What this work covers
Floor sanding and levelling removes adhesive, high spots, and rough residue left after demolition so screed, waterproofing, and new flooring can bond to a stable base. The work needs to reach edges and thresholds as well as open areas, then finish with a flatness check and thorough dust removal.
When this work is needed
It is useful where flooring removal leaves bonded adhesive, raised mortar, or uneven transitions, especially before tile, waterproofing, levelling compound, or bonded timber flooring. If the substrate is already clean and even, first check whether local preparation will meet the next finish's requirements instead of specifying full-area grinding.
Decide before work starts
Use the next finish's substrate requirement to define what must be ground and what needs a different repair.
- Areas of residual adhesive, raised mortar, cracks, and hollow or weak substrate
- Drains, heating pipes, thresholds, and expansion zones where grinding depth must be limited
- Hand sanding at corners, edges, and around pipes that the main machine cannot reach
- Dust extraction, sealed doorways, ventilation, and personal protection
- The flatness and cleanliness standard required by the next floor or waterproofing trade
Check in the quote
Use these questions to distinguish adhesive removal from a complete substrate preparation scope.
- Does the price cover adhesive removal, full-area grinding, or only marked high spots?
- Are corners, thresholds, and pipe surrounds included in hand sanding?
- Are dust extraction and final industrial vacuum cleaning included?
- If cracks or hollow areas are exposed, which trade and cost item covers the repair?
- Who checks flatness, with what tool, and against which handoff standard?
If you have photos of the exposed floor or the sanding quote, I can help separate full-area grinding, local repair, and the flatness required by the next finish.
What to check on site
Sanding is preparation for adhesion, not a cosmetic polish. Identify the residue and target flatness first, then remove only what prevents the next material from performing.
- Set sanding scope and dust control
Light the floor from a low angle and mark adhesive build-up, mortar ridges, cracks, and weak areas. Limit grinding beside pipes and drains, and position dust extraction and temporary screens before creating fine dust. - Grind floor and sand corners
Work down the high areas evenly across the open floor, then use smaller tools at corners and thresholds. Distinguish adhesive staining from material with real thickness so sound concrete is not ground away unnecessarily. - Check flatness and remove dust
After grinding, turn a two-metre straightedge through several directions and mark low spots, cracks, and hollows for repair. Vacuum the fine dust until a hand passed over the surface remains clean, then hand the floor to the next trade.
Where problems usually start
- Adhesive and dust left behind Residual adhesive or fine dust can prevent screed, waterproofing, or tile adhesive from bonding to the substrate.
- Uncorrected unevenness A floor that is not checked with a straightedge can later cause lifted boards, cracked tile, or visible level changes.
- Dust exposure Grinding without extraction and suitable respiratory protection exposes workers to a heavy concentration of fine dust.
If a hand still picks up powder or a sharp ridge can be felt after cleaning, repeat the local grinding and vacuuming before approval.
Do not keep grinding to chase a deep hollow or low area. Mark it for screed or levelling repair instead of weakening the surrounding slab.
Timing and records
Allow roughly four to eight hours for one sanding operator and one assistant. Area, adhesive type, ridge height, and the number of edges can change this, so separate full-area grinding from local repair time.
Keep the marked residue and cracks before work, protected service zones, straightedge checks, finished edges and pipe surrounds, and the vacuumed surface. A signed or photographed handoff helps distinguish preparation from later substrate repairs.
The condition left by floor demolition determines the sanding scope, and unresolved low areas may need levelling rather than more grinding. The linked stages make that boundary easier to judge.