Author: Michael Toomey

Concrete in Cold Weather Guidelines


During extremely cold weather concrete (particularly fresh and early age concrete) can be severely damaged by frost and ice. When fresh concrete cools below 0ºC the water in the mix freezes and expands which causes cracking internally and blistering of the surface. Mature concrete that is saturated can also be seriously affected by low temperatures.

Certain precautions can be taken to minimise and possibly prevent frost damage to concrete and the following advice whilst not exhaustive will help protect concrete against frost damage.
Further guidance can also be got from the Irish Concrete Federations publication “Guidelines for Concreting in Cold Weather” available on

Effects of cold weather on unprotected concrete
• If there is a risk of frost at night it is essential to protect fresh concrete from freezing.
• Fresh concrete strength must reach 5N/mm² to avoid the effects of frost damage.
• Concrete temperature must be kept at or above 5ºC for the first 48 hours to achieve this.
• Low temperatures will slow down concrete strength development for several weeks.
• Strength development is further reduced during cold weather if GGBS or PFA is used.
• Striking times of formwork must be extended during periods of cold weather.
• External slabs, yards and driveways are particularly vulnerable because they have a large surface area and thin section which allows heat to escape rapidly. Particular precautions must be taken to prevent frost damage to these areas.
• While it is common practice to apply de-icing agents such as salt on concrete surfaces to clear ice and snow during winter, these in themselves can damage the concrete surface that they are applied to. Ammonia based de-icing agents are particularly aggressive and should not be used as they can severely damage concrete surfaces.

Precautions to be taken when concreting in cold weather
• Specifications recommend that concreting should not start when the air temperature is 5ºC and falling and should only begin when the temperature is at 3ºC and rising.
• Fresh concrete should never be placed on or against frozen ground.
• Reinforcing bars and shuttering must be free of ice and snow. Cover and insulate the concrete where possible.
• If concrete has to be placed it should be organised so that it is done as quickly as possible.
• Frost blankets should be used to provide insulation and protection for exposed concrete surfaces.
• Wind breaks will reduce wind chill and evaporation and help lower heat loss especially from slabs.
• Heaters may be necessary to provide continuous heating to the concrete to maintain heat.
• Increasing the cement content or grade of concrete will generate more heat in the concrete; consider the use of air entrainment, polypropylene fibres or accelerator.
• The Irish Standard for Concrete : IS EN 206, recommends using C30/37 (37N) air entrained or C40/50 (50N) concrete where wet horizontal surfaces are exposed to significant freeze/thaw cycles.

N17 N18 Gort To Tuam PPP Scheme

The N17 N18 Gort To Tuam PPP Scheme was separated into 3 sections, North, Middle and South.

Roadstone is delighted to see the opening of the new M17/M18, having supplied and laid 1 Million squared metres of blacktop to the job over the last 2 years.

Roadstone won the contract to lay CBGM, Base, Binder and Wearing Course on both the North and Middle sections including all side roads on the Tuam By-Pass and Rathmorrissy interchange.


Rathmorrissy Interchange is the largest on the contract linking M6 Galway to Dublin motorway and M17/M18 Gort to Tuam motorway. The roundabout itself is almost 1 km in circumference and was a very complicated and challenging aspect to the contract.

Annagh Hill interchange is located at Annagh hill on N63. The interchange consists  4 roundabouts and approximately 4km of a road network.


Safe T Certification award

In November 2016 Roadstone Contracts was awarded the highest Safe T rating possible. The audit was carried out on this project, and is a testament to the team working on the project.


Contract in Numbers

Official opening Date                                      27th September 2017 (5 months early)

Contract duration                                            2 years


Tuam By-Pass                                                   4.1km

N17/N18 mainline                                           30km

Rathmorrissy circulatory carriageway        1km

Rathmorrissy slip roads (12no.)                    9km

Annagh Hill Interchange                                4 roundabouts including 4km road network

Side Roads                                                         25



  • Communication is key
  • Advanced planning and programming is vital
  • Dealing with issues quickly and effectively builds confidence
  • Quality and quality control are a key part of any large contract


I.S. EN 206: 2013 Concrete Specification

I.S. EN 206: 2013 – Concrete Specification, Performance, Production and Conformity, is the current Irish standard for the specification and
production of concrete and should be used in conjunction with the Irish National Annex I.S. EN206:2013/NA:2015.

