Podklady pre poľné prístrešky
Základ prístrešku, ktorý odvádza vodu a nezakladá trvalú stavbu
Poľné prístrešky si vyžadujú pevný, rovný povrch, ktorý odvádza moč a mokrú podstielku. Mriežky IBRAN to zabezpečia bez betónovania – prístrešok zostane čistý, suchý a tam, kde je to dôležité, aj prenosný.
Prečo základ rozhoduje
Poľný prístrešok je malá stavba s náročnou úlohou. Kone alebo hospodárske zvieratá v ňom stoja hodiny v najhoršom počasí, na najmokrejšej pôde roka, na jedinom mieste, ktoré si všetky naraz vybrali.
Ak stojí na holej zemi, pôda sa rozbahnuje v priebehu týždňov. Podlaha sa mení na zmes blata a podstielky, ktorú nemožno riadne vyčistiť, moč nemá kam odtekať, hromadí sa na povrchu a amoniak sa stupňuje. Vchod sa premení na najhlbšiu jamu na celom pozemku, pretože ním prechádza každé zviera.
Betón podlahu vyrieši, ale prinesie dva nové problémy. Je nepriepustný, takže moč a splachová voda nemajú kam ísť – tečú po povrchu a von dverami. A ide o trvalú stavbu, čo pri prístrešku určenom na premiestňovanie môže rozhodnúť o tom, či si vyžaduje stavebné povolenie, alebo nie.
Mriežkový základ poskytuje pevnú, rovnú a čistiteľnú podlahu, ktorá odvádza vodu priamo cez seba, drží podstielku namiesto toho, aby ju pohltila, a dá sa zdvihnúť a premiestniť spolu s prístreškom, keď to bude potrebné.
Kde to funguje najlepšie
- Mobilné a lyžové poľné prístrešky
- Statické poľné prístrešky a voľné boxy
- Predsiene a vstupné plochy prístreškov
- Prístrešky pre hospodárske zvieratá a teľacie búdy
- Základy skladov sena a krmiva
- Stanovištia kruhových kŕmidiel a napájadiel
- Základy a prístupy k hnojisku
- Stojné plochy pri prístreškoch
Stručný prehľad
| Podkladová vrstva | 150–250 mm zhutneného štrkodrvového lôžka, viac na mäkkej alebo mokrej pôde |
| Výplň | Frakcia 6–14 mm, hranatý triedený kamenný mix, čistý bez jemných podielov, vyplnený po hornú hranu buniek |
| Celková hĺbka výkopu | Približne 200–300 mm podľa podmienok podložia a výšky mriežky |
| Odvodnenie | Plne priepustné. Moč a mokrá podstielka odtekajú cez podlahu, nezdržiavajú sa na povrchu |
| Podstielka | Pevný rovný povrch, ktorý drží hobliny alebo slamu a dá sa čisto vyčistiť |
| Prenosnosť | Žiadna liata konštrukcia. Mriežky sa dajú zdvihnúť a znovu uložiť pri premiestnení prístrešku |
| Životnosť | 25 rokov pri doloženom spôsobe inštalácie |
| Materiál | 100% recyklovaný polypropylén, udržateľne vyrobený v EÚ |
Mobilné prístrešky a otázka trvalosti stavby
Toto je dôležité pochopiť ešte pred začatím stavby, pretože to môže ovplyvniť, čo vám bude povolené.
Mobilné poľné prístrešky sa často posudzujú inak ako trvalé stavby, a to na základe toho, že sú skutočne prenosné a nie sú pevne spojené so zemou. Postavenie prístrešku na liatu betónovú dosku alebo jeho ukotvenie k trvalému základu môže tento argument oslabiť a prístrešok preradiť do kategórie trvalej stavby.
Mriežkový základ nie je liaty základ. Ide o zhutnenú, ohraničenú kamennú plochu, na ktorej prístrešok stojí, a dá sa zdvihnúť a znovu uložiť inde. Pre mobilný prístrešok je to spravidla vhodnejšie riešenie aj z praktického hľadiska – prístrešok môžete premiestniť kvôli striedaniu pastvy a základ vziať so sebou.
Posudzovanie z hľadiska stavebného povolenia sa líši podľa miestneho stavebného úradu a konkrétnych okolností a závisí od prístrešku, pozemku a spôsobu jeho využívania, nie len od samotného základu. V prípade akýchkoľvek pochybností sa pred začatím stavby poraďte s miestnym stavebným úradom. Je to krátky rozhovor a oveľa lepšie ho absolvovať vopred.
