Protecting grout from humidity

[Garald]

I've been thinking of protecting the grout in my shower-room/kitchen tilings (I'm surprised that the people who did an otherwise good job of laying the tile only protected some key bits (top, corner)). It's not as if there were mold or anything, but why wait until there is a serious problem. (In the wettest wall in the shower, the grout seems to be already starting to change color a bit - and in the kitchen backsplash, things are if anything more visible, according to someone who just helped me clean.) 

 

I've been advised to dry things with a hair dryer and then apply some sort of silicon protection (the French phrase is "mastic silicone").

 

(a) What sort of protection exactly? Something like this?

 

https://www.leroymerlin.fr/produits/materiaux/etancheite-des-murs-et-sols/silicone-et-mastic-etancheite/silicone/silicone-bain-et-cuisine-rubson-blanc-280-ml-69962781.html?megaBoost&at_medium=Sea-Paid&at_campaign=PD-11-PEINTURE-PMAX-SHP-PLA-Tier1-Toprevenue&at_source=google&at_market=M4&at_section=R11&at_campaign_id=20536653576&at_campaign_type=PMAX&at_campaign_sub_type=PLA&at_account=FIL-ROUGE-SHOPPING&at_account_id=921-620-5076&gad_source=1&gclid=Cj0KCQiAyKurBhD5ARIsALamXaH4xtNsscOSrx4vkdN3ccZsOcbF9fr7pOiCEz01xkODu5ZoChdrZz4aAryWEALw_wcB&gclsrc=aw.ds

 

Is it non-toxic? (Thinking of whether I have to remove things from the kitchen first.)

 

(b) Of course I don't have a hair-dryer (why would I?). How many W would be enough - is a regular hair-dryer at 2100W enough? Also, if the information on a hair-dryer says "dries your hair at a lower temperature" (this is the case for a Philips model), is that a good or a bad thing for this purpose?

[SteamyTea]

26 minutes ago, Garald said:

Of course I don't have a hair-dryer (why would I?). How many W would be enough - is a regular hair-dryer at 2100W enough?

Can't really help with the silicone choice, except it would not be my choice to use silicone as a protective layer.

But the hair dryer I can help with.

2100W is the same as the fan heater I heat my whole house with, it is a lot of power.

Is it a hair dryer or a paint stripping gun?

 

The trouble with drying water is the high energy needed to change the state from liquid to vapour (latent heat of evaporation).

https://www.engineeringtoolbox.com/water-properties-d_1573.html

There is a temptation to heat the affected area as quickly and as high as is easily possible.  This can local discolouration of grouts and, possibly material fatigue/failure.

When I was a lad, my Father wanted to paint the kitchen window.  As there was condensation on it, he got me to dry the frame with my Mother's hair dryer (was the 1960's so probably low power).  I held it steady in the corner, loud noise as the windows cracked.

 

Edited December 2, 2023 by SteamyTea

[Garald]

OK, so a lower-temperature dryer is actually better?

 

Also, what would you use to protect grout, instead of silicone, and why?

[joe90]

You need grout protector , I use this with a no 1 paint brush, tedious but very effective https://www.amazon.co.uk/dp/B000IU40JY?tag=track-ect-uk-120267-21&linkCode=osi&th=1&psc=1&ascsubtag=ecSEP1swhjlpo1d511

[Garald]

Ah. What are the advantages compared to silicon? And should I use a hair dryer first?

[SteamyTea]

9 minutes ago, joe90 said:

I use this with a no 1 paint brush

Contains this:

https://en.wikipedia.org/wiki/Methylisothiazolinone

[SteamyTea]

2 minutes ago, Garald said:

Ah. What are the advantages compared to silicon? And should I use a hair dryer first?

It is a biocide, rather than just a water shield.

 

It will need to be dry I would thin.

 

Bathroom/Kitchen tile grout is really a ridiculous material to use as it likes to soak up water, and has a great structure to harbour spores and bacteria.

[joe90]

1 minute ago, SteamyTea said:

Bathroom/Kitchen tile grout is really a ridiculous material to use as it likes to soak up water, and has a great structure to harbour spores and bacteria.

Which is why i would use bath panels rather than tiles nowadays!!!, however i have used that protector in the past to good effect.

[Garald]

3 minutes ago, SteamyTea said:

It is a biocide, rather than just a water shield.

 

Does that mean it has to be reapplied periodically? Or is it *also* a shield?

3 minutes ago, SteamyTea said:

 

Bathroom/Kitchen tile grout is really a ridiculous material to use as it likes to soak up water, and has a great structure to harbour spores and bacteria.

Well, I am asking too late, but: are there alternatives?

[Garald]

8 minutes ago, SteamyTea said:

Contains this:

https://en.wikipedia.org/wiki/Methylisothiazolinone

 

Ah, should I avoid it then? Or: should I use it in the shower but not in the kitchen?

[SteamyTea]

3 minutes ago, Garald said:

Does that mean it has to be reapplied periodically

Probably.

2 minutes ago, Garald said:

should I avoid it then

It is very low concentration, they use it in food packaging.

Just clear the area and if, like me, you are susceptible to contact allergies, wear gloves, or get someone else to do it.

[Garald]

Here is the current state of affairs. It's pretty much indistinguishable from what it was when I looked closely a couple of weeks ago. There's some variation in grout coloring. What obvious problems can you see?