Navigation Menu+
Commercial Flooring News

Why It Can Pay To Watch Your Weight

Stuart Whiteley on lightweight smoothing underlayments

THIS month I will give information and advice on lightweight smoothing underlayments. Some products available are typically half the weight of a normal underlayment when cured.

There are several environments in which the weight of a new flooring installation needs careful consideration. Large-scale, modern, multi-storey developments, for example, may have complex structural loading restrictions.
Alternatively, heritage buildings may have been subject to years of regular traffic, resulting in strict weight bearing limitations. In these types of situations, using lightweight subfloor preparation products offers obvious benefits.

• Density: Some lightweight smoothing underlayments are formulated to offer significant weight savings by utlising the latest cement-technology and replacing sands, fillers and extenders of standard underlayments with lightweight alternatives.

Once cured, the dry density of these compounds means they are typically 50% lighter than standard smoothing underlayments. By using polyacrylonitrile fibres to reinforce the compound, the specialist products remain dimensionally stable, and suitable for regular duty applications.

This weight saving also makes such products attractive for marine applications. When refurbishing the cabin deck of a cruise ship, for example, a suitable lightweight smoothing underlayment can be applied to patch repair small holes, in addition to being used to level an area, before applying a new floorcovering.

It is important to note that products used during marine installations should meet the relevant standards, such as those set by the International Marine Organisation.

• Manual handling: Contractors also benefit from using lightweight smoothing compounds, as the features of the products improve manual handling. An 11kg unit of a lightweight underlayment can provide approximately the same coverage as a 25kg unit of a standard smoothing compound, for example. This is particularly beneficial on multi-level projects where site access is difficult.

Additional benefits: Due to their specialist formulations, and the careful selection of lightweight fillers and aggregates, some lightweight smoothing underlayments offer additional sound insulation benefits, as they can help to reduce the transmission of certain frequencies of sound between internal floors.

In addition, lightweight smoothing compounds have low thermal conductivity in comparison to standard smoothing underlayments, due to the use of certain lightweight fillers which increases their insulation properties.

When working on projects where weight restrictions need to be enforced, select specialist lightweight smoothing underlayments which are formulated to provide contractors with a significant weight saving. Some of these products are typically half the weight of a normal underlayment when cured.

Stuart Whiteley is section leader – cement technology at F Ball and Co

T: 01538 361633

This article has been reproduced from the Contract Flooring Journal website. You can find them at