[Aoba-ku, Yokohama] | Roof Repair | Performed Roof Overlay and Water Heater Removal!

BEFORE

AFTER

Hello!
We are Kakeru Koumuten Co., Ltd., a specialist in roofing, exterior painting, and exterior renovations located in Yokohama, Kanagawa Prefecture!

This is a case study of an exterior renovation in Midori-ku, Yokohama.
The roof repair this time includes a roof overlay (cover method) from slate roof to Super Galtect, as well as the removal of the water heater and replacement of the rain gutters!

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

Construction Data for H Residence, Midori-ku, Yokohama

Roof Overlay Construction Procedure

1. Dismantling Existing Ridge, Snow Stops, and Water Heater

We will dismantle unnecessary parts (ridge flashing) for the overlay method! This time, we also removed the water heater! The durability of wooden purlins is about 10 to 15 years. Exceeding the durability period can lead to corrosion and discoloration, resulting in the ridge flashing coming loose or scattering.

The water heater has 200 to 300 liters of hot water stored in the tank, so it is quite heavy if we don’t drain it! We will dismantle it as much as possible on the roof after draining the water inside!
We will also stop the water flow and remove the hose connected from the tank to the interior!

About Water Heaters

As explained above, water heaters hold 200 to 300 liters of hot water, making them quite heavy. When combined with the weight of the unit itself, it can weigh between 250 to 350 kilograms.
Having that much weight on part of the roof can be burdensome, so if you are not using it, we recommend disposal rather than removal during the roof overlay or replacement process!

2. Roofing Installation (Waterproof Sheet)

Next, we will install the roofing sheet (waterproof sheet)! The roofing used is Tajima Roofing/New Liner Roofing!
This underlayment boasts unparalleled waterproofing and durability, representing the highest quality available. By sandwiching a modified asphalt layer between non-woven fabric and base paper, it fully demonstrates the inherent performance of modified asphalt.
The expected durability is about 30 years! There are various features and durability ratings for roofing sheets, so let’s choose a roofing sheet that considers new roofing materials and the environment!

3. Custom Fabrication (Karakusa and Keraba)

Before the main roof construction, we will fabricate and install custom pieces such as keraba and karakusa!
The custom pieces used are the genuine parts from Galtect, made of SGL copper plate!

4. Main Construction (Aiji Industry/Super Galtect)

After processing the fittings, we will install the Galttect main body up to the ridge! At the same time, we will also install the genuine Galttect snow guard!
Once the installation reaches the ridge, we will set up the necessary materials to secure the ridge board called “kanban.” We offer three types of kanban: cedar, resin, and Galvalume steel, and this time we used the top-grade Galvalume steel!
The durability of the Galvalume steel kanban is approximately 30 to 35 years, making it highly durable and unlike resin or cedar, it won’t crack! If you use cedar kanban, which has a shorter lifespan than the roofing material, it will need to be replaced in about 10 years. It is recommended to match the durability of the roofing material with that of the kanban!

5. Processing and Installation of Ridge Flashing and Rain Diverter Flashing, Sealing at Various Locations

Next, we will process and install the ridge flashing. We will securely apply sealing on the inside of the joints. At the wall edge, we will process and install a component called rain diverter flashing.
The packing screws used for fixing are made of stainless steel, which is resistant to rust!
By using screws instead of nails for fixing, we enhance wind resistance as they won’t pull out like nails!

Rain Gutter Replacement Construction Procedure

1. Dismantling Existing Eaves Gutter

We will remove the eaves gutter and brackets carefully to avoid damaging the fascia! We will repair the nail holes left by the brackets with caulking!

2. Installing New Eaves Brackets

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 crucial! We will touch up the existing bracket marks with the same color!

3. Connecting the Downspout

We will connect the existing vertical and eaves gutters!

4. Water Flow Test and Cleaning

Finally, we will conduct a water flow test and clean up to complete the work!

For the eaves gutter, we used Panasonic/PC50.
It has strength due to the iron plate inside.

5. Cleaning

We will clean up any debris that has fallen onto balconies and other areas. We will thoroughly remove nails and metal scraps that could cause injuries. Additionally, we will wipe away any footprints left on the roof to ensure it looks clean.

Colors

■ Milk White

■ Pearl Gray

■ Modern Beige

■ Oak Brown

■ Shincha

■ Black

This time, the replacement work was beautifully finished with Milk White!
Our customer was very satisfied!
Thank you very much!

