally, the durability period for waterproofing work is between 10 to 20 years.
Of course, the durability can vary depending on the construction method and materials, but for some types of waterproofing, it is recommended to apply only the surface protective agent (top coat) approximately every 8 years (such as urethane waterproofing or FRP waterproofing).
We recommend conducting regular inspections starting from 5 years after construction.
Understanding the types of waterproofing and performing appropriate maintenance is crucial.
If you are unsure about the type of waterproofing, please send us a photo via email or LINE, and we will help you determine it!
Types of Waterproofing Work
1. Urethane Waterproofing
Urethane waterproofing is a method where liquid polyurethane resin is applied in layers to the waterproofing surface.
Since it is liquid before curing, it can be applied to complex shapes, and unlike sheet waterproofing, it can be installed without seams, which is a significant advantage.
It can be widely applied to balconies, rooftops, and more.
We provide detailed explanations about the advantages, disadvantages, and maintenance methods of urethane waterproofing in the article below.
For more information on waterproofing work | Urethane Waterproofing, click here!
2. Rubber Sheet Waterproofing
Rubber sheet waterproofing involves adhering synthetic rubber sheets to the surface to prevent water intrusion.
This type of waterproofing is commonly used on large areas such as rooftops.
Compared to urethane waterproofing, it has the advantage of faster installation since there is no waiting for drying, but it is not suitable for complex surfaces.
We provide detailed explanations about the advantages, disadvantages, and maintenance methods of rubber sheet waterproofing in the article below.
For more information on waterproofing work | Rubber Sheet Waterproofing, click here!
3. PVC Sheet Waterproofing
PVC sheet waterproofing is a waterproof sheet made of polyvinyl chloride, which, like rubber sheet waterproofing, is applied to the surface to prevent water intrusion.
Like rubber sheets, it is not suitable for complex shapes. Although the cost is higher than rubber sheets and urethane waterproofing, its long durability is a significant advantage.
For more detailed information on the advantages and disadvantages of PVC sheet waterproofing and maintenance methods, please refer to the article below.
For waterproofing work | Click here for information on PVC sheet waterproofing!
4. Long Sheet Waterproofing
Long sheet waterproofing, officially known as “slip-resistant vinyl flooring sheet,” is commonly applied in shared areas and staircases of apartments where people walk.
As the name suggests, it is slip-resistant and has high durability and abrasion resistance, making it suitable for walking areas.
Additionally, it comes in various designs, excelling in aesthetic appeal.
However, it tends to be more expensive, and since it does not overlap seams like rubber sheets or PVC sheets, it may give a slightly lower impression of waterproofing capability.
It is rarely used in areas like apartment rooftops where people do not frequently enter.
For more detailed information on the advantages and disadvantages of long sheet waterproofing and maintenance methods, please refer to the article below.
For waterproofing work | Click here for information on long sheet waterproofing!
5. FRP Waterproofing
FRP waterproofing involves creating a waterproof layer by hardening glass mat with epoxy resin to prevent rainwater intrusion.
It is commonly applied in single-family home balconies, with an overwhelmingly short construction period, often completed in as little as one day.
Due to its lightweight and low cost, it is estimated that about 80% of single-family home balconies use FRP waterproofing.
However, it is not suitable for installation on large areas, making it less appropriate for rooftop applications.
For more detailed information on the advantages and disadvantages of FRP waterproofing and maintenance methods, please refer to the article below.
Waterproofing Work | Click here for FRP Waterproofing!
6. Asphalt Waterproofing
Asphalt waterproofing is a waterproof sheet that has asphalt permeated into synthetic fiber non-woven fabric.
The waterproofing shown in the photo is a method where asphalt waterproofing is pressed down with cinder concrete.
This waterproofing is used in buildings with large areas such as rooftops of schools and commercial facilities.
There are various methods of asphalt waterproofing, each with its own advantages and disadvantages, but a significant advantage is its high durability.
For more detailed information on the advantages, disadvantages, and maintenance methods of asphalt waterproofing, please refer to the article below.
