Departure from Datum
LASER LEVEL SURVEY
According to British Standards, a maximum departure of 15mm from datum is considered to be satisfactory for large areas of screed intended for normal purposes, and can be measured by a 2m standard grid, using standard surveying methods.
Screed fails Departure from Datum Tolerance –
Depending on the intended use and the area to be screeded, it is important to specify the maximum permissible departure of the level of the finished surface from an agreed datum plane, right at the design stage of a screeding project. As per the British Standards Code of Practice, a departure of up to 15mm is considered satisfactory for large areas. However, the permissible departure from datum is much lower for smaller areas, and high levels of accuracy is essential for small rooms, along the line of partition walls, in the vicinity of door openings and in areas where specialized instruments are to be placed directly on the floor.
Level surveying for assessing the departure from datum can be done to high levels of accuracy with modern electronic ‘total stations’. In addition to yielding highly accurate measurements, these instruments also help to eliminate manual errors in log keeping by facilitating electronic storage of survey results. Rotary laser level is also common levelling equipment that is used for achieving high accuracy results
The accurate measurement of levels for screeds and substrate levels play a major role in controlling the costs and ensuring high quality standards for the screed. Level survey measurements are generally required for:
- Assessing the level of concrete substrates before commencing screed installation
- Assessing the departure from datum of screed after installation
- Measuring the average level of the installed screed
Right from determining the minimum /maximum depth requirements of screed and ensuring the compliance of screed levels with initial specifications to settling disputes regarding deviation against contract, accurate level surveying is a crucial aspect in screeding projects.
When an inaccurate assessment of level of the concrete substrate could lead to a wrong estimation of screed depth which in turn could translate into- higher concrete, higher costs and longer drying period in case the assessed level is lower than the actual measurement; a higher assessed level than the actual level could lead to judgements of lower screed depth, which can drastically affect the quality and integrity of the screed.
Screed meets Departure from Datum Tolerance –
There are many products on the market and CSC have reached a high industry standard by fully understanding the science behind the installation and associated processes. We have worked very closely with our supply chain to ensure that only the best quality materials are used on all of our sites across the UK.
THE SCREEDER’S JOURNAL
CSC Screeding are members of Constructionline, CHAS and Builders Profile where a predefined Health & Safety questionnaire is pre-completed and our clients have direct access to the information. Documents contained in the pre-qualification system are updated throughout the year, ensuring continued compliance. We have focused on developing the business through constant innovation, implementation and collaboration. We are now ready for the business to grow with the increasing demand.