What is Asphalt Waterproofing? Kakeru Koumuten Co., Ltd. Explains the Advantages and Disadvantages!

Welcome to Kakeru Koumuten Co., Ltd., your exterior renovation specialist in Yokohama!
At Kakeru Koumuten, we handle a lot of asphalt waterproofing projects.
In this article, we will provide a detailed explanation of asphalt waterproofing!

We hope this information will be helpful for those considering maintenance or renovation of sheet waterproofing, so please take a look.

What is Asphalt Waterproofing?

Asphalt waterproofing refers to the waterproof layer formed by

・melted asphalt
・asphalt roofing

It is a method that has been widely used for a long time,

・in schools
・in condominiums
・in public housing

and is often adopted for roofs and rooftops.

There are many types of waterproofing work necessary to protect buildings from rainwater,

but among them, the most popular method is “asphalt waterproofing.”

What are the Advantages of Asphalt Waterproofing?

Next, let’s take a closer look at the unique advantages and disadvantages of asphalt waterproofing.

High Waterproofing Performance

Asphalt has the following characteristics:

・high durability
・high adhesion

For these reasons, it has relatively high waterproofing properties compared to other methods and lasts longer.

Waterproofing work is not something that is completed after one time; it requires regular maintenance.

In the case of asphalt waterproofing, which has high waterproofing and durability, it is easier to maintain functionality over a long period, thus reducing maintenance effort and costs.

Traditional Methods

As explained earlier, asphalt waterproofing is a traditional method, and the know-how and technology related to its construction are well established.

Therefore, precise construction is easier,

making it ideal for those who think, “I want to thoroughly enhance waterproofing.”

What are the Disadvantages of Asphalt Waterproofing?

Next, let’s take a closer look at the disadvantages of asphalt waterproofing.

Slightly Longer Construction Period

One disadvantage of asphalt waterproofing is that it has a slightly longer construction period.

Depending on the construction site, it generally takes about 6 to 10 days,

so if you need to “do waterproofing work immediately,”

it may not be recommended.

However, other waterproofing methods also often take about 4 to 5 days, so it can be said that it is not something to worry too much about.

There May Be Odors or Smoke

During asphalt waterproofing, strong odors or smoke may be emitted during construction.

If this is done in residential areas, there is a high possibility of complaints from neighbors.

However, if you choose the “cold method” introduced later, it can be said that it is easier to suppress smoke and odors, so consult with the contractor about the surrounding environment of the residence and ask for the best method to be proposed.

Are There Different Types of Asphalt Waterproofing Methods?

As explained earlier, there are several methods of asphalt waterproofing.

Below, we will explain three representative methods in detail.

Hot Method

The hot method refers to the process of applying heat to asphalt to melt it and create a waterproof layer.

This method has been passed down for over 100 years, accumulating a wealth of know-how.

However, when melting asphalt, strong odors and smoke are generated, so care must be taken to avoid neighborhood disputes.

Cold Method (Room Temperature Method)

The cold method refers to a method that does not use heat.

Unlike the hot method, it allows for the creation of a waterproof layer without melting asphalt, thus avoiding odors and smoke.

Furthermore, since no fire is used at all, the risk of fire-related accidents is also reduced.

Previously, the hot method was popular, but in recent years, the cold method has been becoming mainstream due to safety and environmental considerations.

However, compared to the hot method, the adhesion of the waterproof layer may decrease, which means there is a possibility that the waterproofing effect may be lower.

Torch Method

The torch method is a technique that uses a torch burner to heat and melt asphalt.

This method allows for seamless bonding of sheets, which can lead to higher waterproofing effectiveness.

“Since it uses fire, it must produce odors and smoke, right?”

I believe some may think this, but compared to the hot method, it is easier to suppress smoke and odors, allowing for a safer execution.

However, since a burner is used to heat the asphalt, it cannot be performed in a confined space.

What is the Cost Range for Asphalt Waterproofing?

The cost range for asphalt waterproofing varies slightly by contractor, but generally, it tends to be around 6,000 to 8,000 yen per square meter.

That said, the cost can fluctuate depending on the construction site, the number of workers, and the availability of equipment, so it is recommended to obtain multiple estimates and consider them carefully.

Possible Subsidies for Asphalt Waterproofing

[Katsushika Ward, Tokyo] Katsushika Eco Subsidy

Eligible Construction

High Reflectivity Coating: Painting work using high reflectivity paint on roofs and exterior walls.

Individual Residential

Subsidy Amount

For roofing or exterior wall work only: 50,000 yen per unit.

For both roofing and exterior wall work: 100,000 yen per unit.

Multi-Family Residential & Business

Subsidy Amount

One-fourth of the eligible expenses or the construction area (㎡) × 1,000 yen
whichever is smaller

Maximum Amount

Multi-Family Residential: 1,000,000 yen
Business: 400,000 yen

Requirements

The solar reflectance in the near-infrared region of the paint used must be 65% or higher.

For more details, please refer to Katsushika Eco Subsidy｜Katsushika Ward Official Site

【Chuo-ku, Tokyo】Fiscal Year 7 Subsidy Program for Residential and Multi-Family Residential Natural Energy and Energy-Saving Equipment Installation Costs

Subsidy Amount

350,000 yen to 100,000 yen

Subsidy Rate

Partial subsidy for the installation costs of eligible equipment (equipment, materials, and installation work)

20% of the costs

Eligible Materials

High Reflectance Paint: Using paint with high solar reflectance reduces the cooling load of the building

Eligible Recipients

Individuals residing in Chuo-ku

Management associations of condominium buildings in Chuo-ku

For more details, please see here.

Long-term Excellent Housing Renovation Promotion Project

The “Long-term Excellent Housing Renovation Promotion Project” implemented by the Ministry of Land, Infrastructure, Transport and Tourism supports renovations aimed at improving the durability, energy efficiency, and deterioration countermeasures of buildings.
This may include subsidies applicable for urethane waterproofing work.

• Subsidy Limit: Up to 1,600,000 yen (Base 800,000 yen + Maximum additional 800,000 yen)

• Eligible Works: Deterioration countermeasures including waterproofing work, energy-saving renovations, and multi-generational living adaptations

For more details, please check the official site.

Summary

Asphalt waterproofing is a highly effective waterproofing method that utilizes the properties of asphalt.

While the smoke and odor can be a drawback, adopting a cold method allows for construction while alleviating such concerns.

The cost range for asphalt waterproofing is typically around 6,000 to 8,000 yen per square meter, but since estimates can vary by contractor, be sure to obtain multiple quotes.

Our company, Kakeru Koumuten Co., Ltd., also performs waterproofing work.

Estimates are free, so if you are considering waterproofing work, please feel free to consult with us.

 

Useful information about exterior renovations can be found here!

LINEConsultations via LINE are also very welcome◎

 

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!