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Fosroc
Conplast WP200 Waterproofing Admixture
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Fosroc Conplast WP200 – High Performance Concrete Permeability Reducer and Integral Waterproofing Admixture
When concrete structures are exposed to water, moisture and long-term environmental conditions, waterproofing cannot always be treated as an afterthought. Applying a coating after the concrete has already been placed may protect the surface, but the concrete itself can still remain vulnerable if the mix has excessive permeability.
This is where Fosroc Conplast WP200 provides a different approach.
Fosroc Conplast WP200 is a chloride-free, high-performance permeability reducing admixture designed for use in waterproof, structural and precast concrete. Instead of creating only an external waterproofing layer, it works as an integral admixture within the concrete mix, helping reduce permeability throughout the concrete.
At Startcore Ventures Limited, Fosroc Conplast WP200 is available in the following pack sizes:
- 10 Litres
- 210 Litres
- 1000 Litres
This makes it suitable for different scales of concrete work, from specialised construction requirements to larger structural and ready-mix concrete projects.
Whether you are a contractor, engineer, precast manufacturer, concrete producer or project manager looking for a concrete waterproofing admixture in Kenya, Conplast WP200 is designed to help produce lower-permeability concrete while also allowing the desired workability to be achieved with lower water content.
The supplied Fosroc technical data sheet describes Conplast WP200 as a formulated blend of dispersants supplied as a brown solution that disperses instantly in water. The dispersants improve the effectiveness of water in the concrete mix, allowing workability requirements to be achieved with reduced water content. This can reduce the water:cement ratio and, consequently, reduce concrete permeability.
What Is Fosroc Conplast WP200?
Fosroc Conplast WP200 is an integral concrete permeability reducing admixture.
It is added directly into the concrete mix rather than being applied only to the finished concrete surface.
The product is designed for use in:
- Waterproof concrete
- Structural concrete
- Precast concrete
It can also be used solely or in combination with Fosroc Conplast WP400, depending on the mix design and project requirements.
The fundamental objective of Conplast WP200 is to help reduce the permeability of concrete.
Concrete may look solid, dense and impermeable to the naked eye, but its internal structure can contain interconnected pores and capillary pathways. The quantity of water used in the concrete mix plays a major role in the resulting structure of hardened concrete.
An unnecessarily high water:cement ratio can increase porosity and permeability.
Conplast WP200 helps improve the efficiency of the water already present in the mix. This means that the required workability can potentially be achieved with less water, subject to correct mix design and dosage trials.
That matters because reducing the water:cement ratio can contribute to lower permeability and improved compressive strength at equivalent workability.
Fosroc specifically identifies these as key advantages of the product.
Why Concrete Permeability Matters
Waterproofing discussions often focus only on visible leaks.
That is too narrow.
The bigger issue is what repeated water penetration can do to a concrete structure over time.
Where water can penetrate through concrete, it may contribute to wider durability challenges depending on the environment and exposure conditions.
For construction professionals, reducing permeability can therefore be an important part of the overall concrete durability strategy.
Common structures where permeability control may be considered include:
- Basements
- Foundations
- Retaining walls
- Water-retaining structures
- Concrete tanks
- Underground structures
- Lift pits
- Parking structures
- Structural slabs
- Precast concrete products
- Infrastructure projects
However, there is an important limitation that should not be ignored:
Conplast WP200 will not turn poor-quality concrete into waterproof concrete.
Fosroc explicitly states that good concrete practice must be followed at all times. The technical data sheet recommends well-graded aggregates and a minimum cement content of 300 kg/m³, while also noting the need for adequate water bars between lifts of concrete and floor bays.
This is critical.
An admixture is not a shortcut around poor batching, poor aggregate grading, uncontrolled water addition, inadequate curing or defective construction joints.
If the concrete system is weak, simply adding a waterproofing admixture does not solve the underlying execution problem.
Integral Waterproofing Instead of Surface-Only Protection
One of the major advantages of Conplast WP200 is its role as an integral permeability reducer.
Surface-applied waterproofing products can provide important protection, but surface systems may be vulnerable to physical damage.
Conplast WP200 works differently because it is incorporated into the concrete itself.
Fosroc states that the product provides integral protection and that this protection is maintained even if surface damage occurs, unlike an applied surface film or coating.
This does not mean that surface waterproofing systems are unnecessary in every project.
In fact, a major construction project may use several layers of protection, including:
- Good concrete mix design.
- Controlled water:cement ratio.
- A permeability reducing admixture.
- Correct placement and compaction.
- Proper construction joint treatment.
- Water bars where required.
- Good curing.
- Surface waterproofing or protective coatings where specified.
The strongest waterproofing strategy is usually based on the entire system rather than relying on one product to carry the entire project.
How Fosroc Conplast WP200 Works
Conplast WP200 is based on a formulated blend of dispersants.
