Welded Wire Mesh and Galvanized Expanded Metal for Architecture Wall Anti-Cracks
As the development of the building energy efficiency and the new wall materials, the wall engineering faces kinds of problems such as, cracking and wall peeling. It has been found that the problems are due to the design, materials, construction, the base wall, the wall surface and the plaster layer. After the studying, the wall anti-cracking skill is summarized as design anti-cracking, material anti-cracking and construction anti-cracking. We have formulated some measures to solve the problems. For the material anti-cracking, we are going to use metal steel mesh, fiberglass mesh grid, chopped high performance organic fibers, elastic compound and so on.
Welded wire mesh with dense mesh opening is good to prevent wall cracks.
Galvanized expanded plastering mesh.
The steel mesh choice
The species of the steel mesh
There are kinds of steel meshes on the market, industrial screen mesh, fence mesh, safety structure mesh, agricultural mesh and screen window mesh. The different applications need different materials. But there is not professional steel mesh for the architecture anti-cracking. Thus there are many kinds of steel mesh for the engineering architecture wall. The following is the different steel mesh species.
- Welded wire mesh includes electro galvanized low carbon welded wire mesh and common redrawing low carbon welded wire mesh.
- Expanded metal includes cold rolled expanded metal and electro galvanized expanded metal.
- Butt welded wire mesh includes electro galvanized low carbon welded wire mesh and cold-drawn low-carbon steel mesh.
The specifications for architecture wall steel mesh
|Steel mesh types||Material standard||Wire species||Shapes||Specifications (mm)||Using ranges|
|Welded wire mesh||carbon steel GB/T 700||electro galvanized low carbon steel wire||Rolled||wire diameter: 0.4–0.9
mesh opening: 9.5–19
|rolled||Wire diameter: 2.2–4.0
mesh opening: 25–50
|electro galvanized low carbon redrawn wire||rolled||wire diameter: 0.4–0.9
mesh opening: 9.5–19
|rolled||wire diameter: 2.2–4.0
mesh opening: 25–50
|Butt welded wire mesh||carbon steel GB/T 700||electro galvanized low carbon steel wire||panels||wire diameter: 2.2–4.0
mesh opening: 25–200
|cold-drawn low carbon steel wire||panels||wire diameter: 2.2–4.0
mesh opening: 25–300
|Expanded metal||cold rolled expanded metal GB/T 708||diamond shape mesh opening, rectangle strand||rolled||sheet thickness: 0.4–1.0
strand thickness: 0.4–1.0
mesh opening: 12 × 25–8 × 16
|interior wall & exterior wall|
|Galvanized welded wire mesh||carbon steel GB/T 700||hot-dip galvanized steel wire||rolled||Wire diameter: 0.9–2.2
mesh opening: 12.7 × 12.7–50.8 × 50.8
|exterior wall thermal insulation|
The choice principle
The principles for choosing the architecture wall steel mesh is summarized based on the use effect.
- When we need the metal mesh the first choice is welded wire mesh but not the woven wire mesh.
- When we need the electro galvanized wire mesh the premier is electro galvanized redrawn welded steel mesh.
- When we need expanded metal the prefer choice is cold rolled galvanized expanded metal. We choose the galvanized steel wire mesh which is galvanized after welded.
The choice for the exterior wall
- When the safety mesh for the exterior wall is to anti-peeling and anti-cracking. To reinforce the anti-cracking effect, welded wire mesh can be used with the anti-cracking fiber mortar.
- The expanded metal is the first choice for the anti-cracking exterior wall. The specification can follow the table 1 above.
- When the target for the exterior wall is to keep safe. We usually choose the butt welded wire mesh.
- The redrawing welded wire mesh and the expanded metal are for connecting part between the exterior wall and the main structure.
- The electro galvanized welded wire mesh and the butt welded wire mesh are for the high building exterior wall anti-cracking. And the expanded wire mesh is not for the high building. The specification depends on the exterior wall density.
The metal mesh choice for the interior wall
The anti-cracking is needed for the parts between the column and the beam, and the parts on the door hole and the buried pipeline, we need welded wire mesh. The diameter of the wire is 1 mm–1.2 mm, and the mesh opening is 15 mm–20 mm. The galvanized expanded metal is also needed. The thickness both of the panel and the strand is 0.6 mm. The mesh opening is 10 mm × 20 mm. The weight is 0.56 kg/m2.
