Hello everyone. I'm new to the group, and so glad I found it. I'm a DIY, weekend warrior who has been searching high and low for information related to an issue I seem to be having – but to no avail. I hope some kind folks out there may be able to shed some light... I bought several square feet of 12x24" basalt tile several months ago, and have been storing them in my garage. I recently began installing them as a new floor in the main entry into our home, and noticed some blotching and other strange dark and light characteristics. I figured that this was just a result of the moisture from the thin set making its way to the surface then evaporating, but some of these pieces have been down for five days now, with fans blowing on them and have shown no change. Before laying them down, the tiles are a nice, consistent medium shade of grey. I'm beginning to panic, and am reluctant to proceed with the install until I can learn more about what may be going on, and whether its a problem or not. I've attached a few photos. Materials/process working up to the surface is: plywood subfloor / vapor barrier / plywood / versabond thin set (grey) / 0.25" cement board (screwed in) / versabond thin set (grey) / basalt tiles Do I need to wait longer for them to dry? Is this an issue with a simple remedy? Am I stuck between a rock and a hard place? If so, what are my options? Please kindly advise if more information is needed. Thank you in advance for any help you may offer.

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looks like residue mate, did you have adhesive seeping through the grout joints when you bedded them into the tile adhesive bed?

Also looks like there is another type of residue on the tile, perhaps tape residue? Were the tiles taped together? The little strap like marks look like they were taped in bundles or something.

You may be able to get this away with LTP Grout stain remover, if the little greasy tape marks dont come off you could try ltp spot stain remover.

Those marks that look like tape residue.. could it be that a tile lippage system was used ?

Originally Posted by Sir Ramic

Those marks that look like tape residue.. could it be that a tile lippage system was used ?

id say yes the wedge type

Hi,
Those patching marks you can see are most probably from the adhesive drying out through the tile. When you use a standard setting tile adhesive the moisture will evaporate through the material. You should find with time that the patches will dry out. The only problem is this can sometimes take a very long time (several months) and if the water was contaminated you may find ring marks where the water dried.

You should always try to use a rapid setting tile adhesive with natural stone, and if you can afford it by ARDEX adhesive with 'Water lock system', this converts the water into crystals when it dries so there is not moisture evaporation.

Basalt sometimes has some pyrite which can cause rust staining on the surface, to avid this you should prime the back of the tile and this will help prevent the moisture passing through the stone.

Hello all, thank you so genuinely for your quick responses. No, i was careful about not over applying thinset, so as to avoid thinset creeping up through the grout joints. The strip marks are indeed from tape - masking tape which I used when setting the tiles and which was in place for 12 hours at the most. My primary concern is the dramatic variance in lightness. Is it possible that when factoring the moisture from the thinset securing the cement board in addition to the thinset securing the tile that there could still be enough moisture present to cause this effect, even after five days? Do I simply need to allow more dry time?Thank you again. I really do appreciate your insight.

Hi,

There really is not a lot you can do. You will need to give it more time and see what happens. I have seen examples of this many times, and it normally will dry out. Do not seal the material as this will slow down the drying process.

What method of fixing did you use to install the tiles..

How deep a bed of adhesive did you use and did you burn in the back of the tiles before bedding into the thinset..?

Besalt can be a strange stone sometimes especially when it is in a honed state. I have had a difficult time getting tape marks off besalt a few times when fabricating stone countertops. Some times it takes actually re-honing the top surface to remove it which I recomend being done by a pro. Then the surface can be allowed to dry, sealed with a penetrating and everything is fine after that. Besalt can also be inconsistant in color to begin with and is often doctored to be one color at the processing plant. Often the color doctoring comes out with cleaning chemicals and you are left with a mess.

I hate to say it but - A stone like that should be sealed before installed to avoid these types of problems but being already installed you should finish the install the way it is and deal with it all at the same time or rip it all out and start over to keep it consistant.

Basalt is a nightmare. I have lost count of how many of these jobs we have been out to. They are a nightmare to sort out even with professional grinding and honing.

Kev Martin
Marble Life Ltd

portlandgrown, Any update on this project?

What color are the tiles again. Just tell me that maybe i will be able to help.