-
Primers + Mesh
Surface Prep
Before you prime and mesh it’s essential that your surface is completely flat, dry and well consolidated, so that there is no chance of movement. Use a small amount of the base coat or a suitable filler to flush out joins and counter-sunk screw holes, then sand until the surface is completely flat. See surface prep for full details of preparing surface for microcement.
Applying Primer 100 & Fibreglass Mesh
Fibreglass mesh adds strength to your microcement and adds strength to the substrate. Cut the mesh to size & then flip it over so that it curls towards the surface. You might find it easier to use Self Adhesive Fibreglass Mesh on corners.
Use a medium pile roller to apply an even coat of primer to the surface and mesh. The primer should help to hold the mesh in place, but you can also use stainless steel staples to hold it down.
Try to get the mesh flat to the surface. If you do get bubbles in the mesh that you can’t flatten, you might need to move on and deal with them when applying base coats by slashing the bubble with your trowel or utility knife and flattening down at that point. If bubbles in the mesh are still showing through after the 2nd base coat, sand them out so that you have a completely flat surface before applying top coats.
Primer 100 is a thick, high-quality product. To get the full consumption out of the bottle, you may need a little water. Add up to 10% water & shake to get all of the primer out of the container.
Fresh Plaster & Concrete
On freshly laid concrete, screed, self-leveller or fresh plaster use Primer 100 mixed with water at a ratio of 50:50 before applying a neat coat. Similar to a mist coat of paint, this will prevent the primer from sitting on the surface and create a strong bond between surface and microcement. The primer needs to sink into the substrate to take hold, which is where the water comes in.
After around 1 hour it should be dry enough to take a neat coat of Primer 100. If the substrate is very absorbent, you might need to buy more primer to complete this stage.
Leave to Dry
Leave the primer to dry. This should take around 1 hour. Primer 100 will loose it’s tack after 8 hours, so you will need to make sure you apply your base coat within 8 hours or apply another coat of re-prime.
When to Choose High Performance Primer
We highly recommend that you choose this option if you are working on load-bearing horizontal surfaces that have joins e.g. OSB/Ply/MDF/Cement Board flooring or across transitions between shower trays and surrounding floors. It also helps to strengthen concrete surfaces that have cracked, however the cracks should be repaired in advance. It’s also useful for bridging joins between boards in furniture and worktops.
This primer helps to inhibit moisture and stains from transferring through from your substrate.
If you think you need High Performance Primer but haven’t got it in your kit, the products are also available to buy separately.
Cemher Primer 100
Highly Absorbent Surfaces e.g. Fresh Plaster / Screeds All Other Surfaces including Non Absorbent Surfaces Process Highly Absorbent Surfaces e.g. Fresh Plaster / Screeds: Diluted Coat followed by Neat Coat All Other Surfaces including Non Absorbent Surfaces: Apply Neat Coat Directly Mix Ratio Highly Absorbent Surfaces e.g. Fresh Plaster / Screeds: Diluted Coat:
50% Water / 50% Primer 100
Neat Coat:
Maximum 10% WaterAll Other Surfaces including Non Absorbent Surfaces: Maximum 10% Water Standard Consumption Highly Absorbent Surfaces e.g. Fresh Plaster / Screeds: 1l per 4 - 6m2 All Other Surfaces including Non Absorbent Surfaces: 1l per 8 - 10m2 Estimated Drying Time Highly Absorbent Surfaces e.g. Fresh Plaster / Screeds: Diluted Coat:
30 minutes
No Maximum
Neat Coat:
Minimum 30 minutes
Maximum 8 hoursAll Other Surfaces including Non Absorbent Surfaces: Minimum 30 minutes
Maximum 12 hoursTools Required Highly Absorbent Surfaces e.g. Fresh Plaster / Screeds: Medium Microfibre Roller
Roller Tray
PPEAll Other Surfaces including Non Absorbent Surfaces: Medium Microfibre Roller
Roller Tray
PPE -
Base Coats
Mixing 1st Coat MicroDur Base
You will need 10kg of MicroDur Base to complete 1 coat over 10m2. Split your MicroDur Base into equal batches of 10kg. Mix no more than 20kg at a time.
