What Is A Rainscreen in Construction?
What Is A Rainscreen in Construction?
A rainscreen is a type of building a wall that has siding or cladding that is set off from the moisture-resistant surface of an air/water barrier by a small gap, known as a capillary break. This allows for drainage and evaporation, which helps to prevent the wall from getting wet.
In some cases, the ventilation openings in a rainscreen wall are large enough for the air pressure to be nearly equalized on both sides of the wall which is known as a pressure-equalized rainscreen wall.
However, this term has been criticized as being redundant and is only useful to scientists and engineers. The goal of a rainscreen system is to protect the wall from moisture but due to the presence of cladding attachments and penetrations such as windows and doors, water may still reach the wall.
To address this, materials are selected that are resistant to moisture and are properly integrated with flashing.
They are typically made of a layer of cladding material that is attached to the main walls with a small air gap in between. This air gap provides insulation and allows moisture to escape through the top and bottom of the rainscreen.
Rainscreens do not significantly increase the overall size of a building, but they are an important part of the structure’s exterior design.
Some rainscreens only allow moisture to escape through the bottom, but having a gap at both the top and bottom can help to equalize pressure and improve the overall effectiveness of the system.
Advantages Of Rainscreens
There are three main reasons why rainscreen are popular with builders and homeowners:
- Rainscreens provide protection against long-term damage by creating a small air space that allows water to drip down or evaporate upward, rather than penetrating the walls of the house.
- Rainscreens provide insulation due to the air pockets they create which can improve the energy efficiency of a building.
- Rainscreens are relatively affordable to add to a construction project with an additional cost of one to two dollars per square foot. This is a relatively small increase in budget compared to the cost of replacing entire walls damaged by moisture.
Disadvantages Of Rainscreens
Rainscreens are a useful tool for protecting walls from water damage, but they are not suitable for all types of walls and may not be cost-effective in all climates.
Additionally, not all builders have experience installing rainscreens, so it is important to carefully choose a builder with the necessary knowledge and experience.
Rainscreens are most effective on walls made of siding and are not suitable for use with brick or stone walls or buildings with large glass panels.
They are most cost-effective in regions with a high risk of sustained water damage, such as the east coast or Pacific Northwest, but may not be worth the cost in areas with low annual precipitation. It is important to ensure that the rainscreen is properly constructed to be effective.
Components Of Rainscreens
A rainscreen is a system that protects the exterior walls of a building from water damage. It is made up of several components including a water-resistant barrier, furring strips, venting material, exterior cladding, and trim.
The water-resistant barrier is a wrap that prevents water from entering the building. Furring strips provide support for the rainscreen and create an air cavity between the water-resistant barrier and the exterior cladding.
Venting material is attached to the furring strips and helps to move moisture away from the wall assembly. Exterior cladding is the outer wall that is exposed to the elements and can be made from various materials like brick, stucco, or siding.
Trim is decorative and serves an aesthetic purpose. When it rains or snows, the rainscreen system helps to deflect most of the moisture away from the exterior walls, while the small air cavity created by the furring strips and venting material allows any remaining moisture to drain away, preventing long-term rot and mold.
Examples Of Different Types Of Rainscreens
There are two main types of rainscreen systems: Drained and ventilated, and pressure-equalized (PE). In drained and ventilated systems, moisture is able to drain or evaporate and vent to the outside, but it is important to detail the façade to prevent water from crossing the gap between the rainscreen and the internal wall construction.
In contrast, PE systems allow air to flow between the inside and outside of the rainscreen, which equalizes pressure and prevents water from being driven or sucked through the joints. However, the definitions of these two types of systems are not always clear cut, and the distinction between them has become somewhat blurry.
Rainscreen cladding can be made from various materials, such as metal sheeting like aluminum, stainless steel, and zinc, or metal composite materials consisting of metal skins bonded to a lightweight core. Other materials such as terracotta, brick slips, stone, timber, and more can also be used.
Conclusion
In conclusion, rainscreen cladding is a great choice for home and building construction. Not only does it provide protection from the elements, but it also increases the energy efficiency of your property and offers a unique aesthetic appeal.
With its many benefits, you can see why rainscreen cladding has become so popular in recent years. Whether you’re looking to protect your home from moisture or just want to upgrade its exterior look, investing in rainscreen cladding is always worth considering.