Why acid-proof lining fails: 6 common reasons

Acid-resistant lining should protect concrete and steel for years. When it starts leaking early, the cause is usually one of these six.

1. The wrong mortar system

A mortar suited to acids may fail under alkalis or solvents, and the reverse. The system must match every chemical the area will see, including cleaning agents.

2. Poorly filled joints

Voids and partly filled joints let chemicals reach the bed and the substrate. Joints must be completely filled and finished flush.

3. No membrane, or a damaged one

In many tanks and floors, a membrane under the brick or tile is the last line of defence. If it is missing or damaged, any leak attacks the concrete directly.

4. Skipped curing or acid wash

Each mortar system needs its own curing, and some need an acid wash before service. Putting the area into use too early weakens the joints.

5. Movement and missing expansion joints

Temperature changes and structural movement crack rigid linings. Expansion joints in the right places absorb this movement.

6. Thermal shock

Hot liquids or steam cleaning on a cold lining can crack bricks and joints. The design should account for real temperatures, including cleaning.

Getting it right

Start with a full chemical list, then choose the mortar, membrane and brick or tile together as one system. See our guide on choosing an acid-resistant mortar.