Is Self-Levelling Compound Flexible?
All self-levelling compound has a certain level of flexibility. This very much depends on the type of self-levelling compound you decide to use. The 3 types of self-levelling compound are listed below:
- Latex mixed – Self-Levelling Compound (Highly Flexible)
- Water mixed – Self-Levelling Compound (Non-Flexible)
- Water mixed – Fibre Reinforced – Self-Levelling Compound (Flexible)
The question should really be, how much flexibility do you need for your scenario?
Latex mixed – Self-Levelling Compound
If you are applying self-levelling compound on an upper floor, you will need a self-levelling compound with an increased level of flexibility as the subfloor may be prone to movement.
Even though you may not notice it, timber joists on the first floor will move slightly. Timber is a flexible material so there will always be a slight amount of spring, in a suspended timber ground or upper floor.
To compensate for this you should ALWAYS use a Latex-mixed self-levelling compound when working on suspended timber ground or upper floors. Overplying the floor may also be advisable on suspended timber floors to help reduce movement over the floor area. We have prepared a quick guide, of the basics here “How to Ply over Floorboards“.
I have attached a link below to a commonly used latex-based self-levelling compound, it comes in a pre-mixed ratio ready to pour. Any product containing a bag of self-levelling cement and a tub of latex would have suitable flexibility.
I also find the self-levelling compound you mix with a tub of latex easier to spread around the room, it leaves a professional-looking finish even if you are new to self-levelling.
Water mixed – Self-Levelling Compound
If you are working on the ground floor and you have a large area to cover then it may be best to use a water-mixed self-levelling compound. These do not offer as much flexibility as their latex-mixed counterparts, but they are perfectly adequate for a solid floor that is not subject to any movement. A, prime example of this would be a solid concrete ground floor.
However, I still prefer to use a latex-based self-levelling compound on ground floors, because I can be more confident using them on almost any floor substrate and they do not require a primer.
If the sub-floor does move for any reason, the flexibility in the latex-mixed self-levelling compound will reduce the chances of any cracking.
I also find that they find their own natural level better than water-mixed self-levelling compounds. They spread better around the room with very little encouragement with a trowel, making them ideal for novices, whose trowel skills may not be up to scratch.