How Long Does Concrete Take to Dry: A Comprehensive Guide

Understanding the Drying Process of Concrete

In construction and DIY projects, it is crucial to know how long concrete takes to dry before it can be properly used or finished. The drying process of concrete refers to the time it takes for newly poured concrete to lose moisture and become stable and solid. This comprehensive guide will provide you with valuable insights into the concrete drying process, factors affecting drying time, and methods to test the dryness of concrete.

What Exactly Happens During the Drying of Concrete?
During the drying process, water in the concrete mixture evaporates, allowing the cement to harden and form a solid structure. This process, known as hydration, is essential for the concrete to gain strength and durability. As the moisture evaporates, the concrete undergoes a chemical reaction, transforming it from a fluid state to a solid state.

Factors Affecting the Drying Time of Concrete
Several factors can influence the drying time of concrete. These include environmental conditions such as temperature, humidity levels, and air circulation. The mix design of the concrete, thickness of the slab, and the presence of admixtures can also impact the drying process.

How Long Does Concrete Take to Dry?
The drying time of concrete varies depending on the specific application and circumstances. It is important to note that concrete does not “dry” in the same way as a wet substance evaporating. Instead, it goes through different stages of setting and hardening.

Initial Setting Time of Concrete
The initial setting time of concrete refers to the time it takes for the concrete to become stiff and no longer workable. This typically occurs within the first few hours after pouring and can vary based on the concrete mix and ambient conditions.

Drying Time for Foot Traffic
After the initial setting, concrete can typically support foot traffic after 24 to 48 hours. However, caution should still be exercised to avoid damage or indentations during this early stage of drying.

Drying Time for Light Use
For light use, such as placing light furniture or equipment, concrete generally requires about 3 to 7 days to dry sufficiently. This timeline may vary depending on factors like weather conditions and the thickness of the concrete.

Drying Time for Heavy Use
If you are planning for heavy use of the concrete, such as installing heavy machinery or vehicles, it is recommended to wait at least 1 to 3 weeks. Waiting for this duration allows the concrete to gain sufficient strength and durability to withstand the applied load.

Full Drying Time for Complete Curing
It’s important to note that concrete continues to cure and gain strength over time. Although it may be usable for various applications within a few weeks, it may take several weeks or even months for concrete to be fully dry and cured.

Factors That Can Accelerate the Drying Process
Certain measures can be taken to accelerate the drying process of concrete:
– Proper ventilation by ensuring adequate air circulation around the concrete slab.
– Utilizing dehumidifiers to reduce moisture levels in the surrounding environment.
– Applying heat using radiant heaters or other heating methods to increase the evaporation rate of moisture.

Factors That Can Delay the Drying Process
Conversely, several factors can extend the drying time of concrete:
– High humidity levels can slow down the evaporation of moisture from the concrete surface.
– Colder temperatures can reduce the rate of chemical reactions and slow down drying.
– Excessive thickness of the concrete slab can impede the drying process, particularly if not properly cured or ventilated.

How to Test the Dryness of Concrete
There are various methods available to determine the dryness of concrete. ASTM standard test methods, such as the plastic sheet method or moisture meter readings, can provide quantitative measurements of concrete moisture content. visual inspections and subjective evaluations of the surface condition can also give indications of concrete dryness.

By understanding the intricacies of the concrete drying process, you can make informed decisions about timelines, usage, and necessary precautions. Taking into account the specific factors affecting drying time and employing suitable methods to test concrete dryness will ensure successful construction or project outcomes.

Understanding the Drying Process of Concrete

1. Preparation: Before pouring concrete, ensure that the surface is clean and free from any debris or moisture. This will help achieve proper drying.
2. Mixing: Thoroughly mix the concrete according to the manufacturer’s instructions to ensure even distribution of components, leading to consistent drying.
3. Placement: Pour the concrete into the desired area and level it with a screed or trowel. Avoid overworking the concrete, as it can extend drying times.
4. Curing: Once the concrete is placed, it needs proper curing for optimal drying. This can be done by covering it with a curing compound, plastic sheeting, or using curing blankets. Proper curing prevents rapid moisture loss and promotes even drying.
5. Absorption: During the drying process, concrete absorbs moisture from its surroundings. Control moisture levels in the environment to avoid excessive or prolonged drying times. Dehumidifiers or ventilation can help with this.
6. Monitoring: Regularly monitor the moisture content of the concrete using moisture meters. This helps determine the progress of drying and allows for necessary adjustments.
7. Completion: The drying process of concrete is considered complete when it reaches the desired moisture content specified by project requirements. This ensures that the concrete is ready for subsequent steps, such as applying coatings or finishes.

