When you are constructing a new home, one of the most important things is to see to it that the floor is as level and flat as possible. This is particularly important with modern precast concrete beam and block floors, which have a distinct camber that can cause problems when it comes to laying floor finishes.
For this reason, it is necessary to install a floor screed over the top of the substrate in order to provide as level a surface as possible on which to lay the final flooring. For many years, a screed has been made from good old sand and cement, but recently, screeds of that type are being overtaken more and more by liquid gypsum screeds, as architects have come to realise the many benefits that they have.
One very big advantage is just how fast a liquid screed can be installed compared with sand and cement. Sand and cement is often mixed on site in a concrete mixer and then barrowed on to the substrate and laid by a man levelling it out with a trowel. On a larger site, it may be delivered to the site ready mixed which at least guarantees a certain consistency.
The liquid screed that we apply at UK Screeds when you use our floor preparation service in Gloucester is also delivered ready mixed. What we do is to set out levelling gauges which are called tripods and set them to the correct depth using a laser. This will ensure that the level is perfect throughout the building. We then attach a pump and a long hose to the delivery truck and simply pump the screed on to the substrate.
Because it is in liquid form it is pretty much self-levelling, so all we need to do is to run over it in two directions with a dappling bar in order to remove any air bubbles. So, the process of laying is very quick indeed. In fact, we can lay as much as 2,000 square metres of our liquid screed in a single day.
Another big advantage is that the screed dries very quickly, so it can take light traffic in as little as 24 hours, and certainly within 48, depending upon weather conditions. While it costs more than sand and cement, the latter working out at around £15 per cubic metre if mixed on site by hand, and £20 if delivered ready mixed, a liquid screed works out at about £25. However, this is offset by the fact that it can be laid much thinner than a sand and cement screed, so you don’t need so much of it.
Of course, the speed of laying means that there is a big cost-saving there as well, because a sand and cement screed laid by hand involves a considerable labour element.
There is one downside to our liquid screeds and that is that as they dry, they form a layer of laitance on the surface. However, we remove this by sanding the surface between 7 – 10 days after the screed is poured. Overall, the many benefits of a liquid screed far outweigh the use of “20th century” sand and cement.