What is Salt Concrete Finish?
As one of the older, more conventional decorative concrete finishes, salt finish concrete has become the most popular in unfreezing / thaw regions around the country. For a little additional cost, you can add texture to just about any hardscape. With the popularity of decorative concrete along with the wide range of decorative finishes available today, the salt finish is not used much currently.
However, Lance Boyer, owner of Trademark Concrete Systems, Oxnard, Calif., says that they occasionally see the finish specified on plans, adding that it is sometimes specified in areas between characteristic panels using more expensive decorative finishes.
The salt finish is more decorative than broom finished concrete, which is often the alternative consideration. Landscape architects who need concrete to look like concrete tend to specify salt finishes for that reason.
Rock Salt Concrete Finish Installation Procedure
Installing rock salt finish concrete requires little extra material or equipment – rock salt, and a roller to press it on the surface of fresh concrete is it. Sometimes an installation also involves colored concrete with either integral or dry-shake color hardeners. As with most decorative finishes, the timing for the installation is critical. There’s little difference about finishing and placing concrete in preparation for a salt finish. During the bull-floating operation, care ought to be taken to remove the lines created by the float.
Finishers often finish a slab either with Fresnos or using hand trowels to get a smooth finish to record the print of the salt better. Make sure to finish just after the water sheen has disappeared from the surface. For the best results, workers should broadcast salt once the concrete is just beginning its initial setting phase. The stiffness of the concrete needs to be the same as it would be for stamping textures or patterns. If you push your finger with moderate pressure to the surface, it must penetrate approximately 1/4 inch at most.
Some finishers also gauge timing by lightly pressing the surface to see if concrete paste or colour sticks for their finger–proceeding when there’s no residue in their finger. Rock salt rated as”coarse” or”extra coarse” would be the most popular sizes to use. Because it’s broadcasted by hand in a similar way to throwing dry-shake colour hardeners, skill is required by the worker to achieve an even distribution. Having good access around the work area also is important, so broadcasting is limited to 15 or 20 lineal feet.
How to Create a Salt Finish?
As its name implies, a salt finish is traditionally achieved with the same coarse rock salt sold to be used in water softeners or as a deicer in winter. Concrete finishers broadcast the salt particles over moist concrete and then press the grains to the surface using a roller or float. After the concrete sets (Final Setting Time of Concrete), they power wash away the salt, revealing a speckled pattern of shallow indentations left by the dislodged salt particles. While salt is relatively quick and easy to master, there are newer methods that may speed up the procedure for doing away with the salt altogether.
Salt finishes are more commonplace in the warmer southern and western regions of the country. The reason in areas subject to freezing weather, water will accumulate from the indentations and freeze, potentially causing spalling. But if you like the look and use of good-quality concrete protected by a waterproofing sealer, a salt finish ought to be durable enough to endure any climate.
Creative Ways of Use a Salt Finish.
Salt finishes are attractive alone but are particularly stunning when used in combination with coloured concrete and other decorative finishes. Some contractors who specialize in stamped concrete usage salt finish as an interesting contrast to brick and stone patterns.
Landscapers have long relied on salt finishes to create rustic garden pathways with the look of natural stone. And the finish is still quite popular with pool contractors, owing to its inherent nonskid texture.
Other Creative Ways to Use a Salt finish Concrete:
- As a decorative Edge for swirl-troweled or broom-textured concrete
- In large panels bordered by bands of smooth concrete
- To add texture to Coloured concrete overlays
- In square or diamond-shaped panel arrangements separated by scored or saw-cut joints
Salt Concrete Finish: FAQs
What is salt concrete finish?
Salt concrete finish is a decorative technique used on concrete surfaces where coarse rock salt particles are pressed into the wet concrete. Once the concrete sets, the salt is washed away, leaving a textured pattern of shallow indentations. This finish adds a subtle texture and is more decorative compared to broom-finished concrete.
Why is salt finish concrete popular in unfreezing/thaw regions?
Salt finish concrete is popular in regions without freezing and thawing cycles because it adds a decorative texture at a minimal cost. However, in areas with freezing weather, water can accumulate in the indentations and freeze, causing spalling. To avoid this, high-quality concrete and waterproofing sealers are recommended.
How does the salt finish compare to broom-finished concrete?
Salt finish is considered more decorative than broom-finished concrete. While broom finish provides a simple, textured surface, salt finish offers a more aesthetically pleasing look with a unique speckled pattern.
What materials and equipment are needed for installing a salt finish?
The installation of salt finish concrete requires coarse rock salt and a roller or float to press the salt into the surface. Sometimes, colored concrete with integral or dry-shake color hardeners is also used.
What is the installation procedure for salt finish concrete
- Preparation: Place and finish the concrete as usual, ensuring a smooth surface.
- Broadcast Salt: Once the concrete begins its initial setting phase, broadcast the coarse rock salt evenly across the surface.
- Press Salt: Use a roller or float to press the salt into the concrete.
- Set and Wash: Allow the concrete to set, then wash away the salt with water, revealing the textured pattern.
When should the salt be applied during the concrete setting process?
The salt should be broadcast when the concrete is beginning its initial setting phase. The surface should be stiff enough to support the salt but still allow for the salt to be pressed in. This is typically when a finger pressed into the surface leaves a slight indentation without sticking.
Can salt finish concrete be used in combination with other decorative techniques?
Yes, salt finishes can be combined with other decorative techniques. They can be used as a contrasting texture with stamped concrete, as decorative edges for swirl-troweled or broom-textured concrete, in large panels bordered by smooth concrete, to add texture to colored concrete overlays, or in square or diamond-shaped panel arrangements separated by scored or saw-cut joints.
Is salt finish concrete suitable for pool decks and garden pathways?
Yes, salt finish concrete is popular for pool decks due to its nonskid texture and is also used for garden pathways to create a rustic look similar to natural stone.
What are the creative ways to use salt finish concrete?
Some creative uses of salt finish concrete include:
- As a decorative edge for other textured concrete finishes.
- In large panels with contrasting smooth concrete borders.
- To add texture to colored concrete overlays.
- In geometric panel arrangements separated by joints for a modern look.
