Burnt clay bricks: water absorption within the standard
Applies only if your house has burnt clay brick walls.
A brick that drinks more than the standard allows will keep drinking — from the mortar as you lay it, and from the damp in the wall for the rest of the building's life. It is the difference between a wall that dries after monsoon and one that never quite does.
What to look at
- A test report naming the class and the absorption percentage
- Bricks ringing rather than thudding when struck together
- No white efflorescence — the white powdery bloom that means salts in the brick bloom on the stack
- Brick test report against IS 3495 naming class and water absorption
Documents to ask for
- Brick test report against IS 3495 naming class and water absorption
How to check it yourself
IS 1077 caps water absorption at 20 percent by weight for common burnt clay bricks, and at 15 percent for the higher classes above 12.5. Ask the supplier for a test report against IS 3495, or have a sample tested — a lot arriving without any is a lot nobody has checked. On site, a brick that rings when struck and shows no efflorescence (a white powdery bloom, meaning salts in the brick) — the white powdery bloom that means salts in the brick is the crude version of the same test.
Where this comes from: IS 1077:1992 — Common burnt clay building bricks; IS 3495 (Part 2) — method of test for water absorption (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
- 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
- Mortar used within its working time, and never re-tempered