What Exactly Happens During the Drying of Concrete?

During the drying of concrete, several important processes occur that contribute to its eventual strength and durability. Here are the key stages that take place:

1. Evaporation of water: As the concrete is poured and begins to set, the excess water starts to evaporate. This evaporation process removes moisture from the concrete surface, allowing it to dry and harden.

2. Hydration reaction: As the water evaporates, the cement in the concrete undergoes a chemical reaction known as hydration. This reaction creates strong chemical bonds that bind the concrete particles together, resulting in the formation of a solid and rigid structure.

3. Curing process: While the concrete is drying, it also undergoes a curing process, which helps to further enhance its strength. Curing involves maintaining the right conditions, including temperature and moisture levels, to support continued hydration. This process ensures that the concrete achieves its maximum strength and durability.

4. Shrinkage: During drying, the concrete undergoes shrinkage as water continues to evaporate. This shrinkage can cause cracks or surface defects if not properly managed. Controlling the drying process and providing support, such as using curing compounds or adding reinforcement, can minimize the impact of shrinkage.

5. Final hardening: Once the concrete has dried and the curing process is complete, it reaches its maximum strength and hardness. At this point, it is ready for use and can withstand the intended loads and stresses.

Understanding what exactly happens during the drying of concrete is crucial for ensuring the proper construction and long-term performance of concrete structures. By following best practices and considering factors such as temperature, humidity, and the use of curing methods, the drying process can be effectively managed, resulting in strong and durable concrete.

Factors Affecting the Drying Time of Concrete

The drying time of concrete can be affected by several factors. Here is a list of factors that can influence how long it takes for concrete to dry:

1. Temperature: Higher temperatures can accelerate the drying process, while lower temperatures can slow it down. Concrete will dry faster in warmer conditions.
2. Humidity: High humidity levels can prolong the drying time of concrete. Moisture in the air reduces the rate at which the water in the concrete evaporates.
3. Air movement: Proper ventilation and air circulation can help speed up the drying process. It allows moisture to escape and promotes faster evaporation.
4. Concrete thickness: Thicker concrete will take longer to dry compared to thin layers. The drying process is influenced by how much water needs to evaporate from the concrete.
5. Mix design: The composition and proportions of the concrete mix can affect the drying time. Different concrete mixes may have different drying characteristics.
6. Curing methods: Proper curing techniques can enhance the drying process. Adequate moisture retention and protection from extreme temperature changes can help the concrete dry more efficiently.
7. Presence of additives: Certain additives or admixtures can affect the drying time. It is important to follow the manufacturer’s recommendations for their usage.

These factors should be taken into consideration when planning construction projects involving concrete. By understanding and managing these factors, contractors can ensure that the concrete dries properly and meets the required specifications.

How Long Does Concrete Take to Dry?

Curious about how long it takes for concrete to dry? In this section, we’ll explore the various stages of concrete drying, ranging from the initial setting time to full curing. Learn about the timings for foot traffic, light use, and heavy use, as well as the intriguing process of achieving complete drying. Whether you’re involved in a construction project or just curious about concrete, read on to discover all the information you need about the drying process.

Initial Setting Time of Concrete

The initial setting time of concrete is an important consideration when working with this construction material. During the initial setting time, the concrete undergoes a chemical reaction that transforms it from a plastic state to a solid state. Knowing the duration of this process is crucial as it determines when the concrete can be worked on or subjected to any load.

To understand the initial setting time of concrete, we can refer to the following table:

Temperature Range	Initial Setting Time
Below 10°C	8-12 hours
10-20°C	4-6 hours
Above 20°C	2-4 hours

From the table, we can observe that the initial setting time of concrete decreases as the temperature increases. This means that concrete sets faster in warmer conditions.

It is important to note that the initial setting time may vary depending on the specific mix design and environmental conditions. Factors such as the type and amount of cement, water-cement ratio, aggregate properties, and additives can all influence the setting time.

