Spacers are the cheapest part of any tiling job and the part everyone gets wrong first. Wrong size, wrong shape, wrong moment to pull them — every one of those costs you a re-lay or a grout failure later. The mechanics are not complicated, but the choices on the merchant shelf are wider than they need to be, and most of the brand differences matter less than the size choice.
This guide is the plain version: which size for which job, what to buy in the UK, and the mistakes that turn a good tile job into a bad one. By the end of it you will know exactly which packet to put in the basket.
Key takeaways
- 2mm is the right default for 90% of UK domestic ceramic and porcelain.
- Cross spacers (+) work on walls and floors; wedges and T-spacers are wall-only.
- Pull every spacer before grouting — never grout over them.
- For tiles 600mm and up, upgrade to MLT clips for the height too.
Why Joint Width Matters More Than People Think
A grout joint is not just decoration. It does three jobs.
Movement absorption. Every tile changes size slightly with temperature and humidity. Even a fired porcelain tile expands and contracts a fraction of a millimetre across a hot bathroom and a cold one. The grout joint is what absorbs that movement. Too tight and the tiles push against each other and crack at the edges.
Manufacturing tolerance. Tiles are made to a target size but no two tiles in a box are exactly identical. UK and EU tiles work to BS EN 14411, which allows up to ±0.6% size variation depending on the class. On a 600mm tile that is 3.6mm of possible difference between two tiles. The joint is what hides that variation.
Visual rhythm. A 1mm joint reads as one continuous surface; a 5mm joint reads as a tile floor. Both can look right or wrong depending on the tile and the room. The wider the joint, the more forgiving the install.
The whole point of a spacer is to set that joint width consistently across the floor. Lay tiles by eye and the joints wander; lay them with spacers and they stay parallel from one side of the room to the other.
Standard Sizes You'll See on UK Shelves
Five sizes do almost everything sold in UK builders merchants and Amazon UK.
| Size | Best for | Avoid for | |---|---|---| | 1.5mm | Polished rectified porcelain, sharp factory edges, modern minimal look | Rustic, off-square or natural stone | | 2mm | UK domestic default — ceramic, standard porcelain, most bathrooms and kitchens | Outdoor, riven slate, very large format | | 2.5mm | Wall tiles where 2mm reads too tight; transitional choice | Floors with high foot traffic | | 3mm | Natural stone, rustic tiles, large-format porcelain over 600mm | Polished porcelain (looks too wide) | | 5mm | Outdoor patio slabs, terracotta, exterior porcelain | Indoor anything except deliberate wide-joint feature |
Beyond 5mm you are in slabs and pavers, where you set joints by eye to match the look. Below 1.5mm you are doing rectified butt-joint work where any spacer is too big — that is a specialist job and a specialist conversation.
When to Use Which Size
1.5mm — Polished Porcelain, Sharp Edges
Rectified porcelain (the kind with cleanly machined 90° edges, no factory bevel) can be laid with very tight joints because the edges are dead-square. 1.5mm gives you a hairline joint that almost disappears into the floor on neutral colours. Fine on stable concrete substrates.
Do not use on timber subfloors or any floor with movement — the joint is too tight to absorb seasonal expansion.
2mm — The UK Default
This is what 90% of UK domestic floor and wall tiling is laid with. It works on:
- Standard glazed ceramic walls (kitchen splashbacks, bathroom walls)
- Porcelain floor tiles up to 600mm
- Most colour-bodied porcelain
If you do not know what size to use, this is the answer.
Vitrex 2mm spacers, 1,000-pack on Amazon → · Buy via TileFlow shop
3mm — Stone, Rustic, Big Format
Natural stone never lays perfectly flat or perfectly square. Tile sizes from a single pallet of travertine can vary by 1–2mm in length, so a 3mm joint hides that variation and lets you keep parallel rows.
Same logic applies to handmade or rustic glazed tiles, and to large-format tiles over 600mm where the slight bow in the centre of the tile needs joint width to absorb. Plank tiles in 1200×200mm look better at 3mm than 2mm.
