Although Crystal varnish is not as popular as it was at a time when it accounted for almost all sales, it’s still a choice some homeowners are making when comes the time to renovate their floor. But what should you know about this unloved floor varnish product?

What you need to know about Crystal varnish

Crystal varnish in a nutshell

Crystal varnish is a vitrifying coating made from urethane resin or polyurethane and solvent, the latter being made from a petrochemical process. It is often used because of the glossy, shiny appearance it provides to rough or freshly sanded floors.

We generally appreciate the really good sustainability of this type of varnish, with a lifespan that can extend up to 25 years. We even compare its resistance with that of water-based varnishes, which are doing very well in this area.

Also, let’s not forget to mention that it’s a low-cost product, which also contributes to his place among the favourites. We must also point out that this type of varnish is available in light or dark versions, depending on the desired result.

The precautions to take during the application process

Since this varnish dries under the effect of moisture, it must be applied in an environment where humidity is located between 50% and 80%. In doing so, windows must stay closed as the floor is being varnished.

Moreover, since it releases certain chemical compounds into the air, it is recommended to leave your residence during its application and even over the next few days. More importantly, it is also important not to leave food in the house to avoid any contamination (except vacuum-sealed food).

Also, if you ever decide to sand your floors and they are covered with a Crystal varnish, it’s strongly suggested to hire a contractor who uses a sander that is equipped with a suction system. This way, you can avoid the dispersion of harmful particles in the air. After the varnishing, your house must also be ventilated for several hours. Given this need, it is logically unwise to carry out this type of project during winter.

Let us continue on this point by stating that people with respiratory problems may be inconvenienced for several weeks following the application of the varnish. This is why individuals with this type of health problem should ideally turn to another option.

Finally, you should know that if you want to change the colour of your walls soon, it’s best to do so before applying the varnish. The reason for this very essential recommendation is that toxic fumes from the varnish will turn the freshly applied paint yellow.

Thinking of renovating your floor soon? Check out our Flooring Renovation Guide to find all the information you need to make your project a success!

The cleaning and maintenance of the floor

To clean a floor with a Crystal varnish finish, it’s better to avoid the use of hot water, ammonia, wax, hot water and vinegar mixtures as well as detergents.

Also, to preserve the appearance of your floor, it’s best not to walk on it with boots during winter. Calcium will eventually damage the varnish and it will lose its luster. You also need to avoid the use of a steam mop and the installation of plants on the ground. Moisture emanating from it will cause dark circles to appear on the ground.

Now that we’ve outlined the practices to avoid if you want to keep your floor in good condition, it’s still necessary to reserve a moment to put forward the right way to maintain a floor that has been finished with a Crystal varnish. In this regard, it’s best to use a wet mop in a mixture of lukewarm water and wood-floor soap, while making sure to wring it out before using it.

Crystal varnish and its impact on the environment

You may be aware of the bad reputation that this type of varnish used to have in the past. Indeed, the Crystal varnishes once available on the shelves of renovation stores released a very large amount of volatile organic compounds into the environment. From now on, all varnishes must comply with standards issued under the Volatile Organic Compounds Act (450gCOV/L), which has been in effect since September 9, 2012.

While the new products on sale have a more modest environmental impact on the ozone layer and now contribute much less to smog production, they are still harmful to humans, hence the need to monitor recommendations previously issued.

The disadvantages

Apart from its toxic nature, which we have just mentioned, we must keep in mind that Crystal varnish will tend to turn yellow over time. This propensity for yellowing will be more evident when 15 years and more have passed since the application, as the following illustration shows.

On some floors, the resin may become particularly hard, which will have the effect of cementing the boards together. This process is known as the ''block effect''.

Warning for the purchase of your varnish

When buying your varnish, don't be fooled by those who display the words ''Crystal'' or ''Crystalex''. It is not a Crystal varnish in the true sense of the word and its durability is not as good as the one offered by the original product.

Do you need advice regarding choosing a material for your new wooden floor? Check out our article What’s the best type of wood for flooring?