Roof Overlay (Cover Method) Construction Costs and Plans
We will introduce suitable roofing materials for the roof overlay method and the cost per square meter of roofing in detail below!
If you are thinking, “I want to renovate my roof, but what kind of roofing material is best…? I also want to know the approximate cost before making an inquiry…” please use this as a reference when making your request!
Asphalt Shingle Material – Asahi Fiberglass / Ridgeway
This is the Ridgeway from Asahi Fiberglass. Ridgeway comes with a 10-year manufacturer warranty.
Since it uses natural stone with baked-on paint on the surface, it is a roofing material that does not require painting, which is characterized by lower maintenance costs.
Additionally, because it uses fine natural stones on the surface, you won’t be troubled by rain noise. It is a lightweight roofing material, so it has strong earthquake resistance as well.
*After installation, some of the surface decorative stones may fall off for about a week, but this does not affect the quality.
Roofing Achievements Using Ridgeway!
Ridgeway | Cost
| Unit price per square meter of roofing material | per square meter / 4000 yen〜 *Varies depending on the shape of the roof. |
|---|---|
| Durability | Approximately 25 to 30 years |
| Warranty | 10 years *Natural disasters are not covered. |
| Weight per square meter | per square meter / 12 kg *Thin slate and colonial are per square meter / 20 kg *Tiles are per square meter / 50 kg |
| Features (Advantages and Disadvantages) |
・The decorative stones on the surface may fall off onto balconies and other areas after installation, but this will stabilize after about a week. There are no quality issues. |
Color Variations
■Dual Black
■Harvard Slate
■Dual Brown
■Vintage Green
■Earthstone Cedar
Here is the web catalog for Ridgeway!
Galvalume Steel Roof Material Inagawa Shouji / Hiranbee 220
The Hiranbee 220 comes with a 15-year paint warranty and a 25-year hole warranty from the manufacturer.
Additionally, we provide a 10-year construction warranty for re-roofing and overlay work!
It is made of Galvalume steel, which is resistant to rust.
Durability, Wind Resistance are excellent, and compared to other roofing materials, it is lightweight, which reduces the sway during earthquakes, making it a good earthquake countermeasure.
Hiranbee is a lightweight roofing material, making it suitable for the roof overlay (cover method) construction.
Roof construction results using Hiranbee 220!
Hiranbee 220｜Cost
| Unit price per square meter of roofing material | 1 square meter / 4,300 yen～ *Varies depending on the shape of the roof and the height of the building. |
|---|---|
| Durability | Approximately 35 years to 40 years |
| Warranty | Coating 15 years / Puncture 25 years *Natural disasters are not covered. |
| Weight per square meter | 1 square meter / 5.4 kg *Thin slate and colonial tiles are 20 kg per square meter *Tiles are 50 kg per square meter |
| Features (Advantages and Disadvantages) |
・Without insulation and soundproofing materials, rain sounds may echo. ・Without insulation, thermal insulation properties are low. |
Color Variations (Kiwami-MAX Type)
■Gray Silver
■Silver
■Sepia KNC
■Moss Green
■Bamboo Green
■Midnight Blue
■Jet Black
■Dark Brown
■Bright Red
Here is the web catalog for Hiranbi 220!
SGL Steel Plate Insulated Roofing Material – Sekino Kousan/Dannetsu Top
Dannetsu Top is a type that comes with a thin insulation material, as introduced above with Hiranbi. The material is the same as Hiranbi, and it also comes with the same warranty of 15 years for the coating and 25 years for perforation from the manufacturer. Additionally, we provide a 10-year construction warranty for re-roofing and overlay work! Being made of SGL steel plate, it is also resistant to rust.
Durability and Wind Resistance are excellent, and compared to other roofing materials, its lightweight nature reduces the sway during earthquakes, making it a good option for earthquake resistance. It is less resonant than Hiranbi, and its insulation properties have also improved. Dan Netsu Top is a lightweight roofing material, making it suitable for roof overlay (cover method) work.
Check out our Dan Netsu Top construction results here!
Dan Netsu Top | Cost
| Unit price per square meter of roofing material | per square meter / 4500 yen～ *Varies depending on the shape of the roof and the height of the building. |
|---|---|
| Durability | Approximately 35 to 40 years |
| Warranty | 15 years for coating / 25 years for perforation *Natural disasters are not covered. |
| Weight per square meter | per square meter / 5.6 kg *Thin slate and colonial tiles are per square meter / 20 kg *Tiles are per square meter / 50 kg |
| Features (Merits and Demerits) |
Rain sounds may resonate slightly. |
Color Variations
SGL Steel Plate Insulated Roofing Material – Aijii Industry/Super Galtect
Aijii Industry’s Super Galtect comes with a 15-year paint warranty and a 25-year hole warranty.
