How thick should a concrete retaining wall be?
- Meet with clients and determine what components they want and how the space will function.
- Design the walls - determine shape, size and placement.
- Remove existing plants, top soil and other debris that may be in the way of construction, Ralston calls this process grubbing.
- Lay out and dig the footings.
- Build forms.
How thick does a retaining wall have to be?
Retaining walls can be tricky to build as they need to be strong enough to resist horizontal soil pressure where there are differing ground levels. One of the things you must get right is the thickness of the wall. It should be at least 215mm thick and bonded or made of two separate brick skins tied together.
What is the standard size for a retaining wall?
The STA Retaining Wall Design Risk Matrix asks seven key questions:
- What is the purpose of the retaining wall?
- What is the type of retaining wall proposed?
- What is the maximum design height?
- What is the wall configuration?
- How many degrees is the natural surface slope?
- How far from the proposed wall are other structures, either existing or proposed?
- How far from the proposed wall are existing services?
What is the cheapest type of retaining wall?
What is the most cost effective retaining wall?
- Treated pine and is the least expensive material.
- Hardwood is more expensive than treated pine.
- Railway sleepers are another – slightly more expensive – option and are built to withstand ground and water contact.
- Concrete sleepers are more expensive.
How deep should a retaining wall be?
The general rule of thumb is to bury about one-eighth of the height of the wall. For example, if your wall will be three feet (36 inches) tall, the first course of blocks should start five inches below soil level. The gravel base should start three inches below this.
Do I need rebar in a retaining wall?
Retaining walls must be stronger than freestanding walls. Insert rebar in the footing when you pour it; this should be done at every three blocks or at intervals specified by your local codes.
Does a concrete retaining wall need a footing?
Every retaining wall needs a footing, but what type depends on the design, material, height and weight of the wall. Large masonry retaining walls built out of rigid materials like concrete, cinder blocks, cement or brick need a concrete footing. Solid masonry walls are stiff and unable to flex because they'll crack.
How deep should a rebar be for a retaining wall?
Rebar Placement in Walls As a minimum, #4 rebar (1/2 inch) is spaced vertically at 36 inches on center, continued to within 8 inches of the top of the wall, placed on the tension side -- the inside face -- of the wall.
Does a 2 foot retaining wall need drainage?
Every retaining wall should include drainage stone behind the wall. Though it is a good idea to install a drainage pipe on all walls, there are certain situations where a perforated drain pipe is absolutely necessary.
Do I need a drain pipe behind retaining wall?
A drainage pipe might be needed if: The retaining wall is at least four feet high or taller. Clay or other poor draining soils are behind the wall. There are buried water sources within 50 feet of the retaining wall location.
How high can you build a concrete retaining wall?
Most retaining walls, whether load-bearing or not, average between 3 and 4 feet in height. As a general rule, you do not want to build any sort of structure over 4 feet in height without including some type of structural support within.
How thick should a 1m retaining wall be?
If your retaining wall is holding back a 1m depth of garden then it needs to be 225mm thick.
How do you build a poured concrete retaining wall?
2:038:36How To Build & Pour A Concrete Retaining Wall - YouTubeYouTubeStart of suggested clipEnd of suggested clipHere you can see our main stakes are approximately five feet on center by the rock being so hard weMoreHere you can see our main stakes are approximately five feet on center by the rock being so hard we have to pre-drill some holes using our makita rotor hammer for us to hammer our stakes. And kickers.
How do you make a strong retaining wall?
Here are three key principles in building any solid retaining wall:Bury the bottom course, or courses, of the retaining wall one tenth the height of the wall to prevent the soil behind from pushing the bottom out.Step back the blocks, rocks or timbers to get gravity working in your favor.More items...•
What is the cheapest way to build a retaining wall?
The cheapest type of retaining wall is poured concrete. Prices start at $4.30 per square foot for poured concrete, $5.65 for interlocking concrete block, $6.15 for pressure-treated pine, and about $11 for stone. Installation or supplies, such as drainage stone or filter fabric, are not included.
How deep should a retaining wall be?
Concrete retaining wall footing size. The depth to the bottom of the base slab should be kept at a minimum of two feet. However, it should always be below the seasonal frost line, and that often is much deeper in northern climates. The length of the base slab is usually about 50% to 70% of the total height of the wall ...
Why is proportioning important in retaining walls?
Proper proportioning of a retaining wall is just as important to its construction as its structural design. Construction-friendly proportions facilitate proper concrete placement and provide sufficient room for structural reinforcement.
