Flowing screeds are ideal for application over both electric and water underfloor heating systems because of the flowable consistency that fully encompasses the heating pipes. Flowing screeds have excellent thermal conductivity and minimal thermal expansion.

RECOMMENDATIONS FOR PREPARATION WORKS - UNDERFLOOR HEATING SYSTEMS

Screedflo Guidelines

All preparation to be carried out by others prior to screed installation.

Setting Levels

The minimum recommended coverage to pipework is 30mm. Due consideration must be given when installing insulation as the depth of this will determine the finished screed thickness.

Base Preparation

All high spots and debris must be removed as these will impact on finished screed thicknesses.

Insulation

Ensure that insulation is installed on a clean and even bed to prevent movement and rocking of boards which are to be butt jointed with staggered joints. If the substrate is particularly uneven, a slurry grout may be required.

Slip Sheets

Provide a polythene slip sheet (minimum 500g) over insulation. All joints must have 100mm laps and be thoroughly sealed with tape prior to installation of the heating system. We recommend the use of single wound polythene (to avoid creases) and 50mm packing tape. Ensure that all air pockets and voids are removed.

Perimeter Details

Provide insulation upstands to all perimeters. We recommend the use of rigid board insulation for cold bridging or 5/10mm polyethylene foam expansion strip to the full depth of the screed. Continue the slip sheet up the face of the upstand, secure with tape to form a watertight seal. Ensure that all junctions with walls and corner details are constructed neatly with the polythene installed fully into the angle leaving no air pockets or voids.

Fixing Pipework

Lay heating system as required ensuring that all pipework is mechanically fixed at 300mm centres. Please be aware that because of the density of the screed, heating systems will lift and 'float' if not adequately secured. We suggest the use of a proprietary fixing system for this purpose. All wet systems should be filled with water to increase density and help prevent lifting.

Holes for Builders Work

Ensure that all apertures are adequately sealed. Any formwork required should be treated as an upstand and prepared as above.

Final Check

Upon completion of installation, inspect the whole system for tears / holes / damage etc and make good to ensure that the whole system remains watertight to receive liquid screed.

Screedflo Installation

During installation of the Screedflo and for three days thereafter, the surface of the screed must be protected from severe draughts. If windows have not already been fixed, clear polythene protection should be installed.

Floor Finishes

When cement based products are applied to the finished Screedflo such as levelling compounds or adhesives, the screed must be primed with a suitable and compatible product as recommended by the flooring manufacturer.

Help Line

Any problems that arise, during the preparation work, should be addressed to 0870 850 8900.