Pro-tip: To ensure accurate and reliable results, it is recommended to conduct tests to determine the initial setting time of concrete on-site using ASTM standard test methods. This will help contractors and construction professionals effectively plan and execute their projects, ensuring the concrete is ready for further work or load application at the right time.

Drying Time for Foot Traffic

The drying time for foot traffic on concrete can vary depending on several factors. Here is a list of considerations to keep in mind:

1. Cement type: Different types of cement have varying drying times. Quick-setting cement can allow foot traffic in as little as 4-6 hours, while standard cement may require 24-48 hours.
2. Weather conditions: Temperature and humidity levels affect the drying time. In warm and dry conditions, concrete can dry faster, while colder and more humid conditions can prolong the drying process.
3. Concrete thickness: Thicker concrete takes longer to dry, as moisture needs more time to evaporate from the deeper layers.
4. Mix proportions: The composition of the concrete mix can impact drying time. Higher water content or additional admixtures may slow down the drying process.
5. Surface finish: Certain finishes, such as sealants or coatings, can prolong the drying time and may require additional cure time before foot traffic is allowed.

Pro-tip: To ensure the proper drying time for foot traffic, it is recommended to follow the manufacturer’s guidelines and consult with a professional if needed. It is essential to avoid placing heavy objects or applying excessive pressure on the concrete surface until it has fully dried to prevent any potential damage.

Drying Time for Light Use

The drying time for light use of concrete can vary depending on several factors. Here are some important considerations:

1. Initial setting time: After pouring concrete, it typically takes around 4 to 6 hours for it to reach its initial setting time. This means it can bear light foot traffic without causing any damage to the surface.
2. Humidity levels: High humidity can prolong the drying process of concrete. Therefore, if you’re in an area with high humidity, it may take longer for the concrete to dry for light use.
3. Temperature: Colder temperatures can also slow down the drying process. In colder environments, it may take more time for the concrete to dry and be ready for light use.
4. Thickness of concrete: The thickness of the concrete slab also affects its drying time. Thicker slabs will take longer to dry compared to thinner ones.
5. Curing time: While the concrete may be dry enough for light use after the initial setting time, it’s important to note that it hasn’t fully cured yet. Concrete takes about 28 days to fully cure and reach its maximum strength.

It’s important to be patient and allow enough time for the concrete to dry and cure before subjecting it to heavier use. This will ensure the durability and longevity of the concrete structure and minimize the risk of damage.

Drying Time for Heavy Use

The drying time for heavy use of concrete depends on various factors such as temperature, humidity levels, and the thickness of the concrete. Here is a table summarising the approximate drying times for heavy use based on these factors:

Temperature	Humidity Level	Concrete Thickness	Drying Time for Heavy Use
Normal	Normal	Up to 4 inches	7-14 days
High	Normal	Up to 4 inches	14-21 days
Normal	High	Up to 4 inches	14-21 days
Normal	Normal	Above 4 inches	21-28 days
High	Normal	Above 4 inches	28-35 days
Normal	High	Above 4 inches	28-35 days

These timelines are approximate and can vary depending on the specific conditions of the concrete pouring and curing process. It is important to ensure that the concrete is fully dry before subjecting it to heavy use to prevent any damage or compromise to its structural integrity.

The drying time for heavy use of concrete can range from 7 to 35 days, depending on factors such as temperature, humidity levels, and the thickness of the concrete. It is essential to follow proper curing practices and allow sufficient time for the concrete to fully dry before subjecting it to heavy loads or foot traffic.

Full Drying Time for Complete Curing

The full drying time for complete curing of concrete is influenced by several factors. Here are the steps to consider:

1. Ensure that the initial setting time of the concrete has passed. This typically takes around 24 to 48 hours, depending on the specific type of concrete used.
2. Avoid any foot traffic on the concrete until it has dried sufficiently. This can take around 3 to 7 days, depending on the weather conditions and the thickness of the concrete.
3. Wait for a longer period before subjecting the concrete to light use. This can take around 7 to 14 days to allow for proper curing and strengthening of the concrete.
4. For heavy use, such as placing heavy equipment or vehicles on the concrete surface, it is recommended to wait for at least 28 days. This allows the concrete to fully harden and achieve its maximum strength.
5. The full drying time for complete curing of concrete varies depending on various factors, including the type of cement used, the thickness of the concrete, and the environmental conditions. In general, it can take anywhere from 28 days to several months for the concrete to fully cure and reach its maximum strength.
6. During the curing process, it is important to protect the concrete from excessive moisture and temperature fluctuations. This can be done by covering the concrete with a curing compound or by applying a plastic sheet to prevent moisture loss.
7. Regularly monitor the moisture content of the concrete using a moisture meter or by performing a calcium chloride test. This will help determine if the concrete has dried sufficiently for further use.