According to the Fosroc technical data sheet, these dispersants improve the effectiveness of water in the concrete mix.
This enables the desired workability to be achieved with lower water content.
Reducing the amount of water required for a given level of workability can reduce the water:cement ratio.
A lower water:cement ratio can result in reduced permeability.
This is the central technical mechanism behind the product.
In practical terms:
Better use of mixing water → lower water requirement → reduced water:cement ratio → reduced permeability.
Fosroc also states that the lower water:cement ratio can improve compressive strength at the same workability.
That creates an important project-level advantage.
The contractor does not necessarily have to choose between workable concrete and lower permeability.
With proper mix design and dosage optimisation, the admixture is intended to help achieve the required workability while reducing unnecessary water demand.
Fosroc Conplast WP200 for Waterproof Concrete in Kenya
Concrete waterproofing is particularly relevant in projects involving:
- High water tables
- Seasonal rainfall
- Underground construction
- Water storage
- External concrete exposure
- Structural foundations
For Kenyan contractors and developers, the cost of fixing a water problem after construction can be significantly higher than addressing permeability at the concrete production stage.
Once a basement wall has been cast, backfilled and finished, repairing water ingress can involve:
- Excavation
- Removal of finishes
- Crack treatment
- Surface preparation
- Waterproofing application
- Reinstatement
That is reactive construction management.
A better approach is to assess waterproofing requirements before the concrete is placed.
Where appropriate, Conplast WP200 can form part of an integral concrete waterproofing strategy.
Typical Performance of Fosroc Conplast WP200
The supplied Fosroc technical data sheet provides typical performance results, while also making it clear that actual results can vary because of differences in concrete materials and conditions.
The typical results listed are:
- 28-day compressive strength: +20%
- Chloride permeability: -20%
- Water absorption according to BS 1881: -25%
Fosroc notes that these figures are typical performance examples and should not be treated as directly comparable with results obtained elsewhere because concrete materials and conditions vary. Trials using the actual project materials and conditions should be carried out to determine the optimum mix design and dosage.
This is an important distinction for engineers and contractors.
Do not market or specify a fixed performance outcome without trial data.
The actual concrete result depends on variables including:
- Cement type
- Aggregate grading
- Cement content
- Water content
- Mix proportions
- Cement replacement materials
- Other admixtures
- Mixing process
- Site conditions
The correct approach is to conduct trials using the materials that will actually be used on the project.
Recommended Dosage of Fosroc Conplast WP200
Fosroc states that the optimum dosage should always be determined through trials using the materials and conditions expected in actual use.
The normal recommended dosage is:
0.40 to 0.75 litres per 100 kg of cement
The final dosage should be established based on the specific mix requirements and trial results.
This point should not be skipped.
Concrete admixtures should not be dosed by guesswork.
A small change in dosage can affect concrete performance.
The correct workflow is:
Step 1: Define the project requirement
Determine whether the priority is:
- Reduced permeability
- Improved workability
- Strength improvement
- A combination of these requirements
Step 2: Establish the concrete mix
Identify:
- Cement type
- Aggregate source
- Aggregate grading
- Water content
- Cement replacement materials
- Other admixtures
Step 3: Conduct a trial mix
Test different dosages within the recommended range.
Step 4: Assess the results
Evaluate:
- Workability
- Setting behaviour
- Strength
- Water absorption
- Permeability requirements where applicable
Step 5: Finalise the dosage
Use the dosage that delivers the required performance for the actual project conditions.
That is the professional approach.
What Happens if Conplast WP200 Is Overdosed?
More admixture is not automatically better.
The Fosroc technical data sheet states that overdosing Conplast WP200 may result in:
- Increased retardation
- Increased workability
This reinforces the importance of accurate dosing equipment.
Do not use informal measuring methods for a critical structural concrete mix.
For consistent concrete production, dosing should be controlled.
Fosroc recommends measuring the correct quantity using a suitable dispenser.
Compatible Cement Types and Materials
According to the supplied technical data sheet, Fosroc Conplast WP200 is suitable for use with:
- All types of Portland cement
- SRC cements
- PFA
- GGBFS
- Microsilica
It is also compatible with other Fosroc admixtures used in the same concrete mix, although the admixtures should be added separately and should not be premixed together before addition.
Where more than one admixture or cement replacement material is used, Fosroc recommends trial mixes because the combination may alter setting time and other properties.
This is particularly important for modern concrete mix designs.
The interaction between different materials can change the behaviour of fresh concrete.
A mix containing:
- Conplast WP200
- Supplementary cementitious materials
- A plasticiser
- A retarder
may behave differently from the base mix.
Trial testing is therefore not optional on technically demanding projects.
It is part of proper quality control.
How to Add Fosroc Conplast WP200 to Concrete
The Fosroc data sheet recommends that the correct quantity of Conplast WP200 be measured using an appropriate dispenser.
