4 Tips for Making an Outdoor Mosaic

Mosaic is suitable for both indoor and outdoor use. Attractive and colorful mosaics are used on table tops, patio floors, garden pots, sculptures, pools, fountains, or birdbaths. Regardless of the location where the mosaic is used, the surfaces on which the mosaic is installed should be strong, dry, and must bear the weight of the mosaic.

Outdoor mosaic can be installed in different ways. Gluing the mosaic tiles directly on the surface and then grouting is a common method. Following are four useful tips for installing outdoor mosaic.

Apply Good-Quality Sand and Cement Grouting Mixture

Grouting is an important step in mosaic installation. Usually, grouting with cement mortar is an easy, durable, and inexpensive technique. The grout should be specifically meant for “outdoor use only.” A small amount of dilute glue can be added to the sand and cement mixture (3:1 ratio) for improved bonding. 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 towards the edges of the tiles. After application, allow the grout to set and dry for 3 days at least. Clean the surface with diluted hydrochloric acid and rinse it to remove the cement residue. Finally, polish the mosaic with beeswax spray or block polish.

Use Thinset Bonding Mortar

Thinset bonding mortar is moisture resistant. It has a very smooth and mud-like consistency, which helps the tiles to strongly bond to the surface. There are two types of the thinset bonding mortar.

• Dry powdered tile mortar: Inexpensive and recommended for large tile areas. However, it requires proper latex additives and equipment to prepare the right mix.
• Premixed thinset bonding mortar: Although expensive, it saves time and effort and can be directly used on the tiles.

The thinset mortar stays wet for a while; in the mean time, you can position the mosaic tiles properly. It can also be used for bridging the gaps between the tiles.

Use High-Quality Sealants

Sealants protect the grout on outdoor mosaics from dirt and weather effects. There are two types of grout sealers: penetrating sealant and membrane sealant. 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; most types are suited for all weather conditions. For outdoor mosaics, it is advisable to use two coats of the sealants and let it dry.

Use the Recommended Outdoor Mosaic Glue/Adhesive

Good-quality sealants and adhesives are easily available from most building material stores. Buy the products that are specifically meant for outdoor mosaic making. Avoid water-soluble adhesives. Solvent-based adhesives are preferable for outdoor walls or table tops.

For best effects, keep 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 patio, it is advisable to use thinset bonding mortar instead of adhesives.

Basically, outdoor mosaics need to be weatherproof and waterproof. For this, you need to use a proper sealant. To make an outdoor mosaic last long, seal the mosaic with a good sealant after the grout cures, i.e., approximately after 48 hours. Importantly, mosaic tiles should always be laid on leveled and dust-free surfaces.