Vitrex 3mm spacers, 400-pack on Amazon → · Buy via TileFlow shop
5mm — Outdoor and Specialty
Outdoor tiling — patios, balconies, pool surrounds — needs wider joints because the temperature swing in a UK summer-to-winter is 30°C, and that is real expansion. 5mm gives you the room. It also takes a flexible exterior grout, which sets harder at depth.
Same size for terracotta and rough-textured exterior porcelain.
Cross vs Wedge vs T-Spacer
Three shapes, three different jobs.
Cross spacers (+ shaped) are the all-rounder. Drop them in where four tile corners meet and they set the joint in both directions. Work on floors and walls. This is what you buy if you only buy one shape.
Wedge spacers are tapered triangles. You slide them between two tile edges and push to set the joint. Used mostly on walls to hold the lower tile up while you bed the upper one. Useful on first courses where you need to pack the joint slightly to keep tiles square against the floor.
T-spacers are flat plastic Ts. The vertical of the T sits in the joint, the horizontal sits on top of the lower tile. They are for wall tiling — they hold the upper course in position while the adhesive grabs without you needing to support every tile by hand.
For most UK domestic jobs, a 1,000-pack of crosses and a small bag of wedges is enough. Skip the T-spacers unless you are doing tall metro-tile walls or large-format wall tiling.
Plastic Spacers vs MLT Clips
This is the upgrade path everyone hits sooner or later.
Plastic spacers set joint width. They do not set joint height — the tile face level. On tiles up to about 450mm the adhesive bed is forgiving enough that you can bed each tile flush by eye and rubber mallet. Beyond that, even half a millimetre of bow in the tile centre shows up as lippage between tiles, and a spacer cannot pull adjacent edges flush.
That is what MLT (Manual Levelling Tile) clips do. The clip foot slips under both tiles, a wedge clamps them flush against each other, and you get zero lippage along the joint. The clip stem also acts as a spacer in many systems — usually 2mm or 3mm.
Use plastic spacers when:
- Tiles are 450mm or smaller
- Wall tiles up to 600×300mm metro
- Mosaic sheets
Upgrade to MLT clips when:
- Tiles are 600mm or larger on any edge
- Plank tiles laid in offset patterns
- Polished rectified porcelain anywhere lippage will show
For the full clip system breakdown — costs, brands, technique — see the tile levelling clips explained guide.
Brand Comparison: What Actually Matters
There are dozens of spacer brands on Amazon and in builders merchants. Most are identical mouldings from a handful of factories with different stickers. The ones worth paying attention to are these.
Vitrex (UK trade default)
Vitrex is the brand every UK tile merchant carries. Tight moulding tolerance, accurate sizing, ridiculously cheap. A 1,000-pack of 2mm cross spacers runs about £2.40 at trade prices, slightly more retail. If I need a fresh bag I default to Vitrex without thinking about it.
The only thing they get wrong is the soft plastic mix on the cheaper packs — pull a Vitrex spacer too late after laying and the leg will snap inside the joint. Pull at 60–90 minutes and they come out clean.
Vitrex 2mm crosses, 1000-pack → · Vitrex 3mm crosses, 400-pack →
RUBI
The Spanish trade-quality option. Stiffer plastic than Vitrex — better for trade use because the spacer holds shape under pressure when you tap a tile down hard, and pulls out cleanly even after 2 hours. About double the price of Vitrex. Worth it if you do this for a living.
RUBI 3mm spacers, 200-pack on Amazon →
Generic mixed packs
Amazon is full of "1,000-piece mixed 2/3/5mm" packs at sub-£10 prices. They are fine for a one-bathroom DIY job. Tolerance is loose — measure a few from a bag and you will see ±0.3mm variance which shows up as wandering joints — but for most domestic jobs the eye does not catch it.
1,000-piece mixed 2/3/5mm pack on Amazon →
Brands to avoid
Anything with no listed manufacturer, no UK customer service, and reviews that mention "snapped in the joint" — those are the soft-plastic ones that break off below the surface. You do not want to be picking 2mm plastic shards out of a freshly laid floor.