The admixture should then be added to the concrete with the mixing water to obtain the best results.
A controlled batching procedure should therefore include:
- Confirming the cement quantity.
- Calculating the required dosage.
- Measuring the admixture accurately.
- Adding it according to the recommended mixing procedure.
- Maintaining control over the total water added.
- Monitoring the concrete consistency.
One of the worst practices in concrete production is uncontrolled water addition.
A properly designed concrete mix can be compromised when water is added casually on site to make concrete appear more workable.
If workability needs to be improved, the solution should be based on the approved mix design—not random additional water.
Fosroc Conplast WP200 for Structural Concrete
Structural concrete has to achieve more than initial strength.
Long-term performance matters.
For structures where water exposure is a concern, reducing concrete permeability can support the broader durability strategy.
Conplast WP200 is designed for structural concrete and can help reduce water demand while maintaining the required workability, subject to proper mix design and trial testing.
Potential applications may include:
- Structural foundations
- Retaining walls
- Basement structures
- Concrete columns
- Suspended slabs
- Infrastructure structures
- External concrete elements
However, the product does not replace structural engineering requirements.
The concrete mix must still meet the specified:
- Strength class
- Durability requirements
- Exposure requirements
- Workability
- Placement requirements
The admixture is part of the concrete system—not a replacement for engineering design.
Fosroc Conplast WP200 for Precast Concrete
Precast concrete manufacturers require consistency.
Each batch should deliver predictable fresh and hardened concrete performance.
Conplast WP200 is suitable for precast concrete according to the Fosroc technical data sheet.
For precast operations, reduced water demand can be particularly useful where workability and controlled concrete quality are required.
A properly optimised mix may contribute to:
- Better water efficiency
- Reduced permeability
- Improved compressive strength at equivalent workability
The final results, however, must be established through trials using the actual production materials.
Conplast WP200 Does Not Replace Good Concrete Practice
This is the most important section for serious buyers.
A permeability reducing admixture is not magic.
Fosroc explicitly warns that Conplast WP200 will not make poor-quality concrete waterproof.
To produce effective waterproof concrete, contractors should focus on:
Proper Aggregate Selection
Fosroc recommends well-graded aggregates.
Poor aggregate grading can affect the internal structure and workability of the concrete.
Adequate Cement Content
The technical data sheet recommends a minimum cement content of 300 kg/m³.
Controlled Water Content
Do not undermine the mix by adding uncontrolled water.
Proper Construction Joints
Adequate water bars should be provided between lifts of concrete and floor bays where required.
Proper Compaction
Poorly compacted concrete can contain voids and defects that increase the risk of water penetration.
Proper Curing
Good curing practice must be maintained.
The supplied technical data sheet recommends methods such as:
- Water spray
- Wet hessian
- Concure spray-applied curing membrane
The strategic point is straightforward:
Waterproof concrete starts with good concrete. The admixture enhances a properly designed system—it does not rescue a badly executed one.
Fosroc Conplast WP200 vs Surface Waterproofing
These products should not automatically be treated as direct alternatives.
Conplast WP200 provides an integral approach by reducing permeability within the concrete.
A surface waterproofing coating creates protection at the external surface.
Depending on the project, you may require:
Only an Integral Admixture
For concrete designed to meet the project's permeability requirements.
Only a Surface Waterproofing System
For structures requiring external moisture protection.
Both Systems
For higher-risk applications where a multi-layer waterproofing strategy is specified.
The correct choice depends on:
- Structure type
- Water pressure
- Soil conditions
- Exposure
- Accessibility for future repairs
- Design specifications
For major projects, the waterproofing strategy should be coordinated with the structural engineer and project specifications.
Why Choose Fosroc Conplast WP200?
The major advantages identified in the supplied Fosroc technical data include:
Integral Protection
The permeability reduction is incorporated throughout the concrete.
No Bitumen
Fosroc states that Conplast WP200 does not incorporate bitumen.
Reduced Permeability
The lower water:cement ratio contributes to reduced permeability.
Improved Compressive Strength Potential
Fosroc identifies improved compressive strength at the same workability as a key advantage.
Compatibility
The product is compatible with suitable Fosroc admixtures and can be used with Portland cement, SRC cement and listed cement replacement materials.
Surface Coating Compatibility
Fosroc states that the product is fully compatible with certain Fosroc surface coatings and finishes.
Available Pack Sizes at Startcore
Fosroc Conplast WP200 is available from Startcore in:
10 Litres
Suitable for smaller specialist concrete works and controlled site applications where a full industrial drum is unnecessary.
210 Litres
Suitable for contractors, precast operations, batching plants and larger project requirements.
1000 Litres
Designed for high-volume users and larger concrete production requirements.
