Setting out

Setting Out

• The process of transferring the dimensions and layout of a building from drawings onto the ground to guide construction.

• It involves marking the position of walls, columns, and other structural elements using pegs, lines, and levels.

Importance of Setting Out

• Ensures the building is constructed in the correct position and alignment.

• Guarantees accuracy in dimensions and levels.

• Prevents encroachment on boundaries.

• Saves time and cost by avoiding errors and rework.

• Forms the foundation for all subsequent work on site.

Tols and Equipment used in Setting Out

• Measuring tape —- Use for measuring distances

• Steel tape/Chain —- Used for accurate linear measurements

• Pegs & pins —- To mark key points and corners

• Mason's line/String line —-  For alignment between pegs

• Plumb bob —- For vertical alignment

• Ranging rods —- Used for sighting straight lines

• Leveling instrument (Dumpy, laser, or automatic level) —- For checking levels

• Theodolite/Total station —- For measuring angles and precise alignment

• Hammer & mallet —- To drive pegs into the ground.

• Profiles and batter boards —- Used to maintain the building lines after excavation.

Profile (Batter Board) Method

• This is the most common and traditional method used for small- to medium-sized buildings.

• Timber profiles (batter boards) are set up around the perimeter of the building, and string lines are stretched across to indicate wall and foundation lines.

Offset Peg Method

• Used when excavation or machinery may disturb the main corner pegs.

• Temporary offset pegs are placed a fixed distance (e.g., 3 ft) away from the actual building line, so the position can be re-established later.

Baseline Method

• A control line or reference line (called the baseline) is first established along a known or fixed boundary.

• All other measurements and right angles are taken from this line.

Theodolite/Total Station Method

• A theodolite or total station is used to measure precise angles and distances electronically.

• It’s the most accurate and modern method, used for larger or complex buildings.

GPS (Global Positioning System) Method

• Modern method using satellite positioning.

• GPS instruments are used to determine layout points from digital coordinates supplied in the design drawings.

Steps Involved in Setting Out

1. Site Preparation

2. Establish a Baseline

3. Mark the Building Corners

4. Fix Profiles/Batter Boards

5. Check for Squareness and Accuracy

6. Marking Excavation Lines