Leave Waterproofing Work in Nerima-ku, Tokyo to Kakeru Koumuten Co., Ltd.!
If you are looking for a waterproofing contractor in Nerima-ku, Tokyo,
come to Kakeru Koumuten
Kakeru Koumuten specializes in exterior renovations.
We receive many requests for waterproofing work for both single-family homes and apartment buildings in Nerima-ku, Tokyo.
“Reasons why Kakeru Koumuten is chosen in Nerima-ku”
“About the costs of waterproofing work”
“How to choose a waterproofing contractor”
“About subsidies and grants available for waterproofing work in Nerima-ku”
We will explain the above four points!
This will definitely be helpful for customers considering waterproofing work in Nerima-ku, so
please take a look!
Reasons why Kakeru Koumuten is chosen for waterproofing work in Nerima-ku, Tokyo
Regarding the reasons why our company is entrusted with waterproofing work by customers in Nerima-ku, Tokyo,
“Our strengths in waterproofing work that cannot be imitated by other companies”
have received high praise from many customers.
“Cost,” “Quality,” “Plan” are our absolute strengths, so
we would appreciate it if you could compare our estimates with those of other companies.
Because we are confident, we welcome competitive estimates!
1.Specialized equipment for exterior renovations
At Kakeru Koumuten Co., Ltd., we have organized the following warehouses and material storage areas to provide more affordable and faster exterior renovations such as waterproofing work.
We have established five bases centered around Aoba-ku, Yokohama for material storage and showrooms.
In-house Ownership of 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 done in-house, we can significantly reduce costs through shortened construction periods!
We have scaffolding materials sufficient 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 canprocure materials at a lower cost!
Additionally, we always have waterproofing components in stock, allowing us torespond quickly to emergency waterproofing work!
In-house waste separation
In waterproofing work, various waste materials are generated.
Most contractors dispose of them all together, but by sorting and recycling waste materials, significant cost reductions in 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 tones.
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 work.
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 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 offer 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 notification for aftercare maintenance once a 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 roof for waterproofing checks, we will utilize drones to assess the condition.
During leak investigations, we can also conduct inspections using thermal imaging cameras.
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 issues; therefore, we maintain a system where the representative remains the same.
6. Human Resource Development
To enhance skills, we create models of various buildings 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 for Waterproofing Work in Nerima-ku, Tokyo
Tax Reduction for Promoting Longevity of Condominiums (Property Tax Reduction)
Requirements for Tax Reduction for Promoting Longevity of Condominiums
Condominiums over 20 years old
Total number of units: 10 or more
Completion of longevity improvement work at least once in the past + completion of the second or subsequent work between April 1, 2023, and March 31, 2027
Condominiums with a management plan certification or those that have developed or reviewed a long-term repair plan with advice and guidance from the local government
The living area of the exclusive portion occupies more than 50% of the total
Tax Reduction Details
Applicable: Property tax on the building portion imposed in the fiscal year following the completion of the work.
Maximum Reduction: Up to equivalent to 100㎡ per unit
Tax Reduction Rate: The tax amount within the above range is reduced by 1/2 (50%)
Others
If damage due to natural disasters is recognized, it may be covered by fire insurance.
For waterproofing, potential damages considered as natural disasters may include “holes in waterproof sheets caused by flying objects or falling debris due to wind damage.”
If you are unsure whether your fire insurance is applicable, please feel free to contact us!
About the Costs of Waterproofing Work
⇧ For the construction menu | Click here for information on waterproofing costs
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: Made of 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 mentioned wanting 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 a direct 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 over the entire area before applying urethane waterproofing.
By applying the ventilation buffer sheet first, the air rising from the building is suppressed by the ventilation sheet and expelled through a “ventilation pipe.”
This can prevent the most common issue with waterproofing, which is bulging in the waterproof layer!
After explaining the materials and methods, you entrusted the project to us among the four estimates!
Timing for Waterproofing Work
Already Experiencing Leaks
If leaks have already occurred, it is necessary to address the issue promptly before the damage spreads.
If left unattended, it can adversely affect the interior and underlying structures, so it is crucial to stop the leaks quickly.
