The Benefits of a Premixed Compound
Premixed urethane grout is a relatively new product to the bathroom home improvement market. It is a handily convenient grout that comes premixed in a bucket ready to use without the hassle of having to pour and mix the dusty dry ingredients of traditional cement and sand based grout with water.
Instead, all you have to do is open the urethane grout bucket, fold in the sand and polyurethane resins together by stirring with a flat edge, and you are ready to grout.
The benefit of using urethane grout over cement based grout is that the urethane grout produces a stronger bond between its sand particles and is color and stain resistant.
Unlike traditional cement based grout which if you add too much water to the mixture can not only reduce the strength of the grout but can also cause discoloration and mottling when the grout dries, urethane grout is premixed for you.
While urethane grout is a great product, there are several issues you should consider when using urethane grout to remodel the tile in your bathroom.
Addressing Common Issues Before Installation
1) Grout shrinkage causes the grout to pull away from the tile which can cause moisture to penetrate into the substrate when tiling your bathroom vanity countertop, backsplash, tile walls or tile floors.
2) Tile movement Grout separating from the tile can be caused by the tile not sticking to the substrate. One way to check to see if this is happening is to take the handle end of a butter knife and tap the ceramic tile and listen to what it sounds like.
Does it sound solid or hollow? Also, you should dig some of the grout out and check if you can lift the tile up off the substrate.
Dealing With Curing Times
Sometimes first time renovators forget that how long your installation is allowed to cure before the grout is applied is very important. An example of this occurring would be if your tile was laid over the original MDF that is typically installed under a Formica countertop. What can happen here is that the underlayment expands when moistened from the thinset mortar.
Sometimes the tile only expands in certain places because the glue used to install the Formica has sealed the MDF, either way, the tile will not seal properly because it will shrink when dry. To see substantial tile separation would almost always indicate a substrate problem causing the tile to move.
Avoiding Stability Complications
The construction of your bathroom countertop, whether plywood or another material and the materials thickness and how many layers are used all come into play when considering the base for your ceramic tiles. The type of tile and even potentially the bonding materials (e.g. Portland-based thinset) you use can all also affect the stability of your bathroom tiles.
Whether you use CBU or mud or a membrane of some sort to ward off moisture seepage, the kind of sealer or grout release applied to the tiles before grouting can all affect your results if not taken into consideration. And make sure you tile at room temperature to avoid grout expansion and shrinkage.
It’s a Good Idea to Follow Instructions
Follow the directions on the urethane grout bucket. Do not add water. It is measured and premixed for a purpose. And do not use a drill to stir the grout, and if you want to hold it together with a flat edge, not whip it into shape.
Be careful what kind of adhesives you use and check to see if it is compatible with the brand of urethane grout that you purchase. Follow best practices: Sanding down Formica and laying tile over the Formica is a practice that is chancy at best.
An interesting thing to note about urethane grout is that color pigments are not added to the mix; instead, it uses colored quartz as its color base, so color consistency is maintained throughout the grout.
Urethane grout has the staining resistance of an Epoxy, and because it is a bit sensitive to temperature fluctuations, they do sell a special water additive for haze cleaning. Use this in moderation because too much may in-adversely affect the grout.
And while going over Formica is probably not going to cause adverse shrinking or separation of the urethane grout if done properly, it is of itself a sometimes unpredictable procedure. Mistakes can sometimes happen; Knowledge is your best defense in these situations to find out as much as you can about the urethane grout product that you are about to use.