AB Natural Stone | 4337 Hamilton Blvd Allentown Pa | 610-398-7200
Landscape Blocks – Natural Stone – Flagstone – Stone Veneer
There are several basic types of gravity-stacked natural wall stones:
- Flagstone – flatter, angular rocks are easier to stack
- Field Stone – rounder, but thicker rocks that assist in wall stability
- Pavers – engineered specifically for dry stacking of low walls
Natural wall stone is suitable for low retaining walls or decorative accents around such areas as:
- walkways
- raised garden beds
Natural wall stone is suitable for low retaining walls because the stones are usually dry-stacked in place rather than mortared. Natural stone is a product of nature. Each piece is individually unique as to vein, tint, density, and other components. Tinting may vary from pallet to pallet.
The stones come in a variety of colors and sizes, including lilac, beige, gray and blue. We offer them with a straight, rounded or natural jagged edge.
Purpose of Your Wall
Most importantly, you should decide what is going to be the purpose of your wall. If you are retaining soil more than 3 feet high, a natural stone, dry stacked wall should not be your first option.
However, if you are simply holding back soil in a small garden or along a path, this could be a perfect solution for your project.
Retaining Walls
The geography and topography in this part of the country can range from slightly rolling to mountainous so we are used to seeing retaining walls. These walls allow homeowners and contractors alike to create steps or level areas on a sloped surface. However, if constructed poorly, the forces of nature will topple a retaining wall. The four basic types of retaining walls are:
Gravity Walls
A gravity retaining wall is usually less than 3 to 4 feet tall and depends on its own weight or mass to retain (hold back) the earth behind it. This type of retaining wall is constructed with a volume of material so that when stacked together, the weight and friction of the retaining wall exceeds the forces of the earth behind it. The wall is thicker at the base than at the top and slants backwards. This is referred to as ‘battering’. The thickness of a gravity wall at its base should be one half to three fourths its height.
Cantilever Walls
A cantilever retaining wall is one that is a uniform thickness, which is tied to a footing. A cantilever wall typically holds back a significant amount of earth, so these types of retaining walls should be engineered. An example of a cantilever retaining wall would be a typical basement wall in a house. The width of the footing for a cantilever wall is very important because it resists tipping or sliding forces of the earth behind the retaining wall. These types of retaining walls require significant steel reinforcing in both the footer and the wall structures so that the two pieces actually become one integral unit. This is why this type of retaining wall needs to be designed by structural engineers. Don’t try this at home!!
Counterfort Retaining Walls
A counterfort retaining wall is very similar to a cantilever wall, except that this type of retaining wall has a triangular shaped wall that connects the top of the wall to the back of the footer. This is necessary added support. The wall is hidden within the earthen or gravel backfill of the wall. The footer, retaining wall and support wall must be tied together with reinforcing steel. The support walls add a great deal of strength to the retaining wall and make it virtually impossible for the wall to become detached from the footer. Just like cantilever walls, a counterfort wall should be designed by a competent structural engineer and not attempted by a weekend engineer.
Buttressed Retaining Walls
A buttressed retaining wall is just like a counterfort wall except that the support wall is on the outside of the retaining wall. They are visible but add incredible strength to the wall system. They are so strong that in order for the retaining wall to fail or tip over, the buttresses would have to be crushed. This buttress concept was used in the construction of many cathedral walls in Europe. The buttresses helped to stabilize them. If you intend to build one of these walls, you should hire an engineer. A mistake in this type of retaining wall could not only be costly, but dangerous.