By following these steps and allowing sufficient time for the concrete to dry and cure, you can ensure its long-term durability and performance.

Factors That Can Accelerate the Drying Process

When it comes to the drying process of concrete, several factors can accelerate the timeline. In this section, we’ll explore the techniques that can speed up the drying process. From ensuring adequate ventilation to utilizing dehumidifiers and applying heat, we’ll uncover the secrets of fast-drying concrete. So, if you’re eager to reduce the waiting time for your concrete project, read on!

Proper Ventilation

Proper ventilation is essential to ensure the efficient and successful drying process of concrete. Here are some important considerations for proper ventilation:

\

• Ensure adequate air circulation: It is important to ensure that fresh air can circulate freely around the concrete surface. This helps to carry away moisture and speed up the drying process.
• Open windows and doors: Opening windows and doors in the area where the concrete is drying allows for increased airflow, helping to remove moisture from the surface.
• Use fans: Placing fans strategically around the concrete can significantly enhance ventilation. Fans help to move air across the surface, promoting faster drying.
• Utilise portable ventilation systems: In cases where natural ventilation is limited, using portable ventilation systems can be beneficial. These systems help to remove moisture-laden air and replace it with drier air, expediting the drying process.
• Start ventilation as soon as possible: Ventilation should be started as soon as possible after pouring the concrete. This allows moisture to be carried away efficiently from the beginning of the drying process.
• Extend the drying area: If possible, extend the drying area to an outdoor space can greatly aid in proper ventilation. Outdoor spaces offer increased air circulation, ensuring that moisture is effectively evaporated.

Ensuring proper ventilation during the drying process of concrete is crucial for achieving optimal results. It helps to expedite drying time and prevents issues such as moisture retention and potential damage to the structure. By following these guidelines, you can ensure that your concrete dries efficiently and effectively.

Utilizing Dehumidifiers

To speed up the drying process of concrete, you can use dehumidifiers. Here are some ways in which dehumidifiers can be helpful:

1. Removing excess moisture: Dehumidifiers extract excess moisture from the air, reducing the overall humidity level and drying out the concrete faster.
2. Preventing mold and mildew: Moisture can promote the growth of mold and mildew, which can hinder the drying process. Dehumidifiers can prevent the growth of these contaminants, ensuring a cleaner and faster drying process.
3. Controlling temperature and humidity: Dehumidifiers also regulate the temperature and humidity levels in the drying area. By maintaining optimal conditions, the drying process can be accelerated.

Using dehumidifiers is an effective way to speed up the drying process of concrete. It ensures efficient removal of moisture, reduces the risk of mold growth, and creates ideal conditions for drying. So, if you want your concrete to dry faster, utilizing dehumidifiers is a pro-tip you should consider.

Remember, the effectiveness of dehumidifiers may vary depending on factors such as the size of the area, the level of humidity, and the thickness of the concrete. It is always recommended to follow the manufacturer’s instructions and consult professionals if needed for the best results.

Applying Heat

When it comes to applying heat to speed up the drying process of concrete, there are a few steps you can follow:

1. Ensure that the concrete has already been properly placed and finished before applying heat.
2. Wait for the initial setting time of the concrete to pass, which usually takes around 1 to 2 hours.
3. Once the initial setting time has passed, you can start applying heat to the concrete.
4. Use appropriate heating methods such as infrared heaters or heat lamps, which should be placed at a safe distance from the concrete surface.
5. Monitor the temperature of the concrete closely to avoid overheating, which can lead to cracks.
6. Keep the heat applied consistently and evenly throughout the drying process.
7. Consider using additional methods like covering the concrete with insulating blankets to retain the heat and promote more efficient drying.
8. Regularly check the moisture levels of the concrete using a moisture meter to ensure that the drying process is progressing as desired.
9. Continue applying heat until the desired level of dryness is achieved.
10. Remember to follow proper safety precautions when using heat sources to avoid any accidents or damage.