The construction technology of installing wire mesh
The normal installing wire mesh technology
We should clean the surface of the masonry and do the base of the surface and choose the steel wire mesh. We should do the prepares for nailing, welded steel wire mesh, mortar plastering, the anti-cracking mortar wire mesh and do the systemic inspection.
The prepares before attaching the wire mesh
- Clean the grease for the base and repair the wall and wet the wall according to the local temperature and humidity.
- Use the professional mortar or cement paste to do the masonry foundation.
- Choose the steel wire mesh according to the designs and do the inspect about the steel wire mesh that there is not removal welded wire mesh, rust and irregular wire mesh.
- Prepare the gun, electric welding machine, hammer, steel nail scissors and other tools based on our needs.
- Prepare the steel wire mesh according to the needs.
The technology of plaster mesh
- The wire mesh is fixed to the connecting parts between the wall and the beam, panel and the column, and the connecting parts between the door hole and the ring beam. The width of exterior wall mesh is 200 mm, the width of interior wall mesh is more than 150 mm and the width of the wire mesh should be 200–300 mm.
- When the wall height is more than 30 m and the ceramic tile for the exterior wall is heavy we should install the steel wire mesh on the extra wall and the lap length is 100 mm. The lap for steel wire mesh should be smooth, continuous and firm, and the lap length should be more than 100 mm. When we use the butt welded wire panels the lap length should be more than 100 mm.
- We should smooth and straighten the steel wire mesh before attaching. The four corners are fastened on the major structure and the masonry foundation, and we should get command of the location so that the steel wire mesh can be fixed to the right location. The way to fix the steel mesh depends on the foundation.
- We could put the expansion bolts into the wire mesh or embed the steel bar with spot welding. The distance between the fixed points should be less than 300 mm–500 mm so that the steel mesh wouldn’t deform. The distance is 5 mm from the foundation surface.
- The connecting of the wire mesh should be flat, continuous and firm. The length of the connecting should be more than 100 mm.
- The protruding part of the wall should be totally attached to the wire mesh because this wall is easy to crack because of the temperature.
Plastering after installing the wire mesh
- Examining the plaster mesh is necessary and then plaster the walls.
- The connecting between the foundation and plastering layer must be firm. The cement paste and the professional mortar of 1 mm–2 mm is used to primer. We should plaster and pack it down hard in layers and make sure that there is not cavity.
- The wall wire mesh must be putted in the plastering layer. The distance between the steel mesh and the foundation should be more than 5 mm and it can prevent the steel mesh from rust.
- There is thickness standard about the plastering.
- For the interior wall, the normal plastering thickness is 18 mm, the intermediate plastering thickness is 20 mm and the advanced plastering thickness is 25 mm.
- For the plastering thickness of the exterior wall, the wall is 20 mm, the plinth is 25 mm and the concrete masonry plastering thickness should be within 15 mm.
The discussion of plaster mesh
The steel mesh for frame fill wall
We have studied about the frame fill wall. The cracks between the masonry and the frame are unavoidable due to the different materials and construction time of frame fill wall structure. Thus the decorative layer would crack and wall would peel sometimes. To prevent the wall cracking and peeling, attaching the steel wire mesh is the first choice among the measures.
The safety of the steel mesh
The effect for the exterior wall steel mesh is to prevent the plastering layer and decorating layer from cracking and accident. We know the certain position and the steel content during concrete casting so the plaster is firm. But the plaster mesh is wrapped with the lime and its wire is thin the firmness with the foundation is not so good. The plastering layer and the masonry foundation have poor performance, the wall foundation and the plastering layer force different stress so it's difficult to make sure the steel wire mesh can last for long time. At present, the steel wire mesh as anti-cracking wall and anti-peeling is used only for safety warning. To a certain extent the steel mesh could prevent the wall from the cracking and cavity for a long time. So it would reduce the probability of the safety accident and the peeling of the wall. We should make a new design for the exterior wall structure safety.
The effect of the steel mesh for the cracking
According to the survey the cracking could cause the leakage, so attaching the steel mesh for the connecting part is necessary. It could reduce the cracking, cavity and leakage. The performance of the steel mesh could not exert well because some high building walls are not so strong and the adhesion is not good. But according to the requires, different steel wire meshes are used for corresponding parts. The cracking can be reduced a lot. The leakage can even be controlled totally. With the development of the anti-cracking technology, the steel mesh is the best choice for anti-cracking. The using effect of the steel wall is related to its material, standard, plaster style and construction.