Installing Onto Dry Screed Panels, Also Known as Screedboards

Dry screed panels, also known as screedboards, differ from particle boards and plywood in that they are not manufactured from timber. It is not expected that flooring contractors will be the installers of the dry screed panels; the following guidance is relevant only to installing onto dry screed panels and is based on the board being installed onto a suitably dry substrate.

Dry screed panels can be used in both new and refurbishment projects. Due to the diverse nature and installation methods for dry screed panels it is important that prior to carrying out any flooring installation it is essential that the manufacturers guidelines are referenced an, understood and explicitly followed.

Dry screed panels can be summarised as consisting of any one of the following constructions.

• Cement fibre board
• Crush backed boards
• Cement particle board
• Calcium sulphate board
• Cement faced polystyrene board

On inspection, boards should be laid as a flat smooth regular base with no rocking. A minimum SR2 surface regularity in accordance with BS 8204 Part 1 should be achieved. All wet trades in the immediate vicinity must be finished.

In certain circumstances the finished surface of the board will be suitable to receive some types of flooring directly i.e., carpet/underlay, wood, ceramic or resilient. Advice must be sought from the relevant flooring manufacturers on this.

Unbonded: cement particle/fibre crush and calcium sulphate panels

On unbonded systems joints should be completely free from deflection/movement. The joints must be created in accordance with manufacturers’ guidelines. These systems may include UFH systems.

Where smoothing is required, prime and apply floor joint finishing compound/smoothing underlayment as detailed by the subfloor preparation manufacturer’s guidance.

Bonded panels

Ensure the cement fibre/particle/calcium sulphate/cement faced polystyrene panels are well secured in accordance with manufacturers’ guidelines.

Where smoothing is required prime and place floor joint finishing compound/floor smoothing underlayment as detailed by the supplier’s instructions.

Where electric wire heating systems are present these must be securely located without the use of plastic faced tapes. Often, floor smoothing underlayment will be required to encapsulate the wire heating system to create a smooth surface ready for the decorative floor covering.

Micro-bore water fed heating systems can be located within screed board panels, in principle these can be covered with deep fill floor smoothing underlayment, due to the complexity of the systems the specifics need to be confirmed with the relevant manufactures.

Specific advice from subfloor/dry screed panels/priming/floor jointing compounds and smoothing underlayment manufacturers should be sought for individual projects.

Find out more

A guidance note on acoustic and dry screed panels has been produced by the CFA, available as a benefit of CFA membership. This document looks more closely at both floating and fully bonded panels in new and refurbished projects.

For more advice about substrates and subfloors, visit the CFA Guide to Contract Flooring.