Kompostbeholdere til haven
En kompostboks der aldrig rådner med i komposten
Kompost nedbryder det der indeholder den. PolyBrick®-bure er upåvirkede: ingen råd, ingen behandling, ingen udskiftning – og åbne fuger der lader bunken trække vejret.
Hvorfor PolyBrick fungerer her
Der er en særlig ironi i en trækompostbeholder. Bunken indeni er en maskine til at nedbryde organisk materiale, og beholderen er lavet af organisk materiale. Paller holder to til tre år. Trykimprægneret træ holder lidt længere og bringer træbeskyttelsesmidler i kontakt med kompost du skal sprede på dyrkede arealer.
PolyBrick er ikke føde for bunken. Det rådner ikke, og materialet er inert, så intet vandrer fra beholderen over i komposten. Det er UV-stabiliseret, så den solvendte side ikke bliver skør mens den skyggefulde side forbliver fugtig.
Den anden fordel er praktisk: fordi blokkene samles med stikforbindelser frem for at være fastgjort, kan en boks tages fra hinanden. Enhver der har forsøgt at vende en bunke eller tømme en beholder gennem en lille låge vil forstå hvorfor det betyder noget.
Hvor dette fungerer godt
- Enkelt kompostbur til haven
- To- og treburs rotationssystemer
- Løvmuldbure
- Kompostering på kolonihaver og fællesarealer
- Opbevaring af græsafklip og haveaffald
- Møddingsbure og gødningsopbevaring
- Opbevaring af flis og bark
- Skole- og fælleshavelager
Overblik
| Samling | Stikforbindelser. Ingen værktøj, ingen mørtel, ingen beslag |
| Adgang | Forreste skifter kan fjernes for at åbne buret til vending og tømning |
| Luftning | Byg med mellemrum mellem blokkene så luft når bunken gennem væggene |
| Bund | Åben mod jord, så regnorme og organismer kan trænge ind og væske dræner væk |
| Kontakt | Inert. Intet udvaskes til kompost beregnet til dyrkning |
| Materiale | 100% genanvendt polypropylen, UV-stabiliseret, fremstillet i EU af genanvendt plast |
| Levetid | 25 år under garanti |
| Vedligeholdelse | Ingen. Skyl det ned hvis du vil; det er omfanget af det |
Byg det til at trække vejret
En kompostbunke har brug for luft. Uden den bliver processen anaerob, hvilket er langsommere, koldere og producerer den sure lugt der får folk til at give op på kompostering.
Byg sidevæggene med bevidste mellemrum mellem blokkene frem for solide, så luft bevæger sig ind gennem væggene langs hele bunkens højde. Det er samme princip som en ribbetræsbeholder – uden at ribberne rådner.
Lad bunden stå åben mod jord. Regnorme, svampe og bakterier koloniserer bunken nedefra, væske dræner væk i stedet for at samle sig, og bunken forbliver i kontakt med den jord den kom fra.
Hvorfor tre bure slår ét
Et enkelt bur er et sted at putte haveaffald. Et treburs-system er en proces, og det producerer betydeligt mere brugbar kompost med mindre arbejde.
Princippet er enkelt: bur ét er det du fylder nu, bur to er det du fyldte sidst og som aktivt rådner, bur tre er færdig kompost klar til brug. Når bur tre er tomt, rykker alt et bur frem, og selve flytningen af materialet vender og lufter det – det er det der accelererer hele processen.
Fordi systemet er modulært kan du starte med ét bur og tilføje de øvrige efterhånden som mængden vokser, frem for at forpligte dig til hele anlægget fra dag ét.
How it goes together
- Choose a level spot with reasonable access. You will be wheeling barrows to it in all weathers, so a route that is not across wet lawn is worth having.
- Clear the ground and level it. Leave the base as bare soil rather than paving it, so the heap stays in contact with the ground.
- Lay the first course and check it level in both directions. Everything above follows it.
- Build up the back and sides in courses, leaving gaps between blocks for airflow, and staggering the joints between courses.
- Build the front as loose, stackable courses that lift out rather than as part of the structure. This is your access.
- Where you are building multiple bays, share the dividing walls between them.
- Cap the top course if you want a finished edge, and leave the top open or cover the heap with a sheet or old carpet to keep rain off.
The removable front
This is the detail that makes a bay pleasant to use rather than a chore, and it is where most bought bins fail.