For each batch, measure 2.5l – 3.0l Water using a measuring jug. Pour the water into your mixing bucket, followed by 10kg MicroDur Base.
Mix thoroughly with a microcement mixer head attachment on a cordless drill. Let the mixture rest for a few minutes before applying.
Mixing Smaller Batches
You will need 1kg MicroDur Base per m2 per coat & 500g Top Coat per m2 per coat. So for 2 x base coats & 2 x top coats, you’ll need 2kg Base Coat & 1kg Top Coat.
The best way to split the colour for MicroDur Base, Medium or Fine is to measure out the full amount of water for 10kg microcement & then add the colour for 10kg Microcement to it. Make sure you get all the colour out of the bottle and stir it in well.
Then you can take the amount of water that you need for each kg & be confident that the colour will be consistent across all the batches.
Applying 1st Coat MicroDur Base
Using a Microcement Trowel, work your way out from one corner creating a random edge pattern. Keep trowel movements small and random, avoid long sweeping arches – as these will show through to your final finish.
Use the grain in the microcement as your level – if you apply the microcement thicker than the size of the grain, the finish won’t be as strong and will require a lot more sanding. Run the trowel back over each section that you have put down to smooth it out and remove excess product.
Completely cover each surface without stopping. For complete rooms, start with ceilings, then walls from left to right (or right to left) and then the floor.
Run your finger or a corner trowel along internal corners to push the microcement into the corner and then gently trowel away the excess product.
Large Floor Areas
For large floor areas, you may find it quicker to use a Squeegee Trowel to apply your 1st base coat.
If you choose to do this, use 3l water per 10kg MicroDur Base.
Pour the Microcement along the width of the room and use the Squeegee to flatten it out over the floor so that it is no thicker than the grain in all areas.
Complete around a metre before wiping the excess off the trowel and going back over the area to remove any raised lines & remove any excess product, before moving onto the next section.
Mixing 2nd Coat MicroDur Base
You will need 10kg Microdur Base per 10m2.
For each batch, measure 2.5l – 3.0l Water using a measuring jug. Pour the water into your mixing bucket, and mix in the Colour for 10kg MicroDur Base. Use the water to rinse out all of the colour from the bottle – to avoid colour variation between batches. Add 10kg MicroDur Base and mix thoroughly.
Let the mixture rest for a few minutes before applying.
Applying 2nd Coat MicroDur Base
Apply the 2nd Coat of MicroDur Base in exactly the same way as the 1st coat.
Leave to Dry
This should take around 3 hours if you are applying another coat of MicroDur on top. If your next coat is Microne, leave for 24 hours until completely dry.
Drying times may vary depending on temperature and humidity.
Sand with 40/80 Grit Sand Paper
Once the base coats are dry and before you apply your Top Coats, you need to make sure the Base Coats are completely flat. Use a strong sand paper, like Silicone Carbide, to prevent colour from the sand paper transfering to your work.
Flatten the MicroDur Base with a 40 or 80 grit sand paper. An orbital sander is ideal, but, for smaller areas, you can do it by hand. And for larger areas you may prefer to use a floor sander.
Use the sand paper to remove ridges and drips that have dried in the microcement.
The top coats are very thin so any ridges or imperfections in the base coats will be visible in the top coats. Take your time to get it completely flat before moving on to the next step.
Vacuum the surface to remove all dust and debris. Do not wet the microcement.
Microcement Sanding Discs are available from Relentless Microcement.
Cemher Microdur Base
Process Apply 2 Coats Microdur Base Mix Ratio 10kg Microdur Medium : 2.5-3.0l Water Standard Consumption 20kg per 10m2 Estimated Drying Time Between Coats:
Minimum 3 hours
No Maximum
Before Sealers:
Minimum 24 hours
No MaximumTools Required Microcement Trowel
Microcement Mixer
Clean Mixing Bucket
Weighing Scales
Measuring Jug
PPE -
Top Coats
Mixing the MicroMetal
You will need 5kg of MicroMetal to complete 1 coat over 10m2.