Waterproofing Work | Click here for Asphalt Waterproofing!
How to Choose a Waterproofing Contractor
There are many waterproofing contractors available in Aoba-ku, Yokohama.
Among the numerous contractors, there are likely many who feel “I don’t know who to ask…”.
Choosing the right contractor can be challenging at first, so I will explain 5 points to keep in mind when requesting waterproofing work.
● Have extensive experience in waterproofing work
● Check for aftercare and warranty availability
● Obtain estimates from multiple contractors (at least 3 companies)
● Confirm whether they perform waterproofing work in-house
● Carefully review the details of the waterproofing estimate, including processes and materials used
By confirming the above 5 points, you will be able to choose a reliable contractor.
Check if they have extensive experience in waterproofing work
About 10-20% of waterproofing work troubles are caused by construction defects during the installation.
To prevent troubles, it is important to hire a reliable contractor with experience!
You need to refer to the contractor’s website for their past work and reviews to make a judgment.
There are also contractors who showcase their achievements on social media platforms like Instagram, so checking those can be effective!
It is also effective to look at waterproofing companies on review sites for reference!
A particularly recommended review site is “Google”.
Since contractors cannot delete low ratings on their own, it provides trustworthy reviews.
If there are many negative reviews or no reviews at all, it may be wise to refrain from making a request.
Check if there is aftercare maintenance and construction warranty
In case of any construction defects or issues after the work is done, let’s confirm if they provide a “construction warranty”!
Contractors who offer warranties are usually confident in their work, making them more trustworthy!
If waterproofing work is done, make sure to take photos of hidden areas during the process for confirmation!
Check for leaks during rainy weather after the waterproofing work, and if there are any issues, contact the contractor immediately as it will facilitate smooth communication shortly after the work is completed!
Also, to ensure early detection of any issues that may arise, check if they provide thorough aftercare maintenance!
Since non-specialized contractors may not notice signs of problems or troubles, having a specialized contractor conduct regular aftercare maintenance can prevent troubles before they occur!
Our company sends out aftercare maintenance DM every year, so if desired, annual aftercare maintenance is possible!
Obtain estimates from multiple contractors (at least three)
When requesting waterproofing work, be sure to obtain estimates from multiple contractors.
We recommend obtaining estimates from at least three companies.
Even for the same waterproofing work, costs and warranties or after-service may differ between contractors.
Additionally, obtaining multiple estimates makes it easier to negotiate prices. To request at the lowest possible cost, obtaining estimates from several contractors is essential.
When comparing estimates, be sure to check not only the costs but also the details such as “types of materials used” and “construction methods”!
Check if they perform waterproofing work in-house
Check if they perform waterproofing work in-house!
If a sales company investigates and then requests a subcontractor, it will incur extra time and costs.
Moreover, there may be cases where your requests are not fully communicated to the subcontractor, leading to troubles.
By having one company handle everything from sales to construction, responsible waterproofing work can be done quickly and cost-effectively. Kakeru Koumuten handles everything from on-site surveys to actual construction in-house!
Furthermore, if any leaks or troubles occur, a company that employs its own craftsmen can respond to and resolve issues quickly!
Carefully Check the Details of Waterproofing Estimates, Processes, and Materials
Even for the same waterproofing work, there are various types such as “methods,” “materials,” and “processes,” and it is necessary to carry out the work with the optimal method and materials depending on the construction site and existing substrate.
For example, even with the same urethane waterproofing, there are different types of processes such as “adhesion method” and “ventilated buffer method,” and there are various types of urethane waterproofing materials, including “high strength specifications,” “heat insulation specifications,” and “anti-slip specifications.” Therefore, it is essential to confirm whether the construction details are appropriate for the installation location!
It is important not to judge solely based on cost, but to carefully check whether “the method is appropriate for the base material?” and “are the materials appropriate?”
So, if the materials used are only “urethane waterproofing materials,” let’s confirm the product name and check what kind of materials they are!