The supplied Fosroc technical data sheet lists the standard supply formats as 210-litre drums and 1000-litre totes, while noting that storage tanks can be supplied for larger users.
For the 10-litre option supplied through Startcore, buyers should use the product in accordance with the same approved technical requirements and confirm availability or packaging details when ordering.
How to Estimate How Much Conplast WP200 You Need
The dosage is based on cement quantity.
The normal recommended range is:
0.40–0.75 litres per 100 kg of cement.
For example, if your concrete mix contains 300 kg of cement per cubic metre, the approximate Conplast WP200 dosage range would be:
- At 0.40 L per 100 kg: 1.2 L per m³
- At 0.75 L per 100 kg: 2.25 L per m³
This is only an illustration based on the stated dosage range.
The actual project dosage must be established through trials using the real materials and conditions.
Do not select the final dosage simply because another contractor used a particular quantity.
Different cement, sand, aggregates and water conditions can produce different results.
Storage and Shelf Life
The Fosroc technical data sheet states that Conplast WP200 has a minimum shelf life of 12 months when stored within a temperature range of 2°C to 50°C.
Fosroc recommends contacting its technical service department for advice if the product has been stored outside this temperature range.
Proper storage should therefore include:
- Keeping containers properly closed.
- Avoiding unnecessary contamination.
- Maintaining suitable storage temperatures.
- Managing stock using appropriate stock rotation.
- Checking product condition before use.
Health and Safety
The supplied technical data sheet states that Conplast WP200 is mildly alkaline.
It should not be swallowed or allowed to come into contact with the skin or eyes.
Suitable protective gloves and goggles should be worn.
Fosroc's safety guidance states:
- Wash skin immediately with soap and water after contact.
- Rinse eyes immediately with plenty of water and seek medical advice.
- If swallowed, seek medical attention immediately and do not induce vomiting.
The product is water-based and non-flammable according to the technical data sheet.
For complete handling requirements, users should refer to the current product Safety Data Sheet.
Cleaning and Disposal
According to the supplied Fosroc data sheet, spillages should be absorbed using:
- Sand
- Earth
- Vermiculite
The absorbed material should then be transferred into suitable containers.
Remaining material can be hosed down with large quantities of water as directed in the data sheet, while disposal of excess or waste material should follow applicable local legislation and regulatory guidance.
Frequently Asked Questions About Fosroc Conplast WP200
What is Fosroc Conplast WP200 used for?
Fosroc Conplast WP200 is a chloride-free, high-performance permeability reducing admixture for waterproof, structural and precast concrete.
Does Conplast WP200 make concrete waterproof?
It is designed to reduce concrete permeability and can be used in waterproof concrete. However, Fosroc clearly states that it will not make poor-quality concrete waterproof. Good concrete practice remains essential.
What is the recommended dosage?
The normal recommended dosage is 0.40 to 0.75 litres per 100 kg of cement, with the optimum dosage determined through project-specific trials.
Can Conplast WP200 improve concrete strength?
Fosroc identifies improved compressive strength at the same workability as one of the product advantages. Its typical performance example lists a 28-day compressive strength increase of 20%, although actual results depend on the concrete materials and conditions.
Can Conplast WP200 be used with other admixtures?
Yes. Fosroc states that it is compatible with other Fosroc admixtures used in the same concrete mix, provided they are added separately and the combined mix is assessed through trial procedures.
What happens if too much Conplast WP200 is added?
Overdosing may increase retardation and workability.
Is Conplast WP200 chloride free?
Yes. The technical data sheet identifies it as a chloride-free permeability reducing admixture and lists chloride content as nil to BS 5075 / BS EN 934.
What sizes are available from Startcore?
Startcore offers Fosroc Conplast WP200 in 10L, 210L and 1000L options.
Buy Fosroc Conplast WP200 in Kenya from Startcore
If your project requires a concrete waterproofing admixture, permeability reducer or integral waterproofing solution, Fosroc Conplast WP200 provides a technically focused solution for properly designed concrete.
It is particularly relevant for:
- Contractors
- Civil engineers
- Structural engineers
- Concrete batching plants
- Precast manufacturers
- Waterproofing contractors
- Developers
- Infrastructure projects
Available from Startcore Ventures Limited in:
10 Litres | 210 Litres | 1000 Litres
Before ordering, confirm your estimated cement consumption and expected concrete volume so the required quantity can be calculated accurately.
For technical projects, the strongest procurement strategy is not simply buying an admixture and hoping for the best.
The correct process is:
Define the performance requirement → design the concrete mix → conduct trials → establish the dosage → control batching → place and cure the concrete correctly.
That is how Conplast WP200 should be positioned.
It is not a shortcut.
It is a performance component within a properly engineered concrete system.
For contractors and project teams looking to reduce concrete permeability while maintaining controlled workability, Fosroc Conplast WP200 offers an integral solution that starts working from inside the concrete mix rather than relying only on surface protection.
