The grout on your bathroom floor has become discoloured and dirty-looking, and black spots tell you that microbial growth has taken hold in the joints. Luckily, the hardware store has a grout pen for just a few euros — apply it to the dirty grout and the bathroom will look brand new! Or will it?
It sounds too good to be true — and it is. In reality, a grout pen may actually make things worse, which is why you shouldn't use one to paint bathroom floor grout or any grout in wet rooms.
Grout pens are not suitable for wet rooms
Grout pens are a fine tool for touching up wall tile grout in dry rooms. For example, kitchen wall tile grout can be neatly refreshed with a grout pen. However, grout pens are not suitable for wet room or floor tile grout.
Tile grout always wears during normal use — there's no getting around this. If bathroom tile grout is painted with a grout pen, the paint wears off relatively quickly, leaving the grout looking even worse than before. The situation is very similar to using tile paint.
Wear is particularly fast on floor surfaces and in damp environments. The bathroom floor is a textbook example of a surface where you should never try to refresh the grout with a grout pen.
I already bought a grout pen — is there any harm in using it?
The fact that you're reading this suggests your problem is dirty, discoloured grout in wet rooms. Perhaps microbial growth has already attached to the joints. Even if home cleaning no longer does the trick, professional products and techniques can get any grout clean.
Before you start painting over the stains with a grout pen, ask a professional to visit and assess the condition of the grout. With 99% certainty, professional grout cleaning will do the job.
Changing grout colour without a grout pen
If you want to change the colour of your bathroom grout, that's also possible without a grout pen — through grout replacement, which is a truly durable solution. First, a suitable amount of old grout is ground away, and then new grout is applied. Grout replacement is considerably more labour-intensive and more expensive than a grout pen, but the result is also long-lasting.
Ask about grout pen use before buying a home
Grout pen use can become a problem when buying a new home. It's unfortunately common for all the grout in a bathroom to be treated with a grout pen during pre-sale staging. This makes the grout look neat just long enough to find a buyer.
When the home finds new occupants and the bathroom starts being used again, the grim truth is revealed and the discolouration hidden by the grout pen resurfaces. It's therefore not a bad idea to ask the estate agent or owner at a viewing whether a grout pen has been used on the bathroom grout.
