About polished concrete

For the how to polish concrete steps jump to the middle of the article.

Multi-Hire have specialised in supplying the trade and consumer polished concrete market for over 10 years.  Multi Hire also have an association with a specialist concrete polishing supplies company called SmartFloor UK who have a dedicated website with helpful information here – www.polishconcrete.co.uk  

Here we have a look at the advantages of polished concrete and everything you need to know on how polish a concrete floor as well as the tools, chemicals and pads that you will need to polish the floor.  For a tailored quote, specific to your project, please get in touch and one of our experts will be more than happy to advise you.  

Advantages of polished concrete  

Polished concrete has become a popular flooring option due to its unique advantages. Here’s a breakdown of the benefits of polished concrete compared to other flooring types: 

1. Durability 

• Long-lasting: Polished concrete is incredibly durable and resistant to wear and tear. It’s highly suitable for areas with high foot traffic, like commercial spaces and warehouses. 
• Resistant to damage: Unlike wood or carpet, it won’t scratch or dent easily. It also resists stains and moisture better than some other flooring materials. 

2. Low Maintenance 

• Easy to clean: Polished concrete floors are non-porous, making them much easier to clean compared to carpets or unsealed concrete. A simple sweep and mop can keep them looking good as new. 
• No waxing or sealing required: Unlike other flooring materials such as hardwood or vinyl, there’s no need to wax or reseal polished concrete regularly, saving both time and money.  Every 1 to 2 years depending on the sealer, this can be extended further by using rejuvenating cleaner.  

3. Cost-Effective 

• Lower installation costs: Compared to hardwood, tile, or even some types of carpet, polished concrete can be more affordable to install, especially if the concrete slab is already in place. 
• Long-term savings: Since it requires little maintenance, you’ll save on cleaning products, repairs, and replacement costs over the years. 

4. Sustainability 

• Eco-friendly: Polished concrete often uses existing concrete slabs, reducing the need for new materials. It’s also a sustainable choice because it doesn’t require the harvesting or manufacturing of new flooring products like carpet or hardwood. 
• Energy-efficient: Polished concrete reflects light better than other flooring types, which can help reduce lighting costs in spaces. 

5. Aesthetic Appeal 

• Modern and sleek look: Polished concrete can achieve a high-gloss, mirror-like finish that’s appealing in modern, minimalist, or industrial designs.  Although aesthetics can’t be guaranteed, if this is the main objective, explore installing an overlay. 
• Customisable: It can be stained, dyed, or combined with decorative aggregates to create a unique look. You can match the flooring to any design style, whether you’re looking for a rustic look or a contemporary, shiny surface. 

6. Improved Indoor Air Quality 

• No allergens: Unlike carpets, that trap dust, dirt, and allergens, polished concrete does not absorb anything, improving air quality by reducing the presence of dust mites, pet dander, and other allergens. 

7. Slip Resistance 

• Safe when polished properly: Polished concrete can be made slip-resistant with the use of a specific sealer or finish, making it safe for both residential and commercial environments.   

8. Versatility 

• Can be used in various environments: Whether for homes, offices, retail stores, or warehouses, polished concrete is adaptable to almost any space and can be used both indoors and outdoors. 
• Compatible with underfloor heating: Polished concrete works well with radiant heating systems, making it a great choice for homes that want to install underfloor heating. 

9. Increased Property Value 

• Appealing to buyers: Polished concrete can add value to your home or commercial property due to its aesthetic appeal, modern look, and low-maintenance nature. 

10. Resistant to Moisture 

• No warping or swelling: Polished concrete doesn’t swell or warp with exposure to moisture like wood or laminate floors might. This makes it especially great for basements, bathrooms, and kitchens. 

