It is often necessary to level a concrete floor as in some older houses the concrete may have dropped slightly, or it could have been damaged. The easiest way to level a concrete floor is by using a floor leveling screed. If the concrete is in good condition and is not damp you can apply the self leveling screed right on top, but if it is damp this will need addressing first. One option to deal with a damp concrete floor is to tank the concrete, please see here- tanking
Before applying the screed you need to buy the correct amount of screed, this can be done by measuring the width and length of the room and multiplying them by the depth of the screed that you need-
Width x Length x Depth = Quantity of screed.
Ensure the floor is clean before applying the screed, a good way to do this is to vacuum the floor before the screeding process begins.
Floor leveling screed finds it's own level to a certain degree (just like water) but some manufacturers recommend screwing screws into the floor at a set distance apart in order to mark the desired level of the floor.
This tub of floor leveling screed has a handy measuring guide on the side of the tub, which shows how much water has to be added to the tub. When filling the tub fill it exactly to the correct level, if you add too much or too little water you get an inconsistent mix. A mixer drill is essential when doing something like this as you will really struggle if you try and mix it by hand.
Preparation is the key here as the screed we are using is quick setting. You need to read the instructions for your screed and check the working time of the product. Our screed came in mixing tubs, but the product was split into two sealed bags. Remove all of the bags from the tubs, then fill all the tubs before you begin with the correct amount of cold clean water.
When mixing any dry powder a dust mask is essential as well as eye protection and safety gloves Carefully empty the contents of the bag into the measured amount of water.
Mix the product thoroughly using a power mixer. Here we are using a dedicated machine but you can use a high torque drill on a slow speed and a mixer paddle. Be aware that if you mix the product for too long you can entrap air in the mixture.
Carefully pour out the screed along the floor, it should start to find it's own level.
Here you can see that the screed is finding it's own level. When you pour the next tub of screed make sure that you overlap the first batch of screed.
Carefully float the screed out using a plasterers trowel if required, this will ensure that the screed runs to a near perfect level.
In order to remove any air that is trapped in the screed it is important that it is rolled using a spiked aeration roller. This will allow trapped air to escape from the screed. If you do not do this you will get bubbles and imperfections on the surface of your screed.