To know which glue is best to use for outdoor mosaic, you need to consider the following factors as these will determine what glue to use:

1. The base that will be used 
2. The specific tiles you will be using 
3. The environment in which the mosaic will be (moisture, temperature, weather conditions)
4. Whether or not the mosaic will be in direct contact with water (submerged)

Various adhesives are recommended for outdoor glue mosaics, but these are usually general recommendations.

Suppose you want the best results, including a strong bond and a durable adhesion that will last.

In that case, you need to choose what glue to use, not based on a general idea but considering the abovementioned factors. 

Continue reading to find out which glue is best for outdoor mosaics. 

The Best Glue For Outdoor Mosaic 

In this section, we won’t only discuss which glue you can use for this project but also what characteristics they offer, considering the important factors we mentioned earlier. 

Choose a glue compatible with the base (or substrate) you are working with. 

The best glue for outdoor mosaic needs to be:

• Waterproof 
• Durable 
• Withstand different weather changes 
• To work for either a horizontal or vertical application 

The following are adhesives that will work best for outdoor mosaics. 

Beacon Mosaic Glue

As the name specifies, this glue is made specifically for mosaics. 

Here is what to know about this mosaic adhesive:

• Dries clear 
• Works both outdoors and indoors 
• Waterproof 
• Strong adhesion
• Non-toxic 

Matei Type 1

This acrylic-based glue is great for outdoor mosaic but chooses it only if you don’t mind that it dries white. 

It works well for both horizontal and vertical applications. 

And yes, Matei Type 1 glue is waterproof. 

Cement Based Adhesives, Also Referred To As Thinset

A cement-based adhesive, also known as Thinset, is great for flooring, including heavy traffic areas for the mosaics. 

It is a great choice for uneven tesserae and the direct method. 

Thinset usually comes in a pre-mixed powder form. You can use this adhesive for vertical and horizontal projects and ones that will be submerged underwater. 

It will also effectively hold the mosaic on a curved surface. 

Mix it with an acrylic additive if you want to improve its waterproof ability. 

This set is ideal for the following:

• Tesserae 
• Outdoor mosaic
• Birdbaths 
• Terracotta 
• Stepping stones 

Weldbond

Weldbond is often used as an alternative to PVA glue, as PVA glue is only recommended for indoor mosaics. 

Weldbond is:

• Waterproof 
• Dries clear 
• It offers a very strong bond 

Liquid Nails

You can choose from clear liquid nails or platinum liquid nails. 

Platinum Liquid Nails glue is extremely strong, but it is also very difficult to work with. 

Clear Nails glue is a great choice for mosaics. 

Here are some of its best features:

• Dries clear 
• It can hold heavier tiles 
• Can compensate for variations in thickness

To apply clear liquid nail glue, add a larger quantity to an old sheet that you won’t mind throwing out afterward. 

Use a spreading tool to apply it and spread it to the surface of the mosaic that will be glued. 

Epoxy Resin

Epoxy resin is a very strong glue. You can use it for outdoor mosaics but also indoor ones. 

If the environment in which the mosaics will be sitting is high in moisture and wetness, then epoxy glue is a great choice. 

It can also hold heavy tesserae tiles. 

It will come in two parts that you will need to mix well together right before you apply. Could you not mix it earlier and let it sit? 

The texture of epoxy glue is runny and very sticky. It usually dries fast.

Conclusion 

You can use several adhesives for outdoor mosaic, but to choose the best one for your project, you need to consider the following aspects:

• What base will you use
• What type of tiles will you work with as your mosaic (glass, ceramic, other types)
• The environment in which the mosaic will be (moisture, temperature, weather conditions)
• Whether or not the mosaic will be in direct contact with water (submerged)

Work in a well-ventilated area and read the manufacturer’s instructions on drying and curing times.