PolyBrick® Seat Walls
Seating that is part of the garden, not put in it
Built-in seating never blows over, never needs storing and is always where you want it. PolyBrick® seat walls go up dry, double as retaining or planting structure, and last decades.
Why build seating in
Garden furniture is a compromise. It gets moved, stacked, blown over, stored for winter, and replaced every few years. A seat wall is simply there: it does not need putting away, it seats six as easily as two, and it makes a space feel designed rather than furnished.
It also earns its footprint twice. A seat wall around a terrace is retaining the edge. Around a fire pit it is defining the space. Along a raised bed it is the bed wall. You are getting seating out of a structure the garden needed anyway, which is why built-in seating is standard in designed gardens and rare in ordinary ones: it usually means a bricklayer.
PolyBrick removes that. The blocks push-fit, so the wall goes up dry in an afternoon, and the material does not rot, rust, spall or need repointing. Nothing about a seat wall then needs maintaining.
Where this works well
- Terrace and patio perimeter seating
- Fire pit and chiminea surrounds
- Sunken seating areas
- Raised bed edges that double as benches
- Dining area enclosures
- Courtyard and small garden seating
- Boundary and retaining walls with a seat top
- Community, school and public garden spaces
At a glance
| Assembly | Push-fit interlock. No mortar, no fixings, no bricklayer |
| Seat height | Modular courses. Build to a comfortable sitting height and cap it |
| Dual purpose | Retains a terrace edge, a raised bed or a level change at the same time |
| Weather | Non-absorbent. Does not soak up rain, so it dries quickly and stays sittable |
| Material | 100% recycled polypropylene, UV stabilised, made in the UK |
| Compression | Tested to 150 tonnes/m² under fixed static load |
| Service life | 25 years under warranty |
| Maintenance | None. No treating, oiling, staining or winter storage |
Getting the sitting height right
This is the whole job. A seat wall at the wrong height is a wall people lean against rather than sit on.
Aim for roughly the height of a dining chair seat. Too low and getting up is hard work, particularly for anyone older; too high and feet dangle, which is uncomfortable within minutes. It is worth sitting on a stack of blocks at the proposed height before you build, for the same reason you walk a flight of steps before committing.
Depth matters nearly as much. A seat needs enough front-to-back for a whole thigh to land, or people perch. Where the wall is also retaining soil behind it, the structure is usually deep enough anyway; where it is freestanding, build it wider than a single block run.
Then cap it. A capped top gives a clean, comfortable edge with no joint line to sit on, and it is what makes the difference between a wall you can sit on and something built as seating.
Making it comfortable to use
A few details separate seating that gets used from seating that gets looked at.
Face the view, not the house. The most-used seat in any garden is the one pointing at something worth looking at, in a spot that catches evening sun.
Build in a back where you can. A seat wall against a raised bed, a boundary wall or a bank has a natural backrest. Freestanding, it is a bench without one, which is fine for twenty minutes and tiring for an evening.
Leave room to get past. Seating round a table needs space behind for chairs and people, and a run of seating tight against a table is decorative rather than usable.
Cushions transform it. Outdoor cushions turn a hard seat into a comfortable one, and because the surface is non-absorbent it dries quickly, so they go back out sooner after rain.
How it goes together
- Set out the seating and check it against how the space is actually used: where the sun falls in the evening, where the table goes, where people walk through.
- Mock the height up before committing. Stack blocks loose, sit on them, and adjust. It takes five minutes and it is the difference between seating that gets used and seating that does not.
- Excavate along the line to firm subsoil, removing soft or made ground.
- Prepare the foundation: compacted and screeded dead level. The first course sets everything above it, and a seat wall that is not level will be visible along its whole length.
- Lay the first course and check level along the run and across the width.
- Build up in courses to your sitting height, staggering the joints between courses.
- Where the wall retains soil or a level change behind it, backfill with clean angular stone rather than the excavated soil, and drain the base of that stone.
- Cap the top course to give a clean, comfortable seat edge.
Seating that retains
The most useful seat walls are doing two jobs, and it is worth designing for both from the start.
A wall along the edge of a raised terrace holds the terrace up and gives you seating facing back into the garden. A wall around a sunken seating area retains the surrounding ground and encloses the space. A raised bed at seat height puts planting directly behind whoever is sitting, which is a very pleasant thing to sit in front of.
