Liquid screed is one of the most reliable flooring solutions you can use on a modern build, but like anything in construction, the final result depends heavily on the preparation and the installer’s attention to detail. We’ve poured enough liquid screed over the years to know that most problems don’t come from the material itself — they come from small mistakes made before, during, or just after the pour.
Some of these mistakes are easy to avoid once you know what to look out for. Others are the kind of lessons you only learn after being called in to fix someone else’s job. This guide walks through the most common issues we’ve seen on site and how to prevent them.
1. Poor Preparation Before the Pour
If there’s one thing we’ve learned, it’s that liquid screed is unforgiving when the prep isn’t right. Because it flows so freely, any gaps, holes, or loose insulation will show up instantly.
We’ve arrived on sites where insulation boards weren’t taped, pipes weren’t clipped properly, or the membrane had gaps big enough for screed to escape. Once the screed starts flowing, it’s too late to fix these issues.
Good prep includes:
- Tight, level insulation
- Fully sealed membranes
- Securely clipped UFH pipes
- Proper perimeter edging
Skipping any of these steps is asking for trouble.
2. Forgetting to Prime the Surface
Priming isn’t optional. It’s one of the most important steps in ensuring the screed bonds properly. We’ve seen floors where the primer was missed or applied unevenly, and the result was a surface that didn’t cure consistently.
A good primer prevents the screed from separating, reduces laitance, and helps the mix settle evenly. It’s a small job that makes a big difference.
3. Incorrect Screed Depth
Liquid screed needs to be poured at the correct depth to perform properly. Too thin, and you risk cracking or weak spots. Too thick, and you slow down drying times and waste material.
We’ve been called to jobs where the installer didn’t check levels properly and ended up with a floor that varied by several millimetres across the room. Once the screed sets, there’s no easy fix.
If you’re comparing screed types, the blog Liquid Screed vs Traditional Screed explains why depth matters more with liquid systems.
4. Not Removing Laitance at the Right Time
Laitance is the thin, dusty layer that forms on top of liquid screed as it cures. It’s completely normal — but it needs to be removed. We’ve seen flooring fail because someone skipped this step and laid adhesive directly onto the laitance.
The ideal time to remove it is usually around 7–10 days after the pour. Leave it too long, and it becomes harder to grind off. Do it too early, and you risk damaging the surface.
Flooring installers always appreciate when this step has been done properly.
5. Rushing the Drying Process
This is one of the most common mistakes we see. Someone gets impatient, brings in heaters, seals the room, or turns the underfloor heating on full blast. Every one of those shortcuts can cause cracking, curling, or uneven drying.
Liquid screed needs ventilation, steady temperatures, and time. Nothing fancy — just the right conditions.
If you want a realistic idea of how long drying actually takes, the blog The Complete Liquid Screed Drying Time Guide gives real‑world timelines.
6. Turning on Underfloor Heating Too Early
Underfloor heating is a brilliant pairing with liquid screed, but only when it’s commissioned properly. We’ve seen floors crack because someone switched the system on after just a few days.
The safe window is usually 7–10 days, followed by a gradual heat‑up cycle. No sudden jumps. No shortcuts.
If you want to understand why UFH and liquid screed work so well together, the blog How Liquid Screed Improves Underfloor Heating Efficiency explains the science behind it.
7. Poor Ventilation During Curing
Liquid screed needs airflow to dry evenly. We’ve walked into sites where every window was shut tight “to keep the heat in,” and the screed took twice as long to dry.
A slightly open window or controlled airflow is enough. You don’t need a wind tunnel — just a way for moisture to escape.
8. Laying Flooring Without Moisture Testing
This is the mistake that causes the most expensive problems. Even if the screed looks dry, moisture can still be present deeper down. Laying wood, vinyl, or laminate too early can lead to warping, lifting, or adhesive failure.
A simple moisture test removes all doubt. We never recommend skipping it.
Final Thoughts
Liquid screed is one of the most reliable and efficient flooring solutions available today — but only when it’s installed correctly. Most of the issues we’ve seen over the years come down to small oversights that could have been avoided with proper preparation and patience.
If you want a floor that performs as well as it looks, choose an installer who understands the process from start to finish. We’ve spent years refining our approach to ensure every pour is clean, level, and built to last.
To learn more about the material itself, you can read our main guide on liquid screed.