By following these steps and applying heat correctly, you can effectively speed up the drying process of concrete.

Factors That Can Delay the Drying Process

Certain factors can sometimes cause unexpected delays in the drying process of concrete. In this section, we will uncover the culprits that can slow down this crucial stage. We will explore how higher levels of humidity, colder temperatures, and excessive thickness of the concrete play a role in hindering the drying process. Let’s dive in and shed light on the factors that can delay concrete drying.

High Humidity Levels

High humidity levels can significantly delay the drying process of concrete. Here are some important points to consider:

1. Concrete drying is a chemical process that involves the evaporation of water from the mixture. High humidity levels in the surrounding air make it more difficult for moisture to evaporate, thus prolonging the drying time.

2. When humidity levels are high, the air is already saturated with moisture. This means that the air has a lower capacity to absorb additional moisture from the concrete, leading to slower evaporation.

3. In areas with consistently high humidity, such as coastal regions or during rainy seasons, the drying time of concrete can be significantly increased. It is important to take these factors into account when planning construction projects.

4. High humidity levels can also negatively affect the strength and quality of the concrete. Excessive moisture can lead to surface cracking, reduced durability, and an increased risk of mould or mildew growth.

5. To mitigate the effects of high humidity on the drying process, proper ventilation is crucial. Ensuring adequate airflow around the concrete can help facilitate the evaporation of moisture.

6. It is also recommended to use dehumidifiers in enclosed spaces or areas with limited airflow. These devices help remove excess moisture from the air, promoting faster drying.

7. Applying heat to the concrete surface can also help accelerate the drying process by increasing the rate of evaporation. Caution must be exercised to prevent thermal cracking due to rapid drying.

8. It’s important to note that the specific impact of high humidity on drying time will vary depending on other factors such as temperature, concrete thickness, and the specific mix design.

By understanding the challenges posed by high humidity levels, contractors and construction professionals can take appropriate measures to ensure that the concrete dries effectively and reaches its desired strength and quality.

Colder Temperatures

When it comes to the drying process of concrete, colder temperatures can have a significant impact. Here are some important factors to consider regarding colder temperatures:

1. Slower drying time: Colder temperatures can significantly slow down the drying time of concrete. This is because low temperatures affect the rate of evaporation, which is crucial for the concrete to dry properly.
2. Risk of freezing: If the temperature drops below freezing point, there is a risk of the water in the concrete freezing. Freezing can cause the water to expand, leading to cracks and damage in the concrete.
3. Extended curing time: Colder temperatures can also extend the curing time of concrete. Curing is the process in which the concrete gains strength and durability. The lower temperatures can hinder the chemical reactions that occur during curing, resulting in a longer curing time.
4. Protective measures: To ensure proper drying and curing in colder temperatures, it is important to take certain protective measures. These may include using blankets or insulating materials to keep the temperature of the concrete elevated, and avoiding pouring concrete in extremely cold weather conditions.
5. Professional advice: In colder temperatures, it is recommended to seek professional advice and adhere to specific guidelines provided by experts in the field of concrete drying and curing. They can provide valuable insights and strategies to mitigate the challenges posed by colder temperatures.

By carefully considering the effects of colder temperatures on the drying process of concrete, you can take appropriate measures and ensure the successful completion of your project.

Excessive Thickness of Concrete

Excessive thickness of concrete can have a significant impact on the drying time. The drying time of concrete refers to the time it takes for the water present in the concrete to evaporate and for the concrete to dry completely.

1. Slower evaporation: When concrete is poured in layers or slabs of excessive thickness, the moisture trapped within the layers takes longer to evaporate. This can prolong the drying time of the concrete.

2. Reduced air circulation: Thicker concrete slabs have a larger surface area, which can reduce air circulation. Proper air circulation is important for the drying process as it allows moisture to escape. Excessive thickness can hinder the air from reaching the inner layers of the concrete effectively, further delaying the drying process.

To mitigate the effects of excessive thickness on the drying time of concrete, it is essential to consider a few factors. Ensuring proper ventilation around the concrete by using fans or openings to allow air movement can promote faster evaporation and drying. Utilising dehumidifiers can help remove excess moisture from the air, thereby accelerating the drying process. Applying heat can also enhance evaporation and speed up drying, but caution must be taken to avoid damaging the concrete.

