[Katsushika-ku, Tokyo] Roof Renovation | We have completed a roof replacement using Hiranbi 220!

BEFORE

AFTER

Hello!
This is Kakeru Koumuten Co., Ltd., a specialist in roofing, exterior wall painting, and exterior renovations located in Aoba-ku, Yokohama, Kanagawa Prefecture!
This is a case study of exterior renovations in Katsushika-ku, Tokyo.
The work this time involves a roof replacement (Hiranbi 220) project!

On this page, we will explain the actual achievements carried out by Kakeru Koumuten!

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

Construction Data for Katsushika-ku, Tokyo

Roof Replacement Construction Photos

1. Existing Roofing Material Dismantling

We will dismantle and remove the existing roofing materials! Since you requested a replacement of the sheathing, we removed the existing sheathing and installed new sheathing! The underlying rafters were in very good condition!

2. New Sheathing Installation

After dismantling the existing roofing materials, we will process and install new sheathing (structural plywood) to fit the dimensions!

3. Roofing Installation (Waterproof Sheet)

We will install the roofing sheet (waterproof sheet) on top of the underlayment! The roofing used is Jouyu Pulp Industry/Sunlight G!
This material is modified asphalt roofing, which is said to have double the durability of regular asphalt roofing.
With the roofing providing secondary waterproofing, if it is properly installed, there will be no leaks!
We will ensure it is securely attached to prevent it from blowing away!

4. Custom Fabrication (Kera and Karakusa)

Before the main roofing work, we will fabricate and install custom pieces such as kera and karakusa metal!
The materials used for the custom pieces are galvalume steel sheets.

5. Main Construction (Inagaki Shouji/Hiranbi)

After processing the special parts, we will install the Hiranbee main body up to the ridge!
Once we have completed the installation up to the ridge, we will install the necessary materials for fixing the ridge board called “kanban.” There are various types of kanban made from cedar, resin, and Galvalume steel, and this time we used the resin type!
The resin type is expected to have twice the durability compared to the cedar type!

6. Processing of Ridge Metal and Sealing at Various Locations

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

7. Cleaning

We will clean up any debris that has fallen onto the balcony and rain gutters. We will thoroughly clean up nails and metal scraps to prevent injuries. We will also wipe off any footprints left on the roof to keep it clean!

About the Roofing Material

The roofing material used is Inagaki Shouji’s Hiranbee 220.
Hiranbee 220 comes with a manufacturer warranty of 15 years for the coating and 25 years for perforation.
For re-roofing and overlaying, we also provide a 10-year construction warranty!
If there are any leaks within 10 years, we will make repairs free of charge.
It is made of Galvalume steel, which is also resistant to rust.
The molded panels have been treated with iris folding and wave processing to prevent distortion and enhance strength, as well as improve rain drainage and aesthetic effects.

Additionally, it excels in finish, durability, sound insulation, and wind resistance, and is lightweight compared to other roofing materials, which reduces the sway during earthquakes, making it a good earthquake countermeasure.
In the overlay (cover) work we performed this time, the roof becomes double-layered, which increases the weight, but Hiranbee is a lightweight roofing material, making it suitable for overlay (cover) work.

Colors

Extreme – MAX Type
■ Gray Silver

■ Silver Black

■ Sepia

■ Moss Green

■ Bamboo Green

■ Midnight Blue

■ Jet Black

■ Dark Brown

■ Bright Red

Standard Type
■ Steel Black

■Marron Brown

■J Silver

You can choose from the above!

This time, the roof replacement work with Silver Black turned out exceptionally well!
Thank you for your request!!

Please check out other roofing work examples 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 over, it is also referred to as “overlapping roofing.”

Advantages of the Overlay Method

Since a “new roof” is placed over the “existing 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 part that requires demolition and waste disposal is the ridge cap, so compared to complete roof replacements, the cost is lower.
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’s website).
Some building materials used in structures built before 2004 contain asbestos. Asbestos-containing materials are difficult to demolish due to their high environmental impact, and the costs for demolition and waste disposal are also high. 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?” 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 us.

Additionally, it can be completed in a shorter time frame compared to painting or complete roof 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, there may be inconveniences such as difficulty entering and exiting or opening windows. Being able to return to 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 continuously receive requests for roof overlay method work without interruption.

The Necessity of Roof Work (Roof Repair) and Maintenance Schedule

◇ Necessity and Purpose of Roof Work and Roof Repair

・Necessity and Purpose of Roof Work

The roof directly suffers damage from rain, wind, and ultraviolet rays, and problems such as cracks and leaks become apparent over time. By carrying out roof work, the durability of the building is enhanced, maintaining a comfortable living space. Additionally, improvements in energy efficiency can be expected. For example, using highly insulating roofing materials can lead to reduced heating and cooling costs.

In terms of long-term cost performance, roof work can be considered an important investment.

・Schedule for Roof Work (Roof Repair)

Depending on the type of roofing material and the local climate, it is generally recommended that roof work (roof repair) be performed every 10 to 15 years. After that, inspections should be conducted approximately every 5 years, with repairs or painting carried out as necessary. Regular maintenance allows for early detection of minor deterioration or damage, which can reduce the risk of large-scale construction or repairs.

However, this is merely a guideline, and the timing may vary based on the material of the roof and environmental conditions such as high humidity, strong winds, and snowfall. Under severe weather conditions, more frequent checks may be necessary. Additionally, since roof work (roof repair) involves working at heights, it is advisable to hire a professional contractor.

Post-Construction Maintenance

◇ Importance of Post-Construction Maintenance

Maintenance after exterior painting and roof repair is a crucial factor in extending the lifespan of the home. Neglecting maintenance can lead to the newly painted exterior and repaired roof deteriorating quickly, resulting in the risk of incurring high costs. The exterior walls and roof of a building are constantly exposed to harsh natural environments such as rain, wind, ultraviolet rays, and temperature changes. Regular maintenance minimizes damage and helps maintain the home’s aesthetics and comfort. Furthermore, it can help avoid large-scale repair work and the associated significant expenses.

◇ Maintenance Methods and Frequency

For post-construction maintenance, inspections by professional contractors are effective. Minor damages can be detected and repaired early. The recommended frequency for maintenance is generally exterior painting every 5 years and roof repair every 3 years. This is just a guideline and may vary based on local climate conditions and the structure of the home.

For Roof Renovations in Katsushika-ku, Tokyo, Trust Kakeru Koumuten!

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

Long-Term Reliability

All roofing materials we use are highly reliable products that offer long-term warranties. For example, the Hiranbi 220 from Inagaki Shouji that we used this time comes with a 15-year coating warranty and a 25-year perforation warranty, allowing you to use it with peace of mind for a long time after just one renovation.
Hiranbi is a lightweight roofing material that excels in durability and cost performance, but we also offer roofing materials with even higher durability and better insulation properties.

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 competitive estimates!
We offer comprehensive construction guarantees and aftercare maintenance, and we have received positive feedback for our appropriate proposals that align with 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 also have information on roof construction 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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