What is Floor Screed?
Concrete is one of the most common building materials in construction projects. In any project, concrete is used to achieve the best results when putting up walls and pillars. Though reliable, concrete flooring is sometimes not the best option; as it damages other materials, it must be topped with a screed or rug.
Screed is a thin layer of material mainly used to level a floor, achieving a better surface. Once placed, you can install any type of flooring, such as tile or carpet. While concrete is courser and more robust, screed helps achieve a smoother finish.
Where is Floor Screed Used?
Floor screed is used in various construction projects, mainly commercial premises such as airports, commercial units, schools or retail units.
What are The Main Types of Screed?
There are three types of screeds; each depends on its application and the project’s requirement.
Bonded screed is applied directly on the substrate (an area where floorcovering material is applied; it can be stone, wood or concrete) with an adhesive.
Due to the thinness of the screed, you can apply any screed, especially on the floor where there is nonstop construction. The thickness of the screed is approximately 25-40mm; above that, one does not need adhesives.
An unbonded screed is not applied on concrete or any substrate floor; a damp-proof membrane is installed between the screed and concrete. In this way, it helps to reduce moisture and shrinkage from collecting.
The unbonded screed can be used for underfloor heating and does not require any adhesives due to its thickness.
Screed is also applied as a floating layer of insulation. This will create a moisture barrier, efficiently eliminating drafts and preventing pipes from freezing.
This is mostly used in underfloor heating installation systems; therefore, they are the thickest of the other screed types.
Underfloor Heating Screed
This screed is laid on underfloor heating pipes as it is proven to be a better alternative to other insulation methods or materials.
What are The Main Types of Floor Screed?
The most common types of floor screed are:
- Traditional Screed
- Self-Levelling Compounds
- Reinforced Screeds
- Liquid Screed
How Much Time Does Screed Take to Dry?
Screed might take up to 24-48 hours to dry, depending on its thickness and type. However, the total duration can be reduced to 12 hours by adding certain additives.
Moreover, if one plans to move with bulky or heavy furniture or items, it is recommended to leave it for at least a week to dry.
Overall, all screed types become robust and durable after about 28 days; the longer the wait, the better the results.
What Can You Do to Make the Drying Process Faster?
The drying process can be sped up; however, it depends on the type of screed used in the construction project and the drying conditions. Only then will it be beneficial; for instance, if certain additives are added, underfloor heating can benefit from it.
Advantages of drying screed quicker
- Other building work will be slower if drying takes more time than expected.
- The construction work can be performed much faster and completed timely; hence, the schedule stays on track.
- The floor finish is laid evenly and efficiently.
- There will be less pressure and time constraint on workers.
How to Tell If the Screed is Ready to Lay a Floor Finish?
Depending on what you intend to lay on top of the screed, you will need to wait a different amount of time for it to dry correctly and completely.
For laminated floors, you must wait two weeks for each added centimetre for up to 4cm. If the thickness exceeds 6 cm, you must wait at least a month for each additional centimetre of thickness. The reason is that the moisture takes a substantial amount of time to migrate completely from the bottom of the screed.
Furthermore, before installing a laminated floor, lay a plastic foil if it is not built-in into the laminated panels.
You can install tiles on the screed after three days, or at least if it is firm enough. Furthermore, the foundation of the screed must be a week old before tiling could begin.
Any substrate – concrete, wood or stone, must be completely dry and clean. The movement joints should be effectively specified, leaving the joints approximately 3mm wide for grouting.
Like tiling, the screed must be dried before carpeting to prevent mould and fungus growth from rising moisture.