Having a floor levelled costs €10–€25 per m² in labour, plus €5–€15 per m² in materials. Doing it yourself saves €10–€25 per m² — on a 25 m² living room that’s a saving of €250–€625. Floor levelling is one of the more achievable DIY jobs when preparation is done correctly. The most common mistakes are applying the compound too thin or too thick, or skipping the primer. This guide covers everything: preparation, product choice, quantity calculation, and the correct step-by-step process.
What Does Floor Levelling Cost? DIY vs. Contractor
Cost Comparison per m²
| DIY (materials) | Contractor (including labour) | |
|---|---|---|
| Thin levelling (up to 5 mm) | €5 – €10 per m² | €15 – €25 per m² |
| Thick levelling (5–30 mm) | €8 – €20 per m² | €20 – €40 per m² |
| Anhydrite screed (5–10 mm) | €10 – €20 per m² | €25 – €45 per m² |
| Primer | €1 – €3 per m² | Included |
Cost Example: Level a Living Room (25 m², 5 mm depth)
| Cost Item | DIY | Contractor |
|---|---|---|
| Self-levelling compound (approx. 10 bags of 25 kg) | €100 – €180 | €100 – €180 |
| Primer (1 tub 5 litres, covers approx. 50 m²) | €20 – €40 | Included |
| Mixing paddle + bucket | €15 – €25 | Included |
| Spreader / gauge rake | €10 – €20 | Included |
| Labour (2–4 hours) | — | €250 – €625 |
| Total | €145 – €265 | €350 – €805 |
Preparation: the Critical Phase
Checklist Before You Start
| Check | How to check | What to do if not right |
|---|---|---|
| Flatness | Lay a straightedge (2 m) on the floor and measure the gap | Gaps > 30 mm: apply floor levelling mortar first |
| Substrate adhesion | Scratch with screwdriver, tap – hollow sound = loose | Remove and repair loose sections |
| Moisture | Tape plastic sheet down, check for condensation after 24 hours | Fix moisture source, allow floor to dry |
| Suction | Drop water on the floor – does it absorb within 30 seconds? | Always apply primer |
| Paint/oil residues | Check for shiny patches | Sand or remove before priming |
Common Preparation Mistakes
- Not filling cracks: self-levelling compound is liquid and will run through cracks in the substrate. Fill all cracks > 1 mm with repair mortar or polyurethane filler.
- Not vacuuming: dust and sand dramatically reduce primer adhesion.
- Forgetting doors: levelling compound runs under doors. Seal door gaps with draught excluder or tape.
Choosing Self-Levelling Compound
Types of Self-Levelling Compound
| Type | Price per 25 kg bag | Layer Depth | Drying Time | Best for |
|---|---|---|---|---|
| Thin levelling (0–5 mm) | €10 – €18 | 1 – 5 mm | 1–3 hours | Minor unevenness, before LVT or carpet |
| Universal compound (0–20 mm) | €12 – €20 | 1 – 20 mm | 2–6 hours | Most common product, most situations |
| Thick layer (5–50 mm) | €14 – €22 | 5 – 50 mm | 4–24 hours | Large unevenness, filling |
| Fast-setting | €18 – €28 | 1 – 30 mm | 30–90 minutes | When you need to proceed quickly |
| Anhydrite compound | €15 – €25 | 3 – 50 mm | 6–24 hours | Specifically for anhydrite screeds |
How Many Bags of Levelling Compound Do You Need?
Calculation Method
Most manufacturers state consumption in kg per m² per mm layer depth. Average: 1.5–2 kg per m² per mm.
Formula:
Floor area (m²) × average layer depth (mm) × consumption per m²/mm = total kg required
Example:
25 m² × 5 mm × 1.6 kg/(m²·mm) = 200 kg = 8 bags of 25 kg
Always order 10% extra for waste and uneven distribution.
Calculation Table (at 1.6 kg/m²/mm)
| Area | 3 mm layer | 5 mm layer | 10 mm layer | 20 mm layer |
|---|---|---|---|---|
| 10 m² | 2 bags | 3–4 bags | 7 bags | 13 bags |
| 20 m² | 4–5 bags | 7 bags | 13 bags | 26 bags |
| 30 m² | 6–7 bags | 10 bags | 20 bags | 39 bags |
| 40 m² | 8–9 bags | 13 bags | 26 bags | 52 bags |
Step-by-Step: Level a Floor in 8 Steps
Step 1: Remove the Existing Floor Covering
Remove carpet, LVT, laminate or timber flooring completely. Remove all adhesive residue and carpet tape — these significantly reduce adhesion. Use a floor scraper or belt sander for stubborn adhesive.
