Aoba-ku, Yokohama | Roof Renovation | We have completed roof replacement work using Yokodori Roof αs!

Hello! We are 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 project in Izumi-ku, Yokohama. There are several types of exterior renovations, and this project involves a roof overlay (cover method) (Yokodana Roof αs)!

We implemented measures against leaks through roofing work! On this page, we will explain the actual results of the work performed by Kakeru Koumuten!

Thank you very much for choosing Kakeru Koumuten Co., Ltd. from among many contractors.

Roof Overlay (Cover Method) Construction Procedure

1. Dismantling Existing Roofing Materials

First, we will dismantle the existing roofing materials (tiles)!

When dismantling the tiles, fragments of plaster and sand may come out, so we will clean up thoroughly using brooms and other tools!

2. Installation of Ventilation Method Battens

Next, we will install the ventilation method battens. The ventilation method battens create a pathway for air to circulate inside the roof and provide an escape route for moisture, which is an important part!

3. Installation of New Sheathing

Next, we will process and install new sheathing according to the dimensions!

4. Installation of Roofing (Waterproof Sheet)

After finishing the installation of the sheathing, we will apply the roofing!

The roofing used is Jouyu Pulp Industry/Sunlight G!
It is made of modified asphalt roofing material, which is said to have double the durability compared to regular asphalt roofing.
With its role as primary waterproofing, if the roofing is properly installed, there will be no leaks!
We will ensure it is firmly applied to prevent it from blowing away.

5. Processing of Accessories (Karakusa and Keraba)

Next, before the main roof construction, we will process and install accessories such as keraba and karakusa!
The cap was installed after the main roof construction!

The accessories used are made of the same SGL steel plate as the horizontal roof body.

6. Main Construction (Nichiha Corporation/Yokodora Roof αs)

After processing the fittings, we will install the main body of the Yokodana roof! This time, since the ridge is a cap, we will install the main body up to the wall of the cap.

7. Cap Processing & Sealing at Various Locations

We will process and install the cap metal. We will firmly apply sealing on the inside of the joints. At the wall edge, we will process and install a component called rain stop metal. We use stainless steel nails and screws that are resistant to rust for fixing!

Rain Gutter Replacement Construction Procedure

1. Dismantling Existing Rain Gutter

We will remove the eaves gutter and brackets carefully to avoid damaging the fascia board!

2. Installing New Eaves Brackets & Eaves Gutter

We will install new eaves brackets. When installing the brackets, we will use kite string or chalk lines to set the slope of the rain gutter, as the slope is important! We will also install the new eaves gutter!

Finally, Clean Up and Complete the Work

Once the roof replacement and rain gutter replacement are completed, we will clean up any debris that has fallen onto the balcony or rain gutters. We will thoroughly remove items such as nails and metal scraps that could cause injuries. Additionally, we will wipe away any footprints left on the roof to ensure it looks clean.

What is the Roof Overlay Method?

The roof overlay method involves leaving the current roof almost intact and placing a new roof on top of it.
Literally, it is a method of covering a roof with another roof. Therefore, the roof becomes double-layered. Since the roof is installed on top of the existing one, it is also referred to as “overlapping roofing.”

Advantages of the Overlay Method

Since a “new roof” is placed over the “existing roof,” there is almost no need for demolition work, meaning that very little waste is generated.
This is its most significant feature, leading 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 more details, please visit the Ministry of Health, Labour and Welfare website).
Some building materials used in constructions completed before 2004 contain asbestos. Asbestos-containing materials are difficult to demolish due to their high environmental impact, resulting in high costs for both demolition and waste disposal. The 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 asbestos-containing materials?” 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, the construction can be completed in a shorter time frame compared to painting or full replacement. A shorter construction period means lower labor costs, which in turn makes the overall cost lower.
The psychological anxiety of having to live in an unusual environment is also reduced.
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, and the roof overlay method is the most frequently performed type of work we undertake. We are very grateful that we have been continuously engaged in roof overlay projects without interruption.

About the Roofing Material

The roofing material used this time is Nichiha Corporation’s Yokodori Roof αS.

Yokodori Roof αS comes with a 15-year paint film warranty, 20-year rust warranty, and 25-year hole warranty.
It is a high-performance metal insulated roof made from metal steel plates (high-durability painted Galvalume steel) combined with insulation material (rigid polyurethane foam) and aluminum laminated backing.
It is lightweight, earthquake-resistant, and exhibits excellent insulation performance throughout the year, achieving long maintenance due to its high durability.

Color

This time, the roof overlay work with Green S turned out exceptionally well!
The customer was very satisfied, and I was also very happy!
Thank you very much!

Please check out other roofing work examples from here!

Roof Material	Nichiha/Yokodana Roof αs
Manufacturer Warranty	Coating 15 years, Rust 20 years, Holes 25 years
Color Used This Time	Green S

For roof renovations in Izumi-ku, Yokohama, trust Kakeru Koumuten!

Our company has extensive experience in roof renovations in Izumi-ku.
We are happy to assist with roof overlay work, roof replacement, and partial roof repairs such as leak repairs.
If you have any questions or concerns like “I just want to know the estimate for the roof renovation” or “I want to know about roofing materials,” please feel free to contact us!

Community-Focused Service

We are an exterior renovation company based in Aoba-ku, Yokohama, and we have handled many roof renovations throughout Yokohama City, deeply understanding the needs of local customers. Whether you want a renovation that lasts a long time, want to keep costs down, or want to improve insulation because your indoors are hot, we provide optimal solutions for your specific requests.

Conclusion

Estimates and inspections are, of course, free! If you have any concerns regarding roofs, rain gutters, exterior walls, or exteriors, please consult Kakeru Koumuten Co., Ltd. in Aoba-ku, Yokohama!

Kakeru Koumuten Co., Ltd. is a remodeling company strong in exterior renovations, and we carry out everything from temporary scaffolding work to roof work and exterior painting completely in-house.
When it comes to exterior renovation work, we are confident that we do not fall short compared to other companies in terms of “cost, quality, and efficiency”!

We are confident in our exterior renovations, so we welcome price comparisons!
We offer comprehensive construction guarantees and aftercare maintenance, and we have received positive feedback for our cost performance and appropriate proposals that align with our customers’ future life plans!

We want you to think, “I’m glad I asked them!” Therefore, we take every request we receive seriously.

We also have information on roof construction costs and pricing plans for the roof overlay (cover method), so please take a look if you are interested!

We look forward to your inquiries. Thank you very much.

Helpful information about exterior renovations can be found here!

LINE consultations are also very welcome◎

For roofing, guttering, and exterior work and repairs in Kanagawa, contact Kakerukoumuten Co., Ltd..

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!