Fosroc Conplast WP200 – High Performance Concrete Permeability Reducer and Integral Waterproofing Admixture
When concrete structures are exposed to water, moisture and long-term environmental conditions, waterproofing cannot always be treated as an afterthought. Applying a coating after the concrete has already been placed may protect the surface, but the concrete itself can still remain vulnerable if the mix has excessive permeability.
This is where Fosroc Conplast WP200 provides a different approach.
Fosroc Conplast WP200 is a chloride-free, high-performance permeability reducing admixture designed for use in waterproof, structural and precast concrete. Instead of creating only an external waterproofing layer, it works as an integral admixture within the concrete mix, helping reduce permeability throughout the concrete.
At Startcore Ventures Limited, Fosroc Conplast WP200 is available in the following pack sizes:
- 10 Litres
- 210 Litres
- 1000 Litres
This makes it suitable for different scales of concrete work, from specialised construction requirements to larger structural and ready-mix concrete projects.
Whether you are a contractor, engineer, precast manufacturer, concrete producer or project manager looking for a concrete waterproofing admixture in Kenya, Conplast WP200 is designed to help produce lower-permeability concrete while also allowing the desired workability to be achieved with lower water content.
The supplied Fosroc technical data sheet describes Conplast WP200 as a formulated blend of dispersants supplied as a brown solution that disperses instantly in water. The dispersants improve the effectiveness of water in the concrete mix, allowing workability requirements to be achieved with reduced water content. This can reduce the water:cement ratio and, consequently, reduce concrete permeability.
What Is Fosroc Conplast WP200?
Fosroc Conplast WP200 is an integral concrete permeability reducing admixture.
It is added directly into the concrete mix rather than being applied only to the finished concrete surface.
The product is designed for use in:
- Waterproof concrete
- Structural concrete
- Precast concrete
It can also be used solely or in combination with Fosroc Conplast WP400, depending on the mix design and project requirements.
The fundamental objective of Conplast WP200 is to help reduce the permeability of concrete.
Concrete may look solid, dense and impermeable to the naked eye, but its internal structure can contain interconnected pores and capillary pathways. The quantity of water used in the concrete mix plays a major role in the resulting structure of hardened concrete.
An unnecessarily high water:cement ratio can increase porosity and permeability.
Conplast WP200 helps improve the efficiency of the water already present in the mix. This means that the required workability can potentially be achieved with less water, subject to correct mix design and dosage trials.
That matters because reducing the water:cement ratio can contribute to lower permeability and improved compressive strength at equivalent workability.
Fosroc specifically identifies these as key advantages of the product.
Why Concrete Permeability Matters
Waterproofing discussions often focus only on visible leaks.
That is too narrow.
The bigger issue is what repeated water penetration can do to a concrete structure over time.
Where water can penetrate through concrete, it may contribute to wider durability challenges depending on the environment and exposure conditions.
For construction professionals, reducing permeability can therefore be an important part of the overall concrete durability strategy.
Common structures where permeability control may be considered include:
- Basements
- Foundations
- Retaining walls
- Water-retaining structures
- Concrete tanks
- Underground structures
- Lift pits
- Parking structures
- Structural slabs
- Precast concrete products
- Infrastructure projects
However, there is an important limitation that should not be ignored:
Conplast WP200 will not turn poor-quality concrete into waterproof concrete.
Fosroc explicitly states that good concrete practice must be followed at all times. The technical data sheet recommends well-graded aggregates and a minimum cement content of 300 kg/m³, while also noting the need for adequate water bars between lifts of concrete and floor bays.
This is critical.
An admixture is not a shortcut around poor batching, poor aggregate grading, uncontrolled water addition, inadequate curing or defective construction joints.
If the concrete system is weak, simply adding a waterproofing admixture does not solve the underlying execution problem.
Integral Waterproofing Instead of Surface-Only Protection
One of the major advantages of Conplast WP200 is its role as an integral permeability reducer.
Surface-applied waterproofing products can provide important protection, but surface systems may be vulnerable to physical damage.
Conplast WP200 works differently because it is incorporated into the concrete itself.
Fosroc states that the product provides integral protection and that this protection is maintained even if surface damage occurs, unlike an applied surface film or coating.
This does not mean that surface waterproofing systems are unnecessary in every project.
In fact, a major construction project may use several layers of protection, including:
- Good concrete mix design.
- Controlled water:cement ratio.
- A permeability reducing admixture.
- Correct placement and compaction.
- Proper construction joint treatment.
- Water bars where required.
- Good curing.
- Surface waterproofing or protective coatings where specified.
The strongest waterproofing strategy is usually based on the entire system rather than relying on one product to carry the entire project.
How Fosroc Conplast WP200 Works
Conplast WP200 is based on a formulated blend of dispersants.