Build the front wall as courses that simply lift out. Fill the bay with the front in place, then remove the courses one at a time as you dig the heap out, so you are always working at a comfortable height with the face of the heap open to you.
Compare that with a plastic dalek bin, where finished compost is at the bottom, under everything you have added since, behind a hatch the size of a letterbox. The removable front is the single biggest reason people actually turn their heaps.
Sizing the bay
Bigger heaps work better. A heap needs enough mass to hold heat, and a small bin loses it to the outside faster than the process generates it, which is why little bins produce cold, slow compost.
Around a cubic metre is the usual working minimum for a heap that heats properly. Below that, composting still happens, it is just slower and stays cooler, which means weed seeds and roots survive it.
Do not go so wide that you cannot reach the middle with a fork. Depth front to back is more useful than width, and if you have the space, another bay beats one enormous one.
Muck heaps and green waste
The same structure works for manure storage, grass clippings and wood chip, and for those the material advantage is even clearer, because these are wetter, heavier and harder on a container than garden compost.
For muck heaps, check what applies to you on storage siting and run-off before you build. Rules on storing manure near watercourses, ditches and boreholes vary, and the position of the heap matters more than the bay it is in.
Get it right first time
The one thing worth knowing: put it somewhere you will actually walk to.
The most common composting failure is not technique, it is distance. A bay at the far end of the garden, across the lawn, behind the shed, gets used enthusiastically in spring and abandoned by October when it is dark and wet.
Site it somewhere on a route you already take, with a firm approach underfoot. Slightly less tidy and considerably more used beats beautifully hidden and full of nettles.
Ask our engineer
Questions about bay sizing, multiple bay layouts or muck heap storage? Ask below, or get in touch directly.
Common Questions
Why use plastic blocks for a compost bay instead of wood?
A compost heap is a machine for breaking down organic material, and a wooden bin is organic material. Pallets last two or three years, and treated timber puts preservative in contact with compost you may spread on food crops.
PolyBrick does not rot and is inert, so nothing moves from the bay into the compost, and it is UV stabilised so the sunny side does not go brittle.
Does a compost bay need gaps for airflow?
Yes. A heap without air goes anaerobic, which is slower, colder and produces the sour smell that makes people abandon composting.
Build the side walls with deliberate gaps between blocks so air moves in through the walls along the full height of the heap. It is the same principle as a slatted timber bay, without the slats rotting.
Should the compost bay have a base?
Leave it open to bare soil. Worms, fungi and bacteria colonise the heap from below, liquid drains away instead of pooling, and the heap stays in contact with the ground.
Paving underneath cuts the heap off from the organisms that do the work.
How big should a compost bay be?
Around a cubic metre is the usual working minimum for a heap that heats properly, because a heap needs enough mass to hold heat and small bins lose it faster than the process generates it.
Below that, composting still happens but stays cool and slow, which means weed seeds and roots survive. Do not go so wide that you cannot reach the middle with a fork.
How do you get the compost out?
Build the front wall as loose courses that lift out rather than as part of the structure. Remove them one at a time as you dig the heap out, so you are always working at a comfortable height with the face of the heap open.
It is the single biggest reason people actually turn their heaps, compared with a bin where finished compost sits at the bottom behind a small hatch.
Is a three bay system worth it?
It turns composting from storage into a process. Bay one is what you are filling, bay two is actively rotting, bay three is finished and ready to use. When bay three empties everything shifts along, and moving material between bays turns and aerates it, which accelerates everything.
Because the system is modular you can start with one bay and add others as volume grows.
Can I use it for a muck heap or grass clippings?
Yes, and the material advantage is even clearer, because manure, clippings and wood chip are wetter, heavier and harder on a container than garden compost.
For muck heaps, check what applies to you on storage siting and run-off before building, since rules on storing manure near watercourses, ditches and boreholes vary and the position matters more than the bay.
Does the bay need a lid?
Not structurally, but covering the heap helps. Keeping heavy rain off stops the heap becoming waterlogged and cold, and retains warmth.
A sheet, a board or an old carpet over the top is enough, and it can be lifted off when you add material.
Will it need any maintenance?
No. There is nothing to rot, treat, stain or replace, and no fixings to work loose. Rinse it down if you want to, but that is the extent of it.
The blocks carry a 25 year warranty and can be dismantled and reused elsewhere if you reorganise the garden.
