From screed, plaster and paint drying, to concrete, wallboard and millwork, construction sites face many humidity issues throughout a project, and many of the materials used can absorb excess moisture.
While a small amount of moisture is necessary for some materials to cure correctly and prevent cracking or distortion, excess amounts pose various problems. High humidity levels can create major issues to the contractor, including delays to finishing and damage to delicate materials, such as wood and lining materials.
Preserving the condition of building materials on site can be difficult, especially during cold and wet weather. Wood and timber products are vulnerable to damage or decay if left in a damp area for prolonged periods. Similarly, steel components are liable to rust very quickly if subjected to wet conditions.
During construction, many new homes and buildings experience problems with mould. Despite being empty, building shells can suffer from water damage. On average, the completion of a one family house requires about 10,000 litres of water, so there is a lot of moisture involved in the initial construction. Screeds can take weeks to dry, while saturated bare brickwork has a drying time of up to 12 months and concrete needs twice as long. Even during the later construction phases, such as plastering inner and exterior walls, enough moisture can be released to make the windows fog up with condensation.
During winter and colder periods, high humidity levels can be detrimental to the building industry, causing corrosion or condensation and hindering critical operations. Time is also a common denominator regardless of your problem, and the sooner drying measures are put into place, the greater the chance of minimising the extent of the damage and shortening the drying time. You can avoid major costs if the drying process is started quickly and it is effective.
Developers are often under pressure with future residents terminating contracts for their old homes and want to be done with the move as soon as possible. However, natural drying takes a long time, and a freshly poured concrete slab will increase relative humidity to 98% at room temperature half a year later. Proper construction drying prevents excessive spending at a later point. Concrete floors and plaster will need to be dry before finishing trades can start their work, otherwise, the process will be ruined. Expensive wooden or resin floors need to be laid on surfaces that are dry, but if the relative humidity is too high, this may take months. Project managers can reduce drying times and allow finishing trades to start earlier to avoid costly delays and penalties.
Humidity problems can sometimes be disguised by using heat or ventilation when the weather is suitable, but these methods are unpredictable, slow and energy inefficient. Depending on the job, applying heat could actually damage the finished result, causing cracking to plastering or paintwork. Heaters are also often inappropriate due to the high running costs.
If excess moisture is not treated quickly and effectively, then mould will become a problem. It will infest the drywall and cause odours, plus rusting and mildew spots. In the long run, mould is harmful to health and deteriorates building material and heat insulation.
With a dehumidifier, sometimes referred to as a 'building dryer', you can extract moisture from the air, lower the relative humidity on-site, and dry the building quicker to reduce the damp and mould risk. This will also allow you to accelerate the drying process and meet your deadlines.
Using a dehumidifier is one of the most popular methods of removing moisture from a space in a controllable, efficient manner. It also allows you to dry an area at a speed that can be dictated to suit the application.
During building construction, dehumidifiers can accelerate the rate of drying wet processes such as concrete floors and plaster. Not only allowing the construction work to proceed more rapidly, but in a way that ensures the drying will not encourage cracking and distortion. Concrete floors that are dried by dehumidifiers will always settle at the correct moisture content.
Dehumidification is a process that involves removing humidity, or water vapour, from the air and is achieved either by cooling the air or using desiccants.
Refrigerant dehumidification uses a refrigerant to cool the air below the dew point temperature. The water vapour in the air condenses on the coil surface in the dehumidifier and drains away. In essence, the equipment removes humidity via condensation. This is often seen in a typical air conditioner, which cannot control humidity at a construction site.
Desiccant dehumidifiers are excellent for construction sites. They contain hygroscopic materials that attract and hold moisture from the air that passes through the equipment. The equipment then releases the trapped moisture through an exhaust airstream. Desiccant dehumidification is very effective at lowering the vapour pressure in a space. In the end, you are left with arid air that can dry the most saturated materials.
Contractors look to temporary climate solutions to prevent and combat moisture-related problems, such as heaters and dehumidifiers.
By knowing which process is better for your application, your moisture control efforts will be more effective.