THE DIFFERENCES BETWEEN WET CAST AND DRY CAST PAVERS
Getting ready to install a new or replacement paver patio or walkway? There are two main types of concrete pavers and you should know a little bit about each one before making a final decision on what material to use. In this blog post, we’re going to break it down for you. Here are the major differences between wet cast and dry cast pavers.
(Photo courtesy of Unilock)
The Manufacturing Process
The main difference between wet cast and dry cast pavers really lies within the manufacturing process. As its name would imply, wet cast concrete is quite liquid. It has a high slump, which gives it the ability to be poured from a mixer, hopper, or truck. (Slump is a relative measurement in concrete consistency. To measure the workability of a mix, a slump test is typically conducted. The test involves filling a slump cone with concrete, carefully removing the cone, and then measuring how much the concrete slumps from the height of the cone.)
To manufacture wet cast pavers, concrete is poured into a mold and then vibrated to release any air bubbles out of the mix. The mold then gets stripped after the concrete has cured and the pavers get palletized for shipping.
The dry cast manufacturing process uses heavy, complex machinery. Typically products like concrete pipes, manholes, and concrete blocks are produced using this method. Dry cast concrete has very little water and has zero slump (more like the consistency of wet sand at the beach as opposed to what you’d normally see come out of a cement truck). It contains only enough water to hydrate the cement. This mix is compressed in a mold with very high pressure and then cured on a rack before being palletized and processed.
Texture, Color, and Size
Due to the differences in manufacturing techniques, the texture, color, and size availability of wet cast vs. dry cast pavers will vary. Wet cast pavers come in a wide range of options. Pavers featuring bold tones like jet black or red are typically made using the wet cast process. Smoother finishes can also be achieved as well as much more intricate surface textures. Many wet cast products imitate natural stone in appearance. Dry cast pavers have historically had fairly basic surface texture and color, however, they have come a long way in the past few years. Modern dry cast pavers can have surface textures that mimic natural stone and 3- and 4-color blends have become quite common.
Both wet cast and dry cast pavers are suitable for residential projects (i.e. driveways, walkways, pool decks, and patios). Dry cast pavers have an optimal water to cement ratio making them incredibly strong. For large-scale commercial projects (i.e. highways and roads), dry cast pavers are the optimal choice due to their very high strength, durability, and load capacity.
Wet cast pavers typically tend to be more expensive than dry cast. For projects with budget restraints, dry cast pavers will most likely be the more economical option.
Considerations For Sealing
Wet cast pavers appear to have a smooth non-porous surface while dry cast pavers visibly look to have a rougher, more porous surface. However, the absorption on each can certainly vary. Porosity and absorption will need to be considered if the pavers are going to be sealed. Oftentimes wet cast is sealed at the factory … another important factor to consider when preparing to apply a sealer.
There are a multitude of sealers available on the market for both wet cast and dry cast pavers. It’s best to read the manufacturer’s recommendations to be sure the sealer will be compatible with the type of pavers it will be applied to. It’s also wise to apply the selected sealer to a small test area before installing it across an entire job.
Understanding the key differences between wet cast and dry cast pavers will allow you to make an educated decision when purchasing products for your next hardscape project. To sign up for more content like this, simply subscribe to our blog!