Winter is coming... not!

It was only a few years ago that building sites had to be vacated in the autumn, only to come back into action in the spring, but now it is not unusual for the construction season to last the full twelve months in every branch of the sector. “When we are drawing up project schedules, we can now discount winter as a factor in them. We do take account of whatever the weather might throw at you, but any negative impact can now be reduced significantly,” explains Piotr Rusinek, the operational director of Arcadis’ buildings division. “Although construction work in winter is associated with additional expenses, it can be predicted to some extent and included in the investment costs. This additional item in the budget can still be lower than the contractual penalties the contractor might have to face if delays occur. For several years winter in Poland has clearly been on the move – November and December used to be the hardest months, but now they are January and February. It’s worthwhile taking this change into account in work schedules,” points out Przemysław Bożek, a project manager at CFE. “Fortunately, winters have also become milder, which is also reflected in our investment plans – work is in progress on the construction site all year round and only slows down slightly in the winter months. Contractors do admit, however, that it is still impossible to predict such ‘forces majeures’ as big freezes or hurricane-force winds, therefore these special cases have to be covered by the contract, so that the client cannot resort to charging penalties in the case of any delays resulting from them.

Expensive physics

Freezing conditions make the so-called ‘wet-work’ more difficult or even impossible to carry out. “Work has to cease completely when the temperature drops below -10⁰ or if there is heavy rainfall – and this has always been the case. Working becomes dangerous in such conditions, employee productivity decreases dramatically, and modern technology can do nothing to rectify this,” admits Piotr Rusinek. Ensuring adequate conditions for employees and the right technological processes in winter is expensive – very expensive. Electric and oil heaters are generally used to allow construction and assembly work to be carried out on façades that are covered with tarpaulins or in enclosed spaces. Specialist equipment is usually rented by general contractors, which is also costly, as is supplying the power for these devices. For example: heating app. 250 cubic metres of a building site costs app. PLN 2,000–3,000 per day. Construction chemicals are also used to allow wet work to take place in winter. These include a variety of additives for concrete or mortar, to enable several kinds of wet work to be done at low temperatures,” explains Waldemar Paszko, the director of investment at 7R. However, these chemicals are also an extra financial burden – contractors estimate that refined concrete for working at lower temperatures is app. 5–10 pct more expensive than traditional concrete. Strong winds, on the other hand, represent an insuperable problem on the construction site (and can happen throughout the entire year, in fact). Wind speeds of more than 10 m/sec. put a brake on the operation of lifts. “It’s important to check the weather forecast. We use the forecasts provided by ICM [ed: the Interdisciplinary Centre for Mathematical and Computational Modelling at the University of Warsaw]. Their three-day forecast is almost 100 pct correct and the two-week one is about 40 pct accurate,” claims Przemysław Bożek. “And predicting changes in the weather is also important in terms of the project’s budget – when winter ensues, the demand for heaters increases dramatically, so the price for hiring them goes up. So it’s worthwhile booking these devices in advance,” he adds.

Weak points

The biggest problems that all contractors and developers encounter in winter are actually related to the earthwork, especially if the construction is being carried out on high plasticity soils sensitive to changes in the weather and prone to turning into a mud pit. In winter it’s also difficult to carry out reinforced concrete work on the ceilings – if there are no walls above them and the ceilings cannot be covered with tarpaulins. “It’s easier with masonry work and interior work is easier still – at least fit-out firms such as ourselves have a roof over our heads,” points out Przemysław Bożek. “That’s why every contractor aims at locking up the building before winter – this gives us more of an opportunity to continue the work,” he adds.

Some branches of the construction sector have their own ‘Achilles heels’. “The weak area for the warehouse industry is laying the concrete floors – the technology we have requires the temperature to be above zero throughout the entire concrete setting period and that the layer under the flooring under construction is also not frozen,” admits Waldemar Paszko of 7R. To be fair, the warehouse construction industry also has its advantages in this regard – in recent years, wet-work has been gradually replaced by prefabrication, which is less sensitive to adverse weather conditions. Therefore it is the construction of ‘big boxes’ that is the most resistant to the onslaught of winter.

The human factor

Construction workers are also vulnerable to poor weather conditions, as both their physical limitations and health and safety regulations prevent them from performing certain types of work. However, in some areas of construction winter results in the greater availability of subcontractors specialising in finishing work, so you can get a better price for their services. “It is therefore a good idea to draw up the work schedule in such a way that the lock-up stage of the building is complete by the autumn and it’s possible to work under a roof from November to February, preferably using the existing central heating installations,” argues Piotr Rusinek of Arcadis. “Smaller companies prefer to work for individual investors in the summer – they can negotiate higher rates and the fee is often cash-in-hand,” adds Przemysław Bożek. However, this kind of work, often on private houses, tends to end in the autumn, because it is not profitable for investors to heat these buildings, so they prefer to wait until the spring. In the autumn workers tend to be looking for jobs on large construction sites where there are no seasonal breaks. The price for finishing work is around 15–20 pct lower in this season.

Winter breaks now only amount to the festive period. The general contractors of Warsaw projects estimate that only about 10–20 pct of their construction workers live in and around Warsaw, while the rest come from the south of Poland and from across the eastern border – and they need a bit more time to get back to their families for Christmas and to come back to work.

Anticipation fail

The winter isn’t the only problematic season – hot summers can also disrupt the work schedule. “There was this well-known case of a delay in a hot summer because of the low level of the river intended to be used to transport gas turbines to the construction site. But general contractors should easily be able to anticipate this kind of contingency, especially since low river levels occur cyclically,” says Piotr Rusinek.