What floor preparation involves
On an existing floor we remove old adhesives, paint and weak laitance by grinding or scabbling, repair cracks and joints, and prime the surface so a new screed or compound can bond. On a new build-up we lay the damp-proof membrane, insulation, slip membrane and perimeter strip so the screed is supported and free to move without cracking.
Why it matters
A bonded screed on a dusty slab will hollow and crack. A floating screed on badly laid insulation will rock. Tiles on a damp screed can debond. Most of the remedial work we are asked to quote for traces back to preparation, so we treat it as part of the job rather than an extra.
- Diamond grinding to remove contaminants and open up the surface
- Scabbling to reduce high spots and key the slab for bonded screeds
- Damp-proof membranes, typically 1200-gauge polythene, lapped and taped
- Insulation and edge strip for floating and underfloor heating floors
- Primers matched to the substrate and the next layer
