Notes tagged
materials
11 notes on materials. All notes.
What a delivery challan is, and what it proves
A delivery challan travels with the goods and says what left the seller's gate. It is not a bill, and on its own it is not proof that anything arrived.
What a goods receipt note is, and why it is not the challan
The GRN is your own record of what arrived, written by your side. Confuse it with the vendor's challan and you have no independent check on anything.
How to read a bill of quantities
A BOQ is a priced list of the work, written so that two people can compete on the same job. Reading one well is mostly knowing what it deliberately leaves out.
Concrete grades: what M25 actually means
The number in M25 is a characteristic strength in newtons per square millimetre at 28 days. Not an average, not a mix ratio, and not a promise about today.
The slump test, and why water is the real argument
Slump measures how far fresh concrete settles when its mould is lifted. It takes two minutes, and it is the only check between you and a weaker structure.
Why measured and docketed quantities disagree
The number on the docket and the number your side measures are rarely identical. Most of the gap is ordinary physics and method. Some of it is not.
Running a site store so the numbers survive
A site store is a warehouse run in mud by one person under pressure. Four disciplines keep its numbers usable; everything else is a matter of preference.
Wastage on site: allowance, loss and arithmetic
Wastage is the difference between what you bought and what ended up in the structure. Most of it is not waste. Almost none of it is measured properly.
The bar bending schedule, and steel by weight
A BBS turns drawings into a cutting list and a weight. The arithmetic is simple and the errors are systematic, which is what makes them worth understanding.
The unit of measure is where the money leaks
A rate agreed per tonne and invoiced per quintal is a factor of ten, and it looks like an ordinary line. Units are the quietest expensive error in purchasing.
Physical stock against book stock
Stock reconciliation is a comparison between what your records claim and what is actually on the ground. The variance is not the finding. The pattern is.