Several thousand square metres of thick section screed have been laid using Ronascreed 8 Day Overlay quick drying screed additive at the Galleries Development in Bristol.
This multi-million pound shopping complex occupies a large site in the centre of Bristol and offers shoppers high profile retail outlets on three levels, connected by lifts, escalators and attractively tiled stairs.
The screeds, ranging in depth from 25mm to 100mm, were laid by specialist applicators B R Hodgson Ltd of Bristol. They proposed the use of Ronascreed 8 Day Overlay as an alternative for the screed for several reasons.
Fast Drying Screed
Ronascreed 8 Day Overlay significantly reduces the water:cement ratio of the screeding mortar and accelerates the rate at which the strength and durability of the floor and allows it to be walked on much sooner than conventional screeds.
It also avoids the floor being damaged by contractors who cannot, or will not, wait days or weeks for the floor to reach enough strength to bear their weight and the stress and impact of tools and equipment on the surface.
Pumpability
Ronascreed 8 Day Overlay also allows the wet screed to be pumped great distances whilst maintaining its strength and handling properties. The distances involved were considerable; up to 115m horizontally with a vertical lift of 15-20m to reach the second floor.
By pumping the screed from the mixer on the ground floor to the screeder on the ground, first or second floor, Hodgsons were able to do all their storage, measurement and mixing at one point on the ground floor and simply deliver as much or as little mixed material to the screeder as and when he needed it.
This made life much easier and quicker and avoided having to use a crane or hoist to transport the mixed mortar from ground level to each floor. The mortar remained consistent and no segregation occurred within the pump or hose.
Ronafix for a better bond
Before the screed was laid the prepared and damped substrate concrete was primed with a mix of Ronafix and cement. This proven system ensures that the screed is bonded and secured to the concrete and prevents the screed curling.
The screed was laid in a continuous operation and followed channels and ducts in the floor which will take power, communication and other cabling throughout the complex.
How is Ronascreed 8 Day Overlay used?
Ronascreed 8 Day Overlay is a liquid additive which replaces some of the water used to gauge the screed. It is added a the rate of 10 litres per m3 to cement and sharp sand and offers all the advantages described plus improved workability and higher physical strengths.