Made of SGL steel plate, it is also resistant to rust. It allows for a cool summer and a warm winter. Additionally, it has soundproofing properties, which reduce the sound of rain. Moreover, it is lightweight compared to other roofing materials, which minimizes shaking during earthquakes, making it a good earthquake countermeasure.
It excels in finish, durability, insulation, soundproofing, and wind resistance, and our company’s construction achievements show that Aijii Industry’s Super Galtect is the most popular choice, receiving significant attention!
Roofing construction achievements using Super Galtect!
Super Galtect | Cost
| Unit price per square meter of roofing material | per square meter / 5500 yen～ *Varies depending on the shape of the roof and the height of the building. |
|---|---|
| Durability | Approximately 40 years |
| Warranty | Coating 15 years / Red rust 20 years / Punctures 25 years *Natural disasters are not covered. |
| Weight per square meter | per square meter / 5 kg *Thin slate and colonial tiles are per square meter / 20 kg *Tiles are per square meter / 50 kg |
| Features (Merits and Demerits) |
None in particular! |
Color Variations
■Shade Black
■Shade Brown
■Shade Moss Green
■Shade Blue
■Shade Charcoal
■Shade Wine Red
Here is the web catalog for Super Galtect!
Zincalume Steel Sheet – D-Trading/Diplomat Star
The Diplomat Star from D-Trading Co., Ltd. comes with a 30-year manufacturer warranty.
The Diplomat Star is a lightweight metal roof made from Zincalume steel sheet, which is equivalent to Galvalume steel, ensuring high durability. The surface is coated with natural stone granules, preventing significant fading and maintaining its aesthetic appeal over the long term.
Thanks to the stone granules on the surface, it can reduce summer heat and rain noise. Additionally, it is lightweight, rust-resistant, and excels in durability and seismic resistance.
Roof construction results using Dipromat Star!
Dipromat Star | Cost
| Price per square meter | per square meter / 6300 yen～ ※Varies depending on the shape of the roof and the height of the building. |
|---|---|
| Durability | Approximately 45 years |
| Warranty | 30 years ※Natural disasters are not covered. |
| Weight per square meter | per square meter / 6 kg ※Thin slate and colonial tiles are per square meter / 20 kg ※Tiles are per square meter / 50 kg |
| Features (Advantages and Disadvantages) |
・The decorative stones may fall off until they stabilize. |
Color Variations
■TERRA COTTA
■CAFE
■EVER GREEN
■ONYX
Here is the web catalog for Diplomat Star!
Cost per Unit for Roof Overlay Work
The cost of roof overlay work varies not only by the type and area of roofing materials,
but also by the quantity and type of materials used, roofing sheets, and ridge base (nail board)!
We will explain the costs of each item in as much detail as possible!
Unit Prices for Each Item of Roof Overlay Work
| Item | Unit Price |
| Temporary Scaffolding Installation | 450 yen～/㎡ |
| Mesh Sheet | 50 yen～/㎡ |
| High-Pressure Washing | 100～200 yen/㎡ |
| Removal of Existing Ridge | 800 yen～/m |
| Removal of Snow Stop | 200～300 yen/per location |
| Roofing Sheet | 600 yen～/㎡ |
| Eaves Water Cutting (Arabesque) | 1,700 yen～/m |
| Gable Flashing | 2,200 yen～/m |
| Valley Flashing | 2,800 yen～/m |
| Roof Body | 4,000 yen～/㎡ |
| Snow Stop Installation | 1,200 yen～/m (700 yen～/location) |
| Nail Board (Ridge Base) | 700 yen～/m |
| Ridge Flashing (With Packing Stainless Screws) | 2,500 yen～/m |
| Sealer (Surface) | 300 yen/m |
| Rain Stop | 2,900 yen～/m |
| Various Sealing (Ridge Flashing, Wall Edges, etc.) | 5,000 yen～/set |
| Change to Stainless Screws for Roofing Material | 300 yen/㎡ |
| Road Use Permit Application Fee | 20,000 yen/per case |
| Traffic Control Personnel Placement | 20,000 yen/per person |
| Transportation Costs Varying by Construction Days and Distance, Waste Disposal Fee | 10,000 yen～/per case |
| Miscellaneous Expenses and Management Fees | 10,000 yen～/per case |
※ If the installation of scaffolding requires the removal and reattachment of fences or carport panels, or if transportation of stairs is necessary, additional costs may apply.