Comparing Polished Concrete to Other Flooring Types: 

Polished Concrete vs. Hardwood: 

• Cost: Hardwood is typically more expensive to install, requiring more maintenance (sanding, refinishing, and sealing) over time. 
• Durability: Hardwood can scratch and dent easily; polished concrete is more resistant to damage. 
• Maintenance: Hardwood requires regular refinishing and cleaning, not so polished concrete. 
• Polished Concrete vs. Carpet: 
• Durability: Carpet wears out over time and stains easily, while polished concrete is durable and stain resistant. 
• Maintenance: Carpet requires frequent cleaning, deep cleaning, and sometimes replacement; polished concrete just needs occasional mopping. 
• Air Quality: Carpet can trap allergens and dust, but polished concrete helps improve indoor air quality. 
• Polished Concrete vs Ceramic Tiles: 
• Cost: Polished concrete is generally cheaper than high-end tiles, like marble or granite, and requires less maintenance. 
• Durability: Tiles can crack, especially in areas with high foot traffic. Polished concrete is less prone to cracks. 
• Cleaning: Both are easy to clean, but tiles can develop grout lines that can be difficult to maintain, whereas polished concrete has a seamless surface. 

In conclusion, polished concrete stands out as a cost-effective, durable, low-maintenance, and eco-friendly flooring choice that offers an aesthetic modern appeal. It’s a great option for a variety of spaces, whether residential or commercial. 

How to polish concrete. 

Polishing concrete is a multi-step process that can give your floors a smooth, shiny, and durable finish. For beginners, here’s a simple guide on how to polish concrete effectively: 

How to polish concrete: Materials and Tools You’ll Need: 

1. Concrete grinder/polisher  

415-v machines are a minimum 3 x quicker than 110-v because of the difference in the weight and power of the machines.  If the floor only needs a light grind, then you may be able to use the HTC 420.  For most jobs, we recommend a minimum of the Husqvarna T5; for medium sized jobs the Husqvarna T6 and large jobs the Husqvarna X8.  If you don’t have 415v the correct power, we can supply a generator. 

2. Diamond metal polishing pads  

25g metal – start with this if the floor is uneven or if you want aggregate exposure. 

50g metal – For either the second stage or to begin the process removing the 25g scratch marks, or the first stage of removing the top of the concrete surface.  

100g ceramics – A transitional shoe that helps move from metals to plastics.  Most scratches should be removed from the concrete after this stage. 

3. Resin polishing tools 

Fenix pads – Very good polishing pads.   

SF pads – Premium polishing pads help to bring the gloss levels up quicker. 

200g – The first step classed as polishing, should start to show a bit of a shine upon completion of this stage.  

400g – Will have a great shine after this stage but not too much.  

800/1500/3000g – Keep adding more gloss levels, increasing the floor shine.  

If you are unsure at what stage you want to stop at, we can send multiple sets on sale or return; only pay for the tooling actually used. 

4. Chemicals  

Concrete densifier – Concrete floors that are not being coated need to be densified.  Jump to the end of the blog for more information on concrete densifiers. The most popular all-rounder is the 3DSF or 3DHS, get in touch for a specific recommendation.  

Grout (optional) – For filling small holes and pin holes, have a look at the Husqvarna GM3000.  This is applied by reducing the vacuum power spraying on the floor and then grinding with the 50g shoes.  The dust from the floor mixes with the GM3000 and fills the holes.  

For anything bigger look at the PG7k which can be trowelled or spread using a spatula.  You then grind it flat using the 50g shoes. 

Sealer – If the desired effect is a matt/satin finish then look at an impregnating sealer like SR2 or SR2wb.  This will give the floor protection but keeps the aesthetics of the floor.  

If it’s a high gloss finish then the 3DSP is a topical sealer, this offers a better protection.  Once applied you will have to use a burnisher.   Both sealers are applied by spraying the surface and wiping with a microfibre mop.  

5. Vacuum Dust Control Unit 

Connects to the machine to reduce airborne dust.  After each grinding stage the floor has to be fully vacuumed to remove loose dust on the floor.   

The 420 requires the 110v cfm. 

The T5 requires the S3 Longopac. 

The T6 requires the S3 Longopac or D60. 

The X8 requires the D80. 

6. Dust mask, ear defenders, boots and safety goggles 
7. Floor buffer  

This can help to bring up the floor at the final stage, it’s needed if using the 3DSP sealer.  We hire 240v burnishers and battery burnishers. 

