Cement Based Tile Adhesive
Also known as Thinset adhesive, powder adhesive.
Cement based tile adhesive is typically available in 20kg per unit bags and is available in a few different types. Cement based tile adhesives are of a high specification and can be used on wall and floor tile installations and also with the full spectrum of different tile types. Cement by its nature is a water resistant material, so cement based tile adhesive can be used in frequently wet areas or even in total immersion of water (such as swimming pools) Also, most cement adhesives can be used externally and are frost resistant, making them suitable for fixing tiles to a garden path, patio or a porch area.
Cement cures by way of a hydraulic nature, which in basic terms means that it does not rely on air to cure it. You can use cement based tile adhesive to fix large format tiles and also tiles with a low porosity such as porcelain and glass tiles without having concerns that it will not cure in reasonable time. Cement adhesives can be built up to a certain degree also, where walls or floors may not be as flat as expected or the tiles are particularly large. Depending on the product, cement based adhesives can be used up to 6-8mm thick generally and up to 12mm thickness in limited areas. There are specialist adhesives which can be used at a thickness of 25mm which are designed for the very large format tiles that are becoming fashionable these days, or the slate tiles you can purchase that are uncalibrated and can vary in thickness wildly. Although cement based tile adhesive has a universal and broad usability factor, one important fact is that if you are tiling onto a gypsum (plaster or plasterboard) substrate, then you must prime the plaster first, this is very important and if ignored can lead to a failure. Please read our notes on priming to understand what to use.
Although cement based adhesive has hydraulic curing, you will need to use a cement based tile adhesive with some degree of polymer (ie. flexibility) to fix your porcelain or glass tiles or other low porsosity tiles. This is because although the adhesive will cure behind these tiles, it cannot cure into the body of the tile and create a good anchor (bond) with the tile. The inclusion of polymer acts basically like glue and sticks to the tile and forms a strong bond. Money saving tip: There are some cement based tile adhesives specially formulated for porcelain tiles which are cheaper than their flexible alternatives and the packaging will reflect it’s suitability. basically these adhesives have a small amount of polymer which is enough to bond to porcelain without being classed as flexible.
Rapidset cement based tile adhesive
Rapidset cement bassed tile adhesives typically have a curing time of three hours approximately. This makes it suitable for fast track installations where the need to finish the job quickly is paramount. The trade off with having a rapid setting cement based tile adhesive is that once you mix the adhesive with water in a bucket, you must use it within 30-45 minutes (this is known as pot life) If it is a particularly hot day it is recommended to revert to a slower setting adhesive as you will find that it can become unusable and be curing in the bucket almost immediately. For these reasons it is recommended that Rapidset cement adhesive is used by professional tilers only, as they can make use of it’s fast setting nature to finish an installation quicker. Obviously there may be times when a non professional will want to use a rapid setting adhesive eg. Family home with only one bathroom, where it will not be possible to stay off the installation overnight until it cures. If you are not experienced and wish to use a rapidset product then please only mix small amount at a time. Although cement based adhesive is suitable for wall or floor tile installations, Rapidset is mostly used only on the floor due to the requirement to be able to walk on the floor quickly.
Standard setting cement adhesive
Standard setting cement adhesive will typically have a curing time of 16-24 hours. The pot life is extended to 4-5 hours as opposed to Rapidset which is 30-45 minutes, this makes it more suitable for the DIY tiler or for wall tile installations where you tend to have more cutting of tiles and the importance of getting the installation into service is not so great.
What colour cement based tile adhesive should I buy?
Cement adhesives are available in grey (cement colour) or white. White will cost significantly more than the gre due to the extra cost of the white cement in the products. As a general rule, if you are tiling a wall or floor with a solid bodied tile such as ceramic, porcelain, vitrified, terracotta, quarry or dark natural stone tiles then you would use a grey cement based tile adhesive. If you are grouting with a lighter coloured grout such as white, Ivory, cream etc and the tile is relatively thin, you may want to change to a white adhesive to avoid the risk of the adhesive discolouring the grout.
If you are wall tiling and using the standard white grout, you would select a white adhesive. The most important requirement comes when you are tiling with a light coloured natural stone such as marble which is translucent by nature. If you are using light coloured stone then make sure you select white adhesive as the grey can stain your beautiful new marble tiles and shade them much darker. When in doubt use a white adhesive or seek advice from your retailer or tiler.
Flexible or Non Flexible cement based tile adhesive?
As to whether you need a flexible or non flexible cement based tile adhesive will depend on several factors, obviously flexible cement based tile adhesive will cost more as the polymers that make a product flexible are the most expensive ingredient. The following installations will require a flexible adhesive.
False or stud type wall tiling (plasterboard or timber walls)
Tiling onto a wooden floor
Fixing a glass or porcelain tile
Tiling onto low porosity substrates
Tiling onto underfloor or undertile heating systems
Tiling onto suspended floors or balconies
Pro’s of Using a cement based tile adhesive
Cures hydraulically, more control over drying time. (Even when used over tanking systems)
Can use on full spectrum of tile types, truly universal.
Choice of rapidset cement based tile adhesive or standard.
Can be used on larger format tiles and built up on uneven surfaces
Most can be used externally, frost resistance.
Cement by nature is always water resistant and can be used in total immersion
White or grey in colour to suit natural stone fixing or standard tiles
Very strong bond with tile and substrate (subject to correct selection)
More control over the material due to mixing yourself.
Con’s of using a cement based tile adhesive
Must prime Gypsum (plaster) surfaces before using cement based tile adhesive
Rapidset can become impossible to use in hot weather
Have to mix the product before use.
Mixing can be a messy process
This guide will hopefully help you to make the right decision when it comes to selecting your tile adhesive for any project you may undertake. Although cement based tile adhesive may seem a mundane, unimportant and unlikely topic for an article, you can be rest assured that the failures that have occurred due to lack of knowledge have proved to be very costly, I want to save you this cost and inconvenience.
My name is Wayne Phipps and I have worked in the tiling industry for 25 years in various technical and sales capacities. Allow me to inform you of all things tiling from my experiences and you may avoid the costly mistakes made everyday by people time after time when undertaking a tiling project.