The Reasons for Using Screed on a Concrete Floor

When it comes to laying the final floor surface in a new building, whatever that surface may be – carpet, tile, wood, stone, and so on – it is vital that it is laid on a surface which is as flat as possible. If you try and lay flooring on top of a cement substrate, that is asking for trouble: many materials such as tile and stone will be subject to movement and cracking.

This is why it is essential to lay a floor screed in order to level out the surface of the concrete. It won’t actually level the concrete itself, but what it will do is to fill in all the dents, gaps, holes, and so on that occur when concrete is drying.

Traditionally, a floor screed has been made from sand and cement and is laid and levelled by hand. This is a very lengthy process and there could often be variations in the mix because the cement was mixed on site, so one batch out of the mixer could well be different from the last one.

However today we are moving forward with the increasing use of liquid screeds. These are delivered to site ready-mixed and are installed through a pump. As you might imagine, because the screed is pumped into position, laying it is very much faster than laying a screed by hand: it is said that a liquid screed can be laid up to 20 times faster. Certainly, some providers can lay as much as 2,000 square feet in a day.

There are other advantages with liquid screeds too. One is that they are ideal for us with underfloor heating because they leave no gaps.

However, when a liquid screed dries it does leave a layer of laitance on the surface, and this needs to be removed by floor sanding machines in Cornwall before the final flooring is laid. If the laitance is not removed, the final flooring such as tiles or stone or wood will not adhere properly. Floor sanding machines in Cornwall can be used about 6 – 7 days after the screed is laid.

Liquid Screed for Floor Preparation in Derbyshire

When you are engaged in any sort of new build contract, or even one where the inside of a building is being gutted and new floors installed, the most important thing from the point of view of longevity of the flooring is that whatever the final floor surface is going to be, it is laid on a surface that is as level as possible.

If you want a floor that is going to last, which you presumably do, then you can’t lay it directly on to the concrete substrate. Hence why today we have screed, which is an intermediate material designed to flatten out all the dips, bumps, and dents in the concrete and provide a perfect surface for the final floor.

For many years now, a screed has been made from sand and cement and is then laid on the concrete by hand. This is a slow process and has some disadvantages compared with the latest technology which is the use of liquid screed.

Liquid screed, which is also known as anhydrite screed, is the best material for floor preparation in Derbyshire. This is made from sand and gypsum, much of which is recycled, and is laid in position using a pump. On any building site, time is money, and companies that specialise in liquid screed will be able to lay it at a rate of as much as 2,000 square metres a day, far faster than you could ever lay a screed by hand.

Because it is a liquid, it is self-levelling, and will usually easily achieve a surface level of SR2. However, you can also get a laser screed. This is not a product but is a process which uses lasers to level the screed surface and achieve a surface regularity of SR1 – and you can’t get better than that. This is the ultimate for floor preparation in Derbyshire.

Liquid screed has several other benefits. One of them is that it is ideal for use with underfloor heating because it completely fills the cavities and envelops the pipes, which ensures an even distribution of heat throughout the floor.  

Some Things To Consider When Laying Floor Screeds

At Liquid Screed we have ten branches across England and Wales, and we can lay liquid screed anywhere in the two countries. Liquid screed is being specified more and more by architects, especially when underfloor heating is being installed. It has several advantages over a sand and cement screed, not the least of which is that it IS a liquid.

Underfloor heating is often regarded as a luxury specification and only appropriate for high-end properties. Therefore, architects often opt for radiators in affordable housing, but it has been shown that underfloor heating used in combination with liquid screeds, also known as self-levelling compounds, is easy and quick to install for any type of property, especially if force drying is included.

Underfloor heating has several advantages over a radiator system, one of which is that the room is heated evenly throughout. The liquid screed totally envelops the heating pipes so there are no gaps, which can happen with a sand and cement screed. Liquid anhydrite screeds also are excellent at absorbing and transmitting heat with about double the conductive properties of sand and cement.

Read more information: Self-levelling compound in Cheltenham