How to polish concrete: step by step: 

1. Preparation 

• Clean the concrete floor: Sweep and mop to remove any debris and dust. 
• Fix cracks or holes: Use a concrete filler or patching compound to repair any imperfections like PG7K.  For cracks you can use Metzger McGuires Refloor. 
• Protect the area: Cover nearby walls, baseboards and other surfaces to avoid damage. 

2. Grinding (Coarse Grit) 

• Start with coarse diamond grinding shoes (either 25g or 50g). 
• Attach the shoes to the concrete grinder by fixing them onto the tool holder and knocking them on with a hammer. For this stage, the machine should be set at a slowish speed, normally, say, speed 2-3 depending on the grinder.  Push the grinder at a slow walking pace north to south across the whole floor. When finished, then go east to west to ensure the whole floor has been ground. 
• Overlap each pass slightly to ensure uniform coverage. Keep the grinder moving to avoid gouging the surface. 
• Use a vacuum to regularly remove dust and debris as you work. 

3. Smooth Out the Surface (Medium Grit) 

• After the first grind, switch to a medium-grit pad (50g). 
• Grind the floor again to remove scratches from the previous grind and smooth out the surface further. 
• Continue vacuuming regularly to keep the surface clean. 
• This is where you can now apply the grout if required. 
• You will now have to attach Velcro pad holders and stick on the 3” Velcro backed ceramic tools. 

4. Polish the Surface (Fine Grit) 

• Densify at this stage (apply it according to the manufacturer’s instructions). It helps to harden the concrete and prepare it for that shiny finish. 
• Swap the tool holders again to the polishing pad holders. 
• Move to a fine-grit pad (200g) to begin polishing. 

Keep polishing with the fine grit pad until the surface begins to shine. Make sure to keep the grinder moving to aavoid uneven areas. 

5. Final Polish 

• For the final step, use an extra-fine polishing pad (400-3000 grit).  
• Now apply the sealer and burnish, if required. 

Tips for Beginners: 

• Practice first: If you’re not familiar with a grinder, practice on a smaller or less important area first. 
• Go slow and steady: Don’t rush through the grinding process. Properly grinding and polishing takes time, but the results are worthwhile. 
• Wear protective gear: Concrete dust can be harmful to your lungs, so always wear a dust mask and goggles. 
• Use a vacuum frequently: This keeps the surface clean and reduces the risk of debris scratching the floor. 

By following these steps and being patient, you’ll be able to polish your concrete floor successfully, even as a beginner! 

How Concrete Densifier Works: 

1. Chemical Reaction: The densifier contains silicate compounds (like sodium or potassium silicate) that penetrate the concrete surface and chemically react with the calcium hydroxide in the concrete. This reaction forms calcium silicate hydrate (CSH), which fills in the pores of the concrete and makes the surface harder and denser. 
2. Enhanced Surface Strength: By filling in the pores and tightening the surface, the concrete strengthened and more resistant to abrasion, and less likely to absorb water, oils, or stains. 
3. Improved Polish ability: When used during the polishing process, densifiers help to harden the surface, making it easier to achieve a high-gloss, shiny finish. This also makes the polishing process more efficient. 

Benefits of Using a Concrete Densifier: 

1. Increased Hardness and Durability: It strengthens the surface, making it more resistant to damage, wear and cracking. 
2. Enhanced Stain Resistance: A densified surface is less porous, making it harder for liquids to penetrate and stain the concrete. 
3. Improved Polishing: Densifiers enhance the polish and shine of concrete, making it easier to achieve a smooth and reflective surface. 
4. Reduced Dusting: It helps reduce the dusting effect (the fine powder that comes off concrete when it deteriorates) by solidifying the surface. 
5. Moisture Resistance: It can make the concrete more resistant to moisture penetration, reducing the risk of water damage over time. 
6. Eco-Friendly: Concrete densifiers are usually low in VOCs (volatile organic compounds), making them an environmentally friendly choice. 

How to Apply Concrete Densifier: 

1. Clean the Surface: Ensure the surface is clean and free of debris, dirt, or old coatings. 
2. Apply the Densifier: Using a sprayer or a roller, apply the densifier evenly over the concrete surface. 
3. Allow It to Absorb: Let the densifier absorb into the concrete. Typically, it will take about 20-30 minutes. 
4. Polishing: Once the densifier has dried, usually within an hour or so, you can begin the grinding or polishing process. 

