What proper re-grouting is all about. What is 'cowboy-regrouting' and where it leads?

Why do we seal grout?

Tile grout is a very porous material. Conventional cleaning methods can do more harm than good in a long run. Over time grout body accumulates dirt and chemicals from waste water. This can lead to permanent grout or even tile discolouration. The only way to keep a tiling job sound and safe is to seal the grout. Once the grout has protective coat it becomes stain-proof.

Can we seal grout ourselves?

It all depends on age of the grout, your skills and the type of sealer you want to use. A “go ahead” scenario would look as follows:
a/ grout has been finished by tilers 3 days ago an no one since was walking on tiled floors
b/ you want to use either penetrating sealer or clear grout sealer (providing the tiles are fully glazed, not matt)
c/ you are a handy person with some technical IQ (trust me that following instructions from a label on a bottle is just not good enough).
Fully glazed ceramic tiles are a must for a newbie. The trick is to let the sealer dwell for couple of minutes on the grout and than wipe off ALL the excess sealer from the tiles. Wet spots left without wiping will become white, powdery stains when sealer is dry. The mock up can be corrected though. The stains can be cleaned with product called Nano Scrub (similar thing to Jiff or Cut’n’Polish). Nano scrub can be obtained from most tiling shops.
Things would look even less pretty if you got tempted to use clear grout sealer on matt tiles. It is almost guaranteed that all tile edges would become shinny. Than… Well, call restorers before you do more damage.
Other than that… By all means, seal the grout! That’s the only way to preserve it’s look.


Can we seal old grout ourselves?

Not, if you want to avoid a fat bill from tile restoration specialist that you WILL end up calling. Cleaning and sealing of grout is relatively cheap providing there are NO EXISTING SEALER COATS involved. Failing sealer coat cannot be painted over (clean or not). Old coat has to go! The only way to remove it is stripping (same concept as paint stripping). The process is slow and painful. Some sealers start to behave like a chewing gum after reaction with stripper. They clog a scrubbing brush after several movements. Cleaning even dirtiest grout is nothing in comparison to some sealers removal.
Properly applied epoxy grout sealer can and should last up to 15 years. Yet people are calling me more and more often asking for my help after they paid someone else for grout restoration less than a year ago!!!
The key to successful sealing is material preparation. There is no such thing as cleaning grout (or tiles) with a scrubbing brush if we want to apply any sealers. Only extraction method prevents waste water from being absorbed by a substrate we clean. This can be done only with specialized equipment.



The only instance when regrouting is necessary is if the existing grout cracks and falls out. Grout does not crack without a reason. And before this reason is clearly identified and removed, no regrouting should take place. The worst thing that can happen is grouting on top of existing grout. It is done very often by amateurs and cowboy-tilers. Unfortunately a mock up of this sort can stay in tact for quite a while and if done properly, it is really hard to identify. Nonetheless it is destined to fail. Such a job has to be completely regrouted. Regrouting means a REPLACEMENT not smearing new grout on top of existing one. Of course regrouting itself does not solve any problems. If we install same type of grout it will crack again unless we remove the cause of cracking and use much stronger grout, often epoxy.
First thing to do when you see grout cracking is to call a tiler. Grout does not crack because it’s old. It’s not a geriatric condition. There’s quite a few reasons for failing grout. Usually customers think that a tiler used a non-flexible grout. This one always makes me giggle… Grout is not a chewing gum. Grout can be called a lot of things but flexible is last of them (absolutely ignore if the label on a bag says otherwise). Half the time cracking grout has nothing to do with tiling. Very often it is caused by wrong architectural design: floor joist too far apart, using wood where metal joist should be used, wrong grade of floor boards, wrong tiling materials specified by others. Tiling straight over butynol  is another common mistake enforced usually by architects or builders. That is precisely why most old decks in Auckland suffer from efflorescence and CRACKS IN GROUT. All caused by usage of adhesives that should never be used in wet areas as ordinary tiling adhesive would never stick to rubbery butynol.

If you’ve got cracks in grout, the situation has to be assessed by a true professional. Hence, so many failed regrouting jobs…