Preparation and Insulation Guide

Preparation

If this stage of the project is not completed properly, there will be delays and potential quality issues with the screed. Doing your due diligence on site is vital for a smooth process. On top of that, make sure you double check the specification and constantly communicate with the site managers to make sure there are no changes to the specification.

Here are some things to think about when preparing a site for materials and a screed pump:

  • How much space is on site? Do you have enough space for the materials needed and the screed pump?
  • Is there access to water near your pump?
  • Is there a waste area near the pump?

The next stage would be to check the actual area that will be receiving the screed. Here are some things to think about when preparing a site for the application of the screed:

  • Check and record the datum levels to make sure the tolerance is in check with the specification.
  • Make sure the weather conditions aren’t too harsh for example, the minimum temperature should be 3 degrees Celsius for the screed to be of good quality and dry in the given time period. Hot summers can also affect the screed as it reduces the moisture which is vital for screed to cure. In these instances, it’s a good practice to apply a polythene sheet over the finished screed to keep as much moisture as possible.
  • The room/building that the screed is being laid in should be water and wind proof.

Insulation Installation

Before any insulation is installed, a polythene membrane a.k.a damp proof membrane (DPM) should be applied to the substrate with roughly a 100mm upstand. All the joints should be taped and the membrane should not have any damage otherwise it will defeat the purpose of installing it which is too keep the moisture out. This will usually be done on floating, modified and unbonded screed. Bonded screed is as the name suggests, bonded directly to the substrate. After the DPM is applied, the area is ready for the insulation to be applied.

Insulation is usually applied in all residential projects but is not limited to just residential. The insulation has one of two purposes, either it is for heat insulation or sound insulation. Sound insulation is very common is apartment blocks.

Heat Insulation

There are quite a few types of insulation that can be installed e.g. Polyisocyanurate (PIR), expanded polystyrene (EPS), rockwool etc. PIR insulation boards are the most common as they have some of the highest efficiency readings. Here are the steps of installing the insulation:

  • The insulation boards will be applied over the DPM.
  • A polythene sheet will then be applied over the insulation but this time without an upstand and will end at the edges. This will act as a separation barrier between the insulation and the insulation.
  • A perimeter/edging strip will then be installed around the edges onto the separation barrier.
  • Then a final check is done before applying the screed.

Acoustic Insulation

Acoustic insulation is great in apartment buildings to reduce the noise for people living above and below you. The two main materials used in acoustic insulation is either rubber or foam. This can be applied directly to the floor substrate without the need of DPM. However, it is good practice to apply a DPM sheet on top of the acoustic insulation to separate the screed from the insulation.

Conclusion

This guide gives general advice. Each project and specification is unique meaning that how you carry out the work will vary. For example, the preparation work and insulation will differ when laying flowing screed or latex screed. The information above is based on traditional screed. The difference in preparation for the other types of screed will be outlined in those individual guides.