Mortar used within its working time, and never re-tempered
Why — act while you have leverage
Mortar that has started to set and is brought back with water has lost most of its strength. It looks identical to fresh mortar in the wall and is the reason joints in the last course of the day are often the weakest.
What to look at
- Batch sizes matched to the crew's pace, not to the mixer's capacity
- Leftover mortar thrown away at the end of a session
- No water hose kept beside the mortar board for softening
How to check it yourself
Mortar is mixed in quantities that can be used within its working time and what is left over is discarded, not revived. Reviving stiffened mortar with water — adding water to stiffened mortar to make it workable again — is the practice to watch for, usually at the end of a shift when nobody wants to waste a batch.
Where this comes from: IS 2250:1981 — preparation and use of masonry mortars; IS 269 / IS 8112 for cement setting times (indian standard or building code)
More masonry and wall checks
- Photograph before this is covered
- Bricks or blocks soaked before laying, and joints filled
- Masonry cured, and lintels bear the specified length
- Laterite blocks: soaked properly, and laid with the right mortar
- Burnt clay bricks: water absorption within the standard
- Concrete blocks: cured and aged before they go into a wall
- AAC blocks: thin-bed mortar, and never soaked
- Fly ash bricks: to the standard, and the right mortar for them
- Mortar measured by gauge box, not by shovel
- Sand bulking allowed for before the mix is batched