Good design starts with understanding exactly what you want to achieve. There are also a number of regulations and best storage practices that should influence your end design. Spending the time to get this right the first time will reduce your long-term costs.
To help get you on the right path to building your perfect Interbloc Silage Bunker, here are some good design basics.
The Site
Spending some time selecting a site will make a big difference in the future. Here are some guidelines to help you pick the best spot.
- Site the bunker away from hedges, trees, and major drains to ensure unimpeded access.
- The bunker should be accessible all year round, so think about drainage and soil types.
- Pests chew through covers which leads to spoilage – the bunker should be sited away from areas where pests may congregate.
- Siting the bunker close to where you will be feeding out will reduce the cost and time .
- Where the bunker is carved out of a hill side, water should be able to easily drain away from the bunker.
- Most milk companies require feed storage to be sited a minimum distance from the milking shed.
- Councils require bunkers to be sited away from surface water, and water tables.
- Increasingly there is a trend among councils to require silage effluent to be drained to your effluent pond. Considering this when choosing a site now could save you significant money in the future.
The Concrete Foundations
Ground Preparation
A concrete slab is only as good as the ground it sits on. Good ground preparation is essential to the structural integrity of the pad.
- All top soil, rubbish, and organic material should be removed. Soft spots should also be dug out and filled with compacted hard fill.
- A layer of compactable hard fill should be spread over the site. Dependent on the ground conditions, CCANZ suggest a layer 75mm thick.
- The subbase should be levelled to provide the required fall for water runoff. A common fall ratio is 1:50 (20mm every 1m).
- The design should allow for drainage at the lower side of the fall.
- The subbase must be well compacted.
- The subbase should be as level as possible. An un-level subbase will increase the likelihood of cracking.
Concrete Slab
The finished quality of the concrete slab is largely influenced by the ground preparation.
- Reinforcing steel doesn’t increase the load capacity of the pad. It is required for shrinkage control.
- CCANZ suggests slabs that are subject to acid attack, and traffic over 3 tonnes, should be between 125 and 150mm thick.
- Concrete shrinks when drying. This shrinkage causes cracking. Stress cuts are placed in the finished pad to control the cracking in a tidy way.
- The openness area of the farm environment makes slabs especially vulnerable to cracking in the days immediately following a pour. The reasons include the temperature fluctuation between night and day, and the increased likelihood of uninterrupted wind flow, which dehydrates the slab.
Other Interbloc Rural Options
If you don’t think a Silage Bunker doesn’t quite fit your needs, we also offer other rural solutions:
- PKE/Feed Bins
- Fertiliser Bins
- Culverts
