Name: moisture control in masonry cavity walls
Uploaded: 2024-09-12T16:16:29.000Z
Duration: 1 min 20 s
Channel: JoVE

캐비티 벽에서는 막히지 않는 캐비티 배수를 보장하기 위해 최소한의 분리가 유지됩니다.
종종 캐비티 내의 연속적인 배수 매트를 사용하여 모르타르 배설물을 편향시키고 깨끗한 배수 경로를 용이하게 합니다.
이 공동으로 들어가는 물은 공동의 바닥에 적절하게 간격을 두고 번쩍이는 것 위에 놓인 배수 구멍을 통해 빠져 나옵니다. 
또한 캐비티 상단 근처의 통풍구는 캐비티 내의 공기 순환을 촉진하고 캐비티 수분의 증발을 돕습니다.
후레싱은 습기가 외벽으로 침투하는 것을 방지하기 위해 외부에 설치하거나 캐비티로 들어가는 물을 외부로 다시 전환하기 위해 내부에 설치할 수 있습니다.
내부 후레싱은 캐비티 바닥과 캐비티가 중단되는 장소에 설치됩니다.
플래싱의 한쪽 끝은 내부 와이드에 제공된 방수 장벽에 의해 겹쳐지는 반면, 다른 쪽 끝은 외부 와이드를 넘어 확장되고 아래로 구부러져 드립 엣지를 형성하여 벽에서 물이 자유롭게 떨어질 수 있도록 합니다.
판금 후레싱, 아스팔트 멤브레인 후레싱, 복합 후레싱 및 합성 고무는 일반적으로 사용되는 후레싱입니다.

석조 벽의 공동 배수 및 플래싱

Cavity Drainage and Flashings in Masonry walls

"일반적으로 공동 벽은 최소 5.08cm의 간격으로 분리된 두 개의 겹으로 구성되며, 단열재를 포함하면서도 최소 2.54cm의 여유 공간을 유지하여 적절한 배수를 용이하게 합니다. 연속 배수 매트를 삽입하는 것과 같은 고급 방법은 효과적인 습기 배출을 보장하는 동시에 이 공간을 더욱 줄일 수 있습니다."

공동 바닥에 전략적으로 배치된 누수 구멍은 축적된 물을 배수하는 데 중요합니다. 이러한 개구부는 종종 해충을 차단하기 위해 스크린으로 보호되는 헤드 이음새를 열어 두어 만들어집니다. 플래싱은 외부 및 내부의 두 가지 형태로 구현됩니다. 금속 코핑 및 카운터 플래싱을 포함한 외부 플래싱은 난간 및 평평한 지붕과의 교차점과 같은 취약한 영역을 보호하여 물이 유입되는 것을 방지합니다. 내부 플래싱은 벽을 시공하는 동안 통합되어 창틀 상부 및 하부의 잠재적인 물 유입 지점에 배치됩니다. 이러한 플래싱은 누수 구멍을 통해 물을 잡아 외부로 보냅니다.

플래싱 재료는 구리와 스테인리스 스틸과 같은 내구성 있고 비싼 금속부터 아스팔트 재료와 합성 고무와 같은 유연하고 비용 효율적인 옵션까지 다양합니다. 내부 플래싱을 교체하는 복잡성과 고품질 재료의 비교적 낮은 비용을 감안할 때, 물 피해와 관련된 미래 비용을 피하기 위해 내구성 있는 플래싱 재료를 사용하는 것이 좋습니다. 플래싱 섹션의 중첩 및 밀봉을 포함한 적절한 설치는 모든 습기가 바깥쪽으로 향하도록 하는 데 필수적입니다.

캐비티 벽에서는 막히지 않는 캐비티 배수를 보장하기 위해 최소한의 분리가 유지됩니다.
종종, 캐비티 내의 연속적인 배수 매트는 ...

cavity-drainage-and-flashings-in-masonry-walls

Education

교육

JoVE Core

Civil Engineering

토목공학

Unit 1

제1단원

Masonry

석공사

KEY TERMS AND CONCEPTS

주요 용어 및 개념

moisture control in masonry cavity walls

Masonry cavity walls use a gap between two wythes, or wall layers, to help control moisture. The cavity is usually at least 2 inches wide, and it may contain insulation. Even with insulation, a clear space of at least 1 inch is kept so water can drain away. Some walls also use a continuous drainage mat to reduce the needed space while still moving moisture out.

