Applying a thin layer of liquid screed is a standard floor construction practice. When poured over the concrete base, this layer acts as the subfloor, which reinforces the structural integrity of the floor and, at the same time, makes the surface smooth and even. Liquid screed is similar to a concrete mix using aggregates, sand, and cement. The primary difference is that screed contains smaller particles and has a flowing consistency.
Two types of screed application
Liquid screed may be applied using two methods:
- Unbonded application. In this type of application, you put a layer of plastic before pouring liquid screed. The purpose of adding a layer of plastic is to prevent moisture from seeping into the flooring. Another reason for adding plastic sheets is to prevent the screed from settling. However, this method may be prone to curling. To avoid this problem, you need to apply a thicker layer of screed.
- Bonded screed application. In contrast with an unbonded application, a bonded application means you are directly pouring the liquid screed over the base layer. Many people prefer this method because the resulting surface does not curl or crack. But the bonded application is only ideal for thin screed layers. If the application reaches a thickness of two inches or more, it will not bond well to the base.
Because of the pros and cons of each method of applying screed, you need to ensure that you choose the right technique to ensure optimum floor performance.
Mistakes to avoid in liquid screed application
Similar to any step in construction, there are dos and don’ts to applying liquid screed. Expert screed contractors like liquidscreed.co.uk understand the importance of avoiding these common mistakes.
- Incorrect space measurement. Subfloors may have uneven areas and slopes, which could affect the amount of screed required. It would be best if you made sure that all areas of the floor are correctly measured so that the contractor can estimate the correct screed amount. In line with this, always consider features such as doors.
- Not enough screed ordered. If you ordered less screed than required for the project, reordering would cost a lot more. It is critical to order the right amount so that you will not experience any delays in completing the project or incur additional costs.
- Incorrectly choosing the liquid screed specification. Product specification varies depending on the flooring material. The traffic conditions on the floor will also matter when choosing screed specifications.
- Not preparing the surface before application. Installation may fail if the screed does not bond properly to the sub-layer. Contaminants may also compromise the integrity of the flooring; hence it is essential that before pouring the liquid screed, the subfloor does not have laitance, dirt, or traces of curing chemicals.
In conclusion, the process of applying liquid screed depends significantly on the preparation of the concrete base. By keeping in mind the best practices of applying screed, you can prevent all known problems and issues which could arise. It is also critical to work closely with the contractor and screed supplier for smoother project completion.