According to the Fosroc technical data sheet, these dispersants improve the effectiveness of water in the concrete mix.
This enables the desired workability to be achieved with lower water content.
Reducing the amount of water required for a given level of workability can reduce the water:cement ratio.
A lower water:cement ratio can result in reduced permeability.
This is the central technical mechanism behind the product.
In practical terms:
Better use of mixing water → lower water requirement → reduced water:cement ratio → reduced permeability.
Fosroc also states that the lower water:cement ratio can improve compressive strength at the same workability.
That creates an important project-level advantage.
The contractor does not necessarily have to choose between workable concrete and lower permeability.
With proper mix design and dosage optimisation, the admixture is intended to help achieve the required workability while reducing unnecessary water demand.
Fosroc Conplast WP200 for Waterproof Concrete in Kenya
Concrete waterproofing is particularly relevant in projects involving:
- High water tables
- Seasonal rainfall
- Underground construction
- Water storage
- External concrete exposure
- Structural foundations
For Kenyan contractors and developers, the cost of fixing a water problem after construction can be significantly higher than addressing permeability at the concrete production stage.
Once a basement wall has been cast, backfilled and finished, repairing water ingress can involve:
- Excavation
- Removal of finishes
- Crack treatment
- Surface preparation
- Waterproofing application
- Reinstatement
That is reactive construction management.
A better approach is to assess waterproofing requirements before the concrete is placed.
Where appropriate, Conplast WP200 can form part of an integral concrete waterproofing strategy.
Typical Performance of Fosroc Conplast WP200
The supplied Fosroc technical data sheet provides typical performance results, while also making it clear that actual results can vary because of differences in concrete materials and conditions.
The typical results listed are:
- 28-day compressive strength: +20%
- Chloride permeability: -20%
- Water absorption according to BS 1881: -25%
Fosroc notes that these figures are typical performance examples and should not be treated as directly comparable with results obtained elsewhere because concrete materials and conditions vary. Trials using the actual project materials and conditions should be carried out to determine the optimum mix design and dosage.
This is an important distinction for engineers and contractors.
Do not market or specify a fixed performance outcome without trial data.
The actual concrete result depends on variables including:
- Cement type
- Aggregate grading
- Cement content
- Water content
- Mix proportions
- Cement replacement materials
- Other admixtures
- Mixing process
- Site conditions
The correct approach is to conduct trials using the materials that will actually be used on the project.
Recommended Dosage of Fosroc Conplast WP200
Fosroc states that the optimum dosage should always be determined through trials using the materials and conditions expected in actual use.
The normal recommended dosage is:
0.40 to 0.75 litres per 100 kg of cement
The final dosage should be established based on the specific mix requirements and trial results.
This point should not be skipped.
Concrete admixtures should not be dosed by guesswork.
A small change in dosage can affect concrete performance.
The correct workflow is:
Step 1: Define the project requirement
Determine whether the priority is:
- Reduced permeability
- Improved workability
- Strength improvement
- A combination of these requirements
Step 2: Establish the concrete mix
Identify:
- Cement type
- Aggregate source
- Aggregate grading
- Water content
- Cement replacement materials
- Other admixtures
Step 3: Conduct a trial mix
Test different dosages within the recommended range.
Step 4: Assess the results
Evaluate:
- Workability
- Setting behaviour
- Strength
- Water absorption
- Permeability requirements where applicable
Step 5: Finalise the dosage
Use the dosage that delivers the required performance for the actual project conditions.
That is the professional approach.
What Happens if Conplast WP200 Is Overdosed?
More admixture is not automatically better.
The Fosroc technical data sheet states that overdosing Conplast WP200 may result in:
- Increased retardation
- Increased workability
This reinforces the importance of accurate dosing equipment.
Do not use informal measuring methods for a critical structural concrete mix.
For consistent concrete production, dosing should be controlled.
Fosroc recommends measuring the correct quantity using a suitable dispenser.
Compatible Cement Types and Materials
According to the supplied technical data sheet, Fosroc Conplast WP200 is suitable for use with:
- All types of Portland cement
- SRC cements
- PFA
- GGBFS
- Microsilica
It is also compatible with other Fosroc admixtures used in the same concrete mix, although the admixtures should be added separately and should not be premixed together before addition.
Where more than one admixture or cement replacement material is used, Fosroc recommends trial mixes because the combination may alter setting time and other properties.
This is particularly important for modern concrete mix designs.
The interaction between different materials can change the behaviour of fresh concrete.
A mix containing:
- Conplast WP200
- Supplementary cementitious materials
- A plasticiser
- A retarder
may behave differently from the base mix.
Trial testing is therefore not optional on technically demanding projects.
It is part of proper quality control.
How to Add Fosroc Conplast WP200 to Concrete
The Fosroc data sheet recommends that the correct quantity of Conplast WP200 be measured using an appropriate dispenser.
