Mistakes Homeowners Make with Porcelain Slabs (and How to Avoid Them)

Introduction

Porcelain paving is becoming an increasingly popular choice for homeowners looking to upgrade their patios, driveways, and garden paths. Known for its sleek look, durability, and low maintenance, porcelain paving is often seen as a premium solution for modern outdoor spaces. However, despite its advantages, many homeowners unknowingly make key mistakes that can lead to long-term problems. In this guide, we’ll walk you through five of the most common errors people make when dealing with porcelain slabs — and more importantly, how to avoid them to ensure your outdoor investment stands the test of time.

Choosing the Wrong Thickness of Porcelain Slabs

One of the most common mistakes homeowners make is selecting indoor porcelain tiles instead of outdoor-grade slabs. While the two may look similar, they differ significantly in terms of thickness and strength. Indoor porcelain is usually around 8 to 10 mm thick, which is not designed to handle the weight and exposure of outdoor use. When installed outside, these thinner tiles are more likely to crack, especially under the pressure of patio furniture, foot traffic, or changing weather conditions. To avoid this, always choose porcelain paving slabs that are at least 20 mm thick. These are specifically manufactured for outdoor use, offering improved durability, slip resistance, and weather resistance — all essential for a long-lasting, low-maintenance patio.

Improper Base Preparation

Another major error is neglecting proper ground preparation before laying the Porcelain slabs. Many homeowners assume that a simple sand or gravel base, commonly used for natural stone paving, will suffice. However, porcelain is a dense, non-porous material that doesn’t bond well unless laid on a solid, properly prepared foundation. Without the right base, slabs can shift over time or develop uneven surfaces. The correct method involves creating a stable sub-base using compacted MOT Type 1 material, followed by a full mortar or concrete bed. Additionally, applying a slurry primer to the back of each porcelain slab before laying is essential. This primer ensures a strong bond between the slab and the bedding layer, preventing lifting or movement over time.

Skipping or Using the Wrong Jointing Compound

Because porcelain slabs are non-porous and manufactured to precise dimensions, the jointing process is more important than with natural stone or concrete. Unfortunately, many homeowners either skip jointing altogether or use inappropriate materials such as dry sand or standard mortar. This leads to weak joints, which are prone to cracking, weed growth, or water ingress. To avoid these issues, it’s best to use a high-quality jointing compound designed specifically for porcelain paving. These products offer strong, flexible joints that resist weathering and help maintain the slab alignment over time. Additionally, it’s important to ensure joints are narrow — typically between 3 and 5 mm — and properly filled to allow for slight movement and efficient drainage.

Neglecting Drainage Considerations

A common oversight in porcelain paving installations is ignoring proper drainage planning. Unlike natural stone, porcelain is completely non-porous, meaning water cannot soak through it. Without a well-designed drainage strategy, water tends to pool on the surface or run off in unintended directions. This can create safety hazards, slippery areas, or long-term damage if water seeps underneath the slabs. To prevent these problems, make sure your paved area is installed with a gentle slope, ideally at a fall ratio of 1:80, guiding water away from buildings and towards drains. If needed, additional drainage channels or soakaways can be installed to manage water effectively and prevent build-up.

Using Harsh Chemicals or Pressure Washers for Cleaning

Finally, while porcelain paving is known for being low-maintenance, that doesn’t mean it's indestructible. Some homeowners make the mistake of using bleach, acidic cleaners, or high-powered pressure washers to clean their slabs. While these methods may offer quick results, they can damage the surface of the porcelain and degrade the jointing compound. Instead, opt for pH-neutral cleaners that are safe for porcelain surfaces. For regular cleaning, a garden hose or a soft pressure washer setting — with the nozzle kept at a reasonable distance — is usually more than sufficient. Routine sweeping also helps prevent the build-up of debris, moss, and algae, keeping your patio looking fresh year-round.

Conclusion

Porcelain paving is an excellent way to elevate your outdoor space with a modern, durable, and stylish surface. However, even the best materials can underperform if they’re installed or maintained incorrectly. By avoiding these five common mistakes — from choosing the right thickness and preparing the base properly to using the correct jointing methods, planning for drainage, and cleaning with care — homeowners can ensure their porcelain slabs look beautiful and function flawlessly for many years. Whether you're starting a DIY project or hiring professionals, being informed is the first step to getting it right.