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Can I use silicone instead of mortar to install glass blocks?

 Hey there 


This is my first bathroom remodel and my first experience in doing anything with mortar and tiles or glass blocks.  So hopefully my question makes sense since some of these terms and ideas are brand new to me.


I'm considering installing glass blocks around my jetted bath tub.  I am a little concerned that the mortar usually used in these installations will allow mold grow over time.  I have asthma and molds are  a big trigger for my asthma.  My Boyfriend thinks using silicone which is usually mold resistant would be a safe alternative.  


Thanks for your time and I appreciate your thoughts on this.



Anchorage AK

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Posted 2013-10-01T08:29:09+0000  by Reneshaddox Reneshaddox

Hi Rene,


Thank you for your question and welcome to our community.


Mold resistant silicone is used as a sealer and is not meant to be to be used as a structural adhesive to bond items like tile.  


You can use a structural adhesive such as Power Grab by Loctite as the bonding agent if you choose and then, you can use a mold sealer, which is available in the paint.  You will be able to fend off any mold build up for about 6 months. 


PowerGrab by Loctite.jpgMold sealer by-Rejuvenate.jpgMold ARMOUR-Mold and mold stain remover.jpg


Since you will be in a bath environment where there will potentially be lots of moisture, you will need to re-apply your sealer about every 4-6 months to prevent any mold from getting a foot hold.  


Be sure that the area where you will be placing your glass blocks will be dry, clean and free of all debris. 


Have fun with your project and be sure to take pictures as you go and share them with the rest of  the community in our Project Library  under "I Did This".


Please let us know if you have any further questions.



Posted 2013-10-01T21:08:06+0000  by Rick_HD_OC

Mortar and grout are largely inorganic - mostly sand and cement.  So they don't really support the growth of mold.  Mold grows on the surface in the residues left by showering or bathing or on an organic substrate behind the tile.  The first place to start is properly constructing the tile system and using the best practices.


Getting rid of moisture in the bathroom is very important too.  That means a properly sized fan that exhausts to the outside and runs for at least 15 minutes after the shower ends.  Putting the fan on a timer is a good way to exhaust moisture while controlling energy costs.


Frankly, the notion of using some kind of adhesive as substitute for mortar is, with all due respect, absurd.  If construction adhesive was a good way to adhere tiles, why would pros go through the trouble of mixing up buckets of thinset?

Posted 2013-10-02T01:20:33+0000  by Adam444
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