Recycled bricks fit permaculture design principles well: they’re a reclaimed material, they have genuine thermal mass, and they’re durable enough to stay in place for decades with minimal maintenance. The structures they suit best herb spirals, thermal mass beds, swale edging, and compost bays are also some of the most common elements in a productive permaculture system. This post covers each structure specifically, with notes on which brick types work best and what to watch for. For broader small-garden brick uses that aren’t permaculture-specific, see our guide to recycled bricks for small urban gardens.
Why Recycled Brick Suits Permaculture Design
A few properties make reclaimed brick particularly compatible with permaculture-based systems:
- Thermal mass – dense clay brick absorbs heat during the day and releases it slowly at night. In a well-positioned herb spiral or raised bed, this moderates soil temperature around plant roots, extends the growing season in cooler months, and creates distinct microclimates within a small space.
- Longevity without replacement – a brick structure in a garden doesn’t need painting, retreating, or replacing. This aligns with permaculture’s preference for low-maintenance, long-lived systems over repeated inputs.
- Reclaimed material – using bricks that would otherwise go to landfill fits the closed-loop resource principle. Bricks sourced locally also minimise transport.
- Drainage compatibility – brick laid dry (without mortar) allows water to pass through joints, which is useful in swale and water-harvesting applications where permeability matters.
Herb Spirals
The herb spiral is one of the most practical permaculture structures, and one of the most common uses of recycled brick in a compact garden. The spiral form creates multiple microclimates in a small footprint sunny and dry near the top, shaded and moist at the base allowing a range of herbs with different requirements to grow in the same bed.
Construction
The spiral is typically built 1–1.5m in diameter and 60–90cm high at the peak, tapering down to ground level. The most common approach:
- Mark the spiral path on the ground first, then build the outer wall in courses, stepping down as the spiral unwinds.
- Lay bricks dry (no mortar) for maximum drainage flexibility and ease of adjustment; mortared walls are more permanent but reduce permeability.
- Fill with a mix of soil, compost, and coarse sand or gravel in proportions that suit the herbs you’re growing.
- Position the spiral so the tallest point faces north in Australia (to maximise sun exposure at the top).
Brick selection
Irregular or slightly varied bricks suit herb spirals well because the curved form means no two courses are exactly alike small variations in brick size are absorbed easily. Sandstock bricks work well for their thermal mass and texture. Avoid bricks with deep cracks if the spiral will be dry-laid, as these may shift under soil pressure.
Thermal Mass Garden Beds
A brick-edged raised bed does more than contain soil the brick walls absorb solar heat and slowly warm the soil from the sides. This is particularly useful in climates with cool mornings or a short frost season, and for crops that need consistent root-zone warmth.
Design considerations
- South-facing walls (in the southern hemisphere) receive the most winter sun position brick edging on the south and west sides of beds to maximise heat absorption.
- Wider walls (two bricks thick) hold more thermal mass than single-brick edging.
- Dark-toned bricks absorb more heat than pale ones older red bricks that have darkened with age can outperform paler new bricks in this regard.
- Bed height of 300–450mm gives enough brick surface for meaningful heat storage. For full construction detail, see our guide to recycled bricks for raised garden beds.
Swale Edging
Swales shallow on-contour channels that slow and spread water across a slope benefit from stable edging to prevent the uphill berm from eroding or collapsing into the channel. Recycled brick is well suited here because it’s heavy enough to stay put, porous enough (if dry-laid) to allow some water movement through the edging, and doesn’t rot or degrade in wet conditions.
How it works
- Lay bricks along the downhill edge of the swale berm, dry-laid in a single course, to stabilise the soil and slow surface water movement without fully impeding it.
- On steeper slopes, a mortared brick edge may be more appropriate the tradeoff is reduced permeability but improved structural stability.
- Brick edging along the uphill side of a swale can also define a planting zone directly above the water harvesting area, where soil stays moist longest.
Compost Bay Walls
Three-bay compost systems one bay filling, one actively composting, one finished are a permaculture staple. Brick compost bay walls are more durable than timber, don’t rot, and don’t leach preservative chemicals into the compost. They also absorb heat in summer, which can accelerate decomposition.
Build notes
- Dry-lay the front face of each bay so bricks can be removed easily when turning or emptying the compost.
- Leave small gaps between bricks on the side walls for airflow oxygen is essential to hot composting.
- Any grade of recycled brick works here appearance doesn’t matter, so this is a practical use for bricks that aren’t suitable for a visible feature.
Guild Planting Beds
In permaculture design, a guild is a group of plants positioned together to support each other typically a central tree or shrub surrounded by companions that fix nitrogen, attract beneficial insects, or suppress weeds. Brick-edged circular or keyhole-shaped beds suit guild planting well, defining the planting zone clearly and providing the thermal mass benefit at the root zone.
For brick edging techniques including vertical, angled, and flat-laid options, see our step-by-step guide on using old bricks for garden edging.
Brick Type Summary for Permaculture Applications
| Brick Type | Best Permaculture Use | Notes |
| Sandstock bricks | Herb spirals, thermal mass beds | Dense, high thermal mass, suits curved forms |
| Red clay bricks | Raised beds, compost bays, guild beds | Versatile, dark tone absorbs more heat |
| Paving bricks | Swale edging, path definition | Flat surface, easy to lay level |
| Lower-grade / mixed | Compost bays, rear-fill of beds | Appearance not important — structural use |
Note: for quantity estimates and available grades, contact The Brick Pit with your project dimensions, or use our brick quantity guide.
Frequently Asked Questions
Should bricks be mortared or dry-laid in a permaculture garden?
It depends on the application. Dry-laying is better for herb spirals, swale edging, and compost bays it allows water movement through joints, makes adjustment easy, and is more in keeping with the modifiable, low-intervention approach permaculture favours. Mortared construction suits anything load-bearing or where structural permanence is the priority.
Do recycled bricks add meaningful thermal mass to a herb spiral?
Yes, particularly in climates with significant day-to-night temperature variation. Dense clay brick holds heat effectively and releases it slowly. The effect is most noticeable in spring and autumn when nights are cool but daytime temperatures are warm enough to charge the brickwork.
Which brick grade is best for a compost bay?
Any structural grade works for compost bays this is a good use for bricks that have minor chips or cosmetic imperfections that make them unsuitable for a visible feature. Avoid bricks with deep structural cracks.
Can I use recycled bricks for a swale without mortar?
Yes dry-laid brick is a good choice for swale edging precisely because it allows water to pass through the joints rather than forcing all flow over or around the edging. On steeper slopes, consider a mortared front face with dry-laid infill to balance stability and permeability.
More Resources
For related applications, see:
- Recycled Bricks for Small Urban Gardens — the broader guide to small-space uses (silo parent)
- Recycled Bricks for Raised Garden Beds — full raised bed construction guide
- Using Old Bricks for Garden Edging — edging techniques including dry-lay and mortared options
To discuss brick supply for your permaculture project, contact The Brick Pit or browse our recycled bricks range.