Why should weepholes be spaced between walls?
Adequate spacing between weepholes allows uniform drainage from behind the wall. Weepholes should always have some kind of filter material between the wall and the backfill to prevent fines migration, weephole clogging, and loss of backfill and caving.
Why is it important to drain water from retaining walls?
Drainage of water as a result of rainfall or other wet conditions is very important to the stability of a retaining wall. Without proper drainage, the backfill can become saturated, which has the dual impact of increasing the pressure on the wall and lessening the resistance of the backfill material to sliding.
What is a footing key in a retaining wall?
In some cases, a footing key is included to increase resistance to sliding. The footing key is generally an extension of the stem and extends below the bottom of the base.
How deep are contraction joints?
Contraction joints are usually about 0.25 inches wide and about 1/2 to 3/4 inch deep, and are provided at intervals of not exceeding 30 feet. Expansion Joints: Vertical expansion joints are incorporated into the wall to account for expansion due to temperature changes.
Can hydrostatic pressure cause retaining wall failure?
Hydrostatic pressure can cause or induce retaining wall failure, or at least damage.
How thick should a basement wall be?
In general, poured concrete basement walls that are 8 feet tall or less and have no more than 7 feet of soil pressing against them from the outside function well at a thickness of 8 inches. When a taller wall or a higher level of soil or both come into play, the thickness should increase to 10 inches. These figures can vary due to differences in local building codes.
How thick is a home foundation?
Although a thickness of 8 inches is typical for a home with 8-foot-high concrete foundation walls, an important exception exists. The 8-inch thickness works well for homes with most types of siding, but does not provide adequate support for a home with brick veneer siding.
What is the purpose of concrete basement walls?
The thickness, or depth, of concrete basement walls plays an integral role in their long-term strength and durability. Concrete foundation walls support the home standing above, so any weakness can undermine the stability of the house.
Is concrete thicker than foundation?
Soil can exert a strong pressure on basement walls; thicker concrete does a better job of resisting lateral stresses.
How deep should a retaining wall be?
The depth to the bottom of the base slab should be kept at a minimum of two feet. Click to see full answer. Besides, how wide should a retaining wall be?
Do I need drainage behind a retaining wall?
Do I need drainage behind retaining wall? Second, a retaining wall must have properly compacted backfill. In order to provide proper drainage, at least 12 inches of granular backfill (gravel or a similar aggregate) should be installed directly behind the wall.
How thick should a concrete foundation be?
Poured concrete foundation walls that are less than 8 feet tall and have soil outside that is 6 or 7 feet deep against the wall can often be 8 inches thick and function quite well. As soon as you go higher or have greater depths of soil pushing against the wall, you need to increase the thickness to 10 inches.
How thick is the foundation wall?
The thickness of the foundation walls you are looking at are not the same. The wall below and the one to the left of the hose bib faucet are only 8 inches thick. The other walls are 10 inches thick even though there is less soil pressing against them. Why?
What is a pilaster in a wall?
A pilaster is a thickened part of a wall in a short distance. For example, a 10-inch thick wall may all of a sudden thicken to 16 inches for just a foot or so. That's a pilaster. A buttress is a short stub wall that extends inside the perimeter of the foundation. It might be 3 or 4-feet long.
What causes a foundation wall to crack?
For example, if soil loads are significant and a house is built into a hillside, vertical reinforcing steel is a must. The pressure of the soil creeping down the hill can cause a foundation wall to develop a horizontal crack much like when you snap a saltine cracker in half with your fingers.
What is the purpose of steel bars in concrete?
Steel bars that are incorporated into poured concrete add enormous strength to the wall system. The placement of the steel is critical depending upon how you are trying to strengthen the wall.
Can I upgrade to 4,000 psi concrete?
You can upgrade to 4,000 psi concrete if you desire, but I would only do this if it was specified by the structural engineer. One last point: Remember that the specifications in the building code are minimum standards. You can always improve upon the guidelines you see in the code.
Does concrete need to be thicker?
DEAR BOB: The answer, although fairly intuitive, is not as crystal clear as you might think. As a poured concrete wall gets taller, it needs to be thicker. But there are many other variables that control the thickness of the wall.
How thick should a concrete footing be?
The footing should be at least as thick vertically as the wall's planned width.
What is a retaining wall footing?
Retention, or retaining, walls provide a practical means to make a difficult slope manageable and hold up some amount of soil and vegetation while lending landscape interest.