Aká hĺbka mriežky?
Číslo v názve mriežky vyjadruje hĺbku ohraničenej kamennej vrstvy. Prístrešky kombinujú stojace zvieratá s príležitostným prejazdom ťažkých vozidiel, preto volte radšej hlbšiu mriežku, ako by ste zvolili pre záhradnú stavbu.
- IBRAN®-X50 odporúčame pre vstupnú predsieň a pre celý základ tam, kde traktor prístrešok ťahá, vyváža hnojivo alebo dováža podstielku.
- IBRAN®-X40 pre samotnú podlahu prístrešku, kde sa manipuluje ručným vozíkom a vidlami, nie strojom.
- IBRAN®-X30 pri kladení na existujúcu spevnenú plochu alebo tam, kde výška musí nadväzovať na susedný dvor.
V prípade pochybností zvoľte pri dverách ťažšiu variantu. Práve tam každé zviera zastaví, otočí sa a stojí – a práve tam každý základ zlyhá ako prvý.
Výber kameniva
Použite hranatý triedený kamenný mix frakcie 6–14 mm, čistý bez jemných podielov, vyplnený po hornú hranu buniek.
Triedený mix je tu dôležitejší ako takmer kdekoľvek inde. Mix sa uloží hustejšie ako jednofrakcové kamenivo, pretože menší kameň vypĺňa medzery medzi väčším. Husto uložený povrch je stabilný: nič sa nepohybuje pod kopytom, nič sa neuvoľňuje, a podstielka leží na pevnej podlahe namiesto toho, aby sa do nej prepadávala.
Kamenivo udržujte jemné a hranatejšie, nie veľké ani okrúhle. Voľné alebo nadrozmerné kamenivo sa môže pohybovať pod kopytom, odrenúť podrážku alebo uviaznuť v podkove – a v prístrešku na ňom zviera stojí hodiny.
Jemné podiely vylúčte úplne. Čokoľvek s prachom alebo kamennou múčkou sa spojí, bude zadržiavať moč a vodu na povrchu a spôsobí problém s amoniakom, ktorému ste chceli základom predísť.
How it goes in
- Choose the position carefully. Shelters want to sit on the driest ground available, with the back to the prevailing wind and the opening away from it, and with somewhere for water to go that is not the doorway.
- Mark out the base well beyond the shelter footprint, taking it out furthest at the opening. The apron outside the door is not optional: it is where the wear actually happens.
- Dig the mud out down to firm subsoil. Poached ground has no bearing capacity, and anything laid on it will sink into it over one winter.
- Lay a woven geotextile across the formation, lapping joins by at least 300mm. On soft ground it is structural, stopping the sub-base punching down and stopping soil pumping up into your surface.
- Lay and compact the sub-base in 50mm layers, to a depth that suits the ground and the vehicles that will come to the shelter.
- Blind with a thin layer of grit sand and screed it level, with a slight fall away from the shelter towards the opening or to one side.
- Push-fit the grids together, staggering the joints. Cut to line around skids, posts and the door opening with a saw.
- Fill the cells with a 6-14mm angular graded blend, level with the cell tops, brushing in thoroughly so no cell is left hollow.
- Set the shelter in position and check it sits level on its skids or bearers before it is used.
Full step-by-step detail is in our installation guides.
The apron outside the door
If you only reinforce one part of a shelter site, make it this.
Every animal using the shelter passes through one opening, and most of them stop in it: half in, half out, watching the field, standing in the same spot for hours. That doorway takes more traffic and more standing time than the whole of the rest of the field put together, and it is the first place to poach.
Take the base out at least a shelter's depth beyond the opening, and wider than the opening on both sides. Where a group shares the shelter, take it further still, because the animals that cannot get in will stand as close as they can and churn the ground doing it.
Get the falls right at the same time. Water running off the shelter roof lands exactly here, and if it has nowhere to go it will undo the work.
Bedding, mucking out and drainage
A permeable base changes how the shelter works day to day.
Urine and moisture drain down through the stone instead of soaking into bedding and sitting on the floor, which keeps the bed drier, reduces ammonia and means bedding goes further. There is no low corner collecting liquid and no wash of muck out through the doorway.
Mucking out is easier because you are working on a firm, level surface: a fork does not dig into the floor, and a barrow wheels rather than sinks. Where a tractor and bucket do the job, specify the deeper grid across the whole floor so the base takes the machine as well as the animals.