Please check out other rain gutter construction results from here!

About Roofing Materials

The roofing material used is the Super Galtect from Aijii Industrial.
The Super Galtect comes with a manufacturer warranty of 15 years for the coating and 25 years for perforation.
We also provide a 10-year construction warranty!
Made of SGL steel plate, it is resistant to rust.
Insulation material is tightly applied from edge to edge of the roofing material, creating a metal plate that integrates steel and insulation.
During installation, insulation is applied even to the parts where the roofing materials overlap, and the surface is coated with a highly heat-resistant paint, allowing for a cool summer and a warm winter.
Additionally, it has soundproofing properties, reducing the sound of rain.
Moreover, it is lightweight compared to other roofing materials, which minimizes shaking during earthquakes, providing earthquake resistance.
It excels in finish, durability, insulation, soundproofing, and wind resistance, and the Super Galtect from Aijii Industrial is the most frequently used in our construction results, gaining significant attention!

Color

■Shade Black

■Shade Brown

■Shade Blue

■Shade Moss Green

■Shade Charcoal

■Shade Wine Red

You can choose from these 6 colors!

This time, the cover work with Shade Black turned out exceptionally well!
The customer was very satisfied, and I was also very happy!
Thank you very much!

Please check out our other roofing work achievements here!

Roof Material	Aiji Giken/Super Galtect
Manufacturer Warranty	Coating 15 years, Red rust 20 years, Puncture 25 years
Expected Durability	Approximately 40 years
Color Used This Time	Shade Black

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 layered, it is also referred to as “layered 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 its most significant feature, leading to various advantages.

The only parts that require demolition and waste disposal are the ridge caps, making it more cost-effective compared to complete roof replacement.
In 2004, regulations regarding the concentration of asbestos in raw materials were changed (for details, please refer to the Ministry of Health, Labour and Welfare website).
Building materials used in constructions completed before 2004 may 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 us.

Additionally, we can complete the work in a shorter time frame than painting or re-roofing. A shorter construction period means lower labor costs, which in turn makes the expenses more affordable.
The psychological anxiety of having to live in a different environment is also reduced.
When scaffolding is set up, you may experience inconveniences such as difficulty entering and exiting or not being able 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 (cover method) is the most frequently performed service we offer. We are very grateful that we have been continuously engaged in roof overlay (cover method) projects without interruption.

For roof repairs in Midori-ku, Yokohama, trust Kakeru Koumuten Co., Ltd.!

Community-Focused Service

As an exterior renovation company based in Aoba-ku, Yokohama, we handle many roof repairs and renovations in neighboring Midori-ku, deeply understanding the needs of our local customers.

Midori-ku, Yokohama, is rich in nature and greenery, making it a very livable area. In locations close to mountains and forests, there can be shorter sunlight hours and colder conditions.
We offer plans tailored to your location and environment, including roofing materials and paints that enhance indoor insulation!

Whether you want “to make it last long with one renovation,” “to keep costs as low as possible,” “to improve insulation because the indoors are hot,” or “just to do a temporary fix on the roof,” we will propose the optimal plan for your specific requests!

Summary

This concludes our record of roof repair projects in Midori-ku, Yokohama!
This time, we completely handled the installation of temporary scaffolding, removal of the water heater, roof overlay (cover method), and rain gutter replacement in-house!
For slate roofs containing asbestos, re-roofing can incur high disposal costs for waste materials, so we recommend the overlay method before the underlying structure deteriorates!
Super Galtect is lightweight and has a long lifespan, making it an ideal roofing material for the overlay method!
When considering the overlay method, it’s important to check not only the roofing materials and estimated costs but also the finer details such as “roofing sheets,” “nailing boards,” and “fasteners” to avoid future troubles!

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 is a renovation company strong in exterior renovations, and we perform everything from temporary scaffolding work to roofing and exterior painting completely in-house.
We are confident that our “cost, quality, and efficiency” in exterior renovation work are unmatched compared to other companies!

We are confident in our exterior renovations, so we welcome competitive estimates!
We offer comprehensive construction guarantees and aftercare, providing proposals that align with cost performance and your future life plans, which have been well-received!

“I’m glad I asked them!” We take every request seriously to ensure you feel that way.

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

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

Helpful information about exterior renovations can be found here!

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