What is laitance?

Laitance is cement and aggregate particles that have risen to the surface of the liquid screed following the liquid screed installation taking place. The presence of laitance is pretty much standard in liquid screed and is often the result of inconsistent material mix ratios within the screed product or because of rain/water ingress.

Both rain ingress and an inconsistent mix ratio will result in the poor curing of the liquid screed resulting in an increase in the formation of a laitance skin. This laitance skin layer, although initially seemingly harmless to the untrained eye, is one of the biggest causes of failure in a liquid screed installation.

Without costly and immediate laitance removal the floor will be vulnerable to stresses of foot traffic, excess stress placed on the bond of the laitance to the screeded surface it highly likely the floor will eventually fail. The bond between both elements (laitance & screeded surface) will break resulting in any attached floor finishes coming loose.

At this juncture there will be a need to undertake expensive remedial work to the floor screed installation to replace all floor coverings and undertake laitance removal.

Laitance Removal | Diamond Grinding | Keying of the surface

A major disadvantage of using poured liquid screed is the removal of laitance following the liquid screed installation. A layer of laitance consisting of cement and aggregate will be present on the surface of the finished screed. The laitance will need to be removed within one to ten days following the liquid screed installation and whilst the screed is undergoing the curing process.

When installing tiles and stone it is good practice to key the surface of the liquid screed using the diamond grind process in order to ensure all laitance is fully removed to allow the tiles to ultimately ‘grip’ to the screed itself.

When should laitance removal be undertaken?

Sanding or diamond grinding of the liquid screed surface should be undertaken one to ten days following the floor screed installation by a professional. The lower portion of the liquid screed is still undergoing the curing process within this time frame therefore it is preferable to sand during the early curing process.

Sanding of the floor screed installation will accelerate the drying process, and will also ensure that a stable surface forms on to the surface of the screed to which floor finishes can be applied following consultation with the finishes installer to ascertain the correct bonding products (adhesives/glues/levellers) to be used.

Advantages of traditional screeds over liquid screed -

• Post completion laitance removal via sanding and/or keying i.e., scabbling of the screed surface is not required saving customer’s time and extra expense.
• Traditional screed requires very minimal preparation and does not require time consuming taping and sealing of tanking membranes.
• Dependent upon the job specification, traditional screeds can be accelerated to dry vastly quicker than liquid screeds.
• Ideal for all building projects including both domestic and commercial, traditional screed is often used in large commercial applications.
• Unlike poured liquid screeds, sand/cement readily lends itself to the formation of falls, in order to marry up to existing levels or differing thresholds.
• Traditional screeds do not require specialist/costly floor finish adhesives and glues.
• Thicker screeds provide a “solid feel floor underfoot” with zero bouncing effect.
• Traditional screed is often far more cost effective than using liquid screed in terms of material cost.

Specialised diamond cutting pads should be used on the screed in order to sand down and remove the layer of laitance flowing the liquid screed installation. Overall, the longevity and durability of the floor screed installation will be dramatically improved ensuring any further application of flooring whether it be laminate, tiles, vinyl etc. will adhere to the screed. The removal of laitance is key in achieving a successful liquid floor screed installation and ensuring that costly remedial works in terms of replacing floor finishes can be avoided.

Laitance Removal Cost

The laitance layer needs to be removed by sanding and needs to be removed between one to ten days following the liquid screed installation. Leaving the removal to a later date can result in difficulty removing a hardened laitance layer.

The area must then be then thoroughly vacuumed to remove residual dust. The cost range for carrying out laitance removal by a professionally dedicated contractor will be between.

£8.00 per m2 - £15.00 per m2 | Extra Over Cost

How Do I Find Liquid Screed Near Me?

There are various factors to consider when choosing a liquid floor screed contractor or liquid screed near me in a specific geographical location within the UK.

Selecting a professional liquid floor screed contractor or liquid screed near me for your project is critical to ensure the execution of your floor screeding is carried out to British Standard and specification.

When deciding on a liquid floor screed contractor or liquid screed near me for your building project the selection criteria checklist should include factors such as experience, expertise, certifications, compliance with regulations, and the ability to manage risks.

It not just as simple as searching for screed near me and selecting a liquid floor screed contractor that may be local to your building project however may not carry the experience, back of house knowledge and accreditations necessary to carry out the works.

When searching for liquid screed near me or liquid floor screed contractor it’s important to carry out the following due diligence:

• High level of liquid floor screed experience.
• Familiarity with the hazards of the liquid floor screed process.
• Previous health and safety performance records and accreditations.
• Safety policies, risk assessments (RAMS) and training records.

Upon considering liquid screed near me in terms of a liquid floor screed installation company, its worth assessing the type of liquid floor screed company you are engaging with. A company with a strong knowledge of the potential pitfalls of the liquid floor screed process it preferable.

The process of screeding is not just as simple as arriving to site with a wagon and trowel. The process of floor screeding from site surveying, batching the screed material (off or on site) to screed material delivery and the ultimately installation is extremally complex, there are important factors that can affect the installation before a single m2 is laid.

Advantages of traditional screeds over liquid screed - Traditional screed is often far more cost effective than using liquid screed in terms of material cost.

Post completion laitance removal via sanding and/or keying i.e., scabbling of the screed surface is not required saving customer’s time and extra expense.

Traditional screed requires very minimal preparation and does not require time consuming taping and sealing of tanking membranes.

Dependent upon the job specification, traditional screeds can be accelerated to dry vastly quicker than liquid screeds.

Ideal for all building projects including both domestic and commercial, traditional screed is often used in large commercial applications.

Unlike poured liquid screeds, sand/cement readily lends itself to the formation of falls, in order to marry up to existing levels or differing thresholds.

Traditional screeds do not require specialist/costly floor finish adhesives and glues.

Thicker screeds provide a “solid feel floor underfoot” with zero bouncing effect.

Sand and cement | The most popular screed

Traditional or sand cement screed is the most popular screed used in the UK. Suitable for all conventional screed applications, including monolithic, bonded and unbounded construction. A number of options increase early strength characteristics of traditional screed. Fibre screed as the name suggests is reinforced with polypropylene fibres.

Key facts about Sand and Cement Screed (traditional screed)

• Ideal for most building projects domestic to commercial
• Surface Regularity from 3mm over 2m (SR1)
• Ideal for projects with underfloor heating
• Perfect when falls in the screed are required