Simpson #8 x 1-1/4 in. Hi-Lo T25 Cement Board Screws are purpose-built fasteners designed for secure, professional installation of cement backerboard in tile and wet-area applications. The high-low thread pattern drives smoothly through dense board materials, while the multilayer corrosion-resistant coating protects against rust stains in the moisture-heavy environments where backerboard is routinely used - making these screws a dependable choice for contractors and serious DIYers tackling tile substrate work.

Key Features

• High-low thread design - reduces driving resistance so the screw seats faster and with less effort through cement board material
• T25 6-lobe drive - provides positive bit engagement that reduces cam-out and extends bit life during repetitive fastening
• Ribbed wafer head with nibs - allows the screw to countersink flush with the board surface for a clean, tile-ready finish
• Multilayer corrosion-resistant coating over a coated zinc base - actively resists rust staining in the wet conditions common to backerboard and tile installations
• T25 driver bit included - lets you get to work immediately without sourcing a separate bit

Why This Product

• Engineered for cement backerboard - the high-low thread and wafer head geometry are specifically developed for fastening cement board substrates, not adapted from general-purpose screws
• Rust protection where it matters most - the distinctive multilayer corrosion-resistant coating is designed for the persistently damp environments behind tile, helping prevent the rust stains that can compromise finished surfaces
• Broad compatibility across major backerboard brands - these screws are approved for use with HardieBacker, Durock, WonderBoard, and PermaBase, covering virtually any cement backerboard project
• Ready-to-use package - the included T25 driver bit means no extra trip to the tool box, keeping installation moving from the first screw to the last

Specifications

• MPN: CBHL114R800
• Screw Size: #8
• Length: 1-1/4 in.
• Head Diameter: 0.38 in.
• Head Type: Wafer Head
• Drive Type: T25 6-Lobe
• Coating Material: Coated Zinc
• Quantity: 800 count

Approved Applications

• Cement board fastening applications
• Installation of HardieBacker cement backerboard
• Installation of Durock cement backerboard
• Installation of WonderBoard cement backerboard
• Installation of PermaBase cement backerboard

What's Included

• 800 Simpson #8 x 1-1/4" Hi-Lo T25 Cement Board Screws
• 6-lobe T25 driver bit included in package

Frequently Asked Questions

What types of cement backerboard are these screws compatible with?

These Simpson cement board screws are designed for use with all cement backerboards, including HardieBacker, Durock, WonderBoard, and PermaBase.

What drive type is required for these screws?

These screws use a T25 6-lobe drive. A replacement driver bit (BIT25T-2-R2) is compatible, and a T25 bit is included in the package for immediate use.

How does the coating protect against rust and corrosion?

Each screw features a distinctive multilayer corrosion-resistant coating over a coated zinc base, which is specifically designed to prevent rust stains - an important consideration in the wet environments typical of tile and backerboard installations.

What is the purpose of the ribbed wafer head design?

The ribbed wafer head includes nibs that allow the screw to seat flush with the surface of the cement board, providing a clean, professional finish that is ready for tile or other surface treatments.

Note: Product dimensions and/or thread length may differ from picture. Please see the item description above for specifications.