Construction example

[Kanagawa Prefecture, Yokohama] | Renovation of a Used Property | We performed a roof overlay using Super Galtect on a slate roof with a skylight!

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 a roof renovation in Yokohama, Kanagawa Prefecture.
The work this time involves a roof overlay (cover method) using Super Galtect!

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

Construction Data in Yokohama, Kanagawa Prefecture

Construction Location

Aoba-ku, Yokohama

Construction Details

Temporary Scaffolding Installation
Roof Overlay (Cover Method)

Background to the Construction

We received the following inquiry from a customer living in Aoba-ku, Yokohama.
“I purchased a 20-year-old used property, and there are many areas of concern on the roof with no previous construction history, so I would like to receive an estimate for repairs and renovations.”

● Proposal Details
First, we conducted a site survey to check the condition of the roof and investigated whether the roof overlay work could be carried out without any issues!
Since the underlying structure was strong enough, we proposed a cover construction using Super Galtect, as per the customer’s request, and they entrusted us with the work!

Materials Used

Materials used for roof overlay (cover method): Super Galtect
Roofing: Tadi Self Cover
Accessories: Galvalume sheet

Price Range

900,000 to 1,000,000 yen

Construction Period

Approximately 5 days

Completion Month

June 2025

Roof Overlay Construction Procedure

1. Dismantling Existing Ridge and Snow Stops


First, we will dismantle unnecessary parts for the overlay method (ridge cap, purlin, snow stops)! The lifespan of wooden purlins is about 10 to 15 years.
The lifespan of wooden purlins is about 10 to 15 years. Once the lifespan is exceeded, corrosion and discoloration can occur, leading to the detachment and scattering of the ridge cap.

2. Roofing Installation (Waterproof Sheet)

Next, we will apply the waterproof sheet! The roofing used is Tajima Roofing / Daddy’s Self Cover!
This is a highly durable non-woven fabric roofing!
With the role of secondary waterproofing, if the roofing is solid, it generally won’t leak!
We will ensure it is firmly applied so it won’t be blown away by the wind.
Since there are various durability years and characteristics for roofing sheets, it is important to choose a roofing sheet that matches the durability years of the new roof and the roof slope!

3. Component Processing (Karakusa & Keraba)


Before the main roof construction, we will process and install components such as keraba and karakusa!
The components used are genuine Galtect components made of SGL steel plate!

4. Main Construction (Aiji Industry / Super Galtect)


After processing the components, we will install the Galtect main roofing up to the ridge!
Once the roofing is completed up to the ridge, we will install the necessary materials to secure the ridge board, known as the kanban. We offer three types of kanban: cedar, resin, and Galvalume steel, and this time, since the customer requested high durability, we used a Galvalume base.

The Galvalume steel plate is expected to have three times the durability compared to cedar! Unlike resin and cedar, it won’t crack, so it’s safe!

Our original integrated waste board made of Galvalume steel for the ridge base is highly durable, has strong fixation, and excellent wind resistance!

Even if rainwater seeps in from the ridge, it has a mechanism to discharge rainwater to the outside, demonstrating high waterproofing performance!

It is ideal for the ridge base of Super Galtect!

5. Ridge Flashing Processing and Sealing at Various Locations

Next, we will process and install the ridge flashing. We will create a waste board around the skylight with metal processing to prevent rainwater intrusion.
We will firmly apply sealing on the inside of the joints. This time, we used Auton Chemical Industry’s Auton Exceed. Auton Exceed is a sealing material with a durability of about 30 years, making it an ultra-high durability sealing material. It is expected to have nearly three times the durability of urethane and silicone-based materials!

The nails and screws used for fixation are made of rust-resistant stainless steel!

Unlike nails, screws with packing are less likely to come out
and securely fix the ridge flashing to the purlin!

 

Although it is not visible after construction,
installing a face plate on the inside of the ridge flashing
enhances waterproofing!
It firmly protects the ridge, which is a critical point of the roof.

6. Cleaning

We will clean up the debris that has fallen onto the balcony and rain gutters. We will thoroughly remove items like nails and metal fragments that could cause injuries. Additionally, we will wipe away any footprints left on the roof to keep it clean.

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.
Our company also provides a 10-year construction warranty!

Made of SGL steel plate, it is resistant to rust.
Insulation material is thoroughly applied from edge to edge of the roofing material, creating a metal sheet that integrates the steel plate and insulation.
When installed, insulation is applied even to the parts where the roofing materials overlap, and the surface is coated with a high heat-reflective paint, allowing for a cool summer and a warm winter.
Additionally, it has soundproofing properties, reducing the sound of rain.
Being lighter than other roofing materials, it also reduces the sway during earthquakes, contributing to 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 achievements, gaining significant attention!

Color

■Shade Black
Shade Black
■Shade Brown
Shade Brown
■Shade Blue
Shade Blue
■Shade Moss Green
Shade Moss Green
■Shade Charcoal
Shade Charcoal
New Color Shade Wine Red

You can choose from these 6 colors!
This time, the cover work was completed very well with Shade Black!
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 15 years for coating, 20 years for rust, 25 years for perforation
Expected Durability About 40 years
Color Used This Time

Shade Black

Shade Black

Leave Your Roofing Work in Kanagawa Prefecture, Yokohama to Kakeru Koumuten!

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

List of Areas in Yokohama
Aoba-ku / Asahi-ku / Izumi-ku / Isogo-ku / Kanagawa-ku / Kanagawa-ku / Kanazawa-ku / Konan-ku / Kohoku-ku / Sakae-ku / Seya-ku / Tsuzuki-ku / Tsurumi-ku / Totsuka-ku / Naka-ku / Nishi-ku / Hodogaya-ku / Midori-ku / Minami-ku

Long-Term Reliability

All roofing materials we use are highly reliable products that offer long-term warranties. For example, the Super Galtect used this time comes with a 15-year warranty for coating and a 25-year warranty for perforation. We also provide a 10-year construction warranty! You can use it with peace of mind for a long time after just one renovation.
Galtect is an excellent roofing material in terms of durability, but we also offer roofing materials with even higher durability and better insulation properties.

Summary

Estimates and inspections are, of course, free! If you have any issues with roofs, rain gutters, exterior walls, or exteriors, please consult Kakeru Koumuten Co., Ltd. in Kanagawa Prefecture!

Kakeru Koumuten Co., Ltd. has become a strong remodeling company specializing 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 in terms of “cost, quality, and efficiency”, we do not fall behind compared to other companies!

We are confident in our exterior renovations, so we welcome competitive estimates!
We also 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 seriously and work diligently on it.

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!

LINE consultations are also very welcome◎

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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!