Weep holes are another key part of cavity drainage. These openings sit at the base of the cavity and let collected water escape. They are often made by leaving head joints open, and screens may be added to keep pests out. This simple detail helps the wall release water instead of trapping it inside.

Flashings guide water back to the outside of the wall. External flashings protect exposed spots such as parapets and places where walls meet flat roofs. Common examples include metal copings and counter flashings. Internal flashings are built into the wall during construction and are placed where water may enter, such as above window heads and at sills.

Different flashing materials offer different strengths and costs. Copper and stainless steel are durable, but they are also more expensive. Asphaltic membranes and synthetic rubber are more flexible and less costly. Because internal flashings are hard to replace, using durable materials and installing them with proper overlap and sealing can help prevent future water damage.

Moisture Control in Masonry Cavity Walls

composite masonry walls

Bonding and Materials in Composite Masonry

Composite masonry walls use two or more wythes, or vertical layers, of masonry to form one unified wall. The wythes may use the same material or different masonry materials. They are joined to work together as a single structure. These wythes can be bonded in several ways. Builders may use mortar-filled collar joints, grouted spaces, or rigid metal ties with reinforcement. Masonry header units can also connect the layers, but this method is rare. Metal ties are often preferred because they...

masonry cavity walls

Masonry Cavity Walls and Moisture Control

Masonry cavity walls use two wythes, or layers, with a hollow space between them. The outer and inner wythes are linked only by corrosion-resistant metal ties. This design helps manage water and improve wall performance. When rainwater passes through the outer wythe, it moves down through the cavity. Flashing catches the water and directs it toward weep holes, where it can leave the wall. The inner wythe often has damp-proofing on the cavity side. This layer also works as an air barrier. The...

masonry loadbearing walls

How Masonry Walls Support Buildings

Masonry load-bearing walls support floors and roofs and carry those loads down to the foundation. They are built from brick, stone, or concrete masonry units. These walls rely on compressive strength, which means they can resist pushes from above very well. Masonry walls may be reinforced or unreinforced, depending on the building needs. They carry dead loads and live loads while using working stresses that stay below the materials' ultimate strength. That safety margin helps the structure...

masonry curtain walls

Masonry Curtain Walls and Support Systems

Masonry curtain walls use brick or stone veneer as an exterior cladding system. The veneer is supported by the building structure, so the wall can be both attractive and functional. Two main construction methods are used for these walls. One method builds the masonry units in place through traditional layering. The other uses prefabricated panels that are assembled on the ground and then lifted into position. In traditional construction, steel shelf angles attached to the spandrel beam carry...

posttensioned masonry walls

How Masonry Walls Gain Extra Strength

Post-tensioned masonry walls gain extra strength from high-strength steel rods or flexible tendons. These tensioning elements are anchored to the foundation and run vertically through the wall. In some walls, they sit inside the cores of the masonry units. In others, they are placed between the masonry wythes, or layers. The wall is built first with the tensioning elements already in place. After the mortar cures fully, the wall is tightened. Steel rods are tensioned by turning nuts against...

cavity drainage and flashings in masonry walls

Masonry cavity walls use a gap between two wythes, or wall layers, to help control moisture. The cavity is usually at least 2 inches wide, and it may contain insulation. Even with insulation, a clear space of at least 1 inch is kept so water can drain away. Some walls also use a continuous drainage mat to reduce the needed space while still moving moisture out. Weep holes are another key part of cavity drainage. These openings sit at the base of the cavity and let collected water escape. They...

thermal insulation in masonry walls

Masonry Wall Insulation Options

Masonry wall insulation can be placed on the outside, inside the wall, or on the interior surface. The best choice depends on the climate, the building design, and whether the wall is being built new or retrofitted. In hot, dry climates, masonry can help smooth indoor temperatures by absorbing heat during the day and releasing it at night. In many other climates, extra insulation is needed to improve thermal resistance. One common exterior method is an Exterior Insulation and Finish System, or...

