Støttemure
Lave støttemure uden mørtel eller hærdetid
Terrassér haven uden en murer. PolyBrick®-blokke samles ved tryk-fit på et korrekt forberedt fundament, så lave støttemure rejser sig på få timer og holder i årtier.
Hvorfor PolyBrick løser opgaven
En støttemur er det projekt, de fleste udskyder. Murværk kræver mørtel, blanding, hærdetid og præcision fra første kurs. Sveller rådner bagfra, hvor man ikke kan se det. Gabioner kræver et øvet blik for at se tilsigtet frem for industrielt.
PolyBrick omgår det meste af det. Blokkene låser sammen ved tryk-fit, så der er ingen mørtel, ingen blanding og ingen hærdetid: muren er færdig, når du holder op med at bygge, ikke tre dage senere. Intet rådner, ruster, krymper eller deformerer, så bagsiden er lige så solid i år femten som forsiden.
Det kræver dog et korrekt forberedt fundament. En støttemur af enhver art koncentrerer belastningen i et smalt stykke jord, så grøften, det kompakterede fyld og niveauet på det første kurs bærer alt det ovenstående. Hvad fundamentet skal bestå af, afhænger af murens højde, undergrunden og det, der skal holdes tilbage, så afklar det for dit specifikke anlæg, inden du begynder.
Velegnede anvendelser
- Haveterrasser og niveauforskelle
- Afgrænsning af højbede og borde
- Kantafgrænsning ved indkørsel og sti
- Trapper og platforme i skrånende haver
- Lave hegns- og skærmvægge
- Plantekasse- og siddepladsvægge
- Indhegning til skraldespande og brændestabler
- Terrasser i kolonihaver og fællesanlæg
Overblik
| Samling | Tryk-fit interlock. Ingen mørtel, ingen cement, ingen specialværktøjer |
| Armering | [Bekræft: stangdiameter, kvalitet, afstand, forankringsdybde, maks. højde, jordbundsforhold] |
| Fundament | Udgravning til fast undergrund, kompakteret og afrettet i vater. Specificeres for det enkelte anlæg |
| Dræning | Frit drænende bagfyld er afgørende. Vandtryk er årsagen til, at støttemure svigter |
| Materiale | 100% genanvendt polypropylen, UV-stabiliseret, fremstillet i EU af genanvendt plast |
| Vedligeholdelse | Ingen. Ingen råd, ingen rust, ingen fugning, ingen behandling |
| Trykstyrke | Testet til 150 tonnes/m² under fast statisk belastning |
| Levetid | 25 år med garanti |
Kend begrænsningerne, inden du begynder
Det er værd at være direkte om dette, fordi støttemure er den eneste havestruktur, hvor fejl har konsekvenser ud over det æstetiske.
En støttemur holder jord tilbage, og jord er tung, særligt når den er mættet med vand. Jo højere muren er, desto større kraft skal den bære, og forholdet er ikke lineært: en mur, der er dobbelt så høj, bærer betydeligt mere end dobbelt så stor belastning.
Til lave haveterrasser, højbede og kantafgrænsning er en korrekt opbygget PolyBrick-mur på et kompakteret fundament fuldt ud inden for sit arbejdsområde. For alt, der er højere, alt der holder en indkørsel eller en konstruktion tilbage, alt på en stejl eller ustabil skråning, eller alt hvor et svigt ville påvirke en nabo, en bygning eller en vej, bør der indhentes ingeniørrådgivning, og muren bør projekteres. Det gælder for ethvert materiale, ikke kun dette.
Er du i tvivl om, hvilken side af den grænse dit projekt befinder sig på, så fortæl os højden, hældningen og hvad der er over og under muren, og vi giver dig et ærligt svar frem for et salg.
Dræning er det, der holder en mur stående
De fleste svigt i støttemure skyldes vand. Jord bag en mur opsuger regn, det vand har vægt og ingen steder at komme hen, og trykket opbygges, indtil noget bevæger sig.
Byg fri dræning ind fra starten. Bagfyld direkte bag muren med rent, kantet skærver frem for den jord, du gravede ud, så vandet løber ned gennem stenene i stedet for at belaste bagsiden. Hvor en mur er mere end et par kurser høj, læg et perforeret drænrør ved bunden af stenlagget og før vandet væk til et egnet sted.
PolyBricks fordel her er, at materialet er ligeglad med vandet. Der er intet, der rådner, ruster eller afskalles, og fugerne er ikke mørtel, der kan vaskes ud. Få dræningen rigtigt, og muren er reelt vedligeholdelsesfri.
How it goes up
- Set out the line of the wall and check what is behind it. On a slope, work out where water currently runs, because the wall will interrupt it.
- Excavate a level trench along the line, wider than the wall itself, and dig out any soft or made ground until you reach firm subsoil.
- Lay a woven geotextile in the trench, then fill with compacted granular material and screed it dead level. This base carries the whole wall, and a wall built on an uneven base will show it in every course above.