Step 2: Clean and Repair the Floor
Vacuum the entire floor thoroughly. Fill all cracks wider than 1 mm with repair compound or PU filler. Allow to dry completely. Remove all loose sections of the substrate.
Step 3: Apply the Primer
Primer is not optional — it is required for almost all levelling products. Primer:
– Reduces substrate suction so the levelling compound does not dry out too quickly
– Improves adhesion between the floor and the levelling compound
– Consolidates the upper layer of the substrate
Primer drying time: 30 minutes to 2 hours, depending on the product. Apply with a roller or brush. Ensure complete, even coverage — no dry patches. Allow to dry fully before pouring.
Step 4: Determine the Reference Height
Use a spirit level or laser level to find the lowest and highest points of the floor. The lowest point determines where you need to apply the compound thickest. Mark the desired finish height on the walls around the room as a reference.
For larger rooms: use height-adjustable reference pins pushed into the floor at the desired finish height.
Step 5: Mix the Levelling Compound
Pour the correct amount of cold water into a clean bucket (always water first, then powder — never the other way round). Add the levelling compound and mix immediately for 2–3 minutes with a mixing paddle on a drill (low speed, 300–400 rpm). The mix should be pourable but not watery.
Working time: 20–40 minutes for standard products. Never mix more than you can pour in one go. For larger rooms: mix multiple batches one after another.
Step 6: Pour the Levelling Compound
Pour the mix onto the floor, starting at the wall furthest from the door. Pour in overlapping runs. Use a gauge rake or spreader to distribute the compound evenly to the correct depth. Work towards the exit so you do not walk over the wet compound.
Tip: have a second person mixing while you spread — this keeps the working time under control.
Step 7: Spike Roll and Finish
Immediately after pouring, run a spiked roller over the surface. This breaks up any air bubbles and improves the self-levelling action. The compound levels itself but may need a little help in corners and at door thresholds using a float.
Step 8: Allow to Dry and Check
Allow to dry and cure according to the product specifications. Do not walk on the floor before the stated time. After drying: check flatness with a straightedge. Maximum tolerance for LVT or laminate: 3 mm per 2 metres.
Drying Times: When Can You Continue?
| Stage | Standard Compound | Fast-Setting Variant |
|---|---|---|
| Do not walk on | Minimum 2–4 hours | 30–90 minutes |
| Lay floor covering | 24 hours | 3–6 hours |
| Full cure | 7–14 days | 24–48 hours |
| Turn on underfloor heating | Minimum 28 days | Per product datasheet |
Underfloor heating: turn off heating at least 48 hours before levelling. After levelling: wait at least 28 days before switching it back on, and then increase temperature gradually.
Common Mistakes
| Mistake | Consequence | Solution |
|---|---|---|
| No primer | Poor adhesion, cracking | Always prime |
| Too little water when mixing | Lumps, uneven spread | Use correct water ratio |
| Cracks not filled | Compound runs through cracks | Fill cracks > 1 mm first |
| Doors not sealed | Compound runs into other rooms | Tape or seal door gaps |
FAQs
What does floor levelling cost?
Material costs are €5–€20 per m² depending on the product and depth. Having it done professionally costs €15–€40 per m² including labour.
How many bags do I need for 20 m² at 5 mm depth?
Calculate at 1.6 kg per m² per mm. For 20 m² at 5 mm: 20 × 5 × 1.6 = 160 kg, which is 7 bags of 25 kg (order 8 including 10% extra).
Do I always need primer?
Almost always yes. Only self-levelling compounds that specifically state they can be applied without primer are exceptions. Always check the product’s technical data sheet.
How long does levelling compound need to dry before laying LVT?
For standard products: 24 hours. For fast-setting products: 3–6 hours. Always check the product specifications.
Can I apply a new layer over existing levelling compound?
Yes, provided the existing layer is firm, dry and dust-free. Apply fresh primer and allow to dry before applying the new layer. Check product compatibility.
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