Bulges or Cracks in the Waterproof Layer
If there are cracks in the waterproof section, 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 it is important to detect and address this early.
Moss or Mold Growth
Moss or mold can develop due to the accumulation of moisture or rainwater.
This can be caused by poor 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 essential.
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 that involves applying liquid polyurethane resin onto the waterproofing surface.
Before curing, it is in liquid form, allowing it to 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 and rooftops.
We provide detailed explanations about the advantages, disadvantages, and maintenance methods of urethane waterproofing in the article below.
For more 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 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 details on the advantages, disadvantages, and maintenance methods of PVC sheet waterproofing, please refer to the article below.
For waterproofing work | Click here for PVC sheet waterproofing work!
4. Long Sheet Waterproofing
Long sheet waterproofing, officially known as “anti-slip vinyl floor 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 have a slightly lower impression of waterproofing performance.
It is rarely used in areas like the rooftops of apartments where people do not frequently enter.
For more details on the advantages, disadvantages, and maintenance methods of long sheet waterproofing, please refer to the article below.
For waterproofing work | Click here for long sheet waterproofing work!
5. FRP Waterproofing
FRP waterproofing involves creating a waterproof layer by solidifying glass mat with epoxy resin to prevent rainwater intrusion.
It is commonly applied in single-family home balconies, and the construction period is remarkably short, often completed in as little as one day.
Due to its lightweight and low cost, it seems that about 80% of single-family home balconies use FRP waterproofing.
However, it is not suitable for construction on large areas, making it less appropriate for rooftops.
For more details on the advantages, disadvantages, and maintenance methods of FRP waterproofing, 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 details 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 Nerima-ku, Tokyo. Among the numerous contractors, there are likely many people who feel, “I don’t know where to ask…”. Choosing the right contractor can be challenging at first, so I will explain 5 points to be careful about when requesting waterproofing work.
● Have extensive experience in waterproofing work
● Confirm the presence of aftercare and warranty
● Obtain estimates from multiple contractors (at least 3 companies)
● Check if 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 poor construction 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 construction achievements 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!
The review site I particularly recommend 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 might 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 a warranty are usually confident in their work, making them more trustworthy companies!
If waterproofing work has been done, make sure to have photos taken 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!
Additionally, to detect any issues early, confirm whether they will conduct thorough aftercare maintenance!
Since non-specialized contractors may not notice signs of problems or troubles, having a specialized contractor perform regular aftercare maintenance can help 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 for waterproofing work (at least three companies)
When requesting waterproofing work, always obtain estimates from multiple contractors.
We recommend obtaining estimates from at least three companies.
Even for the same waterproofing work, costs may vary between contractors, and warranties and after-services may differ as well.
Moreover, 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, check not only the costs but also the “types of materials used” and “construction methods,” and compare the details!
Check if they perform waterproofing work in-house
Let’s confirm whether we handle waterproofing work in-house!
If a sales company investigates and then requests a subcontractor, it can lead to extra time and costs.
Additionally, there may be cases where your requests are not fully communicated to the subcontractor, which can lead to troubles.
By having one company handle everything from sales to construction, we can provide responsible waterproofing work that is quick and cost-effective. Kakeru Koumuten Co., Ltd. conducts everything from on-site surveys to actual construction in-house!
Moreover, in the unlikely event of a leak or trouble, a company that employs its own craftsmen can respond to and resolve issues quickly!
Carefully check the details of the waterproofing estimate, process, and materials used
Even for the same waterproofing work, there are various types such as “methods,” “materials,” and “processes,” and it is necessary to use the optimal method and materials based on the construction location 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-insulating specifications,” and “anti-slip specifications.” Therefore, it is essential to confirm whether the construction details are appropriate for the location!
It is important not to judge solely based on cost, but to carefully check whether “the method is appropriate for the substrate?” and “are the materials appropriate?”
Thus, if the materials used are only “urethane waterproofing materials,” make sure to check the product name and confirm what kind of materials they are!
If you are looking for waterproofing contractors in Nerima-ku, Tokyo, please contact Kakeru Koumuten
Our company has handled many waterproofing projects in Nerima-ku, Tokyo.
