4 Tips for Making an Outdoor Mosaic

colorful mosaic art
  • 1-10 hours
  • Beginner
  • 0-50

Mosaic art can be made with any variety of glass, tile, or stone. Considering that the patterns can be as abstract or colorful as you'd like, your finished product—be it a section of floor, a wall, or even a decorated tabletop—will stand out.

Attractive and colorful mosaics are also commonly used on garden pots, sculptures, pools, fountains, and birdbaths.

Regardless of the location where the mosaic is used, the surfaces on which the mosaic is installed should be strong, dry, and able to bear the weight of the mosaic.

An outdoor mosaic can be installed in different ways. Choose a method and follow these tips to make your project go smoother.

1. Use Thinset Bonding Mortar

Thinset bonding mortar is moisture resistant. It has a smooth and mud-like consistency, which helps the tiles to strongly bond to the surface. There are two types of thin-set bonding mortar—dry powdered tile mortar and premixed thin-set bonding mortar.

Dry powdered tile mortar is inexpensive and is recommended for large tile areas. However, it requires proper latex additives and equipment to prepare the right mix, which is why thin-set bonding mortar is the recommended agent.

Premixed thin-set bonding mortar is expensive, but it saves time and effort, as it can be directly used on the tiles. The thin-set mortar will stay wet for a while, so you have time to position the mosaic tiles properly.

It can also be used for bridging the gaps between the tiles.

2. Use the Recommended Outdoor Mosaic Glue/Adhesive

stone mosaic

There are a wide variety of quality sealants and adhesives on the market, but for the best mosaic result, buy the products that are specifically meant for outdoor mosaic making.

Solvent-based adhesives are preferable for outdoor walls or tabletops over water-soluble adhesives, which should be avoided for this project.

For the best effects, have the adhesive mix ready beforehand and apply it on each tile just before installing. Grouting should be done after the setting of the adhesive.

For pools, fountains, or patios, it is advisable to use thin-set bonding mortar instead of adhesives.

3. Apply Good-Quality Sand and Cement Grouting Mixture

Grouting is an important step in the mosaic installation. Grouting with cement mortar is an easy, durable, and inexpensive technique.

Even if your project is ultimately going to reside indoors, grout that is meant for outdoor use is the best way for grout to stick.

When the mix acquires a damp crumble consistency, gently pour it onto the mosaic and spread it evenly. Remove excess cement mix and work the grout toward the edges of the tiles.

After application, allow the grout to set and dry for three days at least.

Tip: A small amount of dilute glue can be added to the sand and cement mixture (3:1 ratio) for improved bonding.

Clean the surface with diluted hydrochloric acid and rinse it to remove the cement residue. Finally, polish the mosaic with a beeswax spray or block polish.

4. Use High-Quality Sealants

mosaic stepping stone in the grass

Outdoor mosaics need to be weatherproofed and waterproofed. In order to achieve this, as well as a long lifespan for your mosaic, you need to seal the mosaic after the grout cures. This curing process will take approximately 48 hours.

Sealants protect the grout on outdoor mosaics from dirt and weather effects. There are two types of grout sealers: penetrating sealant and membrane sealant.

A penetrating sealant is made of latex or silicone, and it soaks into the grout and fills in the spaces. This keeps away dirt, grease, and water from the grout.

Membrane sealants stay on the grout surface by forming a membrane and give a glossy finish. Sealants are easy to apply and clean with most types suited for all weather conditions.

For outdoor mosaics, it is advisable to use two coats of the sealants and let it dry. Remember, mosaic tiles should always be laid on leveled and dust-free surfaces.