Grouting Sponge Extra Large


large foam rubber sponge ~7.5 inches for high water holding capacity and efficient grouting and clean up.

In stock

SKU: grouting-sponge-extra-large Category: Tags: ,


Extra Large Grouting Sponge is foam rubber for high water holding capacity and efficient grouting and clean up. We also make use of recycled/reused rags in our studio when grouting, but a sponge is essential for this process because it is more easily and quickly rinsed clean; it doesn’t hold sand as much as woven fibers, and it softer and less likely to erode grout from the gaps between tile.

Grouting Sponge Extra Large

  • foam rubber
  • width: ~5.5 inches
  • length: ~7.5 inches
  • thickness: ~2 inches

Grouting Tips

Grouting outdoors is best, especially some place you can run a water hose and don’t mind a little sand and residue being rinsed. Excess grout can kill grass or plants, so scoop up what you can and wash away what is left.

Grout and concrete harden by BINDING water not by drying out. If you let grout or concrete dry out while it is curing, then it will be soft and crumbly. This also happens if you did not add enough water to the grout when you mixed it up. Cover your mosaic with plastic if you are grouting in strong heat, sunlight, air conditioning, wind, or any other condition that accelerates drying.

Make sure you rinse all the water out of your sponge so that it is moist but not leaving drips of water when you rub it on the mosaic. You do not want to get drips of water in the grout in the gaps when you are rubbing the residue off the faces of the tile.

Do not pour left over grout or grout sludge down plumbing or drains. Grout is concrete and can harden under water. Even sand can clog drains. Instead, pour your grout and grout water into an old plastic container. After it hardens, you can pour off the water and dispose what is left as solid waste.

We use traditional grouts and NOT the new epoxy-grouts, and all our advice is written for traditional grout. If you use the new epoxy-base products, then make sure you read manufacturer recommendations for safety and disposal.


Always wear safety glasses with side shields when mixing and applying grout. Grouting is a physical process with lots of mixing and rubbing and wiping, and these motions cause pieces of sand and grit to fly unexpectedly.

Grout is mildly caustic and can irritate skin, sometimes severely if you have sensitive skin. The sand and rubbing required in grouting aggravate the problem. Wear heavy-duty rubber gloves while grouting to protect your skin.

Grout contains powdered silica (sand) and is slightly caustic due to the lime it contains. Avoid breathing the dust. Wear an ordinary dust mask rated N95 when mixing or use a misting water bottle to avoid creating dust.

How To Make Mosaics

For more advice on designing your mosaic project or mounting, cutting, and grouting tile, please see our page of Mosaic Frequently Asked Questions or our Mosaic Information Guide, which lists instructional pages described by topic. We also post new articles about making mosaics at our How to Mosaic Blog.