Add the MicroMetal to a mixing bucket and add a small amount of Metal Resin, mix thoroughly, then continue to add small amounts of Metal Resin until it reaches a workable consistency. The amount of Metal Resin required does vary depending on the metal. You will need 500ml – 1l Metal Resin per 5kg MicroMetal.
Let the mixture rest for a few minutes before applying. Keep a lid on it between coats. Working time is 1 – 3 hours.
Applying the MicroMetal
Using a Microcement Trowel, work your way out from one corner creating a random edge pattern. Keep trowel movements small and random, avoid long sweeping arches – as these will show through to your final finish.
Use the grain in the liquid metal as your level – if you apply it thicker than the size of the grain, the finish won’t be as strong and will require a lot more sanding. Run the trowel back over each section that you have put down to smooth it out and remove excess product.
Run your finger or a corner trowel along internal corners to push the microcement into the corner and then gently trowel away the excess product.
Polishing the Metal
Work over the whole area with a 400 grit sanding disc on an orbital sander, sand all areas evenly so that you achieve a uniform depth across the area.
The 400 grit will expose the metal, where as subsequent grits will polish the exposed metals. Before moving to the next grit ensure you are happy with the level of cut in your work.
Continue to work up the grits, increasing the speed as you go. The following table shows the relative speed for each of the grits.
400 low speed
500/800/1000 medium speed
3000 high speedCemher Iron Micrometal + Metal Resin
Oxidising the Metal Polishing the Metal Process Oxidising the Metal: Apply 1 coat of liquid metal & oxidise Polishing the Metal: Apply 2 coat of liquid metal & polish Mix Ratio Oxidising the Metal: 5kg Metal Powder : 500ml - 1l Metal Resin Polishing the Metal: 5kg Metal Powder : 500ml - 1l Aquatix Standard Consumption Oxidising the Metal: 5kg per 10m2 Polishing the Metal: 10kg per 10m2 Estimated Drying Time Oxidising the Metal: Before Accelerator:
Minimum 30 minutes
No Maximum
Before Sealers:
Minimum 24 hours
No MaximumPolishing the Metal: Between Coats:
Minimum 30 minutes
No Maximum
Before Polishing:
Minimum 24 hours
No MaximumTools Required Oxidising the Metal: Microcement Trowel
Microcement Mixer
PPEPolishing the Metal: Microcement Trowel
Microcement Mixer
PPECemher Copper Micrometal + Metal Resin
Oxidising the Metal Polishing the Metal Process Oxidising the Metal: Apply 1 coat of liquid metal & oxidise Polishing the Metal: Apply 2 coat of liquid metal & polish Mix Ratio Oxidising the Metal: 5kg Metal Powder : 500ml - 1l Metal Resin Polishing the Metal: 5kg Metal Powder : 500ml - 1l Aquatix Standard Consumption Oxidising the Metal: 5kg per 10m2 Polishing the Metal: 10kg per 10m2 Estimated Drying Time Oxidising the Metal: Before Accelerator:
Minimum 30 minutes
No Maximum
Before Sealers:
Minimum 24 hours
No MaximumPolishing the Metal: Between Coats:
Minimum 30 minutes
No Maximum
Before Polishing:
Minimum 24 hours
No MaximumTools Required Oxidising the Metal: Microcement Trowel
Microcement Mixer
PPEPolishing the Metal: Microcement Trowel
Microcement Mixer
PPECemher Bronze Micrometal + Metal Resin
Oxidising the Metal Polishing the Metal Process Oxidising the Metal: Apply 1 coat of liquid metal & oxidise Polishing the Metal: Apply 2 coat of liquid metal & polish Mix Ratio Oxidising the Metal: 5kg Metal Powder : 500ml - 1l Metal Resin Polishing the Metal: 5kg Metal Powder : 500ml - 1l Aquatix Standard Consumption Oxidising the Metal: 5kg per 10m2 Polishing the Metal: 10kg per 10m2 Estimated Drying Time Oxidising the Metal: Before Accelerator:
Minimum 30 minutes
No Maximum
Before Sealers:
Minimum 24 hours
No MaximumPolishing the Metal: Between Coats:
Minimum 30 minutes
No Maximum
Before Polishing:
Minimum 24 hours
No MaximumTools Required Oxidising the Metal: Microcement Trowel
Microcement Mixer
PPEPolishing the Metal: Microcement Trowel
Microcement Mixer
PPE -
Sealers
-
After Care
Light Use After 48 Hours
You can start to use the microcement surface 48 hours after the final sealer has been applied. By this time, the microcement is sufficiently waterproof, so you can use showers & taps.