Pro-tip: When dealing with excessive thickness of concrete, it is advisable to divide the pour into smaller sections or use additives that can help accelerate the drying time. Consulting with a professional concrete contractor can provide valuable insights and solutions to address excessive thickness and ensure efficient drying.

How to Test the Dryness of Concrete

Testing the dryness of concrete is essential to ensure its durability and reliability. This section will discuss various methods for determining if your concrete has completely dried. We will cover industry-standard ASTM tests as well as commonly used techniques to help you evaluate the readiness of your concrete project. Whether you are a homeowner or a construction professional, learning these invaluable methods will equip you with the necessary knowledge for successful concrete projects.

ASTM Standard Test Methods

are widely used to determine the dryness of concrete accurately and reliably. These test methods provide specific guidelines and procedures for conducting tests to assess the moisture content and dryness of concrete. Here is a table summarising some common ASTM Standard Test Methods used for testing concrete dryness:

Test Method	Description
ASTM F1869	Calcium Chloride Test Method for Moisture Vapor Emission Rate (MVER)
ASTM F2170	In-Situ Relative Humidity Testing using Probes
ASTM F710	Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring
ASTM E1907	Standard Guide for Methods of Reducing the Risk of Moisture-Related Damage

These test methods provide accurate and standardised results that can help ensure the concrete is sufficiently dry for the intended use. It is essential to follow the guidelines and procedures outlined in the ASTM Standard Test Methods to obtain reliable results.

Pro-tip: When testing the dryness of concrete, it is always recommended to use ASTM Standard Test Methods for accurate measurements. These test methods have been developed and validated by experts in the field and provide reliable information on the moisture content of concrete. By following these standardised procedures, you can ensure that the concrete is dry enough for the intended application, avoiding potential issues such as moisture-related damage or flooring failures.

Other Common Methods to Test Concrete Dryness

There are several common methods to test the dryness of concrete, in addition to the British Standard test methods. These methods can provide additional information and assurance when determining the dryness of concrete. Here are some of the other common methods to test concrete dryness:

1. Moisture meter: This handheld device measures the moisture content of the concrete. It provides a numerical reading that indicates the level of moisture present.

2. Plastic sheet test: This test involves placing a plastic sheet on the surface of the concrete and sealing the edges. After 24 hours, if there is condensation on the underside of the plastic sheet, it indicates the concrete is still drying.

3. Calcium chloride test: This test measures the moisture vapour emissions from the concrete. A calcium chloride kit is placed on the surface of the concrete for a specified period of time, and the change in weight of the kit indicates the moisture level.

4. Electrical impedance meter: This device measures the electrical resistance of the concrete. Moisture affects the conductivity of the concrete, and the meter provides a reading that indicates the moisture content.

5. Carbide moisture test: This test involves drilling a hole into the concrete and placing a small amount of calcium carbide into the hole. The reaction between the calcium carbide and the moisture in the concrete produces gas, which can be measured to determine the moisture content.

These other common methods can be used in conjunction with the British Standard test methods to gain a more comprehensive understanding of the dryness of the concrete. It is important to follow the specific instructions for each method to ensure accurate results.

Frequently Asked Questions

How long does it take for concrete to dry?

Concrete typically takes 24 to 48 hours to dry enough to walk on, but it continues to dry and gain strength for 25 to 28 days.

What factors affect the drying time of concrete?

The drying time of concrete can be affected by various factors, including weather conditions, moisture content of the mix, temperature, and slab thickness.

Can I walk on concrete before it is fully dry?

Yes, concrete can be walked on and used for normal tasks after one week. However, heavy machinery should not be driven on it during this time.

How does the water mix ratio affect the drying time of concrete?

The right amount of water in the concrete mix is crucial for it to set at maximum strength. Too little water can lead to quicker drying but weaker concrete, while too much water can prolong the drying time.

Should the surface of concrete be covered or sealed during drying?

No, the surface of concrete should not be covered or sealed during drying to allow moisture inside to evaporate. Sealing agents can hinder the drying process and affect the overall structural integrity.

How can I speed up the drying time of concrete?

To speed up the drying time of concrete, you can ensure the water mix ratio is correct, use accelerants, reduce moisture in the air with a dehumidifier, avoid covering or sealing the surface, use concrete blankets in cold weather, and turn on central heating to a low temperature.