Floor screeding is something you have to get right to avoid costly delays to a construction project.

Get the screeding wrong and it could lead to serious problems when the time comes to laying the floor.

While floor screeding should be a straightforward process, there are some common issues that arise when you don’t do enough planning.

For the most part, laying screed might seem like a fairly simple and straightforward process, but it isn’t always the easiest thing to get right. 

Here are some of the most common problems with floor screeding and how you can fix them: 

  1. Using poor quality screed

If a low quality screed has been used it can crumble and deteriorate quickly over-time. This is usually caused by screed that hasn’t been mixed properly, that’s either too wet, too dry or doesn’t contain enough cement.

If your mix is too wet:

  • You’ll be left with a friable, weak and dusty surface
  • Shrinkage cracking will occur, which is when excess moisture is released and the mix shrinks. This is a particular problem over larger areas or screed laid near corners or edges.
  • The finish will be poor

If your mix is too dry: 

  • You’ll struggle to cover the area
  • Your surface will be friable and weak
  • Compaction will be poor, which could lead to cracks or the screed crumbling under weight
  • Not all cement will hydrate, which can lead to cracking and severe deterioration.
  • You’ll get an uneven surface after the screed is down

Mostly caused by improper surface assessments, you’ll know your surface is uneven if you’re having problems laying flooring and it won’t line up properly. 

Surfaces might also be uneven because you haven’t prepped the floor properly. 

The best thing you can do to avoid uneven surfaces is make sure you’ve cleaned the floor thoroughly before the screed is laid to make sure there’s no debris and that the screed itself isn’t too wet – so it doesn’t run or drip. 

  • Too much moisture in the screed mix

There’s not very much you can do if the floor has already been put down, and is best to prevent this in the first place. 

You’ll know the mixture is too wet when it bubbles up and a damp smell comes from under the floor. 

To stop this from happening, carry out a moisture test and make sure the screed is mixed and being laid properly and that you’re allowing it enough time to dry. 

  • Using the wrong amount of screed

Before anything, you should carry out a reliable level survey. 

Inaccurate assessments will result in you not being able to fully cover the area, as not enough materials will have been supplied. 

If you’re struggling to maintain appropriate coverage, having difficulty fitting insulation or the alignment of fixed positions (stair treads, window and door thresholds, etc) is off, then you probably don’t have the right amount of screed.

  • Poor compaction of screed

During the installation process, applicators will compact the screed.

Failure to compact the mixture properly will lead to a weak screed that has pockets of air in it. 

If the screed is especially thick, it should be applied in two layers; if it’s done all at once it wont compact effectively. 

Half should be laid and compacted; the process repeated once the first half is dry. 

It might take a little longer, but it will achieve a great smooth and level base.  

  • Laying the floor covering too soon

This is likely to happen if you’re pressed for time and decide to lay the final floor finish before the screed has completed its drying time. 

The residue of moisture from the screed will eventually try to escape, only to be trapped by floor covering. 

This will soften the adhesive which binds the floor finish to the screed, weakening the bond and causing the covering to lift away from the surface. 

Never lay your floor finish prematurely and always follow the manufacturers recommended drying times – even if you’re working to a tight deadline – it will only cause more problems in the long run. 

If you plan everything first and take your time with the project, these problems are easily avoidable – prevention is always better than cure.

If something doesn’t go to plan, there’s always something you can do to fix it and following these few simple steps can help you stay away from having to make expensive repairs or replacements in the future.