Calcium sulfate screeds

Last updated: 8 September 2021
Grant rate/tier: £140 (Tier 2)
Grant code: GET3026

Overview

The purpose of this standard is to provide the delegates with knowledge and skills relating to calcium sulfate screeds.

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Duration

2 days of 6 learning hours per day.

Purpose/scope

The purpose of this standard is to provide the delegates with knowledge and skills relating to calcium sulfate screeds.

Scope:

introduction to calcium sulfate screeds
interpretation of contract information
personal protective equipment (PPE)
screed selection
equipment & delivery methods
laying methods
coverage rates
test methods
screed repairs
waste disposal & cleaning of equipment.

Occupational relevance

Training delivered against this standard would be relevant to the following occupational group(s):

operative and craft.

Delegates pre-requisites

There are no delegate pre-requisites as part of this standard.

Instruction/supervision

As a minimum, course trainers must be able to demonstrate that, in relation to this standard, they have:

an award in education and training (or equivalent, as per requirements for approved training organisations)
successfully completed training to this standard
at least 2 years relevant industrial experience
a verifiable CV.

Delivery

Delivery may be in an on or off the job environment.

All materials and equipment must be of a suitable quality and quantity for delegates to achieve learning outcomes and must comply with relevant legislation.

The class size and delegate/trainer ratio must allow training to be delivered in a safe manner and enable delegates to achieve the learning outcomes.

The following delivery methods may be used in the delivery of this standard:

classroom / practical learning
e-learning
a blend of classroom and e-learning.

This standard is considered to contain 51% or more practical training.

This standard is considered to be set at an intermediate level.

Assessment

For the successful completion of training, delegates must complete an end of course practical assessment or knowledge test that measures all learning outcomes and has a pass or fail criteria.

Where this training is assessed using multiple-choice questions, a minimum of 10 questions must be asked and delegates are required to achieve an overall pass mark of at least 80%.

Quality assurance

Assured

Quality assurance against this standard will require initial approval of the training organisation and their content mapped to the standard.

CITB will also conduct an approval intervention, either desk-based or centre visit, to ensure the training organisation can meet the requirements of the training standard.

Approved training organisations (ATOs) will be required to present information on records of training and assessment upon request to CITB for desk-based analysis. They will also be visited annually by the CITB quality assurance team.

Renewal

Refresher every 3 years

Buffer/grace period

3 months

Classification

Recommended Refresher

Approval date

May 2021

Review cycle

On request or 3 years from approval date.

Learning outcomes

Learning outcomes
The delegate will be able to:	Additional guidance to support learning outcome
interpret and understand guidance and information relating to the work specification	Contract information: job sheet, method statement and risk assessment site induction company policies Product/system information: product datasheets (store materials on site in a secure location to meet manufacturer’s specified storage conditions) safety (COSHH) datasheets delivery notes (check material type, quantity and batch numbers) Legislation: roles and responsibilities legal obligation to protect yourself, the area and members of the public.
select and use appropriate PPE for the work	Function of PPE Correct fit Storage, maintenance and cleaning Replacement Equipment manufacturers’ operator’s manual Risk assessment Including: eye protection, head protection, safety footwear, gloves, ear defenders, respiratory protective equipment, high visibility clothing
explain the legal obligations to protect themselves, the area and members of the public	Establish a safe area of work Use of barriers and signage Provision of suitable ventilation if required Risk assessment Hazards including use of hazardous materials and equipment
explain the composition of calcium sulfate screeds	What is anhydrite and where does it come from Components of a calcium sulfate screed (anhydrite, aggregates, water & admixtures)
describe the benefits and factors affecting the choice of calcium sulfate screed	Selection factors: project type thickness required surface finish required underfloor heating Benefits: sustainable minimal cracking & curling – self-curing reduced need for construction joints rapid strength development design flexibility fast application cost competitive protein free - will not harbour bacteria weight saving due to low design thickness
outline screed delivery and installation methods	Site mixed or ready mixed “site batching” systems Site delivery of ready mixed screeds Screed pumps
recognise the importance of subfloor quality and be aware of common preparation methods including bonded, unbonded and floating construction	Including but not limited to: Mechanical removal of laitance (if necessary) Scabbling of in situ concrete Shot blasting pre-cast units Coarse aggregate exposure Vacuum removal of dust and debris Substrate moisture content < 75% RH Primers and bonding slurries (including polymer and epoxy primers BS8204:7:2003
describe the importance of priming the substrate	Risks and mitigations Types of primers and bonding agents e.g. epoxy, polyurethane, acrylic Preventing out-gassing/pin-holing from the substrate Mitigating the effects of moisture in the substrate BS8204:7:2003
describe methods used to install calcium sulfate screeds	Manual installation Pump installation Use of stands/tripods and laser levels Typical thicknesses
explain curing and drying requirements for newly installed screeds	Curing Assisted drying Underfloor heating systems Drying out periods
identify common screed repair methods	Crack repairs (static and live cracks) Screed strengthening De-bonding (stitch pinning/resin injection)
describe factors to be considered when planning an installation	Layout including: starting point and how to progress movement joints site conditions and building envelope daywork joints, terminations and continuing from previous day’s work number and position of mixing stations – pumps or missing units lighting disposal of waste protection
mix calcium sulfate screed (bagged) using appropriate mixing equipment under supervision	Following manufacturer’s recommendations Mixing methods and equipment Ambient temperature requirements Dust extraction requirements Hazards associate with mixing (dust, noise, splashing, fatigue)
apply calcium sulfate screed using appropriate equipment (pump) and method of application to achieve required thickness, levels and surface finish under supervision	Following manufacturer’s recommendations Check thickness achieved Delivery methods Hazards Importance of discharge maintenance on site
describe inspection and testing methods during and after application	Quality and preparation of base Priming of the base Ambient conditions during application and cure Mixing of materials Applied thickness Levels and surface regularity (SR1, SR2, SR3 etc.) Departure from datum Screed workability - flow testing Compressive strength Flexural strength In situ crushing resistance Moisture content Curing
explain how to achieve joint and edge details	Movement joints Restraint Mechanisms of cracking Daywork joints Acoustic joints Edge joints Crack control joints (door thresholds, constrictions, corridors, corners etc.) Thermal bridging
protect floor area following installation	Manufacturer’s recommendations Signage Barriers
clean tools and equipment and understand the safe use of solvents and other cleaning materials in line with health & safety guidelines	Manufacturer’s data sheets Waste material hazards Control of Substances Hazardous to Health (COSHH) Risk assessments
dispose of waste in a responsible manner	Hazardous and non-hazardous waste disposal Handling of waste material Handing of waste packaging

Additional information about this standard

Industry guidance:

Proprietary Screed Manufacturers Guidance
BS 8204:7:2003 – Code of practice for Pumpable Self Smoothing Screeds
BS8204:1:2003 – Code of practice for Screeds, Bases and In-situ Floors
BS EN 13454 - Binders, composite binders and factory made mixtures for floor screeds based on calcium sulfate
BS EN 13813 - Screed material and floor screeds — Screed material — Properties and requirements
FeRFA Guide to the Specification & Application of Screeds, The Resin Flooring Association
www.ferfa.org.uk/wp-content/uploads/2018/05/SpecGuideCPD.pdf