Panel restraints
Witches hats
Witches hats are an efficient solution for restraining panels, ideal for fixing to the underside of the slab.
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Applications and features
Applications:
- Provides lateral restraint to precast panels.
- Typically fixed to the underside of the slab.
Features:
- It can be placed close to the top of the precast panel.
- Good adjustment for cavity variations.
- Lightweight and easy to install.
- A cost-effective way of providing lateral restraint for panels.
Product variants
| Product variants | |||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Load class | Dimensions | ||||||||||||||||||||||||||||||
| Profile size | Load range [kN] Load capacity group | Design load [kN] Vrd | Dowel [-] | Depth [mm] | L1 [mm] Embedded length | Load group [T] | D [mm] Metric thread | M [mm] Metric thread | L [mm] Length | x [mm] Depth | y [mm] Width | L2 [mm] Length | Ø D1 [mm] Diameter | Ø D2 [mm] Diameter | Ø D3 [mm] Diameter | L [mm] Length | c [mm] | Rd [mm] Diameter | e [mm] Length | j [mm] Hole width | a1 [mm] Gap between holes | ∠ Angle [°] Angle in degrees | C [mm] Hole to edge distance | Matching profile Compatible part | hp [mm] Profiling depth | Weight [kg/m] +-10% | e1 [mm] Length | Max supported height [mm] | B [mm] Box width | Load group [T] | Max lateral load [kN] |
| WH-M16 | 11.5 | ||||||||||||||||||||||||||||||
| WH-M20 | 20.0 | ||||||||||||||||||||||||||||||
Attachment type
Witches hats can be manufactured in two different variants based on the attachment type used for the installation.
Variant A
The standard hole version is for applications with a cast-in channel.
Variant B
Variant B is the slotted version used for post-fix with FAZ anchors, to allow some tolerance if they hit rebar.
Specification
| Type | Threaded bar diameter | Attachment type | Length of the threaded bar |
|---|---|---|---|
| WH | M16 | A | 100 |
WH-M16-Attachment type-Length of the threaded bar
Example:
- WH-M16-A-100
Witches hat to be used with M16 bar 100mm long, using channel attachment to the concrete structure.
The precast cast-in part (cast-in channel) needs to include captive lock-in plate in order to be compatible with this product. These can be bought separately but it is important to make sure the correct fixing was chosen.
Assembly note
The assembly consists of:
- Witches hat
- Cast-in channel in precast panel (this varies based on panel thickness, please see accessories)
- Captive locking plate
- Threaded bar (DIN976)
- 3x full nut (DIN934)
Based on the variant of attachment:
- Cast-in channel and 2xT-bolts to suit
- 2x Postfix FAZ Anchors
We can advise you based on your requirements and preferences.
