Repair Systems — 03 — Facade & External Envelope
Sulphamic acid efflorescence remover
Technical product reference for sulphamic acid (amidosulfonic acid) efflorescence remover for masonry facade remediation on Australian Class 2 strata buildings. Mildest of the common masonry acid cleaners — very low fuming, available as safe solid crystal form or pre-mixed, suitable for occupied buildings and semi-enclosed areas where HCl fuming is unacceptable. Pre-wetting mandatory; PPE required; do not mix with bleach-based cleaners.
What is sulphamic acid efflorescence remover?
Sulphamic acid (amidosulfonic acid) is the mildest of the three common masonry acid cleaners — gentler than both hydrochloric and phosphoric acid. Available as a crystalline solid dissolved on site to 5–10% working solution, or as a pre-mixed ready-to-use formulation. Very low fuming compared to HCl, making it the preferred choice for efflorescence removal in occupied buildings, semi-enclosed courtyards, or areas where HCl fuming is a health or safety concern. The solid crystal form is significantly safer to transport and store than liquid acid cleaners.
Product Reference
2 product systems — sulphamic acid efflorescence remover — scroll to view all
Crystalline sulphamic acid — site-mixed 5–10% solution
Sulphamic acid efflorescence remover — crystalline solid — site-mixed — external masonry
System Description
Crystalline sulphamic acid (amidosulfonic acid) is a mild, low-fuming solid acid dissolved in clean water at working concentration (5–10% w/v) for removal of light to moderate efflorescence from brick, concrete, and ceramic tile facades on Class 2 strata buildings. Available from pharmacies, pool supply, and chemical suppliers as crystalline powder or granules. The solid form is significantly safer to transport and store than liquid HCl or phosphoric acid — no liquid acid spill risk during transit. Dissolve in cold water on site at the required concentration before use. Very low fuming — suitable for use in partially occupied buildings or semi-enclosed areas where HCl fuming would be unacceptable. Biodegradable — lower environmental burden in waste water disposal than HCl. Pre-wet the masonry before application; apply with brush or sponge; allow 2–5 minutes dwell; scrub and flush thoroughly with clean water. Do not mix with bleach-based cleaners — chlorine gas can be generated. Prohibited on sandstone, limestone, and calcium silicate brick where acid dissolves the substrate.
Technical Properties
- Acid type: Sulphamic acid (amidosulfonic acid) — mild, low-fuming organic acid in crystalline solid form
- Site preparation: Dissolve crystals in cold water at 5–10% w/v before use — do not add water to crystals in a sealed container
- Very low fuming — suitable for occupied buildings and semi-enclosed courtyards where HCl fuming is not acceptable
Limitations
- Less effective than HCl for heavy Portland cement mortar smear — specify HCl or phosphoric acid for thick mortar deposits
- Still prohibited on sandstone, limestone, and calcium silicate brick — sulphamic acid dissolves calcium-based substrates
- Do not mix with bleach or chlorine-containing cleaners — chlorine gas generation is a risk if products are combined
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
Pre-mixed sulphamic acid efflorescence remover
Sulphamic acid efflorescence remover — pre-mixed RTU — external masonry
System Description
RLA Polymers and Bondall manufacture pre-mixed sulphamic acid efflorescence removers distributed through hardware merchants and trade supply outlets for removal of efflorescence and calcium carbonate deposits from brick and concrete masonry on Class 2 strata buildings and residential structures. The pre-mixed formulation provides a consistent working concentration without on-site dissolution of crystals — reducing handling error and ensuring correct acid strength at the point of application. Available in 1 L, 2 L, and 5 L containers from Bunnings, Mitre 10, and trade supply outlets nationally. Low fuming — more suitable than HCl for partially occupied buildings or semi-enclosed areas. Pre-wet the masonry surface before application; apply with brush or sponge; allow dwell time per manufacturer directions; scrub and flush thoroughly. PPE required for all acid cleaning operations. The same substrate prohibitions apply: not for use on sandstone, limestone, or reconstituted stone.
Technical Properties
- Pre-mixed at working concentration — no site dissolution step; consistent acid strength at point of application
- Sulphamic acid with surfactant — improved wetting and contact on masonry surfaces compared to straight crystal solution
- Available in 1 L, 2 L, and 5 L containers — hardware and trade merchant distribution nationally
Limitations
- Not for heavy mortar smear — specify HCl for thick Portland cement mortar deposits that resist sulphamic acid
- Prohibited on sandstone, limestone, marble, or reconstituted stone — acid cleaning damages calcium-based substrates
- May require repeat applications for deep or longstanding efflorescence — allow 24 hours drying between cycles
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
System Comparison
Side-by-side comparison of sulphamic acid efflorescence remover options. Confirm substrate suitability and do not mix with bleach or chlorine-based cleaners.
| Supplier | Product | Concentration | Compatible | Distribution | Key feature | Primary use |
|---|---|---|---|---|---|---|
| Chemist / Hardware | Crystalline sulphamic acid | 5–10% site-mixed | Clay brick + concrete | Chemist / pool supply / hardware | Solid form — safe storage + transport | Efflorescence — occupied areas |
| RLA Polymers / Bondall | Pre-mixed efflorescence remover | Pre-mixed RTU | Clay brick + concrete | Hardware merchants nationally | Pre-mixed consistent strength | Efflorescence — general use |
Do not confuse sulphamic acid efflorescence remover with:
- Hydrochloric acid (HCl) brick cleaner — much more aggressive than sulphamic acid, high fuming; for heavy mortar smear on fired clay brick; do not substitute sulphamic acid where HCl strength is required for heavy deposits
- Phosphoric acid brick cleaner — gentler than HCl but more aggressive than sulphamic acid; suitable for calcium silicate brick where sulphamic acid may not provide sufficient cleaning action for mortar stain
- Alkaline cleaners (TSP, sodium hydroxide, bleach-based) — completely different chemistry for biological, oil, and carbon staining; CRITICAL: do not mix sulphamic acid with bleach or any chlorine-containing cleaner — chlorine gas will be generated
- Poultice cleaning systems (attapulgite, kaolin) — entirely different mechanism for deep stain extraction from heritage and sensitive masonry; not a substitute for acid wash on clay brick efflorescence
- Sulphamic acid is for efflorescence (calcium salt deposits) only — it will not remove oil, rust, organic staining, or mortar smear; identify the stain type before selecting any acid cleaner
Disclaimer
This page provides general technical information only. Sulphamic acid cleaner selection and application must be confirmed for the specific masonry type and defect. Never apply acid cleaners to sandstone, limestone, or reconstituted stone. Do not mix with bleach-containing cleaners. OH&S requirements for chemical handling must be complied with.