※ Unit prices vary depending on the height and size of the building.
※ High-pressure washing is performed in cases of severe dirt, such as moss. Costs may vary depending on the area and whether bio-cleaning agents are used.
※ The cost for roofing materials varies significantly depending on the type of flashing (such as arabesque, eaves, valleys, etc.), resulting in a wide range of prices.
Unit Prices by Material
Roofing Materials
| Product Name | Features | Unit Price |
| Ridgeway Alma | Asphalt shingle material | 4,000 yen～/㎡ |
| Hiranbee 220 | Galvalume steel roofing material | 4,300 yen～/㎡ |
| Dannez Top | SGL steel roofing material with insulation | 4,500 yen～/㎡ |
| Super Galtect | SGL steel roofing material with insulation | 5,500 yen～/㎡ |
| Diplomat Star | Zinc-aluminum steel | 6,300 yen～/㎡ |
Underlayment (Roofing)
| Product Name | Durability (Years) | Unit Price |
| Sankara Roofing | ・Asphalt Roofing 940 ・Durability approximately 10 years |
600 yen～/㎡ |
| Sunlight G | ・Modified Asphalt Roofing (Rubber Asphalt Roofing) ・Durability approximately 20 years |
800 yen～/㎡ |
| New Liner Roofing |
・Modified asphalt roofing (rubber asphalt roofing) |
1,200 yen～/㎡ |
| Tadis Self | ・Adhesive roofing ・Durability of approximately 20 years |
1,300 yen～/㎡ |
| Tadis Self Cover | ・Adhesive roofing ・Durability of approximately 30 years ・Recommended for covering roofs with many cracks! |
1,500 yen～/㎡ |
Ridge Board (Base for Ridge)
| Material Type | Unit Price (yen) |
| Wood (Durability of 10 years) | 700 yen～/m |
| Plastic (Durability of 20 years) | 900 yen～/m |
| Galvalume (Durability of 30 years) | 1,400 yen～/m |
※We also handle roofing materials and roofing sheets other than those listed above!
Reference Example for Super Galtect Quote
This is an example of the estimated cost for covering the slate roof with the Super Galtect method.
Construction Details
Construction Type: Roof overlay (cover method) work
Building: 2-story detached house
Existing Roof Material: Slate roof (moss-heavy)
New Roof Material: Super Galtect (SGL steel plate) expected durability of 35 to 40 years
Roof Shape: Hip roof
Roof Slope: 4 shaku
Roof Area: 64 square meters
High-pressure Cleaning: Yes
In-house Warranty: 10 years
Manufacturer Warranty: 15 years for coating, 20 years for rust, 25 years for perforation
Notes
・Due to the heavy moss, the cover work will be done after high-pressure cleaning.
・The roofing sheet and ridge base will use materials with durability similar to Super Galtect.
Estimate (Example)
| Construction Details | Specifications | Quantity | Unit Price | Amount | ||||||||||||||||||||||||||
| 1. Temporary Construction | ||||||||||||||||||||||||||||||
| Temporary Scaffold Installation | Wedge-type Scaffold | 231㎡ | 500 | 115,500 | ||||||||||||||||||||||||||
| Debris Prevention Measures | Mesh Sheet | 231㎡ | 50 | 11,550 | ||||||||||||||||||||||||||
| 2. Roof Overlay (Cover Method) | ||||||||||||||||||||||||||||||
| High-Pressure Washing | 64㎡ | 200 | 12,800 | |||||||||||||||||||||||||||
| Existing Ridge Demolition | Ridge Flashing and Purlin Demolition and Removal | 20m | 800 | 16,000 | ||||||||||||||||||||||||||
| Removal of Existing Snow Guards | 52 Locations | 200 | 10,400 | |||||||||||||||||||||||||||
| New Underlayment (Roofing) |
New Liner Roofing Durability Approximately 30 Years |
64㎡ | 1,200 | 76,800 | ||||||||||||||||||||||||||
| New Eaves Flashing (Arabesque) | SGL Steel Plate / Renovation Arabesque Setback Type |
29m | 2,400 | 69,600 | ||||||||||||||||||||||||||
| New Eave Flashing | SGL Steel Plate / Eave Flashing | 0.4m | 2,700 | 1,080 | ||||||||||||||||||||||||||
| New Main Roofing | Super Galtect Expected Durability: 35 to 40 Years |
64㎡ | 5,700 | 384,000 | ||||||||||||||||||||||||||
| Additional Cost for Roofing Material Screws | Stainless Steel Disco Treatment | 64㎡ | 300 | 19,200 | ||||||||||||||||||||||||||
| New Snow Stop Installation | Super Galtect Original Snow Stop | 52 Locations | 1,000 | 52,000 | ||||||||||||||||||||||||||
| New Ridge Base Installation (Nail Board) |
Galvalume Steel Plate Durability Approximately 30 to 35 Years |
40m | 1,400 | 56,000 | ||||||||||||||||||||||||||
| Face Plate Installation | Galtect Dedicated Flat Face Plate | 40m | 300 | 12,000 | ||||||||||||||||||||||||||
| New Ridge Cap |
SGL Steel Plate / Ridge Cap |
Stainless Steel Screws with Packing 20m |
2,500 |
50,000 |
Sealing at Various Locations |
Oton Exceed |
Durability Approximately 30 Years 1 set |
5,000 |
5,000 |
|
Transportation Cost |
|
1 set |
10,000 |
10,000 |
Waste Disposal Cost |
|
1 set |
10,000 |
10,000 |
Management Fees and Miscellaneous Expenses |
|
1 set |
10,000 |
10,000 |
| ||||
| Subtotal (Excluding Tax) | 921,930 yen | |||
| Adjustment Discount | -4,123 yen | |||
| Total Amount (Including Tax, 10%) | 1,010,000 yen | |||
The above is an example of a quote for performing a roof overlay construction from a slate roof to Super Galtect!
