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February 12, 2023

Unlocking the Mystery: Understanding the Importance of Control Joints in EIFS Systems

Why Does EIFS Require Control Joints? The primary cause of EIFS cladding failure is inadequate waterproofing protection. Usually, this issue arises due to improper selection and application of sealants or lack thereof. Incorrect back wrapping around insulation boards at joint edges and terminations is another common source of problems. Alternatively, reinforcing mesh may not be […]

Why Does EIFS Require Control Joints?

The primary cause of EIFS cladding failure is inadequate waterproofing protection. Usually, this issue arises due to improper selection and application of sealants or lack thereof.

Incorrect back wrapping around insulation boards at joint edges and terminations is another common source of problems. Alternatively, reinforcing mesh may not be properly embedded in the base coat or read through at these areas.

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Understanding the Importance of Control Joints in EIFS Systems

Substrate Movement

When a substrate shifts, the cladding system must adjust accordingly. This can be caused by various factors such as thermal changes, dimensional shifts and humidity variations. Cracking in the EIFS may compromise its aesthetic appearance and even lead to premature failure in extreme climates.

Depending on the substrate and where it's situated, cladding systems might require control joints in order to avoid cracking in certain areas. This is especially pertinent when the substrate is composite material such as polystyrene; jointing helps prevent cracking.

Some EIFS producers have developed special jointing systems that permit changes in substrate without need for traditional joists, battens and other attachment methods. These "nonstandard attachment systems" can be employed to address certain tricky situations that might otherwise require alternative solutions when using a conventional cladding system.

These systems can be beneficial in many circumstances, but they can also present challenges if the substrate materials don't adhere well to the cladding system. Some substrates like gypsum board and oriented strand board (OSB) may prove challenging to attach with EIFS systems.

EIFS typically consists of three substrates: gypsum board, OSB and fiberglass insulation. Each material has the potential for deterioration in certain climates so it's essential that you select the correct one for your project. Furthermore, make sure the gypsum board, OSB or fiberglass insulation is installed securely to prevent moisture absorption.

Substrate Compatibility

The substrate on which EIFS is installed is critical in determining its performance and longevity. It's essential to select a quality substrate compatible with insulation and that has been properly installed. Substrates with significant defects may lead to premature failure of insulated building cladding and other components, leading to leaky walls, wet substrates, mold growth and deterioration of underlying materials.

Common EIFS substrates include exterior gypsum board, oriented strand board (OSB), and plywood. Of the three, OSB has been known to experience moisture absorption issues that make it unsuitable for humid or damp climates; gypsum board has similar issues but tends to be less severe.

Plywood, especially when exposed to wet or humid climates, can absorb excessive moisture and cause the EIFS (Exterior Finish System) to separate from its substrate. This can prove costly and time-consuming as an entire EIFS assembly may need replacement.

Paper faced gypsum sheathings are another concern, as moisture can penetrate between them and the EIFS. To avoid this issue, use a substrate with a special gypsum core treated with glass mat bonding - an advanced bonding process developed specifically for this purpose.

Maintaining an effective EIFS substrate is paramount for the performance and long-term viability of the entire system. A properly installed and coated EIFS substrate can help minimize water intrusion issues, reduce insulation maintenance requirements, and enhance a building's energy efficiency.

Furthermore, the substrate used for EIFS construction can have a major impact on its moisture, mold, and fire resistance performance. For instance, using mineral-based fiberglass sheathing coupled with gypsum core treated with glass mat bonding technology helps avoid lamination issues and provides superior moisture, fire, and mold resistance.

Successful EIFS assemblies consist of a high-quality gypsum-based sheathing; quality insulation; an effective waterproof membrane; and a strong, noncorrosive adhesive or mechanical fastener compatible with both materials. Selecting the right sheathing can make all the difference between long-lasting energy-efficient walls and costly ineffective ones.

Substrate Joints

Installing an exterior insulation finishing system (EIFS) correctly requires control joints to prevent shifting and damage caused by cross-grain shrinkage. These joints should be located at floor and ceiling heights as well as changes in building height, ensuring that EIFS remains intact during movement of its structure without causing harm.

The primary cause of this phenomenon is wood construction and other structural materials can experience cross-grain shrinkage, while EIFS insulation may shift as a result. These problems may lead to damage to either the underlying material or EIFS insulation, leading to inadequate performance from both layers - leading to poor EIFS performance as well as problems in the building envelope.

Installing control joints is a relatively straightforward task with foam boards and an adhesive that's compatible with both insulation board and substrate wall. To ensure adequate strength, the insulation board should be thick enough to withstand expansion/contraction of the insulation; vertical joints should be staggered in a running bond pattern with boards tightly abutted one another. Gaps between boards filled with base coat or adhesive may crack, so thin pieces of insulation should be wedged in where necessary for additional support.

In addition to keeping the EIFS stable, a well-placed control joint is crucial for avoiding damage due to cross-grain shrinkage, especially where wood frame construction is involved. That's because, without it, the EIFS may sag and flex, potentially leading to tears in its underlying components such as wood framing, sheathing, studs and more.

When installing EIFS, various control joints are employed. Some are purely aesthetic while others provide necessary relief from bending in a specific area.

Are you ready to transform your home or business with beautiful, durable stucco? Look no further than Wallder Construction LLC. Our team of expert stucco professionals is dedicated to delivering top-quality results on every project. Contact us today to schedule your consultation and take the first step towards enhancing the beauty and value of your property. Don't settle for anything less than the best – choose Wallder Construction LLC for all your stucco needs!

Disclaimer: This post was created with the assistance of Artificial Intelligence, and we have edited it to the best of our abilities for accuracy and relevance. Please note that pricing may vary and is not one-size-fits-all. Additionally, we have no affiliation with any of the companies or products listed in this post besides Wallder Construction LLC.

Article written by Samuel
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