Sunday, December 26, 2010

Thumbrules for Estimating Quantities in Residential Buildings

Expert estimators are able to work out the quantites of concrete, steel, brickwork, plaster and finishing material based on the total built-up area of a residential building without even looking at the building plans.

So here's a rough guide on working out the quantites for a residential building of approx 1 lakh square foot built-up area.

Concrete-  Approx 4500 cum of concrete would be required for the structural frame of the building. The thumrule to follow is 0.045 cum of concrete per square foot of built-up area. This quantity would increase slightly for a building having basements as extra concrete would go in the raft, retaining walls and to the ramps to the basement.

Rebar- Approx 540 tons of rebar would be required. The thumbrule to follow is 120 kg of rebar per cum of concrete. Highrise buildings require more steel in the colums and the amount of steel per cum of concrete would increase with the height of the building.

Brickwork - Approx 1.3 lakh sq feet of wall would be present in the building with 1 lakh square feet area. However, the total area of the walls would depend a lot on the size of rooms.

Plastering and Paint Area - is approximately 3 times of the brickwork area . Note that this also includes ceiling and staircase plastering.

These numbers only apply to large residential towers and not to small housed and bungalows. Please apply these numbers with caution as they may vary for your particular project.

Tuesday, December 14, 2010

Monthly Site Running Costs - Overheads

Salary of Staff Deployed at Site
Accomodation Expense for Staff
Staff Welfare Expense
Vehicle Running and Transportation Charge (local)
Head Office to Site Travel Expense
Water Charges
Electricity Charges
Telephone and Internet Expense
Office Stationary and Furniture Expenses

Wednesday, December 1, 2010

Various Types of Waters at Power Plants

Raw Water -  Water coming externally from a cross country pipeline into the plant and is stored in the raw water reservoir.

Clarified Water - Raw water after Primary Treatment becomes Clarified Water

DM Water - Part of the Clarified Water is sent to the DM Plant for removal of dissolved salts. This water is used for filling up the boiler is called Boiler DM Water. A part of DM water is also used for cooling the various pumps and equipments in the BTG area and is called DM Cooling Water.

Cooling Water - A part of the Clarified Water is sent to the cooling water forebay for cooling of the condensor. Steam exiting the turbine is condensed into water in the Condensor with the help of Cooling Water

Auxillary Cooling Water -A part of the Cooling Water is used to cool the DM Cooling water via Plate type Heat Excanger. The water used to cool the DM Cooling Water is called Auxillary Cooling Water

Potable Water - is used for drinking and cooking purposes

Service Water is used for generally cleaning, washing, firefighting etc is called Service Water

About Pipes - Part 1

Pipes are generally made of  metal, plastic or concrete.

Metallic pipes are of Cast Iron, Galvanized Iron, Carbon Steel, Mild Steel, Stainless Steel, etc
Plastic Pipes maybe of PVC, HDPE, FRP etc
Concrete Pipes are made of various concrete mixes

Mettalic pipes maybe manufactured by extrusion (also called seamless pipes), centrifugal casting and spinning or welding.

Pipes generally are classified by their Nominal Bore which is their Outer Diameter and by Pipe Schedule which is the thickness of the pipe shell.

Pipes may be joined together by Welding, Flanging or Threading.

If pipe is joined by welding ( either Butt Welding or Socket Welding) then radiographic inspection of the welded joint would be required by the client.

If a mettalic pipe is to laid underground then the pipe must be protected from corrosion by wrapping and coating and also by cathodic protection.