

Hello!
I am Yamanaka from Kakeru Koumuten Co., Ltd., a specialist in roofing, exterior painting, and exterior renovations located in Aoba-ku, Yokohama, Kanagawa Prefecture!
This is a case study of an exterior renovation in Aoba-ku, Yokohama, Kanagawa Prefecture.
There are several types of exterior renovations, and this project involved a roof replacement (Colonial Grasa) and exterior painting!
We implemented measures against leaks through the roofing and exterior painting work!
On this page, I will explain the actual results of the work performed by Kakeru Koumuten!
We received a request from our trusted renovation partner, Company S!
Thank you very much for choosing Kakeru Koumuten Co., Ltd. among many contractors.
目次
- 1 Roof replacement construction procedure
- 2 What is the Roof Overlay (Cover Method)?
- 3 Exterior Painting Work Procedure
- 4 Leave Your Exterior Renovation in Aoba-ku, Yokohama to Kakeru Koumuten!
Roof replacement construction procedure
1. Demolition of existing roofing materials
2. Installation of new sheathing
3. Roofing Installation (Waterproof Sheet)
It is made of modified asphalt roofing, which is said to have double the durability of regular asphalt roofing.
As a primary waterproofing measure, if the roofing is properly installed, there will be no leaks!
We will ensure it is securely attached to prevent it from blowing away.
4. Custom Fabrication (Decorative Elements)
The materials used for these elements are Galvalume steel sheets.
4. Main Construction (Keimyuu/Colonial Grasa)
Once the roofing is completed up to the ridge, we will install necessary materials called “nail boards” to secure the ridge cap. There are types of nail boards made of cedar and resin, and this time we used the resin type!
The resin type is expected to have three times the durability compared to the cedar type!
5. Ridge Cap Fabrication & Sealing at Various Locations

At the wall edge, we will process and install a component called a rain guard metal.
We use stainless steel nails and screws that are resistant to rust!
6. Cleaning
The roofing material used is Kaimu’s Colonial Grasa.
Colonial Grasa is a roofing material that does not contain asbestos and has improved durability compared to Colonial NEO.
Additionally, it has a treatment called Grasa Coat that prevents fading, making it a highly durable material that shows little color change even after about 30 years.
Among colonial roofs, it is the one that retains color the longest and eliminates the disadvantages of other colonial materials that require regular maintenance.
Color
■ Black

■ Pearl Gray

■ Coconut Brown

■ Irish Green

■ Midnight Blue

■ Ash Gray
■ Ice Silver
■ Rusty Green

■ Pure Black

■ Walnut Brown

■ Bordeaux Red
■Weathered Green
■Glass Brown
■Provence Beige
■Mellow Orange
■Euro Red
There are 16 colors and a wide variety!
This time, the cover work with Ash Gray turned out very well!
Thank you for your request!!
Please check out other roofing work achievements from here!
What is the Roof Overlay (Cover Method)?
The roof overlay method involves leaving the current roof almost as it is and placing a new roof on top of it, effectively covering it.
Literally, it is a method of covering a roof with another roof. Therefore, the roof becomes double-layered. Since the roof is laid on top of another, it is also referred to as “overlapping roofing.”
Advantages of the Overlay Method
Since a “new roof” is placed over the “current roof,” demolition work is almost unnecessary, meaning that very little waste is generated.
This is the biggest feature and leads to various advantages.
The only part that requires demolition and waste disposal is the ridge cap, so compared to a complete roof replacement, the cost is lower.
In 2004, regulations regarding the concentration of asbestos in raw materials were changed (for details, please visit the Ministry of Health, Labour and Welfare website).
Some building materials used in constructions completed before 2004 contain asbestos. Because materials containing asbestos have a high environmental impact, their demolition is also difficult, resulting in high costs for both demolition and waste disposal. The roof overlay method, which generates almost no waste, is ideal for such roofs.
Some may wonder, “Is it safe to live in a building that uses materials containing asbestos?” but rest assured. As long as there is no destruction or crushing, it will not disperse into the air.
If you are unsure about the type of roof on your home, please feel free to consult with us.
Additionally, it can be completed in a shorter time frame than painting or a full roof replacement. A shorter construction period means lower labor costs, which in turn makes the overall cost lower.
This also reduces the psychological anxiety of having to live in an unusual environment.
When scaffolding is set up, you may experience inconveniences such as difficulty entering and exiting or being unable to open windows. Being able to return to your normal life in a short period is a significant advantage.
Our company specializes in roofing work, but the roof overlay method is the most frequently performed type of work we undertake. We are very grateful that we have been continuously able to carry out roof overlay projects without interruption.
Exterior Painting Work Procedure
1. High-Pressure Washing
2. Protection of Various Areas
3. Primer Application

