# Building Curves

Building curved and serpentine retaining walls is simple. Allan Block's patented design allows for easy installation of both inside and outside curves. Most curves can be built with no cutting involved.

Offset the vertical seams

- Try to maintain an offset of the vertical seams by at least ¼ of the block length from the courses below. Cutting a block in half or using the half width blocks, will assist in creating a proper offset.
- Before beginning construction, review the plans and layout the retaining wall to eliminate tight radii. More gentle sweeping curves produce more aesthetically pleasing retaining walls. See radius chart for more details.

Outside Curve

Inside Curve

## Outside Curves with AB Fieldstone

- Place the facing units to form a flowing curve.
- Remove one or both of the wings from the anchoring units to achieve an outside curve.
- Set the anchoring units in place
- Use the radius chart to determine the minimum radius on the base course.

## Inside Curves with AB Fieldstone

- On inside curves, place the facing units to form a flowing curve. Keep the front of the blocks tight together.
- Set anchoring units in place with the back of the anchoring units fanned out to form teh curve.

## Working with Radii

Refer to the Radius Chart to confirm that the AB product you are using will accommodate the desired wall radius.

The tightest or smallest radius at the top of any AB wall using full size block is 1.2 m, and 0.8 m using the half width blocks. The final height of the wall will determine what the minimum radius at the base course must be.Curved walls have a greater setback, which causes a coning effect to occur causing your retaining wall to have its tightest radius at the top of the wall which in turn creates the need for a larger radius at the base course.

Use the radius chart to determine what the minimum recommended radius of the base course of the wall needs to be, so the top course of the wall will not be less than 1.2 m.

### Starting a Radius

From the point of where the curve will start, measure straight back from the wall the required amount (shown in the radius chart) and drive a stake into the ground. This will be the center of the curve. Attach a string line to the stake the length of the radius and rotate it around to mark the location of the base course. Install the blocks with the front of the blocks lining up with the mark.

- To transition the curve back into a straight wall or another curve, lay out the curve and the first couple blocks of the next section. Adjusting 1 or 2 of the blocks will help in the transition of the next section of the retaining wall.

## Capping Curves

Place two caps on top of the wall, spaced so a third cap will fit tightly between their widest point

Mark the overlap on the bottom of the center cap

Cut cap on marks to fit between caps

Measure the distance of the gap between the 2 caps (x) at the front of the wall

- Place two caps on top of the wall, spaced so a third cap will fit tightly between their widest point.
- Set another cap on top of the first two caps in the center and mark where they overlap on the bottom of the center cap.
- Remove the center cap and cut along the marks. Then set in place so the three fit tightly together.
- Repeat this process as often as needed to cap the entire curve.
- It's a good idea to secure caps with a high strength construction adhesive once they are all cut.

More options for finishing your retaining wall.

### Capping Tighter Curves

- For and outside radius, place two caps on top of the wall, with the back of each cap tight together. A gap will appear in the front.
- Measure the distance of the gap between the 2 caps (x) at the front of the wall.
- Measure out this distance (x/2) on the back of each of the cap and mark.
- Draw a line from the mark to the front corner.
- Use a masonry saw to cut each cap.
- The above steps work for both inside and outside radiuses.

More options for finishing your retaining wall.