Concrete is the basis of nearly all farm buildings; it’s literally the foundation upon which walls stand on and girders are bolted to. While it is recommended that for larger jobs farmers delegate the work to a certified contractor who has a relevant “concrete ticket”, the reality is that some farmers who previously worked in the industry or have built up experience on their own farm will tackle the small/medium projects by themselves.
Type
Concrete strength is measured by newton metre, or N/mm2. The two most common strengths of concrete for farm building works are 37N/mm2 and 45N/mm2. For walled silos, silo slabs, silage aprons, silo channels and purpose-built silage effluent tanks, concrete shall be purchased on the basis of a characteristic 28-day cube crushing strength of 45N/mm2, equating to a minimum cement rate of 360kg/m2 of concrete. The higher rate of cement is required due to the corrosive nature of silage effluent, as is visible on many dated silage slabs or indeed along feed barriers in sheds. Concrete can be ordered through asking for “S.100 Mix A” or simply asking for “45N concrete with 360kg cement minimum”.
For all other concrete works, including slurry tanks and channels, shed walls, concrete footings and stanchion pads, 37N/mm2 concrete is perfectly acceptable, even for slurry tanks to which effluent will periodically drain to. A minimum cement content of 310kg/m3 is required, with concrete available to order through requesting “S.100 Mix B” or “37N concrete with 310kg cement minimum”.
Amount
Concrete is ordered in m3 form, and the amount of concrete required is generally easy to calculate through multiplying length x breadth x width.
Stanchions
Stanchions/RSJs (upright girders) should be built in to, or bolted on to a pad measuring 600mm x 600mm with a depth of 600mm. A hole of this size should be dug to as accurately as possible, meaning 0.21m3 of concrete will be required for each stanchion. In reality, digging a square hole to this level of accuracy is difficult, so 0.25m3 of concrete should be allocated for each hole required.
45N concrete is required for silage aprons, silage walls and silage effluent tanks due to the corrosive nature of effluent. \ Michael Mc Laughlin
Where there is no mass concrete floor to be poured, a 900mm x 900mm x 900mm concrete base should be poured for buildings up to 7.6m in span, increasing to a 1.2m3 base for buildings of a greater span.
Foundations
For mass concrete or block walls, foundations should measure a minimum of 600mm width and 300mm, meaning 0.18m3 of concrete will be required for each linear metre. It is recommended by the Department that four 12mm steel reinforcement bars, a minimum of 50mm from the bottom of the foundation, be installed for increased stability.
Floors
Solid floors are required to be a minimum 125mm in depth, laid smooth with a non-slip finish, especially important for livestock housing and handling. A minimum 150mm hardcore base shall be laid and compacted, followed by a fine layer of sand over which a 1,000 gauge polythene DPC membrane is laid. The polythene shall be taken up along the sides of the wall to prevent and movement of water. At a depth of 125mm, 0.125m3 of concrete is required for each m2.
It’s critical that floors are properly prepared in advance of concrete arriving in to the yard. Appropriate falls should already have been built in to the hardcore base, with calibration using a laser level before, during and after pouring essential.
Concrete is the basis of nearly all farm buildings; it’s literally the foundation upon which walls stand on and girders are bolted to. While it is recommended that for larger jobs farmers delegate the work to a certified contractor who has a relevant “concrete ticket”, the reality is that some farmers who previously worked in the industry or have built up experience on their own farm will tackle the small/medium projects by themselves.
Type
Concrete strength is measured by newton metre, or N/mm2. The two most common strengths of concrete for farm building works are 37N/mm2 and 45N/mm2. For walled silos, silo slabs, silage aprons, silo channels and purpose-built silage effluent tanks, concrete shall be purchased on the basis of a characteristic 28-day cube crushing strength of 45N/mm2, equating to a minimum cement rate of 360kg/m2 of concrete. The higher rate of cement is required due to the corrosive nature of silage effluent, as is visible on many dated silage slabs or indeed along feed barriers in sheds. Concrete can be ordered through asking for “S.100 Mix A” or simply asking for “45N concrete with 360kg cement minimum”.
For all other concrete works, including slurry tanks and channels, shed walls, concrete footings and stanchion pads, 37N/mm2 concrete is perfectly acceptable, even for slurry tanks to which effluent will periodically drain to. A minimum cement content of 310kg/m3 is required, with concrete available to order through requesting “S.100 Mix B” or “37N concrete with 310kg cement minimum”.
Amount
Concrete is ordered in m3 form, and the amount of concrete required is generally easy to calculate through multiplying length x breadth x width.
Stanchions
Stanchions/RSJs (upright girders) should be built in to, or bolted on to a pad measuring 600mm x 600mm with a depth of 600mm. A hole of this size should be dug to as accurately as possible, meaning 0.21m3 of concrete will be required for each stanchion. In reality, digging a square hole to this level of accuracy is difficult, so 0.25m3 of concrete should be allocated for each hole required.
45N concrete is required for silage aprons, silage walls and silage effluent tanks due to the corrosive nature of effluent. \ Michael Mc Laughlin
Where there is no mass concrete floor to be poured, a 900mm x 900mm x 900mm concrete base should be poured for buildings up to 7.6m in span, increasing to a 1.2m3 base for buildings of a greater span.
Foundations
For mass concrete or block walls, foundations should measure a minimum of 600mm width and 300mm, meaning 0.18m3 of concrete will be required for each linear metre. It is recommended by the Department that four 12mm steel reinforcement bars, a minimum of 50mm from the bottom of the foundation, be installed for increased stability.
Floors
Solid floors are required to be a minimum 125mm in depth, laid smooth with a non-slip finish, especially important for livestock housing and handling. A minimum 150mm hardcore base shall be laid and compacted, followed by a fine layer of sand over which a 1,000 gauge polythene DPC membrane is laid. The polythene shall be taken up along the sides of the wall to prevent and movement of water. At a depth of 125mm, 0.125m3 of concrete is required for each m2.
It’s critical that floors are properly prepared in advance of concrete arriving in to the yard. Appropriate falls should already have been built in to the hardcore base, with calibration using a laser level before, during and after pouring essential.
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