
Hello!
I am Yamanaka from 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 a roof renovation in Chofu City, Tokyo.
The work involved a roof overlay (cover method) (Pamir to Ridgeway)!
We implemented leak prevention measures through the roof overlay work!
Thank you very much for choosing Kakeru Koumuten Co., Ltd. from among many contractors.
We received a request from Company A, whom we always appreciate!
Roof Overlay Construction Procedure
1. Dismantling Existing Ridge and Snow Guards
We will dismantle only the ridge flashing and snow guards that will obstruct the overlay work.


2. Roofing Installation (Waterproof Sheet)
The roofing used this time is modified asphalt. It offers double the durability of standard asphalt roofing!

3. Custom Fabrication (Curlicue, Eaves, Valley, Waste Board)
We will process and install the eaves, curlicue, valley metal, and waste board metal.

4. Main Construction
Once the main roofing is completed, we will install a ridge board.
This time, we used a cedar ridge board, but there are also ridge boards made of corrosion-resistant resin.


6. Ridge Metal Fabrication
We will process and install the ridge metal. We will ensure that sealing is properly applied on the inside of the joints.
At the wall edge, we will process and install a component called rain stop metal, and sealing will also be applied thoroughly.


7. Cleaning
We will remove any debris that has fallen around the house and inside the rain gutters, and do some wiping clean.
We strive to ensure that the area looks cleaner after the work than it did before!
With that, the construction is complete!
The roofing material used is the Ridgeway from Asahi Fiberglass.
Ridgeway comes with a 10-year manufacturer warranty.
Since it uses natural stone that is baked onto the surface, it is a roofing material that does not require painting, thus reducing maintenance costs!
Additionally, because it uses fine natural stones on the surface, you won’t be troubled by rain noise.
Moreover, it is a lightweight roofing material, making it strong against earthquakes and providing seismic resistance.
Color
■Dual Black

■Harvard Slate

■Dual Brown

■Vintage Green

■Earthstone Cedar

You can choose from these 5 colors!
This time
the existing roof “Nichiha/Pamir” ~ after construction “Asahi Fiberglass/Ridgeway” color: Dual Brown
will be a cover construction!
・About the existing roofing material Nichiha Pamir
Nichiha Pamir has already been discontinued, and it is a defective product that exhibits cracking and the “mille-feuille phenomenon”…
It is quite prone to cracking, making it difficult to replace just the broken parts. There is a high possibility that other roofing materials will crack during replacement.
Although the existing roofing material was painted, Pamir is a roofing material that cannot be painted.
Rather than being unable to paint, even if painted, it will crumble or crack immediately, making painting pointless and a waste of money.
You often see Pamir that has been painted, but honestly, the construction costs are a waste…
Some painters may not have knowledge about roofs, so caution is necessary.
In this case, I don’t think there was any negligence in the painting; rather, I believe they simply did not know about the roofing material.
It is important to always hire a contractor who has knowledge about roofs for roofing work!
I will introduce roofing materials that cannot be painted (or are ineffective when painted) in future staff blogs!
This construction was a roof cover project!
We were able to construct without any issues as the substrate was in a strong condition!
The customer was very satisfied, and I was very happy as well!
Thank you very much!
What is the roof overlay (cover method)?
The roof overlay (cover method) involves leaving the current roof almost intact 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 “重ね葺き” (kasane-buki).
Advantages of the Cover Method
Since the “new roof” is placed over the “current roof,” there is almost no need for demolition work, meaning that very little waste is generated.
This is the biggest feature and leads to various advantages.
The only parts that require demolition and waste disposal are 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 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 cover method, which generates almost no waste, is ideal for such roofs.
You may be wondering, “Is it safe to live in a building that uses asbestos-containing materials?” but rest assured. As long as they are not destroyed or crushed, they 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, the construction can be completed in a shorter period than painting or a 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, 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 can be considered a significant advantage.
Our company specializes in roofing work, but the roof overlay (cover method) is the most frequently performed type of work we undertake. We are very grateful that we are continuously able to carry out roof overlay (cover method) projects without interruption.
If you have any concerns regarding roofs, rain gutters, or exterior walls, please consult Kakeru Koumuten Co., Ltd.!
We carry out everything from temporary scaffolding work to roofing and exterior painting work entirely in-house. We are confident that our costs, quality, and efficiency in exterior work surpass those of other companies!
We welcome competitive estimates with confidence!
We are committed to ensuring that you feel, “I’m glad I chose you!” for every request we receive.
We look forward to your inquiries. Thank you very much.
For helpful information about exterior renovations, click here!
・The Necessity and Timing of Exterior Wall Painting…
・Kanagawa and Tokyo Exclusive | For Those Who Want to Try DIY Exterior Wall Painting! Scaffold Installation Only! Roof and Wall Painting DIY Plan!
・Introducing Roof Materials That Cannot Be Painted or Recommended!
・What Are the Average Costs of Roof Remodeling? Types of Construction and How to Choose a Contractor
・Introducing Current Roof Materials and Remodeling Methods!
・Roof Renovation | What is Roofing? An Introduction to the Important Roofing Material: Roofing Sheets!
・What are the Market Prices for Rain Gutter Repair and Cleaning? Tips on Timing, Fire Insurance, and Choosing Contractors!!
・Renovation Store in Yokohama, Kanagawa Prefecture | What is Roof Overlay (Roof Cover Method)?
We also welcome inquiries via LINE◎
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!