4. Middle Coat

5. Top Coat

6. Painting of Additional Parts (Rain Gutter, Eaves, Shutters, Cap)
Rain Gutter
・Eaves
・Cap
・Shutter
・Balcony Top Coat
Please check out other painting work results from here!
Material Introduction
| Exterior Wall Paint |
![]() ![]() |
|---|---|
| Wall Color | N-70![]() |
| Accessory Paint | SK Kaken/Clean Mild Silicon![]() |
| Accessory Color |
Black
|
| Roof Material | Keimyu/Colonial Grasa |
|---|---|
| Expected Durability | About 30 years |
| Color Used This Time | ■Ash Gray![]() |
Leave Your Exterior Renovation in Aoba-ku, Yokohama to Kakeru Koumuten!
Our company is based in Aoba-ku, Yokohama, and we have extensive experience in exterior wall and roof renovations.
We are happy to assist with partial repairs such as exterior painting, roof work, waterproofing, and other construction.
If you have any questions or concerns, such as “I just want to know the estimate” or “I want to know about suitable paints for my home,” please feel free to contact us!
Community-Focused Service
As an exterior renovation company in Aoba-ku, Yokohama, we have handled many exterior renovations in the area and deeply understand the needs of local customers. Whether you want to “make it last long with one renovation,” “keep costs down as much as possible,” or “want to do a color simulation for the exterior wall,” we provide optimal solutions for your specific requests.
Summary
Estimates and inspections are, of course, free! If you have any concerns regarding roofs, rain gutters, exterior walls, or exteriors, please consult with Kakeru Koumuten Co., Ltd. in Aoba-ku, Yokohama!
Kakeru Koumuten is a renovation company strong in exterior renovations, and we carry out everything from temporary scaffolding work to roof work and exterior painting completely in-house.
We are confident that our “cost, quality, and good planning” are unmatched compared to other companies in exterior renovation work!
We are confident in our exterior renovations, so we welcome competitive estimates!
We offer comprehensive construction guarantees and aftercare maintenance, and we have received positive feedback for our appropriate proposals that match cost performance and our customers’ future life plans!
“I’m glad I asked them!” We take every request seriously to ensure you feel this way.
We look forward to your inquiries. Thank you very much.
Useful information about exterior renovations can be found here!
・Aoba-ku, Yokohama | We conducted exterior wall painting work using premium silicon!
・Aoba-ku, Yokohama | We carried out exterior wall painting and roof cover work!
・Aoba-ku, Yokohama | Exterior painting | We conducted exterior painting using Art Fresh!
・Summary of Popular Exterior Wall Paint Colors! We will introduce recommended color combinations!
・For those who want to try DIY painting of roofs and exterior walls! Scaffolding installation only! Roof and exterior wall painting DIY plan!
・Latest! Subsidies in Kanagawa Prefecture! We will introduce grants and reduction systems!
・What is the cost range for roof remodeling? Types of construction and how to choose a contractor
・How much does exterior wall painting cost? Are there tips to reduce costs?
・How much does roof construction cost? We will introduce the cost range!
・What is the cost range for rain gutter repair and cleaning? Tips on timing, fire insurance, and choosing a contractor!
・How much does exterior wall painting cost? Are there tips to reduce costs?
Consultations via LINE are also very welcome◎
AAA is a young company with an average age in the early 20s, but our technology is second to none.
One of our greatest strengths is that we can do all of our own scaffolding, roofing, and painting work. In this industry, where work is generally divided, we are able to provide a complete set of services, which saves time and effort in management and reduces costs. Above all, if there is any trouble, we will come to you right away!
We can confidently declare this. We are the youngest and most friendly renovator in Kanagawa!







