A block retaining wall is an easy way to contain groundwater around your property. This natural element can place an excessive amount of pressure on the backside of a retaining wall, which could result in its collapse. To prevent this problem, you can install drainage provisions, like backfilling space behind the blocks with crushed stone. Additionally, you can buy perforated drain pipe from The Home Depot, which is also known as drain tile. When installed properly, this pipe will carry groundwater to the end of the wall, where it can drain harmlessly away.
Installing retaining wall blocks
Retaining wall blocks are an attractive, functional way to stabilize a sloped yard or garden area. This type of wall is made of a variety of materials, including poured concrete, large timbers, and natural stones. Manufacturers also produce a variety of colors and shapes, so you can choose a retaining wall that complements your existing outdoor furnishings or creates a dramatic contrast with your landscape design. Stone and concrete retaining walls are more durable and reliable than their timber counterparts, which can rot when exposed to moisture. In addition to their aesthetic value, installing a retaining wall can boost your home’s curb appeal.
Backfilling the wall requires that the base course of each block has a perforated drainage pipe. Water is moved away behind the wall when the drainage pipe is installed properly. The RCP recommends using 3/4″ crushed gravel as backfill. Backfilling the wall with sand or gravel ensures that water will be directed away from behind the wall and will not pool behind it. Backfilling the wall with gravel or sand is a necessary step in building a retaining wall.
To install a retaining wall block, first mark the location. Select the location by measuring the height and width of the retaining wall. You may also need landscape design fabric to cover the area. A pair of gloves and safety glasses are also recommended. A level and a string for marking the area are also essential. If the wall is over four feet tall, you will need to obtain a building permit. If you’re planning to use a geogrid to support the wall, you can consult with a licensed engineer.
Next, prepare the soil for installation. Prepare the site by leveling the surface before placing the blocks. Make sure to keep the soil level as it rises. It’s important to ensure that the wall tilts backward, as well as that there is sufficient room between the wall and the soil. If the soil is particularly sandy, use a rake or a piece of lumber to create a screed. Then, slide the new block units into place.
Checking the level of each block
Before you begin laying your blocks, check that they are level before you begin. If your wall is short, use a carpenter’s level or a small level to make sure the bottom layer is level. If the wall is long, set stakes on both sides to check for levelness and use a string level to create a reference line as you install blocks.
When building a block retaining wall, the base course of each block should be level. The perforated pipe should run the length of the wall and direct water away from it. When connecting blocks to the base course, place a drainage pipe on the base. When building a block retaining wall, make sure the backfill material is properly poured. Proper backfill eliminates hydrostatic pressure. Clean 3/4″ Crushed Gravel is a good choice.
If the foundation is uneven, adjust the retaining wall blocks with a dead blow hammer or coarse sand to level the base course. Keep in mind that the base course of a block retaining wall becomes more uneven as it stacks up, so check the level of each block before starting. If there are any hollow cores in the blocks, fill them in to prevent shifting.
After placing the first course of blocks, check to make sure that the entire wall is level from side to side. The units should be firmly resting on the base-leveling pad. Once the first course is completed, backfill the base course with approximately 1/2 of the blocks and then start the next layer of blocks. When building a block retaining wall, you can use a running bond pattern. This method is recommended because it layers the stones in an offset pattern and makes the wall more stable and more aesthetically appealing than straight stacking.
When building a block retaining wall, it is important to remember that sloping soil requires a certain amount of blocks per linear foot, and it is best to purchase at least 10 percent more than you need. Before you begin, it is important to mark out the length and width of the retaining wall. Once you have done that, use a string and mason’s line to mark the level of the soil before you start laying your blocks. Once you’ve marked your area, you can use landscape marking paint or flour.
Backfilling with gravel
When building a retaining wall, leveling is crucial. Checking the level of the structure often is important to avoid instability. Backfilling the wall with sand or gravel is an excellent way to fill any eight-inch gap in the trench. Ensure that the backfill is level with the top layer. When you have finished installing the walls, backfill the trench with a second layer of sand or gravel.
When backfilling a block retaining wall, it’s best to use clean crushed rock or base material. This type of material won’t increase the active earth pressure. Clay and silt, however, can hold water and increase the wall’s stability. It’s a good idea to overdesign gravel to avoid rusting the footing or wall. Whether or not to add more gravel will depend on your design goals.
A good base material for a retaining wall is 3/4″ crushed rock or minus. You can also use a mix of these materials. Crushed rock is better than natural gravel because it’s less compacted and stays compacted better. If you have a concrete retaining wall, it’s important to follow the manufacturer’s instructions for backfilling. The base material should be a resembling of the surrounding landscape.
If you’re planning on using gravel to backfill a block retaining wall, you should consider the geotechnical properties of the gravel. It has excellent load-bearing properties and is ideal for building purposes. The retaining wall should be backfilled to a depth of 15 cm, with the rest of the retaining wall filled with native soil. Ideally, you’ll place gravel at least six inches above the top layer of the wall.
For drainage, your block retaining wall should be backed up with a layer of granular material that’s at least 12 inches thick. The gravel should be porous and allow for proper drainage. For open cores or cavities, use 3/4-inch crushed gravel. When backfilling an open core or cavity, you can use native soil or gravel as backfill. Make sure to use a level for each brick.
Calculating the height of the wall
If you’re building a block retaining wall, you’ll want to calculate how high the finished wall will be. It’s important to remember that the first course of blocks should be embedded below grade. As with any construction project, you should plan to add extra blocks if there’s any waste or bad material, as well as a few extra inches to the height. To do this, divide the total height of the wall by two, then multiply the length of the first course of blocks by the height of the second course.
For most projects, the height of a block retaining wall should be three to four feet. A wall over this height should have a structural support to avoid collapse and erosion. This means that the height of the wall can be a few feet higher, but should not exceed this limit. In any case, it’s better to have a solid support underneath it, so make sure to build a retaining wall with extra support.
Block retaining walls are constructed using blocks in rows and columns. Experts recommend that the first course of blocks be embedded ten percent below grade. This will provide support for the wall. A six-foot-tall wall should have a base buried seven to eight inches below grade. Then, multiply the total height of the retaining wall by the number of columns and rows. If the wall will go higher than four feet, an engineer should check it to make sure it won’t collapse under its own weight.
Once you have calculated the height of the wall, you can begin to add gravel behind it. For a three-foot-high wall, you should bury the bottom row one eighth of its height. You can also use a cubic yard calculator to calculate the depth of the gravel. To make sure that the first course of blocks is perfectly level, you can use a leveling device to ensure that the blocks are perfectly level. An unbalanced first course will affect the finished wall’s alignment.