Table of Contents
Base width = 1/2 to 1/3 of the height of the wall. Base thickness = 1/8 of the height of the wall but not less than 12 inches. Stem thickness = 6 inches + ¼ inch for each foot of wall height.
Do I need a concrete footing for a retaining wall?
A buried structural footing is usually required for larger retaining walls. To create this, a landscaper pours concrete below frost level (the depth to which the ground will freeze during the winter). Footings poured too shallow are prone to shifting and moving if moisture in the soil freezes and heaves.
How thick should a 4 foot retaining wall be?
A typical cantilever reinforced masonry (or concrete) retaining wall will utilize a footing with a thickness of at least 12 inches. Based on this minimum footing thickness, a retaining wall with a maximum retained wall height of 4 feet would correspond to maximum exposed wall height of 3 feet.
How thick should a retaining wall footing be?
The footing dimensions will largely be determined by the size of the wall. A poured concrete footing for concrete, block or brick walls should be at least twice as wide as the planned wall. The footing should be at least as thick vertically as the wall’s planned width.
How deep should retaining wall foundations be?
All footings should be a minimum of 150mm (6″) in depth, with the bottom 350 – 400mm (14-16″) below ground level on most soils. For clay soil however, thicker and deeper footings should be used.
Does a 2 foot retaining wall need drainage?
These walls need a drainage system regardless of the wall height. If there are poor draining soils such as clay behind the wall, there needs to be drainage incorporated the wall system. Clay when wet is very weak, so it is essential to provide a way for water to escape from behind the wall.
What is the easiest retaining wall to build?
For the average do-it-yourselfer, building a retaining wall is easiest when using masonry blocks that will be stacked no taller than three feet, with no mortar binding the stones or concrete members.
How high can a concrete block wall be?
It is not uncommon to create designs with an h/t from 32 to 50. That could produce wall heights of up to 33 feet for walls built with 8-inch concrete masonry units (CMU), 41 feet for 10-inch CMU, and 50 feet for 12-inch CMU. Regionally, 14- and 16-inch CMU are available, which extend possible wall heights even further.
Are poured concrete walls cheaper than block?
Is a poured concrete foundation cheaper than a block wall foundation? Usually, the cost of construction varies from place to place. But as a matter of fact, poured walls cost about 20% less than the block foundation walls.
How long does a concrete retaining wall last?
Using a concrete footing will actually prevent the wall from being able to naturally shift. How long will my retaining wall last? For a permanent wall structure, the general lifespan is generally between 50 and 100 years. This does, however, depend on the conditions of the soil and groundwater at your site.
How thick should concrete footings be?
Eight inches is the minimum thickness for a footing. Ten inches is better and twelve inches is highly desirable. The depth of the footing in the ground depends on: the local frost depth.
How thick does a concrete foundation need to be?
For masonry or concrete construction, the minimum foundation wall will be 6 inches. The minimum reinforced concrete footing thickness will be 6 inches or 1-1/2 times the length of the footing projection from the foundation wall, whichever is greater.
How deep should a concrete footing be?
Depth of Footings Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or must be frost-protected.
Do concrete retaining walls need weep holes?
Retaining walls allow steep, unusable slopes to be avoided. There are several ways to prevent water from building up behind a retaining wall. Weep holes should be drilled through the wall. Weep holes allow water to escape from behind the wall.
How far apart should posts be for a retaining wall?
Retaining wall posts should be at least three feet apart. The distance can be slightly longer or shorter if it works better with your measurements. However, you shouldn’t go more than seven feet apart to make sure your wall is sturdy enough.
Do I need a French drain behind a retaining wall?
If you’re building a retaining wall, add a French drain behind the first course of stones or blocks. Otherwise, water moving down the hill will build up behind the wall and undermine it. The pipe should rest on the same compacted gravel base or concrete footing that supports the wall.
Can you put retaining wall on concrete?
While you can build a retaining wall on concrete, it isn’t that straightforward. If you have an existing concrete base, you cannot just build your wall on top of it. Without being secured into the concrete, your wall will slide due to the soil pressure against the wall.
WHY DO retaining walls fail?
There are many causes of a failing retaining wall: Lack of site investigation: Soil compression, backfill materials, water tables, landslides and building codes restricting soil bearing capacity should all be thoroughly investigated to reduce the probability of retaining wall failure.
Can you build your own retaining wall?
Choose a DIY-friendly building material. Retaining walls can be made from wood, bricks, natural stones or concrete blocks. For DIYers, it’s best to use concrete retaining wall blocks, which can be interlocking and are heavy enough to stay in place without cement or other adhesive.