Where the wall is retaining anything, treat it as a retaining structure first and seating second: firm foundation, free-draining backfill, drainage at the base. The seating is what you get on top of doing that properly.
For anything more than a low retained height, or where the wall is holding back a significant bank, take engineering advice and have it designed.
Fire pit and dining surrounds
A ring or square of seating around a fire pit is one of the most-used structures anyone builds in a garden, and the geometry is worth thinking about.
Set the seating further back from the fire than feels right on paper; people move closer when it is cold and cannot move away when it is hot. Leave gaps in the run for getting in and out, rather than a continuous enclosure everyone has to climb over.
Keep the blockwork itself away from direct flame and heat. This is a plastic product: it should form the seating and the surround, with the fire itself contained in a proper firebowl, pit liner or masonry hearth with a sensible separation between the two.
Get it right first time
The one thing worth knowing: sit on it before you build it.
Seat height is a few centimetres either way, and those few centimetres decide whether the seating is comfortable for an evening or awkward after ten minutes. It is almost impossible to judge from a drawing and completely obvious the moment you sit down.
Because the blocks build dry, you can stack the height loose, sit on it, get up from it a few times, and adjust before anything is permanent. Nobody does this and everybody should. It is the single biggest determinant of whether the seating gets used.
Ask our engineer
Questions about seat heights, retaining a terrace edge or planning a seating layout? Ask below, or get in touch directly.
Common Questions
What height should a garden seat wall be?
Roughly the height of a dining chair seat. Too low and getting up is hard work, particularly for anyone older; too high and feet dangle, which is uncomfortable within minutes.
Because the blocks build dry, stack the height loose and sit on it before committing. Seat height is a few centimetres either way and those centimetres decide whether it gets used.
How deep does a seat wall need to be?
Enough front to back for a whole thigh to land, or people perch rather than sit. Where the wall also retains soil behind it, the structure is usually deep enough anyway.
Where it is freestanding, build it wider than a single block run and cap the top for a clean, comfortable edge with no joint line to sit on.
Can a seat wall also retain a raised terrace or bed?
That is the best use of one. A wall along a raised terrace holds the terrace and gives seating facing back into the garden, and a raised bed at seat height puts planting directly behind whoever is sitting.
Where the wall retains anything, treat it as a retaining structure first: firm foundation, free-draining backfill, drainage at the base. For anything more than a low retained height, take engineering advice.
Is it comfortable to sit on?
Capped and built to the right height and depth, yes, and outdoor cushions transform it further.
Because the surface is non-absorbent it does not soak up rain, so it dries quickly after a shower and cushions go back out sooner than they would on timber or stone.
Can I build seating around a fire pit?
Yes, and it is one of the most-used structures anyone builds in a garden. Set the seating further back than feels right on paper, since people move closer when cold and cannot move away when hot, and leave gaps for getting in and out.
Keep the blockwork away from direct flame and heat: this is a plastic product, so contain the fire in a proper firebowl, pit liner or masonry hearth with sensible separation.
Why build seating in rather than buying furniture?
Built-in seating does not blow over, need storing for winter or get replaced every few years, and it seats six as easily as two. It also earns its footprint twice, since a seat wall around a terrace is retaining the edge and a bed wall at seat height is doing both jobs at once.
Built-in seating is standard in designed gardens and rare in ordinary ones mainly because it usually means a bricklayer.
Does a seat wall need maintenance?
No. There is nothing to rot, rust, spall or repoint, no annual oiling or staining, and nothing to store over winter.
The material is UV stabilised recycled polypropylene and carries a 25 year warranty.
What foundation does a seat wall need?
Excavated to firm subsoil, compacted and screeded dead level. The first course sets everything above it, and a seat wall out of level is visible along its whole length.
What the foundation should consist of depends on the height and on whether the wall is retaining anything, so establish it for your site.
Should seating have a back?
Where you can, yes. A seat wall against a raised bed, a boundary wall or a bank has a natural backrest.
Freestanding it is a bench without one, which is fine for twenty minutes and tiring for a whole evening, so site the main seating where something can serve as a back.