Conclusion: 

A concrete densifier is a key product in concrete polishing; strengthening the surface to make it more durable, resistant to wear, and aesthetically appealing. It’s particularly useful for commercial or high-traffic areas where concrete needs extra strength and longevity. 

How to choose your concrete sealer 

There are several types of polished concrete sealers available, each providing different levels of protection, finish, and durability for concrete surfaces. The choice of sealer depends on the look you want to achieve and the type of protection you need. Here’s a rundown of the main types of concrete sealers commonly used with polished concrete: 

1. Penetrating Sealers (Chemical Hardeners) 

• Description: These sealers penetrate deep into the concrete, reacting with the minerals in the concrete to form a hardened barrier. They do not sit on top of the surface like other sealers but chemically bond with the concrete to enhance its durability and moisture resistance. 
• Types:  
• Silicate-based sealers (most common): These create a hard surface by reacting with calcium hydroxide in the concrete, filling the pores and creating a dense, durable surface. 
• Siliconate-based sealers: Similar to silicates, with even greater water-repellent properties. 
• Advantages:  
• Long-lasting and durable. 
• Provides moisture resistance and stain protection. 
• Low maintenance and doesn’t change the look of the concrete. 
• Best for: Commercial floors, industrial spaces, and areas where durability and stain resistance are crucial. 

2. Film-forming Sealers 

• Description: These create a protective layer on the surface of the concrete, forming a “film” that shields it from damage. They are available in various finishes, from matt to glossy. 
• Types:  
• Polyurethane Sealers: These provide a more durable, hard finish and are more resistant to abrasion and chemicals than acrylics. They are ideal for high-traffic areas. 
• Topical sealer : Creates a barrier on the surface of the floor. 
• Advantages:  
• Provides an attractive finish with a glossy appearance. 
• Protects against stains, spills, and abrasions. 
• Easier to maintain and clean than unsealed concrete. 
• Best for: Residential spaces, retail, and decorative applications where appearance and protection are key. 

4. Water-based Sealers 

• Description: Water-based sealers are an environmentally friendly option, offering a protective layer without harsh chemicals or solvents. They are less toxic and emit fewer odours than solvent-based options. 
• Advantages:  
• Low VOCs, making them more environmentally friendly and safer to use indoors. 
• Can provide a matt, satin or glossy finish. 
• Easy to clean up with water. 
• Best for: Residential or commercial spaces where low-VOC products are a priority, and for those looking for a more natural look. 

5. Solvent-based Sealers 

• Description: Solvent-based sealers are durable, protective coatings that create a strong, long-lasting finish. These sealers offer excellent stain resistance and provide a glossy, durable finish. 
• Advantages:  
• Provides a glossy, wet look. 
• Offers high resistance to water, stains, and chemicals. 
• More durable than water-based sealers and can handle heavy foot traffic. 
• Best for: High-traffic areas, industrial spaces, or outdoor concrete surfaces that need a tough, long-lasting finish. 

6. Hybrid Sealers 

• Description: Hybrid sealers combine the benefits of both penetrating and film-forming technologies. They penetrate the surface for added durability but also form a protective film on the surface for added shine and protection. 
• Advantages:  
• Offers the best of both worlds: moisture and stain resistance from penetrating sealers, combined with the protective finish of film-forming sealers. 
• Provides an excellent balance of durability and aesthetics. 
• Best for: Areas where both protection and aesthetics are important, such as commercial and residential spaces with high foot traffic. 

Summary of Key Sealer Types: 

Choosing the Right Concrete Sealer: 

• For high-traffic commercial spaces: Film forming, penetrating or solvent based sealers are excellent choices for their durability and protection. 
• For residential or decorative applications: Hybrid or water-based sealers provide attractive finishes while being safer and easier to maintain. 
• For outdoor applications: Solvent-based or Hybrid sealers offer UV protection and high resistance to the elements. 

Each sealer offers different benefits, so the choice depends on the level of protection you need, the type of finish you’re looking for, and the environment in which the concrete will be exposed.