Landscape Newsletter Issue 12
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Old and New Come Together with Style
Mario Iantosca is old school. He learned his trade from his father in Naples Italy, where stonemasons have practiced their trade for thousands of years. When Mario immigrated to the Boston area, he carried on the family tradition. He began installing brick, block and stone the old fashioned way, with mortar and footings. When Allan Block was introduced in his area in the early 1990’s, Mario was one of the first to try the “new product”.

“My first Allan Block project was a set of three terraced walls, each about four ft. high (1.2 m). I made sure the walls were spaced properly and the rest was easy. With Allan Block, all you need is good crushed stone and some common sense. The blocks go together like butter on bread. I drive by that wall from time to time and it still looks great,” says Mario.

AB Collection Pattern Wall
AB Collection, terraced wall

Patterned wall with stairs 		Steve and Civita Fulchini were just getting settled in to their new home in Hammersmith Village. Their homeowner association required all landscaping to be completed much sooner than they had anticipated, and knew they needed retaining walls. They stopped in at Linden and Malden Supply in Malden, MA and talked to John Rappoli for advice. John, a long time Allan Block dealer through Gilbert Block, took them through the AB Collections, explaining the price and color options along the way. Civita loved the look of the AB Europa Collection, Allan Block’s antiqued line of products, and especially liked the patterned walls. Steve found a color in the AB Ashlar Collection that complimented their home’s brick exterior perfectly, and at a more affordable price. They decided to go with an AB Ashlar Blend patterened wall. Mario Iantosca was recommended to install the project.

“I visited Steve and Civita at the site and they were thinking one larger wall would do the job. But I could see a set of three walls with a planting space in between, and they liked that idea too. When I brought the engineer out to check the site and soil conditions, he wondered how I would get the stairway up through the walls and still meet code. I told him not to worry and to come back in a couple days to check the job. If you are used to working with your hands, Allan Block is easy. I get more block up in a day because you don’t need footings or mortar, and the walls turn out beautiful,” says Mario.

Steve and Civita are ecstatic with the work. They liked the front walls so well, they had Mario use the AB Stones in a matching color to build small walls in back and along the side of the drive. And Mario is happy to be building the same quality of walls his family has been building for generations. Old world craftsmanship with Allan Block.

Building a Landscape Wall - Basic Installation

Following is an excerpt from the new Landscape Walls Guide and the How To Install DVD.

You should have a detailed design to ensure your wall and landscape project will be built correctly. Before building, use the AB Landscape Walls Guide to plan and design out the entire project to ensure the project will come together smoothly.

The following shows how to build a gravity wall. See the Maximum Wall Height Chart to determine if your project will need reinforcement.

AB Collection

Base Preparation for a Landscape Wall (gravity wall application)

  • To start your layout, place stakes to represent the location of the front of the wall. Using a string line or paint, mark out the entire length. A garden hose is an excellent tool to use when laying out curved walls.
  • Excavate the area by removing all surface vegetation and organic materials from the area. These cannot be used as backfill material.
  • If the wall needs geogrid reinforcement due to height or soil conditions, see the AB Landscape Walls Guide for complete installation information.
  • Starting at the lowest point, dig a base trench 24 in. (600 mm) wide the length of the wall. For walls where the base trench steps up, see the AB Landscape Walls Guide for more information.
  • The depth of the trench will be 6 in. (150 mm) plus an additional 1 in. (25 mm) for each 1 ft. (300 mm) of wall height for the amount of buried block that is needed.
  • Compact the base trench making a minimum of two passes with a walk behind plate compactor.
  • Foundation soils at the bottom of the base trench must be firm and solid. If the soils are made up of heavy clay or wet soils, or the areas have been previously excavated, remove this material and replace with a granular material, compacting in 8 in. (200 mm) lifts or less.

Base Material

  • A drain pipe is required for any reinforced wall or any wall over 4 ft. (1.2 m) tall. Place the drain pipe at the lowest possible point toward the back of the trench and vent to daylight every 50 ft. (15 m).
  • Place a minimum of 6 in. (150 mm) of wall rock in the base trench and rake smooth.
  • Compact the wall rock making a minimum of two passes with a plate compactor.
  • Check the entire length for level, and adjust as needed.

Start at the lowest elevation

Install Base Course

  • Begin the base course at the lowest wall elevation.
  • Place all blocks with the raised front lip facing up and forward on the base material near the front of the base trench.
  • Check and adjust each block for level from side-to-side and front-to-back.
  • Make minor adjustments by tapping the AB blocks with a dead blow hammer. It is acceptable to place up to 0.5 in. (13 mm) of coarse sand under the blocks to help level the base course.
  • Irregularities in the base course become larger as the wall stacks up. Careful attention to a straight and level base course will ensure a quality finished wall.

Backfilling and Compaction

  • Fill in the area in front of the blocks with on-site soils. This will keep the base course blocks from shifting while filling and compacting.
  • Fill the hollow cores of the base course and 12 in. (300 mm) behind the block with wall rock to the height of the block.
  • Use infill or approved on-site soils to backfill behind the wall rock in lifts of no more than 8 in. (200 mm).
  • Use a plate compactor to consolidate the wall rock directly behind the block then compact in a path parallel to the wall, working from the back of the block to the back of the excavated area with a minimum of 2 passes.
  • Check the base course for level and adjust as necessary.
 Mark and Excavate Area
Mark and excavate area

Base Trench
Base Trench Specifications

Compact
Compact

Install drain pipe, wall rock and level
Install drain pipe, wall rock and level

Install base course, level and align
Install base course, level and align

Backfill wall rock and infill soils. Compact.
Backfill wall rock and infill soils. Compact.

Install next course. Level and align.
Install next course. Level and align.

Backfill and compact.
Backfill and compact.

Additional Courses

  • Remove all excess material from the top surface of all blocks. This prepares a clean, smooth surface for placement of the next course.
  • Stack the next course of blocks so that the vertical seams are offset from the blocks below by at least 1/4 the length of the block.
  • Check each block for level and alignment, making adjustments as needed.
  • Fill the hollow cores and 12 in. (300 mm) behind the block with wall rock to the height of the block.
  • Use infill or approved onsite soils to backfill behind the wall rock in lifts of no more than 8 in. (200 mm).
  • From the 2nd course and above use a plate compactor to compact directly on the blocks as well as the area behind the blocks. Compact in lifts of 8 in. (200 mm) or less.
  • Repeating these steps, complete the wall to the desired height. See the AB Landscape Walls Guide for information on finishing wall options.

Check here to see if your project can be built without AB Reinforcement Grid.