Our greatest strength is our ability to conduct everything from proposals to temporary scaffolding installation and waterproofing work in-house!
Kakeru Koumuten Co., Ltd. promises “high-quality waterproofing work at low cost”, and we have received high praise from many customers.
We continue to update our annual construction performance, and we will strive to improve quality to satisfy even more customers in the future.
We are also happy to handle small partial projects!
Not only waterproofing work but also roofing work, exterior painting, and exterior covering methods can all be conducted in-house.
We are confident that we will not be outdone by other companies in terms of cost, quality, and organization for exterior work!
We welcome competitive estimates with confidence!
Estimates are completely free, and if our company is found to be inferior to others, you are welcome to decline!
For information on exterior renovations in Nerima-ku, Tokyo, click here!
For information on exterior painting in Nerima-ku, Tokyo, click here!
For information on roof renovations in Nerima-ku, Tokyo, click here!
For information on leak repairs in Nerima-ku, Tokyo, click here!
Features of Nerima-ku, Tokyo
Nerima-ku, Tokyo, is the newest ward among the 23 wards of Tokyo. While it has developed as a residential city, it is also an area rich in nature and offers a calm living environment. The Seibu Ikebukuro Line, Seibu Shinjuku Line, Tobu Tojo Line, and Toei Oedo Line run through the area, providing excellent access to Ikebukuro, Shinjuku, and Shibuya, making it convenient for commuting and schooling.
Additionally, Nerima-ku has the largest agricultural land area among the 23 wards, where fresh vegetables can be obtained at direct sales outlets and urban agricultural parks. Large parks such as Hikarigaoka Park and Shakujii Park are also scattered throughout the area, allowing residents to enjoy a life surrounded by nature. Culturally, there are facilities like the “Nerima Art Museum” and “Chihiro Art Museum, Tokyo,” which are popular among families and seniors for their artistic engagement.
Furthermore, the number of newly built and renovated homes in the ward is increasing, attracting more families.
Our company offers a wide range of waterproofing construction services in Nerima-ku. We can handle all exterior renovations, including waterproofing, roofing, and exterior wall painting, with our own staff.
If you have any concerns, please feel free to consult with us!
Waterproofing Service Areas
Kakeru Koumuten Co., Ltd. accepts requests throughout Kanagawa Prefecture and all of Tokyo.
List of Areas in Nerima-ku, Tokyo
Asahigaoka, Nerima-ku / Asahimachi, Nerima-ku / Oizumigakuencho, Nerima-ku / Oizumicho, Nerima-ku / Kasugacho, Nerima-ku / Kamishakujii, Nerima-ku / Kamishakujii Minamimachi, Nerima-ku / Kitamachi, Nerima-ku / Mukaiyama, Nerima-ku / Kotakecho, Nerima-ku / Sakaemachi, Nerima-ku / Sakuradai, Nerima-ku / Shimoshakujii, Nerima-ku / Shakujii-dai, Nerima-ku / Shakujii-cho, Nerima-ku / Sekimachihigashi, Nerima-ku / Sekimachiminami, Nerima-ku / Sekimachikita, Nerima-ku / Takayanodai, Nerima-ku / Takamatsu, Nerima-ku / Tagara, Nerima-ku / Tatenocho, Nerima-ku / Toshida, Nerima-ku / Toyotamaue, Nerima-ku / Toyotamachu, Nerima-ku / Toyotamaminami, Nerima-ku / Toyotamakita, Nerima-ku / Nakamura, Nerima-ku / Nakamura Minami, Nerima-ku / Nakamura Kita, Nerima-ku / Nishioizumi, Nerima-ku / Nishioizumicho, Nerima-ku / Nishiki, Nerima-ku / Nuki, Nerima-ku / Nerima, Nerima-ku / Hazawa, Nerima-ku / Hayamiya, Nerima-ku / Hikarigaoka, Nerima-ku / Hikawadai, Nerima-ku / Higashioizumi, Nerima-ku / Fujimidai, Nerima-ku / Heiwadai, Nerima-ku / Minamioizumi, Nerima-ku / Minamitanaka, Nerima-ku / Mihara-dai, Nerima-ku / Tanihara, Nerima-ku
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!