The admixture should then be added to the concrete with the mixing water to obtain the best results.
A controlled batching procedure should therefore include:
- Confirming the cement quantity.
- Calculating the required dosage.
- Measuring the admixture accurately.
- Adding it according to the recommended mixing procedure.
- Maintaining control over the total water added.
- Monitoring the concrete consistency.
One of the worst practices in concrete production is uncontrolled water addition.
A properly designed concrete mix can be compromised when water is added casually on site to make concrete appear more workable.
If workability needs to be improved, the solution should be based on the approved mix design—not random additional water.
Fosroc Conplast WP200 for Structural Concrete
Structural concrete has to achieve more than initial strength.
Long-term performance matters.
For structures where water exposure is a concern, reducing concrete permeability can support the broader durability strategy.
Conplast WP200 is designed for structural concrete and can help reduce water demand while maintaining the required workability, subject to proper mix design and trial testing.
Potential applications may include:
- Structural foundations
- Retaining walls
- Basement structures
- Concrete columns
- Suspended slabs
- Infrastructure structures
- External concrete elements
However, the product does not replace structural engineering requirements.
The concrete mix must still meet the specified:
- Strength class
- Durability requirements
- Exposure requirements
- Workability
- Placement requirements
The admixture is part of the concrete system—not a replacement for engineering design.
Fosroc Conplast WP200 for Precast Concrete
Precast concrete manufacturers require consistency.
Each batch should deliver predictable fresh and hardened concrete performance.
Conplast WP200 is suitable for precast concrete according to the Fosroc technical data sheet.
For precast operations, reduced water demand can be particularly useful where workability and controlled concrete quality are required.
A properly optimised mix may contribute to:
- Better water efficiency
- Reduced permeability
- Improved compressive strength at equivalent workability
The final results, however, must be established through trials using the actual production materials.
Conplast WP200 Does Not Replace Good Concrete Practice
This is the most important section for serious buyers.
A permeability reducing admixture is not magic.
Fosroc explicitly warns that Conplast WP200 will not make poor-quality concrete waterproof.
To produce effective waterproof concrete, contractors should focus on:
Proper Aggregate Selection
Fosroc recommends well-graded aggregates.
Poor aggregate grading can affect the internal structure and workability of the concrete.
Adequate Cement Content
The technical data sheet recommends a minimum cement content of 300 kg/m³.
Controlled Water Content
Do not undermine the mix by adding uncontrolled water.
Proper Construction Joints
Adequate water bars should be provided between lifts of concrete and floor bays where required.
Proper Compaction
Poorly compacted concrete can contain voids and defects that increase the risk of water penetration.
Proper Curing
Good curing practice must be maintained.
The supplied technical data sheet recommends methods such as:
- Water spray
- Wet hessian
- Concure spray-applied curing membrane
The strategic point is straightforward:
Waterproof concrete starts with good concrete. The admixture enhances a properly designed system—it does not rescue a badly executed one.
Fosroc Conplast WP200 vs Surface Waterproofing
These products should not automatically be treated as direct alternatives.
Conplast WP200 provides an integral approach by reducing permeability within the concrete.
A surface waterproofing coating creates protection at the external surface.
Depending on the project, you may require:
Only an Integral Admixture
For concrete designed to meet the project's permeability requirements.
Only a Surface Waterproofing System
For structures requiring external moisture protection.
Both Systems
For higher-risk applications where a multi-layer waterproofing strategy is specified.
The correct choice depends on:
- Structure type
- Water pressure
- Soil conditions
- Exposure
- Accessibility for future repairs
- Design specifications
For major projects, the waterproofing strategy should be coordinated with the structural engineer and project specifications.
Why Choose Fosroc Conplast WP200?
The major advantages identified in the supplied Fosroc technical data include:
Integral Protection
The permeability reduction is incorporated throughout the concrete.
No Bitumen
Fosroc states that Conplast WP200 does not incorporate bitumen.
Reduced Permeability
The lower water:cement ratio contributes to reduced permeability.
Improved Compressive Strength Potential
Fosroc identifies improved compressive strength at the same workability as a key advantage.
Compatibility
The product is compatible with suitable Fosroc admixtures and can be used with Portland cement, SRC cement and listed cement replacement materials.
Surface Coating Compatibility
Fosroc states that the product is fully compatible with certain Fosroc surface coatings and finishes.
Available Pack Sizes at Startcore
Fosroc Conplast WP200 is available from Startcore in:
10 Litres
Suitable for smaller specialist concrete works and controlled site applications where a full industrial drum is unnecessary.
210 Litres
Suitable for contractors, precast operations, batching plants and larger project requirements.
1000 Litres
Designed for high-volume users and larger concrete production requirements.
The supplied Fosroc technical data sheet lists the standard supply formats as 210-litre drums and 1000-litre totes, while noting that storage tanks can be supplied for larger users.
