Removing Tile Grout, Mortar, and Drywall Mud From Bathtub

Empty bathroom of luxury house
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Bathtubs are not meant to be storage areas for construction debris, tools, or materials during bathroom remodeling or new construction.

Yet walk into many homes under construction or remodels you will find tubs brimming with paint cans, thinset, drywall joint compound, grout, mortar, garbage, empty coffee cups, and tools.

Unfortunately, some contractors find bathtubs to be a convenient enclosed area in which to store--and often spill these things.


One reader relates an all-too-common story:

We just recently fired the contractors from hell and are trying to manage the mess of a half-done, half-effort job. While removing bags of garbage, open paint cans and empty coffee cups they had left to sit around all weekend in what is meant to be the bathroom of our dreams, we noticed large, dried clumps of what we imagine to be drywall mud of compound from tiling. This tub is brand new, and unfortunately, we have no way of getting this money back from the scammers. Is there a way for us to get this out without damaging the tub, preferably at all?

Most contractors and trades do not do this, and they hate hearing about this even more, because it stains the reputation of their profession.

Still, what are your options when your tub is coated with dried grout, mortar, or drywall compound?

Drywall Compound:  Water

If it's drywall "mud" (i.e., drywall compound), it is water-soluble.

 Unfortunately, the mud will not magically dissolve the instant water comes into contact with it; you still need to work at it.

If you were cleaning drywall tools, you would hit them with hot water and scrape them off with another drywall tool.  But with a tub surface, you do not have the luxury of scraping with a metal blade.

After removing the junk from your tub, fill the tub with soapy hot water and let the water sit for about 30 minutes.  Drain the tub.  Gently scrape with with a plastic paint scraper or the edge of a discarded credit card or plastic hotel key.

Because drywall compound contains silica, quartz, mica, and gypsum, it is an abrasive material.  So be careful when scraping away the mud.

Grout or Mortar:  Careful Scraping

If it is tile grout or mortar, removal will be more difficult and damage to the tub surface may occur.

Tile grout is very abrasive. American Standard Corp. recommends using a wooden popsicle stick or tongue depressor to remove tile grout.

In addition, when you push against the grout or mortar, try to avoid scraping the material across the surface any farther than you have to.

When all is done, American Standard recommends granular Spic and Span® mixed with water to clean the remainder.

Finally, if you do end up with any dulled areas, they can be restored by rubbing with a white automotive-type polishing compound and waxing with a liquid wax.