The unit price can vary significantly depending on the roofing sheets and ridge materials used!
Service Areas
Tokyo Metropolis
Akishima City / Akiruno City / Adachi Ward / Arakawa Ward / Itabashi Ward / Inagi City / Edogawa Ward / Ome City / Edogawa Ward / Ome City / Ota Ward / Katsushika Ward / Kita Ward / Kiyose City / Kunitachi City / Koto Ward / Koganei City / Kokubunji City / Kodaira City / Komae City / Shinagawa Ward / Shibuya Ward / Shinjuku Ward / Suginami Ward / Sumida Ward / Setagaya Ward / Taito Ward / Tachikawa City / Tama City / Chuo Ward / Chofu City / Chiyoda Ward / Toshima Ward / Nakano Ward / Okutama / Nishi-Tokyo City / Nerima Ward / Hachioji City / Hamura City / Higashi-Kurume City / Higashimurayama City / Higashiyamato City / Hino City / Fuchu City / Fussa City / Bunkyo Ward / Machida City / Mitaka City / Minato Ward / Musashimurayama City / Musashino City / Meguro Ward
Kanagawa Prefecture
Aikou-gun Aikawa Town / Ashigarakami-gun Oi Town / Ashigarakami-gun Kaisei Town / Ashigarakami-gun Nakai Town / Ashigarakami-gun Matsuda Town / Ashigarakami-gun Yamato Town / Ashigarashimo-gun Hakone Town / Ashigarashimo-gun Manazuru Town / Ashigarashimo-gun Yugawara Town / Isehara City / Odawara City / Kamakura City / Kawasaki City / Kawasaki City Kawasaki Ward / Kawasaki City Asao Ward / Kawasaki City Saiwai Ward / Kawasaki City Takatsu Ward / Kawasaki City Tama Ward / Kawasaki City Nakahara Ward / Kawasaki City Miyamae Ward / Koza-gun Samukawa Town / Zushi City / Chigasaki City / Nakagun Oiso Town / Nakagun Ninomiya Town / Hadano City / Hiratsuka City / Fujisawa City / Miura-gun Hayama Town / Miura City / Minamiashigara City / Yokosuka City / Yokohama City / Yokohama City Aoba Ward / Yokohama City Asahi Ward / Yokohama City Izumi Ward / Yokohama City Isogo Ward / Yokohama City Kanagawa Ward / Yokohama City Kanazawa Ward / Yokohama City Konan Ward / Yokohama City Kohoku Ward / Yokohama City Sakae Ward / Yokohama City Seya Ward / Yokohama City Tsuzuki Ward / Yokohama City Tsurumi Ward / Yokohama City Totsuka Ward / Yokohama City Naka Ward / Yokohama City Nishi Ward / Yokohama Hodogaya Ward / Yokohama City Midori Ward / Yokohama City Minami Ward / Sagamihara City / Sagamihara City Midori Ward / Sagamihara City Minami Ward / Sagamihara City Chuo Ward / Ebina City / Atsugi City
・Saitama Prefecture, Chiba Prefecture, and parts of Yamanashi Prefecture (Please consult us)
What is the Roof Overlay (Cover Method)?
The roof overlay (cover method) involves leaving the existing roof largely intact and placing a new roof over it.