For the 10-litre option supplied through Startcore, buyers should use the product in accordance with the same approved technical requirements and confirm availability or packaging details when ordering.
How to Estimate How Much Conplast WP200 You Need
The dosage is based on cement quantity.
The normal recommended range is:
0.40–0.75 litres per 100 kg of cement.
For example, if your concrete mix contains 300 kg of cement per cubic metre, the approximate Conplast WP200 dosage range would be:
- At 0.40 L per 100 kg: 1.2 L per m³
- At 0.75 L per 100 kg: 2.25 L per m³
This is only an illustration based on the stated dosage range.
The actual project dosage must be established through trials using the real materials and conditions.
Do not select the final dosage simply because another contractor used a particular quantity.
Different cement, sand, aggregates and water conditions can produce different results.
Storage and Shelf Life
The Fosroc technical data sheet states that Conplast WP200 has a minimum shelf life of 12 months when stored within a temperature range of 2°C to 50°C.
Fosroc recommends contacting its technical service department for advice if the product has been stored outside this temperature range.
Proper storage should therefore include:
- Keeping containers properly closed.
- Avoiding unnecessary contamination.
- Maintaining suitable storage temperatures.
- Managing stock using appropriate stock rotation.
- Checking product condition before use.
Health and Safety
The supplied technical data sheet states that Conplast WP200 is mildly alkaline.
It should not be swallowed or allowed to come into contact with the skin or eyes.
Suitable protective gloves and goggles should be worn.
Fosroc's safety guidance states:
- Wash skin immediately with soap and water after contact.
- Rinse eyes immediately with plenty of water and seek medical advice.
- If swallowed, seek medical attention immediately and do not induce vomiting.
The product is water-based and non-flammable according to the technical data sheet.
For complete handling requirements, users should refer to the current product Safety Data Sheet.
Cleaning and Disposal
According to the supplied Fosroc data sheet, spillages should be absorbed using:
- Sand
- Earth
- Vermiculite
The absorbed material should then be transferred into suitable containers.
Remaining material can be hosed down with large quantities of water as directed in the data sheet, while disposal of excess or waste material should follow applicable local legislation and regulatory guidance.
Frequently Asked Questions About Fosroc Conplast WP200
What is Fosroc Conplast WP200 used for?
Fosroc Conplast WP200 is a chloride-free, high-performance permeability reducing admixture for waterproof, structural and precast concrete.
Does Conplast WP200 make concrete waterproof?
It is designed to reduce concrete permeability and can be used in waterproof concrete. However, Fosroc clearly states that it will not make poor-quality concrete waterproof. Good concrete practice remains essential.
What is the recommended dosage?
The normal recommended dosage is 0.40 to 0.75 litres per 100 kg of cement, with the optimum dosage determined through project-specific trials.
Can Conplast WP200 improve concrete strength?
Fosroc identifies improved compressive strength at the same workability as one of the product advantages. Its typical performance example lists a 28-day compressive strength increase of 20%, although actual results depend on the concrete materials and conditions.
Can Conplast WP200 be used with other admixtures?
Yes. Fosroc states that it is compatible with other Fosroc admixtures used in the same concrete mix, provided they are added separately and the combined mix is assessed through trial procedures.
What happens if too much Conplast WP200 is added?
Overdosing may increase retardation and workability.
Is Conplast WP200 chloride free?
Yes. The technical data sheet identifies it as a chloride-free permeability reducing admixture and lists chloride content as nil to BS 5075 / BS EN 934.
What sizes are available from Startcore?
Startcore offers Fosroc Conplast WP200 in 10L, 210L and 1000L options.
Buy Fosroc Conplast WP200 in Kenya from Startcore
If your project requires a concrete waterproofing admixture, permeability reducer or integral waterproofing solution, Fosroc Conplast WP200 provides a technically focused solution for properly designed concrete.
It is particularly relevant for:
- Contractors
- Civil engineers
- Structural engineers
- Concrete batching plants
- Precast manufacturers
- Waterproofing contractors
- Developers
- Infrastructure projects
Available from Startcore Ventures Limited in:
10 Litres | 210 Litres | 1000 Litres
Before ordering, confirm your estimated cement consumption and expected concrete volume so the required quantity can be calculated accurately.
For technical projects, the strongest procurement strategy is not simply buying an admixture and hoping for the best.
The correct process is:
Define the performance requirement → design the concrete mix → conduct trials → establish the dosage → control batching → place and cure the concrete correctly.
That is how Conplast WP200 should be positioned.
It is not a shortcut.
It is a performance component within a properly engineered concrete system.
For contractors and project teams looking to reduce concrete permeability while maintaining controlled workability, Fosroc Conplast WP200 offers an integral solution that starts working from inside the concrete mix rather than relying only on surface protection.
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