#9 x 1-5/8 in. Cement Board Screws: A Los Angeles Guide to Fastening Backerboard Right

Tile is only as solid as the fasteners under it. Whether you're screwing down backerboard for a Pasadena shower remodel or a Downtown LA tenant improvement, the right cement board screw keeps your substrate flat, flush, and rust-free for the life of the tile. Our #9 x 1-5/8 in. cement board screws (575-pack) are the bulk, contractor-grade option for fastening 1/2 in. backerboard to wood or light-gauge steel studs.

Why cement board screws — not drywall screws?

It's tempting to grab whatever's in the pouch, but standard drywall screws corrode in wet areas and their bugle heads don't sit right in cement board. Purpose-built cement board screws solve both problems: a serrated head that countersinks flush at any angle for a smooth tile surface, a corrosion-resistant finish that stops rust from bleeding into grout, and a star drive (T-25) recess that installs one-handed without cam-outs. These meet ANSI A108.11 for cement board attachment, so they hold up to code and to LA's damp bathrooms and kitchens.

Key features at a glance

• Serrated head countersinks flush at any angle
• Star drive (T-25 bit) for one-handed driving, no cam-outs
• Serrated threads need less torque and drive faster
• Sharp point bites immediately — no pre-drilling
• Attaches close to the edge without cracking or blowouts
• Corrosion-resistant finish; meets ANSI A108.11
• Fastens cement board to wood or light-gauge steel studs

Which length and pack size for your LA job?

Screw length follows board thickness, and pack size follows job size. If you're setting a shower pan and a small backsplash, a 140-count box is plenty; if you're boarding a whole restaurant kitchen, the 575-count pro pack keeps you off the supply run. Here's the full lineup we stock — the same serrated-head, star-drive screw in every size:

Want the smaller box for a one-off? Grab the 1-5/8 in. 140-pack instead, or see every option in our cement board screws collection.

Matching screw length to board thickness

The rule of thumb: the screw should pass through the board and bite at least 5/8 in. into the framing. For 1/4 in. backerboard, 1-1/4 in. screws are right; for 1/2 in. board, step up to these 1-5/8 in. screws; for thicker or double-layer assemblies, use 2-1/4 in. If you still need the board itself, see our cement backerboard guide or browse the full cement boards selection.

How to fasten cement board correctly

Set your board in thin-set, then drive screws every 8 in. across the field and around the perimeter, keeping about 2 in. off the corners and 3/8 in. from edges. Let the serrated head sink just flush — don't overdrive and crush the board face. Because these bite on contact, there's no pre-drilling, and the star drive keeps the bit seated so you can run a whole sheet one-handed. Tape and thin-set the seams, and you're ready to tile.

Buy cement board screws in Los Angeles

Supply Ontime keeps #9 x 1-5/8 in. cement board screws in stock for same-day pickup and scheduled delivery across Los Angeles, in both small boxes and bulk pro packs. Add the 575-pack to your order below, and round out the job from our fasteners collection.