Sealing
Buying time rather than building a barrier. The stone trade corrects the name itself: these are impregnators, and they are repellent rather than stain-proof.
In detail
A sealer applied to a porous surface — stone, grout, unglazed tile, concrete — does not close the pores. The stone institute is unusually direct about this, calling the products impregnators and describing them as repellent rather than a sealer, making stone more stain resistant and specifically not stain-proof. What they do is slow absorption, which extends the window in which a spill can be blotted up before it becomes a stain. That is genuinely valuable and it is a different promise from the one the word implies. Three consequences follow. A sealed surface still needs spills dealt with promptly, and the trade's instruction to blot immediately rather than wipe applies unchanged. A sealer is a wear item that has to be reapplied on a schedule set by traffic and cleaning, not once at installation. And sealing does nothing at all about etching, which is the acid dissolving the stone itself rather than a stain sitting in it — a sealed marble worktop etches exactly as an unsealed one does. A paving manufacturer adds a further caution for outdoor use: it does not stipulate sealants, and warns that one affects colour, appearance and slip resistance.
Why
- Sealing is explained by Porous and non-porous surfaces
- Sealing is explained by Capillary absorption
- Sealing is explained by Etching versus staining
Sources for this page
Sources
Care & Cleaning of Natural Stone
Natural Stone Institute · Trade or professional body
Relied on for: That sealers are impregnators, repellent rather than a sealer, making stone more stain resistant and not stain-proof, and that etch marks are not a cleaning problem but a re-polishing one. (states this directly)
Verification: a person has read the passage relied on.
Read on — Sprint 29 read all nine sections. Earlier sprints had read three: the siliceous-versus-calcareous classification, cleaning products, and sealing. Supports a wider statement — our claim was widened. Three sections of nine had been read and the source treated as complete. The unread six carry the whole preventive programme - coasters, trivets, non-treated dry mopping, slip-resistant mats, worn vacuum wheels, blot-don't-wipe - none of which the register held. They also answer a priority-1 row reading 'no route answers this yet': the authority's position on etch marks is that they are not a cleaning problem and need professional re-polishing. Two oddities are worth the record: dry 0000 steel wool is permitted on water rings, and efflorescence is removed dry because water makes it worse.
Cleaning & Maintenance Guidelines — Gardens & Driveways
Marshalls plc · Manufacturer documentation
Relied on for: That the manufacturer does not stipulate sealants outdoors, that a sealant affects colour, appearance and slip resistance, and that it must be reapplied over the life of the paving. (states this directly)
Verification: a person has read the passage relied on.
Read on — General Advice, Power Washing, Acid Washing, Seasonal Maintenance, Sealants, the per-stain sections and Organic Growth. Supports the claim as stated.
Last reviewed by a person on .