Management

Continuing construction in the Siberian blast

26 February 2018 | By Matthew Cooper, Revival

Image: Lowerkase/Dreamstime.com

Matthew Cooper looks at what plummeting temperatures mean for the construction industry and what businesses can do to ease the freeze.

Matthew Cooper

Winter weather has always caused a headache for the construction industry and this season has been no exception with another bout of cold weather causing disruption for many parts of the country.

The trouble with winter weather is it’s often unpredictable, changes quickly and we’re often ill-equipped for it. However, with some preparation, planning and the ability to respond quickly, a cold snap doesn’t have to cause delays. Here we look at some of the obstacles the winter brings and how businesses can get around them.

Workers and materials both struggle in the cold

One of the immediate challenges with dropping temperatures is the impact it has on the workforce and their ability to safely work in sometimes freezing conditions. Dangers include slipping on ice, as well as, serious illness such as cold stress.

It’s not just people that struggle to work in the cold – certain materials also have a hard time when the temperature drops, as is the case with pouring concrete, as once the temperature goes below 4°C it is difficult to cure and below this the water aspect of it freezes.

One solution to help this is modern additives, but they don’t fully solve the problem. Fresh concrete maintains some warmth during its initial curing as part of its chemical reaction but if it’s too cold, the chemical reaction slows and curing stops, leading to structural weakening.

Another complication is that pours that contain a heavy mass means that the core may maintain its temperature but the edges can cool and lead to uneven curing and stress fractures.

The cold can also affect wet trades such as plastering and brickwork, for similar reasons as concrete. It’s essential that maintaining a core temperature is a priority on these jobs which can be achieved by providing high energy systems.

Teams we work with are able control temperature and conditions to aid drying, as well as provide heat to keep workers warm. The systems can be controlled and monitored remotely so that you can get the temperature to the desired level ready for when the work force arrives. 

Materials maintain water

Materials are often unprotected from wind and rain whilst a structure remains roofless. Often when the roof is in place, no drying takes place and the trapped rain water and water in the wet construction materials that have been stored outside remains in the property.

This causes materials to degrade and mould starts to proliferate, if the mould is on paperback products, such as plaster board, then plaster beetles and book lice appear as they search for mould to eat. Tens of thousands of these can manifest, horrifying property users.  

Properly drying the building before it’s ready for use prevents these issues occurring and eliminates the need for further work and cost.

Low temperatures affect drying times and completion dates

Delayed drying times can mean penalties for missing or extending deadlines, so preventing the disruption to workflow needs to be a priority. Traditional drying methods, especially combined with an unheated site, can take a long time in winter weather.

Once concrete and plaster etc. has cured, it can be dried using advanced systems, however, left to its own devices, concrete dries at the rate of 1mm per day. Once cured, the free moisture can be driven off at a much greater rate and at 50 C°, concrete and bricks can be dried at the rate of 15mm per day.

Frozen ground can cause delays to tasks such as foundation laying, which, when you look at winters such as 2010/2011, where temperatures in some areas of the UK hit -14°C and remained that low for a number of days, can have a significant impact on a project.

High energy systems can be used to thaw the frozen piles of aggregate and ballast required to make the concrete foundation in the first place.

With the right knowledge systems in place you can avoid some of the issues winter weather brings to sites. Indeed, you may also find these systems handy throughout the year as they can help speed up completion dates and meet tight deadlines. 

Matthew Cooper is CEO of disaster restoration specialist Revival

Comments

While some of the article is correct there is a lot that is misguided. First the UK needs to really reduce the fixation with wet trades. Go to North America to see real dry trade construction. It is faster and simple. Also it is quicker to enclose a building. The faster the roof is in place the quicker the building becomes dry. The ready-mix concrete industry need to provide heated aggregates, use of hot water can really help to avoid setting problems, pre-heating the face of the formwork with a propane torch takes the chill out of the formwork surface. Also cover with insulated tarps the night before a pour avoids snow getting into the formwork and cover up again after the pour to retain heat. Winter construction in northern North America costs 50% more. Hang tarps over buildings to keep the wind out.

Roger Ward FCIOB PQS(F), 22 February 2018

have we never had cold weather before? how will we survive this cold snap,

alan, 26 February 2018

The comments made by Matthew are more easily said than done. Firstly, in the construction costs, enough allowance is never made for winter working due to single stage tendering. Secondly, despite using best endeavours in using chemical additives and heat, the productivity slows down during cold spells, and this lost time cannot be claimed to extend the completion date under most contract conditions due to a 1in 12 year event. The client takes full advantage of this by imposing high LAD's with the already low margins that the construction companies are forced to work under.

Kanji Kerai, 27 February 2018

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