Jan 10
15
Retaining walls are commonly made from either real or artificial rock. Although real rocks can give an interesting look, they can be more difficult to use when creating a retaining wall, due to their irregular shapes and sizes. Artificial rocks are commonly made from a concrete mixture, molded into shapes that are based on the shape of an actual rock. These artificial rocks are strong, long-lasting and have a more uniform shape and size that can make building a wall easier.
Planning a Retaining Wall
Retaining walls are commonly used to hold back soil and provide drainage for areas of the yard which are higher in elevation than others. Since in most cases a retaining wall is a structural element that needs to be sturdy enough to hold back the weight of the earth behind the wall, careful consideration needs to be made in regards to support and drainage. A concrete foundation and drainage pipes should be used to avoid the wall collapsing due to pressure. Retaining walls shorter than four feet can usually be built by homeowners, using a non-reinforced gravity building method. Walls which are higher than four feet should be reinforced, and unless the homeowner is skilled in the techniques needed, these taller walls should be left to the professionals for the sake of safety.
Preparations for Building a Retaining Wall
When building an artificial rock retaining wall, plan first where the wall is to be built. If the wall is shorter than four feet, the weight of the rocks alone should be enough to hold back the earth. Plan to backfill the retaining wall with a material that has good drainage, such as rounded gravel, especially if you live in an area that has cold winters. This is to prevent damage to the wall from frost damage, which can cause the wall to heave when water builds up behind the wall and freezes. The area will first need to be excavated to remove the soil from the area, to allow the wall to be built. Never build a retaining wall directly on top of the topsoil, as this will not provide enough support. Either dig down to the more solid subsoil level to start the first course of stones, or optimally lay a concrete foundation for the rocks. Calculate the amount of rock that will be needed by measuring what will be the front square footage of the wall, multiplying the length of the wall by the height of the wall.
Dry-Stacked Artificial Rock Retaining Walls
Gravity and the weight of the rock have the ability to hold a retaining wall\’s structure, if the wall is built properly. Because there isn\’t any mortar to crack, a dry-stacked wall can often hold up better to frost heaving. Dry-stacked walls are also easier to construct. When building a wall, move each course of block just slightly back towards the slope, so that it will hold up better to the pressure of the earth behind it. The wall should be built on a solid level foundation, and each course of block should be carefully placed, arranging the artificial stones in a uniform fashion.
Mortar Artificial Rock Retaining Walls
Stone retaining walls can also be constructed using mortar to cement the rocks together. Unless you are skilled at using mortar, you should practice the technique first using spare rocks. Mortar should be fairly stiff for rock walls, because the mortar mix will stay wet for a longer period of time than if you were making the wall from brick or concrete block. As with a dry-stacked wall, start the first course of rock on a solid and level surface, then carefully mortar the remaining courses of rock in place, placing each row just a little back towards the slope so that it will withstand the pressure better. Don\’t backfill the wall with the drainage gravel and the soil until the mortar is cured.
Mr. Peter Heiss and Mr. Mark MacIsaac – are the preeminent designers in the Pacific Northwest and have spent a lifetime studying and emulating all of nature\’s beauty. We can create pools, hot tubs, waterfalls and every other feature out of any rock you choose. At Raincity Rock & Waterscapes
Related Reading:
The Essential Garden Design WorkbookThe Essential Garden Design Workbook guides the reader through every stage of planning a garden — how to survey a site, how to choose landscaping materials, and how to develop planting schemes. This fully revised and updated second edition features new U.S. case studies and new photographs. Valuable tips on green gardening are new to this edition, and include how to harvest rainwater, how to design a green roof, tips on sustainable planting, and a guide to composting. Tailor-made for hands-on gardeners, the workbook approach is accessible, practical, and can be used to create a garden from scratch and to redesign an existing garden. Gardeners will find easy ways to measure large spaces, estimate the height of a tree, and find the right proportions for a deck. They'll also find tips on space, light, and color. Includes hundreds of easy-to-follow line drawings and diagrams.
