Roundtower Newbuild Fine

Roundtower Newbuild Fine is factory blended mortar using a 2mm down kiln dried sand, hydrated lime and specialist cements, combined with carefully selected additives to improve the mortar’s physical and mechanical properties, whilst maintaining many of the virtues of a pure Natural Hydraulic Lime mortar and the strength of modern cement based renders.

Binder Strength – HL5

Usage:

Roundtower Newbuild Fine mortar is a multi-purpose mortar, predominately used for fine render applications. It can also be used for bedding, building and pointing applications where a finer mortar is required.

Suitable for applications in contemporary construction such as modern timber frame and cavity wall. The Newbuild mixes offer a vapour permeable and highly flexible render, with a dramatically reduced embodied carbon content when compared to market alternatives.

We do not advise this product to be used on solid wall or traditional building fabric, unless specified or stated.

The Roundtower Newbuild range is an environmentally friendly alternative when compared with conventional mortars used in modern construction. With 50% less embodied carbon than a sand and cement mortar and the ability to absorb 30kg of CO2 for every tonne used, or the equivalent to the amount of CO2 absorbed by a young tree over 3 years.

The Roundtower Newbuild range can be directly applied to concrete, cement, brick and block. Designed as a mortar and render, the Newbuild range can be used for all manner of construction applications.

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Colour:

Roundtower Newbuild Fine mortar is entirely natural in colour. No pigments or colourants are added.

For applications where colour is important (pointing, unpainted render finish), we strongly advise that sufficient quantities of mortar are purchased and all bags from the same batch to ensure consistency.

Preparation:

In general, this will be determined by the purpose and application of the mortar.

We would expect appropriate preparation in accordance with best practice; where the surface is clean, free of dust and other debris.

Where necessary the background should be adequately dampened to promote adhesion/bond with the host surface.

Dense impervious backgrounds/materials are unlikely to be very absorbent and require little to no dampening, whereas more absorbent backgrounds/materials require adequate dampening in order to prevent rapid drying.

Whilst this mix includes additions to try and mitigate these issues, best practice still needs to be followed.

Mixing:

A 25kg bag of mortar will require 4 to 5 litres of clean potable water. The water addition will vary according to the application and desired consistency/workability of the mortar. Always avoid making the mortar too wet, as this can promote shrinkage issues, especially when used as a render.

For drum type mixers, it is essential not to overfill the mixer.

As a dry mixed material, it is possible that some settlement or separation may occur in the bag during transit; when mixing part bags, it is especially important that the dry contents are thoroughly blended prior to mixing with water.

Best Practice/Advised Mixing - First add 60 to 70% water of the total water into the mixer, followed by the mortar and turn the mixer on. Allow the mortar to mix until the water is thoroughly distributed, then add additional water to achieve desired consistency.

Mix for 5-8 minutes but no longer.

Other mix methods - We accept that it is generally site practice to add the water to the mortar, providing the mortar is well mixed and not too wet, this method will be sufficient.

Quenching - Like most lime mortars this mix will benefit from Quenching; allow the mortar to stand for 10 to 20 minutes after mixing, before use.

Should additional water be needed after quenching to maintain workability, this can be added and mixed thoroughly through the mortar.

Once water has been added, this mortar has an open time of at least 8 hours. Longer in colder weather.

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