Click on this link to download an easy-to-use introductory guide to understanding and interpreting the new standard, courtesy of Roadstone, the standard-bearers for excellence in concrete production.

Notable changes to the standard include revised requirements for fibre reinforced concrete, recycled aggregates and additions (fly ash & GGBS).
The requirements for conformity assessment have also been revised including additional requirements for Self Compacting Concrete and concrete for geotechnical works. The National annex takes these changes into account for Irish conditions with reduced cement contents for some exposure classes, reduced the slump tolerances and increased the strength class for Freeze Thaw.
Alternative equivalent design mixes can now be supplied in place of standard prescribed mixes, if supplied from third party accredited, I.S. EN 206:2013, ready mix concrete producer. See Table NB.2: Alternative Equivalent Design Mixes.
The National Annex also provides specific additional information and responsibilities for the specifier, user and producers in Ireland. Refer to I.S. EN 206 :2013: Tables NA5, NA6 & NA77 (table NC1 to NC6 where the design life & cover are known). The format for specifying and ordering concrete remains the same as that previously specified in I.S. EN206-1: 2002 including compressive strength, consistence and exposure classes.

If you have any questions on concrete specifications or require further technical information on any Roadstone products please contact us via this quick contact form and we’ll gladly assist with your query.

Alternatively please browse our complete concrete range of products by clicking on the following Roadstone website link:

Roadstone Concrete Range

Roadstone wins prestigious award

Roadstone, the leading manufacturer and supplier of building materials in Ireland, is celebrating after their Thermal Liteblock picked up the award for ‘Best New Product Innovation of the Year’ at the recent Irish Building and Design Awards.


Organised and hosted by leading event organisers CMG, the black tie ceremony was held in the Ballsbridge Hotel, Dublin. Over 500 Professionals from architecture, engineering, construction and design attended the industry’s blue ribbon event to celebrate the nation’s best building and design projects over the past 12 months.

The judging panel for the 2016 ceremony included some of the leading industry professionals such as Martin Lang, CIF Director of Main Contracting and Tim Brick, Executive Director of the Irish Academy of Engineering. This year’s awards received the largest number of submissions since the event’s inception six years ago with each judge commenting on the high standard.
Roadstone led the way in the ‘Best New Product Innovation of the Year’ category for its innovative Thermal Liteblock.

Arthur Lambert - Alan Lowe - Michael Toomey

Arthur Lambert – Alan Lowe – Michael Toomey from Roadstone receiving the award

Thermal Liteblock is a lightweight, durable and thermally efficient concrete block that provides improved energy efficiency in the design and construction of new buildings. The product was developed to meet new building regulations in particular Part L. Launched in May 2015 it includes thermal modelling of a wide range of building junctions which means that we can provide our customers with design solutions and validated thermal performance calculations, through the Roadstone technical support team.

The Thermal Liteblock product launch program included a number of regional seminars throughout Ireland that were well attended by architects, BER assessors, engineers and building contractors. A designated page has been developed on the Roadstone website for Thermal Liteblock that includes technical guidance, DOP and  contact details for our technical support team as well as a large range of technical drawings available to download in various formats.

ISO 50001 Ireland Conference

Kevin Donovan at the ISO50001 Ireland conference 2015

ISO50001 Ireland 2015 on the 20th of May in Croke Park saw the event celebrate it’s 3rd anniversary. The event brought together delegates from Irish processing who are considering the transition to the International energy management standard ISO 50001, but yet to make the journey. The theme/profile of the event is simply to create an exchange of information between organisations who are about to make the transition to the Energy Management Standard ISO 50001 and companies who have already made the transition. Speakers were carefully selected based on their experiences and knowledge of this standard and who are keen to network with delegates in an effort to develop the standard further within Ireland.

This year saw a collection of presentations from a broad selection of industry sectors, including Food, Pharmaceutical, Medtech, ICT, Transport and representing the Construction sector was our own Kevin Donovan from Roadstone Ireland.

Kevin had the opportunity to share with over 200 of his peers from Irish industry the achievements of Roadstone Ltd to date in adopting the ISO 50001 energy efficiency standard. Now boasting 21 Locations, and Transport Sector the strategy is to continue accreditation of ISO 50001 across the group. Kevin says; “It was an excellent opportunity for me and Roadstone to highlight the significant developments we have achieved in energy efficiency in recent years. It is a credit to the entire Energy/Facility Teams, as well as Senior Management who without their support these accreditations would not be possible.”