Literally, it is a method of covering a roof with another roof. Therefore, the roof becomes double-layered. It is also referred to as “重ね葺き” (kasane-buki), meaning overlapping roofing.
Roof Overlay (Cover Method) | Advantages
Since a “new roof” is placed over the “existing roof,” demolition work is almost unnecessary. This means 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 replacement, the costs are 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 website).
Asbestos Comprehensive Information Portal Site | Ministry of Health, Labour and Welfare
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 their disposal costs are also high! The cover 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 consult us.
Additionally, we can complete the work in a shorter period 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, there can be inconveniences such as difficulty entering and exiting or opening windows, so being able to return to normal life in a short time is a significant advantage.
Our company specializes in roofing work, so the roof overlay (cover method) is the most frequently performed work by our company. We are very grateful that we are constantly able to carry out roof overlay projects without interruption.
Roof Overlay (Cover Method) | Construction Steps
1. Existing Ridge and Snow Stop Demolition
2. Installing Roofing (Waterproof Sheet)
3. New Custom Metal Work (Arabesque, Eaves) Processing and Installation
4. New Roofing Material Installation and Snow Stop Installation
5. Ridge Cap Metal Processing and Installation
6. Wall Rain Guard Metal Processing and Installation
YouTube Explanation
We have provided a detailed explanation on YouTube, so if you are interested, we would be happy if you could take a look!
For detailed roofing work achievements, click here!
Voices of Customers Who Have Had Roofing Work Done
■ A-san, Aoba-ku, Yokohama
Since I could see that the roof was peeling, I requested a quote. I thought I couldn’t afford a large roofing project, but Kakeru Koumuten’s estimate was relatively cheaper compared to other companies, so I decided to go with them.
Moreover, the estimate was thorough and easy to understand, and I had no doubts compared to other companies, so I felt secure in my decision.
Thank you very much for considering the costs.
■ B-san, Totsuka-ku, Yokohama
I was considering a roof overlay project, and there was someone in the neighborhood who had work done by Kakeru Koumuten, so I got a referral after the work was completed.
I was thinking about requesting them after seeing the work in the neighborhood, but their attention to detail before and during the construction was excellent, and the roofing work went smoothly, so I asked Kakeru Koumuten before requesting estimates from other companies.
This time it was a roof overlay, but I received photos after the completion, and their response was very courteous, so I would like to request other work as well.
■ C-san, Setagaya-ku, Tokyo
I requested a roof overlay project. Kakeru Koumuten was very responsive, and they quickly answered any concerns I had, allowing me to feel at ease throughout the entire process.
They were a very considerate company, offering some services at no charge and even removing unnecessary debris. The roof was finished beautifully, and I am very satisfied.
If anything comes up again, I would like to request their services.
For roofing work, please leave it to Kakeru Koumuten, the exterior renovation specialists!
Our company is based in Aoba-ku, Yokohama, and we have extensive experience in roof renovations in Tokyo and Kanagawa Prefectures. We are happy to assist with everything from roof overlay work, roof replacement work, to partial roof repairs such as leak repairs.
“I just want to know the estimate for the roof renovation” or “I want to know about roofing materials”, if you have any questions or concerns, please feel free to contact us!
Summary
Estimates and inspections are, of course, free! If you have any issues with your roof, rain gutters, exterior walls, or exterior structures, please consult with Kakeru Koumuten Co., Ltd. in Aoba-ku, Yokohama!
Kakeru Koumuten is a renovation company strong in exterior renovations, and we perform complete in-house construction from temporary scaffolding work to roof work and exterior wall painting work.
We are confident that in terms of “cost, quality, and efficiency”, we will not be outdone compared to other companies!
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 the 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 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!
・No need for temporary scaffolding for our exterior wall cleaning plan!
・Setagaya Ward, Tokyo | Roofing | We performed a tile to Galtect roof replacement!
・Aoba-ku, Yokohama | Roof Overlay Method | We completed a roof overlay using Super Galtect!
・Aoba-ku, Yokohama | Roofing | We performed a roof replacement using Super Galtect!
・Miyamae-ku, Kawasaki City | We performed a roof overlay using Hilanbee 220!
・For those who want to try DIY painting of roofs and exterior walls! Scaffolding only! Roof and exterior wall painting DIY plan!
・What is the cost range for roof remodeling? Types of construction and how to choose a contractor, etc.
・Latest! About subsidies and reduction systems available for remodeling!
・How much does it cost to repair the roof? We will introduce the cost range!
・What is a kasagi? We will explain the role and repair methods of kasagi in detail!
・Renovation store in Kanagawa Prefecture, Yokohama | What is roof overlay (roof cover method)?
LINE consultations 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!
