Inside Corner With Gravity Extenders

Corners, Gravity, Inside Corner

Inside Corner With Gravity Extenders

STEP

First Course of MagnumStone Inside Corner units

Quick Steps

Always start building retaining walls at their lowest point. If the construction site is level, begin with the corner.
Align and position the first MagnumStone base block with the inside corner’s pivot point.
Center the second MagnumStone base block at a 90° angle, perpendicular to the first base block.
The blocks should be tight together and level, aligned to meet halfway along the second block’s facing to create the inside corner.
Continue to lay the MagnumStone base course on either side of the corner until the first course is complete.
Each block should be placed in direct contact with adjacent blocks, pressed as tightly together as possible to ensure there are no gaps between the blocks.
At the discretion of the project engineer, impermeable materials can be placed and compacted at the toe of the wall. If this is specified, the amount of impermeable material should reach the desired height of the perforated drainpipe.
If no gravity extender units are required, proceed to install adequate drainage, fill the hollow core blocks with clear crush drainage gravel, then add and compact layers of backfill behind the blocks as outlined here in these steps of the MagnumStone Unit Installation section.
Sweep any excess stones off the top of the blocks before beginning to place the next course of retaining wall blocks.

STEP

Gravity Extenders for First Course of Inside Corner

Quick Steps

If MagnumStone gravity extender units are part of the approved engineering design, they can be added once the first course of MagnumStone base blocks are properly installed.
The size of gravity extender units required will vary depending on the retaining wall design.
Follow the retaining wall’s approved design to install 2 ft. (0.61 m.) or 4 ft. (1.22 m.) gravity extender units to the next MagnumStone base blocks along the rest of the first course.
At the discretion of the project engineer, impermeable materials can be placed and compacted at the toe of the wall. If this is specified, the amount of impermeable material should reach the desired height of the perforated drainpipe.
Once gravity extender units are installed, proceed to install adequate drainage, fill the hollow core blocks and surround the gravity extenders with clear crush drainage gravel, then add and compact layers of backfill behind the blocks as outlined here in these steps of the MagnumStone Unit Installation section.
Sweep any excess stones off the top of the blocks and gravity extenders before beginning to place the next course of retaining wall blocks.

STEP

Laying Second Course of Inside Corner Units

Quick Steps

Beginning at the corner of the wall again, place the first MagnumStone standard block of the second course perpendicular to overlap the lower corner units.
NOTE: The MagnumStone block design’s built-in setback results in a 1” (25 mm) setback for each additional course of the retaining wall. For inside corners, the first inside corner block will need to be placed 1” (25 mm) further inward to maintain the corner’s half-bond pattern alignment and structural strength.
Once the first standard block is placed 1” (25 mm) further inward on the inside corner of the second course (with SecureLugs in the hollow cores below), center the second MagnumStone standard block at a 90° angle, perpendicular to the first standard block.
The blocks should be tight together and level, with the facings meeting halfway along the second block’s facing.
Continue to place MagnumStone blocks along the second course in a running bond pattern along both sides of the inside corner until second course is complete.
Each block should be placed in direct contact with adjacent blocks, pressed as tightly together as possible to ensure there are no gaps between the blocks.
If no gravity extender units are required, proceed to install adequate drainage, fill the hollow core blocks with clear crush drainage gravel, then add and compact layers of backfill behind the blocks as outlined here in these steps of the MagnumStone Unit Installation section.
Sweep any excess stones off the top of the blocks before beginning to place the next course of retaining wall blocks.

STEP

Gravity Extender Units for Second Course of Inside Corner

Quick Steps

If MagnumStone gravity extender units are part of the approved engineering design, they can be added once the second course of MagnumStone base blocks are properly installed.
The size of gravity extender units required will vary depending on the retaining wall design.
Similar to the first course, begin placing gravity extender units to standard blocks in the corner of the retaining wall first.
Continue placing 2 ft. (24”) or 4 ft. (48”) gravity extender units as required by the retaining wall’s design plans for the remainder of the second course.
Once gravity extender units are installed, proceed to install adequate drainage, fill and compact the hollow core blocks and surround the gravity extenders with clear crush drainage gravel, then add and compact layers of backfill behind the blocks as outlined here in these steps of the MagnumStone Unit Installation section.
Sweep any excess stones off the top of the blocks and gravity extenders before beginning to place the next course of retaining wall blocks.

STEP

Higher and Top Courses of Inside Corner

Quick Steps

Repeat the same steps, placing the first block of each course 1 inch (25 mm) further inward and attach MagnumStone gravity extender units as outlined in the approved retaining wall design plans.
Properly install layers of clear crush gravel and approved backfill materials for each course as outlined in the previous steps.
Sweep any excess stones off the top of the blocks.
For the final course of the retaining wall, install MagnumStone top blocks for a clean finish and more versatility for top of wall details.
Add and compact gravel in the hollow core’s top block and install approved backfill materials behind the wall, until both are level with the back of the top block.
Lay soil separation fabric from the back of the top block’s facing over the block and approximately 12” (0.3 m.) over the backfill area.
Atop the remaining 8” (0.2 m.) behind the block facing, install planting soil to cover the soil separation fabric and backfill zone.