expansion and contraction in masonry walls

expansion-and-contraction-in-masonry-walls

Masonry Wall Joints for Temperature and Moisture

Masonry walls change size slightly as temperature and moisture change. Builders account for this movement so the wall does not crack or shift out of place. Thermal movement is usually easy to measure and plan for. Moisture movement is harder to predict. New clay masonry units often absorb water and expand over time in normal outdoor conditions. New concrete masonry units behave differently. They usually shrink as they lose extra moisture gained during production. These opposite changes make...

movement joints in buildings

How Buildings Handle Structural Movement

Buildings are designed to handle movement from temperature changes, moisture changes, and structural deflection. If these changes are ignored, they can cause visible damage or even unsafe conditions. Movement joints give building materials room to move without creating distress. Working joints are the simplest type. They are placed during construction and help materials cope with change as the building goes up. Shingled roofs and wood bevel siding are common examples because they can move with...

types of building separation joints

Building Joints for Movement and Stability

Building separation joints help large or complex buildings move in a controlled way. They split a structure into smaller, separate units. This reduces stress when the building shifts under different forces. The joints are grouped into three main types: volume-change joints, settlement joints, and seismic separation joints. Volume-change joints handle expansion and contraction caused by temperature changes and moisture changes. They are placed where the building mass has discontinuities,...

efflorescence in masonry

Stopping White Salt Crystals on Masonry

Efflorescence is the white, fluffy crystal layer that can form on masonry walls. It happens when water-soluble salts in brick, stone, concrete, or mortar are dissolved by water and carried to the surface. When the water evaporates, the salts are left behind as a powdery deposit. New efflorescence is often seen soon after construction. In many cases, it can be cleaned with water and a brush. It may also fade over time as rain leaches salts out of the masonry surface. If efflorescence appears...

mortar joint deterioration in masonry

Repairing Damaged Mortar Joints in Masonry

Mortar joints in masonry can break down when water collects in them and freezes. The repeated freezing and thawing makes the water expand and shrink. That process creates cracks in the joints and can spread damage over time. As the mortar worsens, pieces may spall, or break off from the joint surface. Loose masonry units can follow, and the wall becomes weaker. Damaged joints also let moisture move into the wall, which adds to the problem. Good construction helps protect mortar joints. Using...

masonry in cold and hot weather conditions

masonry-in-cold-and-hot-weather-conditions

Protecting Mortar During Weather Changes

Masonry work changes in cold and hot weather because mortar must stay at the right temperature and moisture level. If mortar freezes before it cures, its strength and watertightness can drop. For proper hydration and curing, mortar should stay between 60°F and 80°F. When the weather is below 40°F, the water used for mortar must be heated. The water should not exceed 120°F, because very hot water can reduce compressive strength and bond strength. Masonry units and sand should also stay dry and...

masonry paving

Masonry Paving Materials and Base Layers

Masonry paving uses bricks, stones, and concrete masonry units to create durable walking and driving surfaces. These materials are selected for their shape, color, strength, and resistance to abrasion and weathering. Masonry units can be used in different paving setups depending on the site and the load they must carry. Some paving systems are installed dry on a thin sand layer over a gravel base. Others are set in mortar or asphalt on a concrete slab. For areas with heavy vehicular loads, a...

key terms and concepts

Learn how cavity walls drain water with clear spaces, weep holes, and flashing at roofs, parapets, windows, and sills to help prevent moisture damage.

Moisture Control in Masonry Cavity Walls | JoVE K12

JoVE Core Civil Engineering offers a foundational exploration of essential construction materials such as bricks, stones, steel, wood, and concrete, along with fluid mechanics topics like flow over immersed bodies, open channel flow, and dimensional modeling. It also covers key surveying concepts, including leveling, traverse adjustments, curve design, topographic mapping, and geospatial technologies (GPS & GIS). Science-in-action videos showcase laboratory research on materials, fluids, and surveying practices in real-world engineering systems.

civil engineering

Moisture Control in Masonry Cavity Walls

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