If you are looking for a waterproofing contractor in Aoba-ku, Yokohama, please contact Kakeru Koumuten Co., Ltd.
Our company has handled many waterproofing projects in Aoba-ku, Yokohama.
Our greatest strength is that we can handle everything from proposals to the installation of temporary scaffolding and waterproofing work in-house!
Kakeru Koumuten promises “high-quality waterproofing work at low cost”, and we have received great praise from many customers.
We continue to update our construction performance every year, and we will strive to improve quality so that even more customers will be satisfied in the future.
We are also happy to respond to small partial projects!
In addition to waterproofing work, we can handle roofing work, exterior painting, and exterior cover methods, all of which can be done in-house.
We are confident that we will not be outdone by other companies in terms of cost, quality, and efficiency in exterior work!
We are confident, so we welcome competitive estimates!
Estimates are completely free, and if our company is found to be inferior to others, please feel free to decline!
Click here for exterior renovations in Aoba-ku, Yokohama!
Click here for exterior painting in Aoba-ku, Yokohama!
Click here for roof renovations in Aoba-ku, Yokohama!
Click here for exterior cover work in Aoba-ku, Yokohama!
Click here for leak repairs in Aoba-ku, Yokohama!
Features of Aoba-ku, Yokohama
Aoba-ku, located in the southeastern part of Yokohama City, is an area characterized by a beautiful coastline facing Tokyo Bay and lush hilly terrain!
Historically, it was a thriving area for ports and fishing, but in recent years, it has developed into a region with coastal tourist spots and leisure facilities, as well as various features such as industrial zones and residential areas.
If you live in Aoba-ku and have any concerns regarding waterproofing work or your home, please feel free to contact us!
Waterproofing Work Service Areas
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and all of Tokyo.
Aoba-ku, Yokohama Area List
Aoba-ku Aobadai / Aoba-ku Akane-dai / Aoba-ku Azamino / Aoba-ku Azamino Minami / Aoba-ku Ichigaocho / Aoba-ku Utsukushigaoka / Aoba-ku Utsukushigaoka Nishi / Aoba-ku Umekogaoka / Aoba-ku Egotan / Aoba-ku Eda Kita / Aoba-ku Eda Cho / Aoba-ku Eda Nishi / Aoba-ku Enokigaoka / Aoba-ku Oba Cho / Aoba-ku Onda Cho / Aoba-ku Kakinokidai / Aoba-ku Katsuradai / Aoba-ku Kamitayanomoto Cho / Aoba-ku Kamoshida Cho / Aoba-ku Tetsumachi / Aoba-ku Kurosuda / Aoba-ku Sakuradai / Aoba-ku Satsukigaoka / Aoba-ku Jikecho / Aoba-ku Shimotayanomoto Cho / Aoba-ku Shiratoridai / Aoba-ku Shin Ishikawa / Aoba-ku Susukino / Aoba-ku Sumiyoshidai / Aoba-ku Tachibanadai / Aoba-ku Tana Cho / Aoba-ku Chigusa-dai / Aoba-ku Tsutsuji ga Oka / Aoba-ku Nara Cho / Aoba-ku Nariai Cho / Aoba-ku Fujigaoka / Aoba-ku Matsukaze-dai / Aoba-ku Mitakidai / Aoba-ku Midoriyama / Aoba-ku Moegino / Aoba-ku Moto Ishikawa Cho / Aoba-ku Momino Kidai / Aoba-ku Wakakusa-dai / Aoba-ku Misuzugaoka / Aoba-ku Nara
Consultations via LINE are also very welcome◎
株式会社翔工務店へ
株式会社翔工務店は平均年齢20代後半の若い会社ですが、技術はどこにも負けていません。
いちばんの強みは、足場工事、屋根工事、塗装工事とすべて自社で行えること。一般には分業されるこの業界にあって、一式で頼めるので管理に手間がかからず、コストも抑えることが出来ます。何より、トラブルがあればすぐにかけつけます!
自信をもって、宣言できます。私たちは、神奈川で一番若くて親切なリフォーム屋です!





