Some vital guidelines for measuring staircase dimensions and designs

A staircase mainly includes a series of steps which involve a tread (the horizontal portion, where the foot stands) and a riser (the vertical portion).

In every step, there are one or more landings, handrails, and a small nosing. The latter obtrudes from the tread over the lower step, facilitating to raise its size devoid of inclusion of centimeters to the overall dimensions of the staircase.

By using the following formula, find out the exact dimensions of a convenient and efficient staircase in accordance with its use.

2 Risers + 1 Tread = 63-65 cm

The required space to attain these optimal dimensions is unavailable sometimes, but it's suggested to approach them as much as possible.

A schematic illustration of a steep and low-transit staircase.

(2 x 21) + (1 x 21) = 63 cm

A schematic illustration of an optimal staircase.
(2 x 18) + (1 x 28) = 64 cm

A schematic illustration of a loose staircase, desirably for exterior application.
(2 x 13) + (1 x 39) = 65 cm

Sample measurement of a staircase that should be 2.60 meters high.

1. Workout the required number of steps - Assume an ideal riser of 18 cm, the height of the space is divided with the height of each step. The result should always be rounded up:
260/18 = 14.44 = 15 steps

2. Workout the height of every riser - The height of the space is divided with the number of steps already acquired:
260/15 = 17.33 cm height for each riser.

3. Workout the width of the tread - It can be calculated with the following formula:
(2 x 17.33 cm) + (1 x tread) = 64

Each tread will be computed as 29.34 cm

The consequential staircase will contain 15 steps of 29.34 cm of tread and 17.33 cm of riser.

Based on the use and local regulations, there should be a minimum width of 80 cm for stairs in single-family homes, and more than 1.00 meters in public buildings.

Preferably, a stairway shouldn't contain in excess of 15 steps in a row. After 15 steps, a landing should be arranged. It's suggested that a landing is calculated minimum the same as 3 treads.

The height among the steps and the ceiling should remain 2.15 meters at minimum. The height of the handrail differs among 80 and 90 cm from each step.

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Published By
Rajib Dey
www.constructioncost.co
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Method of silt content test

Sand is considered as one of the vital construction materials for concrete, plastering, brickwork and flooring. Therefore, it is always recommended to use standard quality sand in the construction works.

To check the quality of sand, silt content test should be conducted. Silt content stands for a fine material that is lower than 150 micron. It becomes unstable in the existence of water.

When silty sand is applied for bonding, the strength will be decreased and rework should be required. It is mostly found when the plastering is going on for roof where the plaster continuously peels off at the time of being plastered with the mortar.

Extreme quantity of silt decreases the bonding of cement and fine aggregates as well as hampers the strength and stability of work.

In the job site, it is required to carry out silt test for each 20 Cum of sand although it may differ.

Silt Content Test for Sand

Purpose: Determine the silt content in sand (fine aggregate).

Necessary Tools:

• 250 ml measuring cylinder
• Water
• Sand & Tray

Test Method:

• Initially, the measuring cylinder should be filled with 1% solution of salt and water up to 50 ml.
• Include sand to it unless the level goes to 100 ml. Then fill the solution up to 150 ml level.
• Cover the cylinder and shake it properly.
• Once 3 hours are completed, the silt content settled down over the sand layer.
• Now record the individual volume of silt layer as V1 ml (settled over the sand).

• Then record the sand volume (underneath the silt) as V2 ml.
• Apply the method twice to obtain the average value.
• Silt Content = V1 / V2 x 100

The allowable silt content in sand percentage should be only 6%.

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Published By
Rajib Dey
www.constructioncost.co
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EMMA calculator for measuring electrical quantities

A generic 'EMMA' for work with bulk electrical quantities.

A multi-use EMMA should be applied for any 'mass' activity, that entails a physically quantifiable unit of construction work scope measured in tens, hundreds or thousands. As for instance, electrical cable tray or racking or cable laying/pulling are perfect individual subjects for this EMMA.

The EMMA contains 3 'pages', called 'INPUT' (Basic data that should be entered to make EMMA functional), 'TABLES' (Spreadsheets used for entering target & actual progress percentages, man hours etc), and 'CHARTS' (Here accessed spreadsheets should be demonstrates as curves & histograms). The EMMA is applied for different purposes which are described below:

1. To arrange target rate of progress (S-curve);
2. To make an estimate regarding man-hours, converted to manpower requirements (histogram);
3. To register units computed as complete every month;
4. To register man-hours used each month, in that way automatically matching the actual rate of development and genuine handling of manpower, with premeditated rates.
5. Besides, unacceptable trends can thus be recognized and work re-scheduled, together with automatic adjustments to manpower requirements, that will lead achievement of target completion.

Primary needs for inputting are:

a. The projected total quantity;
b. Meaning of the unit (eg m3);
c. A valuation of man-hours necessary for each unit;
d. The average number of hours to be conducted each day;
e. The average number of days to be conducted on every week.

Subsequently, inputting should be compliant with notes provided.
Application of an EMMA will help in creating specific interest to anyone for taking liability to finish a work scope package before schedule.
6.11.B. Earthing tape, cable racks & trays, cables, terminations

The calculator demonstrated below can be employed for calculating man hours required for any one, or all, concerning the activities related to cabling which are incorporated. Besides, entering quantities, the user will be able to modify the unit manhour rates provided, for rates more in keeping with that User's environment.

To obtain a hypothetical example, click Real-time Sync, provide secret key 'electrified' and click connect.

To start calculation, click on the following link farrell-and-co.com

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Published By

Rajib Dey

www.constructioncost.co

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