What is the minimum depth for floor screed?

What is the minimum depth for floor screed?

Traditional screeds, when floating, must be a minimum of 75mm thick for commercial projects and may be reduced to 65mm for domestic only situations. A floating Cemfloor screed would need to be minimum 35mm thick for a domestic application and 40mm thick for a commercial application.

What does anhydrite screed mean?

Anhydrite screeds are made from inert fillers such as sand, with a binder system based on calcium sulphate. Consequently they can look very similar to a sand/cement screed.

How long does it take for anhydrite screed to dry?

about 49 days
This means that a typical anhydrite screed dries in about 49 days – compared to around 21 days for Ordinary Portland Cement.

Is Cemfloor an anhydrite screed?

Cemfloor is a BBA approved cement based liquid screed. The primary benefits are similar to other flowing screeds but with quicker drying, there is no need for special preparations before applying floor finishes, and no risk of incompatibility with the range of cement based adhesives and levellers.

How thick should screed layers be?

The optimum thickness of a sand and cement bonded screed is 25–40mm, an unbonded screed should have a minimum thickness of 50mm, whilst a floating screed should have a thickness greater than 65mm for lightly loaded floors and 75mm for more heavily loaded floors.

What is anhydrite subfloor?

ANHYDRITE SCREED AS SUBFLOOR Every subfloor must be level, permanently dry, firm, free of cracks, dust, dirt and adhesion-inhibiting substances and well-bearing. The pores of an anhydrite floor are narrower than those of a concrete floor and must be sanded for sufficient adhesion.

Is flow screed anhydrite?

Anhydrite – Flowing Screeds Flowing screeds are designed to provide a level surface in both commercial and domestic buildings prior to the application of floor finishes. It can be used as a bonded, unbonded, or floating construction and is particularly suited to use with underfloor heating.

How do you dry anhydrite screed?

BAL DPM can be used on anhydrite screeds up to 87% RH. As a general rule thumb the drying time for a Calcium Sulfate screed, so the moisture content reaches 0.5% w/w, is approximately 1mm per day up to 40mm in ideal drying conditions – i.e. air temperature of 20C with a relative humidity not greater than 65%.

How long does 75mm screed take to dry?

It is therefore reasonable to expect a levelling screed 50 mm thick, drying under good conditions, to be sufficiently dry in about 2 months.” It is generally accepted that between 50mm thickness and 75mm thickness, 2 days should be allowed for drying of each millimetre of thickness and a 75mm thick screed with no …

How long before you can walk on self leveling compound?

It’s suitable for foot traffic in 30 minutes and ready to tile onto in 45 minutes. Sealed coverings such as vinyl can be laid on top of the surface just 90 minutes after application.

What is Cemfloor screed?

A Liquid Screed Solution Cemfloor is a high-performance cement based, free flowing, self-compacting liquid screed developed by McGraths. It can be installed quickly up to 2000m2 per day saving time, foot trafficked in 24-48 hours and dries with minimal drying shrinkage (<0.05%).

Are anhydrite screeds suitable for underfloor heating?

Easy to lay, low cost, fast-drying, pumpable, self-levelling and offering minimal shrinkage, anhydrite screeds are perfect for domestic or commercial projects. They are also suitable for underfloor heating so long as the pipes and associated heating elements are covered with at least 25mm of screed.

What is the drying time for anhydrite screeds?

BAL DPM can be used on anhydrite screeds up to 87% RH. As a general rule thumb the drying time for a Calcium Sulfate screed, so the moisture content reaches 0.5% w/w, is approximately 1mm per day up to 40mm in ideal drying conditions – i.e. air temperature of 20C with a relative humidity not greater than 65%.

What is the moisture content of calcium sulfate screed?

Before laying onto Calcium Sulfate screeds it is vital to ensure that the moisture content is at the correct level for the required floor finish. Typical values for moisture sensitive floor finishes are less than 0.5% Water by Weight or less than 75% relative humidity (RH) for impermeable floors and less than 1% w/w for more permeable floors.

What is anhydrite laitance?

Laitance is a weak layer of fine particles deposited on the surface of the screed as the anhydrite cures. This layer is too weak to tile onto and can also inhibit drying of the screed.