- Lay the first course and check it with a spirit level along its length and across its width. Everything above follows this course, so take the time.
- Build up in courses, pushing blocks together and staggering the joints between courses so no vertical joint runs through the wall.
- Backfill behind the wall with clean angular stone as you go, not soil, and add drainage at the base of that stone on anything more than a low wall.
- Finish the top course with caps, and bring topsoil up behind to the level you want.
Full detail is in our project guidance, and we are happy to advise on a specific build before you order.
Getting the base right
This is the part that decides whether the wall is still straight in ten years, and it is the part most likely to be rushed.
A retaining wall concentrates a lot of load into a narrow strip of ground. If that ground is soft in places, made ground, or has never been compacted, the wall settles unevenly, courses open up and the line goes.
Dig out to firm subsoil, put a proper compacted granular base in, and screed it level rather than raking it. Check level along the run and across the width. It is an hour of work that determines everything above it, and it is the only part you cannot go back and fix.
Terracing a slope
Two low walls usually beat one tall one.
Where a garden falls away, stepping the level change into two or three shorter terraces reduces the load on each wall considerably, gives you usable planting space between them, and looks better than a single high face. It is also far more forgiving to build.
Set each terrace back from the one below rather than stacking them vertically, and drain each one separately. Water that runs off the top terrace should not arrive behind the bottom one.
Finishing and planting
A PolyBrick wall reads as a deliberate structure rather than a landscaping compromise, and it takes finishing well.
Cap the top course for a clean line. Plant trailing species along the top to soften the face over a season, or run planting in front of the wall so the structure becomes the backdrop rather than the feature.
Where a wall doubles as seating, keep the height comfortable and cap it properly. Where it forms a raised bed, line the soil face if you want to keep the fill separate, though the material itself is inert and will not leach into the soil.
Get it right first time
The one thing worth knowing: drain behind the wall, not just in front of it.
Almost every retaining wall that fails, in any material, fails because of water pressure behind it rather than the weight of soil alone. Saturated ground is dramatically heavier than dry ground, and it pushes.
Backfill with clean angular stone rather than the soil you dug out, run a drain at the base of it, and give that drain somewhere to discharge. It costs a bulk bag of stone and an afternoon. It is the difference between a wall that is still straight in twenty years and one that starts leaning after the first bad winter.
Ask our engineer
Questions about wall height, reinforcement, drainage or whether your project needs designing? Ask below, or get in touch directly.
Common Questions
How high can a PolyBrick retaining wall be built?
For low garden terracing, raised beds and edge retention, a properly built wall on a compacted base is well within its comfort zone. Beyond that the answer depends on the slope, the soil, the drainage and what sits above and below the wall.
For anything taller, anything retaining a driveway or structure, or anything where failure would affect a neighbour, a building or a highway, take engineering advice and have the wall designed. Tell us your height and site and we will give you an honest answer.
What foundation does a PolyBrick retaining wall need?
A trench excavated to firm subsoil, filled with compacted material and screeded dead level. What that foundation should consist of depends on the height of the wall, the ground beneath it and what it is retaining, so establish it for your site rather than assuming.
Whatever you build, that base carries the whole wall: screed it rather than raking it and check level along the run and across the width. It is the only part of the build you cannot go back and fix.
What should I backfill behind a retaining wall with?
Clean angular stone, not the soil you dug out. Most retaining wall failures in any material are water failures: saturated soil is dramatically heavier than dry soil and it pushes.
Free-draining backfill lets water travel down through the stone instead of loading the back face, and on anything more than a low wall a perforated pipe at the base of that stone should take it away.
Do PolyBrick walls need maintenance?
No. There is nothing to rot, rust, spall or repoint, and no mortar joints for water to wash out. The material is UV stabilised recycled polypropylene, so it does not need treating, painting or sealing.
Get the base and the drainage right at the start and the wall is genuinely maintenance free.
How does it compare to sleepers or concrete blocks?
Sleepers rot from the back where you cannot see it, and need replacing. Concrete blocks mean mortar, mixing and curing, and a wall that is finished three days after you stop working.
PolyBrick pushes together dry, so the wall is finished when you stop building, and nothing degrades from the buried side.
Is it better to build one tall wall or two shorter ones?
Two shorter ones, usually. Stepping a level change into two or three terraces reduces the load on each wall considerably, gives usable planting space between them, looks better than a single high face and is far more forgiving to build.
Set each terrace back from the one below and drain each one separately.
Will the plastic leach into my soil?
No. The material is inert recycled polypropylene and will not leach into soil, which is why the same blocks are used for raised beds and planters growing food. It locks the waste plastic up rather than releasing it.
Do I need planning permission for a garden retaining wall?
Low garden walls are usually permitted development, but height limits apply and they are lower where a wall adjoins a highway.
Rules differ across the UK and are tighter for listed properties and conservation areas. Check with your local planning authority if your wall is anything other than low and clearly within the garden.