Where drainage from a shelter could reach a watercourse, ditch or borehole, check what applies to you before building. Rules on managing run-off from areas used by livestock vary and are worth confirming with your local authority or environmental regulator.
Anchoring and wind
Field shelters blow over. They are large, light, and usually in the most exposed spot on the holding.
A mobile shelter on skids relies on its own weight and its skids bedding into the ground, and a firm level base makes that behaviour more predictable rather than less. Where the manufacturer specifies ground anchors, these can fix through the base into the compacted sub-base beneath, which is another reason to compact that layer properly rather than tipping and raking it.
Follow whatever the shelter manufacturer specifies. It is their structure, and their anchoring recommendation accounts for its size, shape and exposure in a way that generic advice cannot.
Get it right first time
The one thing worth knowing: build the base bigger than the shelter.
A base that stops at the walls solves the floor and leaves the real problem untouched. The mud simply forms at the threshold instead, and everything then walks through it to get inside, dragging it onto the clean floor you just built.
Extend the base out into the field at the opening, round the sides where animals shelter from wind, and to wherever a barrow or tractor comes and goes. The extra area is the cheapest part of the job and it is what turns a dry shelter into a dry shelter you can actually reach.
Ask our engineer
Questions about depths, apron sizing, drainage or which system suits your shelter? Ask below, or get in touch directly.
Common Questions
Do I need a concrete base for a field shelter?
No, and for a mobile shelter concrete is often the wrong answer. A grid base gives a firm, level, cleanable floor that drains straight through rather than holding urine and wash-down on the surface, and it is not a poured foundation, so it can be lifted and relaid if the shelter moves.
It is also considerably quicker to build and needs no curing time.
Will a concrete base make my mobile field shelter permanent?
It can affect how the shelter is treated. Mobile field shelters are often treated differently from permanent buildings on the basis that they are genuinely movable and not fixed to the ground, and standing one on a poured slab or bolting it to a permanent foundation can undermine that.
Planning treatment varies by authority and circumstance, so ask your local planning authority before building if there is any doubt.
How deep should a field shelter base be?
Around 200mm to 300mm in total, made up of 150mm to 250mm of compacted MOT sub-base plus the grid depth, with more on soft or wet ground.
Dig out to firm subsoil first: poached ground has no bearing capacity, and anything laid on it will sink into it over one winter.
What stone should I use in a field shelter base?
A 6mm to 14mm angular graded blend, clean and free of fines, filled level with the cell tops. A blend packs tighter than a single size, and a densely packed surface is a stable one, so nothing rolls underfoot and bedding sits on a solid floor rather than sinking into it.
Keep the stone fine and angular: loose or oversized material can move under a hoof, bruise a sole or lodge in a shoe.
How far should the base extend beyond the shelter?
Take it at least a shelter's depth beyond the opening and wider than the opening on both sides. Every animal passes through one doorway and most of them stand in it, so that spot takes more traffic and standing time than the rest of the field put together.
Where a group shares the shelter, extend it further, because animals that cannot get in will stand as close as they can.
Does a permeable base help with bedding and ammonia?
Yes. Urine and moisture drain down through the stone instead of soaking into the bedding and sitting on the floor, which keeps the bed drier, reduces ammonia and makes bedding go further.
There is no low corner collecting liquid and no wash of muck out through the doorway.
Is it easier to muck out than bare ground?
Considerably. You are working on a firm level surface, so a fork does not dig into the floor and a barrow wheels rather than sinks.
Where a tractor and bucket do the job, specify the deeper 50mm grid across the whole floor so the base takes the machine as well as the animals.
Which grid depth should a field shelter use?
The 50mm grid for the entrance apron, and for the whole base where a tractor tows the shelter, mucks it out or delivers bedding. The 40mm for the shelter floor where handling is done by barrow and fork. The 30mm where you are laying over existing hard standing or matching an adjoining yard level.
If in doubt, take the heavier option at the doorway.
How do I anchor a field shelter on a grid base?
Follow the shelter manufacturer's recommendation, since it accounts for the structure's size, shape and exposure. A mobile shelter on skids relies on its own weight and its skids bedding in, and a firm level base makes that behaviour more predictable.
Where ground anchors are specified, they can fix through the base into the compacted sub-base beneath, which is a further reason to compact that layer properly.
Can the base be moved with the shelter?
The grids can be lifted and reinstated, which suits ground rotation or a shelter that changes position.
Bear in mind the excavation and sub-base stay behind, so the reusable element is the grid itself rather than the whole build-up.
Ask our engineer
Questions about depths, sub-base, edging or which system fits your project? Ask below.
