For a long time, Indian sandstone was the number one choice for homeowners across the UK. The product emerged in the mid-1990s and gained popularity overnight. For Landscapers, Indian sandstone was much cheaper and easier to work with than the British equivalent, like Yorkstone paving. At the time, my dad was buying it by the freight container load. Indian sandstone opened up a variety of different colours and mixed sizes that people couldn’t get enough of. There were, however, some teething problems. Landscapers up to this point had been accustomed to laying slabs on spots of mortar. It’s likely that if your patio is more than thirty years old, it’s probably laid on spots. But if you laid this new sandstone on spots, two things would happen. Firstly, the slab would not bond to the mortar like a concrete slab would. In fact, soon after being laid, you could lift them back up with your hands. Moisture would seep between the slab and mortar, causing it to become unattached. Secondly, the spots would show up on the topside of the slabs like strange spotty shadows. There was a time when contractors were continually called back to fix these problems, and it took a little while to eradicate these teething problems. People soon figured out that the slabs were very porous and absorbed moisture like a sponge. Landscapers across the land had to find a way to seal the slab from moisture and stick it to the mortar.

Behold the invention of primer. There are many kinds of primers with many methods of application. A mixture of SBR, cement powder and water is common. You can also just use cement powder and water, which acts like tanking slurry. You would paste the back of each slab before being laid. This made it stick like glue and create a moisture barrier between the slab and the mortar. Additionally, slabs started being laid on full mortar beds. This ensured there was full contact with the slab and kept moisture pockets to a minimum. A full bed also strengthened the patio and minimised slab detachment and subsidence. 

Now that the issues under the slabs had been solved, new problems arose in the form of black mould and cracked pointing. The mould was due to the water hanging around on the slab surface. In a country where it’s warm and dry, these slabs would take decades to discolour. However, we live in Great Britain, and it rains here more than anywhere, it seems, in the world. The water soaks into the stone, and the sun doesn’t get a chance to dry it out before it turns into fungal growth. The moisture that was retained within the slab would freeze and disrupt the pointing joints, causing cracking. This also caused layers of stone to detach from the surface of the slab, which destroyed many patios. Again, things needed to change. 

Up until the late 1990s, joints in patios were filled in with mortar. It was a long and messy job that stained the porous material like mud on a white T-shirt. A new way of pointing was needed, and the answer came in the form of resin jointing compound. It was essentially resin mixed sand and other binding agents. It came in a vacuum-sealed bag and started going off as soon as you opened it. But the amazing thing about it was that you could spread it all over the slab whilst filling the joints in, and it wouldn’t stain the slab, and it was much quicker. The next and final step was to seal the slab from the topside with liquid resin. So now, you can have a beautiful sandstone patio that is strong and long-lasting. Then along came its arch-rival – Porcelain.

Indian sandstone had been the obvious choice since the turn of the century, but now, a rival was about to pave a new way for Great Britain. People liked the look of Indian sandstone, but they still had a few lingering issues, like keeping the patio looking good after a few winters. Not all landscapers were following the rules, and patios were still turning black and coming loose. Also, a natural product like this will never be a perfectly flat surface, and tables still need propping up to keep them level. People were still looking for that ultimate finish. Porcelain had been used in the UK, but only in very posh houses shown on Grand Designs. It was traditionally imported from places like Spain and Italy, which was very expensive. However, places like India and China figured that they would have a go at making porcelain, and it turns out, they were blinking good at it. The new boys on the block started making slabs faster and cheaper than ever before. Then something happened that I never expected. Somehow, the ‘cheapest paving ever’ (sandstone) and the ‘most expensive paving ever’ (Porcelain) had ended up equal in price. Bear in mind that in the year 2000, sandstone was £15 per square meter, and porcelain was £45 per square meter. It was a monumental shift in supply and demand, and is one I’ve been directly involved in over the past 20 years. Today, the average costs for both types are around £30 per square meter, with concrete products not far behind. Bizarrely, you can now quote a blanket price (£35 per square meter) and the homeowners can select pretty much any slab they want.

So why choose porcelain?

It’s flat, it’s non-porous, and it comes in a range of colours. What’s not to like? Well, there are again some teething issues. Much like the sandstone, it needs to be primed and laid on full beds. Otherwise, you will get adhesive and cavity issues. If you lay them on spots and then drop a large food bowl on the patio, you’ll probably crack the slab. Being such a dense, non-porous material comes with its flaws. It’s like dealing with glass as a material, and it is notoriously hard to cut. I remember getting to grips with porcelain, and it was not easy. The slab would chip and crack very easily, and cutting blades didn’t stand up to the task. Large cutting tables and super-strong blades were quickly flying off the shelves in builders’ merchants as the demand for porcelain rose. I waited three months for a cutting blade once, and it cost me £400. A new outdoor grouting method has been perfected that makes the small joints in porcelain look flawless. The small joints have a lower risk of letting water get under the slab as well. But now that all the installation processes are nailed, it comes down to suitability.

If you want a modern, contemporary look with low maintenance. Porcelain is the best.

If you want a more classic or countryside look. Sandstone is the best. (just make sure you clean it and reseal it once a year)

By Rick Labbẽ – GardenWise founder

Design  –  Insight  –  Guidance