That is a fair enough question when you are constructing a new building, or even renovating an old one.
Let’s take a look at laying a new lawn. If you had just moved into a property, or had one built, and you wanted a beautiful green lawn with those lovely stripes, where you could sit all afternoon on a sunny day relaxing on a recliner, you would want that lawn flat.
Before even considering calling up a turf supplier, the first thing that you would do would be to ensure that the site where you were going to lay the turfs is as level as possible. Now the ground may already be fairly flat, but equally it could be hilly, have mounds, bumps, dips, and so on. Laying your turf on that lot is gong to be a total waste of money, because while you may have a lawn that is green it is going to take forever to mow as you go up and down over all the bumps. Probably more importantly, it is going to look a mess. That might be all right if you want a field full of sheep, but if you want a lawn that looks great and draws gasps of admiration from visitors, then it needs to be level.
So, depending just how bumpy the soil is, the very least you would do would be to get out your spade and level off the bumps and use the soil to fill in the dips. Then you’d rake it flat.
Or maybe, if the soil was really bumpy, you would call in a contractor with a digger to come and level it all out. Only after that you would call the turf supplier to come and lay the turf. And yes, then you would have a lovely green lawn that would serve you for years to come.
Much the same thing applies when you are going to lay a floor in a new or refurbished building. You need the sub-floor to be as flat and level as possible. Think about this: if it isn’t and you lay, let’s say, tile on top of a floor which has bumps and dips, those tiles are not going to last very long when people start walking over them. They will split and crack.
Unfortunately, concrete, which is what is used as the base floor in most buildings, contains large aggregates which help to give it the strength that is needed. This means that the surface of concrete when it cures is never going to be all that flat and level. It may look OK to the untrained eye, but a difference of a few millimetres here or there can make a very big difference to the final flooring when it is laid.
So what we do is to put a layer of fine material similar to concrete in some respects, over the top in order to level out the surface. This then allows the final flooring to be laid without trouble.
This layer of material is a screed and has traditionally been made of sand and cement with very fine aggregates. It is mixed and laid on to the concrete sub-floor and levelled out by a man using a hand trowel. This will provide a better surface. However, it won’t be perfect. Without going into detail, there are measurements of surface regularity used as standard, and this type of screed will not achieve the highest of them.
If you want the very best screed for a project in Gloucestershire, you need a liquid screed, also known as a self-levelling screed, which is what we provide at UK Screeds. This is made using anhydrous calcium sulphate instead of cement and we pour it into position using a pump and a hose. This will produce a far better surface than you could ever get with a traditional screed.
Yes, of course, there is a drawback, but it is not a very big one. As our screed dries it produces a layer of laitance – very fine particles – on the surface, and these must be removed by sanding in Gloucestershire before the final flooring is laid. We do this some 7 – 10 days after laying the screed, using a diamond cutting pad. This will remove all the laitance and then you have the perfect surface for laying your final flooring.