While we always recommend that our beautiful paving products are installed by an experienced professional we understand our clients are always keen on advice and the best practices pertaining to the paving we supply. As porcelain paving has increased in popularity over the years we’ve seen increasing enquiries from retail and trade clients as to how best to lay it. In this article we’re going to cover how to prepare the area to be paved, what materials should be used in the sub-base and other levels beneath the paving and then how to adhere the outdoor porcelain tiles themselves to the base.
Porcelain Paving Sub-Base
No matter the material you should always lay paving on a properly prepared sub- base and consider where your patio will drain from the outset. Ideally your patio should drain away from the building via a fall of 1:80. This means for every 80 units of distance away from the building your property travels it should drop by 1 unit. If this is not possible suitable drainage slots and groundworks should be installed. Your paving should be laid two brick courses below the damp poof course of the property. The strength of the Sub-Base should come from either a compressed granular material like Type 1 Scalpings or a concrete pad. If you’re going the concrete pad route it’s advisable you lay a compacted sub-base beneath the concrete and have a total depth of around 180mm. If you’re installing the paving using mortar and compacted Type 1 then it’s advisable your compacted base is 100mm or over to provide a solid foundation for the tiles and the foot traffic that will be happening on top of them.
Mortar v Exterior Tile Adhesive
When we’re talking about the layer immediately underneath your porcelain paving it should be noted that you should always lay the tiles on a full mortar bed or prepared concrete screed and never ‘dot and dab’ – this will give the paving tiles and their corresponding joints full support and ensure they will not rock over time. If using mortar you should use a mix of 6 parts sharp sand (grit) to 1 part cement or stronger. It’s usually recommended to use a mix of 4:1 or 5:1. Your mortar bed should be around 30-40mm thick.
If you’re using a full concrete base then we advise you adhere the tiles using a suitable exterior grade tile adhesive. Each adhesive will have it’s own recommendations in terms of the thickness of the bed (refer to the manufacturer’s guidance on this) but it’s possible with some adhesives to lay this bed as thin as 10mm or thinner.
Using a Bond Bridge or SBR
If you are using a concrete base in combination with exterior tile adhesive you may not need to use a bond bridge like SBR. Many tile adhesives do not require you to prime the underside of the slabs with an additional agent – you should however check with the manufacturer before installing. If you are looking to lay your porcelain paving tiles onto a mortar bed then it is absolutely imperative that you use a bond bridge – something like SBR or a ready made priming slurry. Without this your paving will not adhere to the base. You’ll find a bond bridge is recommended with Slate and our Porcelain Tiles but it can be required on other materials – consult your product guide for more information. The bond bridge should be made by mixing SBR with cement until a thick soup-like substance is created. You should then paint this mixture onto the back of the pavers before laying them onto your mortar bed. Be aware that this mixture is extremely effective and very difficult to remove once applied. With this in mind take extra care not to get any on the top surface of your paving material. If you do – wipe it off immediately with a clean wet sponge or cloth. Once in contact with your mortar bed the bonding slurry or bridge will aid adhesion and ensure your paving sticks beautifully and stays there long into the future. Always consult the relevant product guide and a landscape professional if you are in doubt.
Porcelain tile grout is the best way to fill the jointing gaps in our porcelain paving range. The grout we provide is a cement based compound that can be used externally and internally so you can flow joins from inside to outside if that’s what floats your boat. Our grout can fill joins as narrow as 2mm all the way up to big wide 20mm joins. It also contains a fungicide to inhibit the growth of mould and reduce dirt pick-up. Available in 3kg bags and a wide choice of colours to match any of our beautiful porcelain tile options. We stock four different colours of porcelain tile grout to suit different design schemes and tastes. The colour options range from light beige through to grey and black; check our website or better still, pop in to see us for further information and samples. When cure this grout provides a smooth finish that is very slightly granular – similar to the finish of a smooth fine cement.
For most grouts to work efficiently you’ll need a period of 36 hours or so of dry weather and the temperature needs to be above 5C. Ensure that the adhesive the tiles are bedded on is fully dry, as long as it is – you’re ready to get grouting. Our grout is best when mixed with roughly 1 litre of water per 3kg bag however if you’re not using our product you should consult the instructions or the manufacturer. Mix the grout compound with the appropriate amount of water either by hand or with a slow speed paddle until a creamy paste is created. You’ll need to use this mix within one hour and don’t add additional water to improve the workability of the mix – if the paste becomes unworkable, discard it. Using a grouting tool or squeegee work the grout thoroughly into the tile joins. Remove excess grout as you go with a wet cloth – be careful not to use something too fibrous on our outdoor tiles as the anti-slip surface will pick up the fibres. Then use a suitable tool to compact and smooth the grout mix into the joins. After initial hardening of the grout, clean the tile surface once more using a non-fibrous cloth. Work diagonally across the grout lines so as not to disturb them. To aid cleaning you may want to use Stone and Masonry Cleaner, or some other suitable detergent but be careful not to get any into the grout joins before they’ve had a chance to fully set. Protect the paved area from damp for 24 hours after grouting. Once the grout is completely set you may find there is some light grout hazing. This can be removed with a full clean of the area using a product like HG Cement Grout Film Remover.
Luckily, as porcelain is so good at resisting water you do not need to seal porcelain paving at all. So once you’re jointing has set you can sit back and enjoy your lovely new paving!
Hopefully this has inspired you to consider porcelain paving for your project, if you’d like some further inspiration go check out our porcelain paving options.