Gardenstone™ - Design and Installation Guide

Gardenstone™ Block

240L x 190W x 120mm H
4.2 Blocks per lineal metre
6.5kg each

Gardenstone™ Cap

240L x 190W x 120mm H
4.2 Blocks per lineal metre
9kg each

* Please Note: Gardenstone™ blocks should not be used for walls over 6 courses high, and are not suitable for load bearing walls. For these instances please refer to the 'Norfolk™' or 'Tasman™' Retaining wall specifications

Calculating Quantities

WALL HEIGHT	BLOCKS PER LINEAL METRE		CAPS PER LINEAL METRE
120mm (1 block high)	D	+	4.2
240mm (2 block high)	4.2	+	4.2
360mm (3 block high)	8.4	+	4.2
480mm (4 block high)	12.6	+	4.2
600mm (5 block high)	16.8	+	4.2
720mm (6 block high)	21.0	+	4.2

Example wall: 600mm high wall x 10 metres long =
Wall Blocks required 168 (10 metres x 16.8 blocks per metre)
Capping Blocks required 42 (10 metres x 4.2 blocks per metre)

Step 1	Dig out trench appprox. 150mm deep. The trench should be 500mm wide. Place and compact 100mm of fine crushed rock (gravel)
Step 2	Spread 25mm of sharp sand over the compacted base. This should be in straight line and checked with a level. If the wall tapers, run a string line at the desired finish level, then gauge down at multiples of 120mm.
Step 3	The first block course is now bedded into the sand bed. The use of a level and string is recommended to ensure that the first course is layed correctly. Make sure approx. 75mm of the first block course is buried below the finish ground level with gravel well compacted along the front of the block to stabilise.
Step 4	Where an agpipe or strip drain is used, place behind base of the first course. Backfill behind the blocks using a clean free draining material (e.g. blue metal). Allow 200mm wide for walls over half metre. Now compact backfill material thoroughly to remove all voids. Also fill the Gardenstone™ blocks to remove all voids. If backfill is needed behind the drainage area, existing sire soils may be used. (Do not use heavy clay.)
Step 5	Lay the second and subsequent courses following the same proedure e.g. use the correct backfill material and fill the blocks. Continue to lay and compact behind each block course. A Gardenstone™ capping block is layed as the final course (see above).
Curved Walls	If building a curved wall, be conscious that the length of courses will vary for a concave or convex wall, e.g.: the course length will shorten if the wall is convex and lengthen if concave.
Minimum Diameter	850mm (internal dimension). This is the minimum diameter. Adjust lower courses allowing for 25mm step back.