You can also install fittings, but its important that you follow the guidance outlined below, for the first 14 days.
First 14 Days
Like all cementitious products, microcement takes 28 days to full harden. Which means it’s at it’s softest for the first 14 days after laying. It also needs to be kep well ventilated so that air can freely flow from the microcement into the atmosphere as it cures.
During this time it should only be subjected to light use and light foot traffic. And no part of the microcement should be covered over. So no leaving bottles in shower areas or rugs on floors.
Heavy work is not recommended during this time, but if it does take place then we recommend covering the floor with a breathable material and only covering down whilst work is taking place. Protection should lifted off for the majority of the time and certainly through the night. The surface needs to dry out and harden. If airflow is restricted, it could stain permanently & not cure to full strength.
Fixing to Microcement Surfaces
Microcement can be drilled and screwed into using bits that are suitable for the substrate. Any holes or cuts will need protecting from moisture penetration by either putting silicone into screw holes or by surrounding fixtures & fitting entirely with silicone. Use 100% pure silicone for this job, to ensure good adherance to the sealed microcement.
Care must also be taken not to scratch the sealers whilst installing fixtures & fittings.
No Dragging or Dropping
Dragging heavy objects over the surface, or dropping them onto the surface is not recommended at any time, as damage could occur. Lift furniture rather than dragging it, and use lids or felt pads to protect flooring from pressure points or abbrasive surfaces.
Microcement is strong, but due to its limited thickness, it will deform in the event of a strong blow if the support beneath deforms. Generally, abrasion and impact resistance is comparable with hard wood.
Stain Resistance
Chemical resistance depends on the sealer used to protect the product. Our sealers are among the best in the industry for both hardness & strength.
Products containing dyes & acidic or alkaline products like tumeric, vinegar, lemon juice or bleach, may leave slight marks on microcement if left on the surface for prolonged time. If cleaning is done quickly, they shouldn’t stain.
If water stains appear at any time, let the stain dry out & reseal immediately. Stains may become permanent if not treated quickly.
Prolongued Exposure to Water
If water is trapped against the surface for a prolonged length of time it may stain & potentially cause the microcement to blister. It is not advisable to leave wet towels, plant pots, wet shampoo bottles etc. in direct, prolongued contact with the microcement.
Cleaning
Microcement surfaces can be cleaned with any pH neutral cleaning products.
Do not clean microcement surfaces with aggressive or descaling products, such as those which contain chlorine, bleach and ammonia as they can damage the sealers.
Aftercare
Use Cemher Floor Protect every 2 -3 months to protect you microcement and to help build up the sealers. This specially designed product is formulated to maintain and protect microcement surfaces by waterproofing, reviving, and safeguarding previously sealed areas. It effectively restores minor scratches in floors without the use of wax, ensuring that the surface remains scratch-free when walked on.
To use, simply dilute 100ml of the product in 7 liters of water and apply it with a mop or cloth. For optimal results, repeat the application every 2 to 3 months.
Fail to Prepare, Prepare to Fail
Surface prep is the most important part of any job. And because microcement is only 3-4mm finished, it’s more important than ever. But don’t worry, we’ve got you covered. Check out our Surface Prep for detailed guidance on preparing a wide range of surfaces for the microcement application.
Surface Prep
Need Help with your Kit?
Installation issues can happen, but we’re here to help. Our comprehensive troubleshooting guides cover common challenges and proven solutions for microcement application.
View Troubleshooting Guides