Kevin’s full presentation  can be accessed on the event website using   the  password: “iso2015”.

New Thermal Liteblock System – A fabric first approach for compliance with Part L of Building Regulations

Launch of Roadtone Thermal Lite Block


Roadstone Ltd is proud to introduce the Thermal Liteblock System, an exciting new product innovation which was launched recently at an event in Dublin.

The Roadstone Thermal Liteblock is a robust and durable, lightweight block which was developed for use with traditional masonry after extensive research aimed at producing a cost-effective solution for architects, engineers, assigned certifiers and building contractors to comply with Part L of the Building Regulations.

When used in conjunction with Roadstone’s standard Concrete Block range, the system improves thermal conductivity by an impressive 300%.  The mitigation of heat loss at thermal bridges, which is a key challenge in the construction industry, also results in reduced energy bills.

The Roadstone Thermal Liteblock is made from a special mix which includes lightweight aggregrates to achieve conductivity values of 0.33W/mK.  It is manufactured in Ireland and has an average weight of just 11.5kg compared to the standard 20kg concrete block.  Heather in colour to facilitate traceability on site, the Roadstone Thermal Liteblock is also CE marked 2+.

The Thermal Liteblock is used at targeted key locations in conjunction with the Roadstone Concrete Block range, providing a cost effective solution to the construction of new buildings and allowing greater flexibility in the development of designs.

Speaking at the launch event in City Hall Dublin, guest of honour Mr. Tom Parlon, Director General of the Construction Industry Federation said, “Energy efficiency remains the best way to offset energy costs and reduce the carbon emissions of new buildings.  For these reasons, improved energy efficiency standards in new residential, business and public developments are at the core of the new Building Regulations and the Government’s Construction 2020 Strategy.  I welcome this product innovation from Roadstone and the contribution it will make towards achieving these standards.”


Tom Parlon, Director General of the Construction Industry Federation and Larry Byrne, Managing Director of Roadstone Ltd pictured at the launch of Roadstone’s Thermal Liteblock System

Tom Parlon, Director General of the Construction Industry Federation and Larry Byrne, Managing Director of Roadstone Ltd pictured at the launch of Roadstone’s Thermal Liteblock System

Mr. Larry Byrne, Managing Director of Roadstone Ltd added, “Roadstone continually strives to produce only the highest quality products and to give the best service in our industry. In this regard, we are committed to product innovation aimed at meeting national energy efficiency standards. The Thermal Liteblock System is an innovative, cost-effective and Irish-made product, designed for the needs of the Irish construction industry. We are confident that it will play a major role in the industry for many years to come.”


Alan Lowe, Product Development Manager, Roadstone Ltd pictured at the launch of Roadstone’s Thermal Liteblock System

Alan Lowe, Product Development Manager, Roadstone Ltd pictured at the launch of Roadstone’s Thermal Liteblock System

Over 100 industry experts attended the official launch of the Thermal Liteblock System, which included a technical Questions and Answers session on its role in Irish construction.

Thermal Liteblock FAQ’s

Irish Wind Energy Output Reaches Record Heights

Irish wind energy output reached a record high on of 1,942MW on Wednesday. 

The output is enough to power over 1.26 million Irish homes according to figures published by EirGrid, who monitor electricity generation and usage nationally.

The new record is the second such record to be established already in 2015 and overtakes the previous record set on New Years Day of 1,872MW.

Since the start of the year, Irish wind energy has met a third (33%) of all Irish electricity demand from Irish consumers and with high winds forecast beyond the coming weekend, this trend is set to continue.

Roadstone are playing an important part in building on this cleaner, sustainable solution to Ireland’s energy problems. Material supplied by Roadstone includes stone fill for access roads and high strength concrete required for turbine bases and grid networks.

A turbine base can require between 400-800m3 of concrete all supplied in a single pour.

Pictures attached are of one such project – The Garracummer Wind Farm in Co. Tipperary, which went into operation two years ago.  Roadstone supplied the concrete for this project. Due to the national network of concrete plants and quarry locations, Roadstone are ideally located to successfully service similar projects well into the future.