How Many Spacers Do You Need
A rough field calculation, assuming cross spacers at every four-tile junction.
| Tile size | Spacers per m² | 1,000-pack covers | |---|---|---| | 200×200mm mosaic | 25 | 40 m² | | 300×300mm | 11 | 90 m² | | 400×400mm | 6 | 165 m² | | 600×600mm | 3 | 330 m² | | 1200×200mm plank | 8 | 125 m² |
Always buy 25–50% more than you need. Spacers fall down cracks, get kicked around the room, end up in your kneepad pocket, and disappear. A 1,000-pack at £2.40 is half the price of one extra trip to the merchant.
When to Pull the Spacers
Timing is the part most DIYers get wrong.
Too early (before 30 minutes): the adhesive has not gripped yet and pulling a spacer can lift the tile slightly or open up the bed.
The right window (60–90 minutes): the adhesive has skinned and gripped the tile but has not fully set in the joint. Spacers come out clean with a flat-blade screwdriver or a pair of long-nose pliers.
Too late (3 hours plus): the adhesive has set around the spacer leg. Pulling now risks snapping the leg off below the surface, where you cannot reach it. If this happens, leave it — it is buried 4mm down so the grout will cover it, but the joint depth will be reduced.
If you cannot get back to pull spacers within 90 minutes, leave them where they are and pull at 24 hours with a screwdriver. They will come out, just less cleanly.
Never grout over a spacer. Ever. The plastic flat at the top sits within 1–2mm of the tile face, so the grout above it is too thin to hold up to foot traffic. It cracks within months and the spacer pops out, leaving a hole.
Common Spacer Mistakes
Wrong size for the tile type. 1.5mm on natural stone — joints wander immediately because the tiles are not square. 5mm on polished porcelain — looks like a 1980s public-loo tile job.
Mixing sizes within one floor. Do not put 2mm crosses in some joints and 3mm in others because you ran out. The eye catches the difference instantly. Buy enough.
Leaving spacers in to grout over. Already covered — never do this.
Pulling spacers before adhesive has gripped. Kicks the tile out of position. Wait 60 minutes minimum.
Cheap mixed packs on a precision job. ±0.3mm spacer variance becomes visible joint width variance. For a kitchen feature wall, spend the £4 on Vitrex or Rubi.
Ignoring expansion joints. Spacers set tile-to-tile width but do not handle room-to-room expansion. Any room over 6 metres in any direction needs a flexible silicone expansion joint at least every 6m and at every wall perimeter. See the tile adhesive buying guide for the bigger picture on movement.
Recycling and Waste
Most plastic spacers are unmarked polypropylene. They are technically recyclable as soft plastic but most kerbside collections will not take them — too small for the sort. Drop a bag at a supermarket soft-plastic recycling point. Do not throw them in the regular plastic bin where they bounce out of the sort and end up as litter.
Some manufacturers (Mapei, Schluter) sell 100% recycled-content spacer ranges. Same job, slightly higher cost, less guilt. Worth a look if you do volume.
Bottom Line
Get the size right and the brand barely matters. 2mm Vitrex crosses for almost everything, 3mm for stone or large format, 5mm for outdoor. Pull at 60–90 minutes, never grout over them, and buy more than you think you need.
For tiles 600mm and larger, the conversation moves from spacers to MLT clips — see the tile levelling clips explained guide for that side of it. For everything else underneath the spacer choice — adhesive class, subfloor flatness, cutter type — start with the tile adhesive buying guide and the how to choose a tile cutter guide.
Vitrex 2mm 1000-pack on Amazon → · Vitrex 3mm 400-pack on Amazon → · Browse the TileFlow shop
For a complete starter kit including spacers, see the best budget tiling tools UK roundup.
Sources:
- BS EN 14411:2016 (Ceramic tiles — Definitions, classification, characteristics, evaluation of conformity, marking)
- BS 5385 Parts 1–5 (Wall and floor tiling — Code of practice)
- Vitrex product datasheets (vitrex.co.uk, 2024)
- RUBI Tools UK technical guides (rubi.com/uk, 2024)
Affiliate disclosure: TileFlow UK is an Amazon Associate (tag: tileflowuk-21). The Amazon links in this post pay a small commission if you buy — at no extra cost to you. Full affiliate disclosure here.