COUNTRY MANOR TM DIY RETAINING GUIDE

Transcription

1 COUNTRY MANOR TM DIY RETAINING GUIDE HOW HIGH Keystone Country Manor can be installed as a gravity retaining wall, a reinforced retaining wall or a free standing wall. The maximum heights for the gravity retaining wall are 600mm near vertical or 900mm with the 9 degree battered set back. For a free standing wall the maximum height would be 600mm. For geogrid reinforced Country Manor retaining walls please contact your local Firth representative for more information. INSTALLATION Safety First know what is below your proposed excavation before you dig, contact your local authority if in doubt. Always start at lowest point of wall, excavate a working trench 500mm wide and deep enough to allow a bedding course of 150mm gap20 or gap 40 after compaction. The block needs to be embedded below your finished ground by a minimum of 50mm. Ensure that when placing the blocks the channel groove is on the bottom face of the block, the pin holes are on top. When building with the Country Manor system the units can be oriented in two positions open or closed. For retaining walls either the open or closed position will work. For free standing walls, parapets, column s and pilasters the closed alignment should be used, when using the open alignment be sure that the drainage aggregate fully fills the gap. It is important that the first course goes in level, take time to ensure that the blocks are level front to back and side to side, time taken here will speed the installation of further courses. Pins are a separate item and need to be ordered separately. The Keystone Country Manor system has varied pin holes to adapt to different circumstances. If building a near vertical wall use the pin hole that aligns through the middle of the block. For the battered wall use the pin hole at the back when looking at the face of the wall. After installing pins, clean drainage material 20/6 (clean stones from 6mm to 20mm in size with no fine sand or chip in it) or similar is to be used to fill the voids of Country Manor blocks and the drainage zone (the area 300mm behind back of block). Fill each course and sweep blocks clean of all loose material before installing the next course. Behind the drainage zone backfill the cut in lifts of 150mm using sand or gravel. Avoid using a media that holds water or that can shrink or swell depending on water content. For Gravity wall applications, site fill is ok to be used for backfill. Place next course of units over fibreglass pins, aligning pins with long receiving channel groove of units above. If pins do not connect with channel groove but instead align with core of unit above, place drainage material into core to provide unit interlock with pin FIRTH 1 firth.co.nz

2 CAPPING After cleaning off the last course in preparation for the caps, use construction adhesive for a mechanical bond. Cap may be flush or overhanging as required by aesthetics and design. ALIGNMENT Check the alignment by running a stringline along the pin holes for a straight wall, and using a level to check front to back. If correction is required, slide the block back or forward to line the pin holes up, if the blocks are leaning back inorganic shims can be used at the rear of the block to bring level in small increments. If the blocks are leaning forward i.e. they are higher at the back than front, immediate action to correct must be taken, the use of inorganic shims at the front of the block can utilised to correct the lean in small increments. If the lean exceeds 20mm from the back of the block to the front then the wall will need to be disassembled and rebuilt with corrective actions to fix the lean undertaken. TERRACING The distance between walls when terracing must be greater than twice the height of the lower wall, where this cannot be achieved the total height of the retaining must be calculated as one wall. GEOGRIDS Country Manor walls over 900mm high or any walls supporting vehicles, building foundations, slope or other load that requires geogrid soil reinforcing will need to be engineered, consult your local Firth representative (0800 FIRTH 1) for more information and advice.

3 ESTIMATING TABLE Wall Length Wall Height 1m 2m 5m 10m 20m 30m 0.15m ( 1 course ) 2 sets 3 sets 6 sets 13 sets 25 sets 37 sets 0.3m ( 2 courses ) 3 sets 5 sets 13 sets 25 sets 50 sets 75 sets 0.45m ( 3 courses ) 4 sets 8 sets 19 sets 37 sets 75 sets 112 sets 0.6m ( 4 courses ) 5 sets 10 sets 25 sets 50 sets 100 sets 146 sets 0.75m ( 5 courses ) 6 sets 13 sets 31 sets 62 sets 125 sets 187 sets 0.9m ( 6 courses ) 8 sets 15 sets 37 sets 75 sets 150 sets 224 sets Cap (units) FIRTH 1 firth.co.nz

4 DESIGN DETAILS Corners with Setback Near Vertical Corners

5 DESIGN DETAILS Curves Column Corner

6 DESIGN DETAILS Bracing free standing walls 0800 FIRTH 1 firth.co.nz