FastenMaster Common Questions (FAQ)

We've gathered the most commonly asked questions about FastenMaster. If your question isn't answered here, you may also contact us with any questions you may have.

Cortex Hidden Fastening

How does Cortex Deck Fastening System work?

Every box of Cortex includes deck screws, plugs, and special driver bits. The screw cuts a precise cylinder into the decking board. The plug is inserted into the board. The special driver bit controls the depth of the installed screw and the cylinder depth. By using the Cortex for Decking screw and driver bit you are assured of the proper fit.

Are Cortex plugs visible once they are installed?

If installed per the instructions these plugs are difficult, if not impossible to find. Many people report once the Cortex deck plugs or Cortex trim plugs are tapped into place, they blend in and disappear. As the deck boards and plugs weather they typically blend in better.

What keeps the Cortex plugs from coming out?

Cortex deck plugs and Cortex trim plugs are designed to stay in place.

  • Plugs are sized with a slight interference fit between the cylinder and the installed plug
  • Plugs are made from the manufacturer deck boards so thermal expansion and contraction doesn't result in a plug being squeezed or being loose in the cylinder. Plugs grow and shrink at the same rate as the board does so the slight interference fit is maintained at all times.
  • As the screw is driven in, it is cutting the cylinder below the decking's surface the screw imparts a texture on the inside wall of the cylinder. This texture gives the plug a friction fit.
  • After the screw is driven to depth with the setting tool the plug is firmly driven into the cavity with a hammer. This compression drives air out from beneath the plug and seals screws head off from the elements.

What PVC and composite decking boards are compatible with Cortex?

What is included in a box of Cortex for Decking?

The 100 sq ft box contains everything needed to fasten 100 sq ft of deck boards to joists spaced 16' apart. It contains 350 screws, 400 plugs, and 3 special driver bits. The 300 sq ft box contains everything need to fasten 300 sq ft of deck boards to joists 16' apart. It contains 1050 screws, 1200 plugs, and 6 special driver bits. Note: If the joists are spaced 12' apart add 1/3 more to the total.

What type of drill or driver is needed to install Cortex for Decking?

A contractor-grade 1/2" chuck drill powered by an 18v battery or a corded unit drawing 7 amps or higher is recommended. An impact driver may be used on PVC boards such as Azek or Trex Escape.

Can I use Cortex for Trim for deck boards?

No, Cortex for Trim screws are specifically designed for thinner trim boards. The plugs are a different size and made from a different material.

What product is recommended for fascia boards?

Cortex for Fascia provides a smooth, clean finish for fascia boards. Fascia plugs are available in several colors.

LOK Line

What is a FlatLOK fastener?

FlatLok is a multi-purpose structural wood-to-wood fastener that is an alternative fastening method to using nails and through bolts when attaching multi-ply LVL, dimensional beams, interior corridor ledgers, and girder trusses. FlatLOK requires no predrilling and features a flat head that sits flush to allow for easy application of drywall or trim. The TORX ttap drive system maximizes bit fit and reduces the potential for stripping. The TORX ttap drive bit is included in every box.

What is a HeadLOK fastener?

HeadLok is a version of a TimberLOK with a 5/8" diameter disc type head. It uses a spider drive recess and driver bit which are supplied with the fasteners. HeadLOK is also available in versions for various thicknesses of steel. HeadLOKs can be used in nearly any place a TimberLOK can. It is particularly useful to fasten structural insulated panels and fasten rigid foam during deep energy retrofits.

What is LedgerLOK?

LedgerLOK is a code-compliant structural wood screw engineered to fasten a deck ledger board to the rim joist of a house with no predrilling.

What is ThruLOK?

ThruLOK is a faster, easier, stronger approach to the carriage and hex head bolts with its nuts and washers. ThruLOK requires no predrilling and only a drill to drive the fastener in.

What is a TimberLOK fastener?

TimberLok is the "duct tape" of FastenMaster's LOK line. It is available in common sizes. TimberLOK's small size is deceptive compared to its strength. One of the most interesting uses for the TimberLOK is attaching a rafter or a truss to a double top plate of a wall. In most cases, a single TimberLOK can replace a hurricane tie and the 10 nails it uses.

Deck Screws

How many deck screws do I need to build a deck?

FastenMaster requires two screws to be used to attach the deck board at every joist. Not following this requirement can void the screw's warranty. If the joists are spaced the standard 16' apart and the deck boards are perpendicular (90 degrees) to the joists, simply multiply the number of square feet by 3.5. In this example, 100 sq ft would require 350 screws. If the joists are spaced closer at 12' apart and the deck boards are perpendicular (90 degrees) to the joists, multiply the number of square feet by 4.7. For example, 100 sq ft would require 470 screws. If the deck boards are placed at 45 degrees to the joists, be sure to add 1/3 more fasteners to the totals above. These totals above do not include steps, fascia boards, or handrails.

Where should stainless steel deck screws be used?

Stainless Steel screws have two advantages and two disadvantages when being compared with screws made of case hardened steel. Stainless steel offers a level of corrosion protection greater than steel. Stainless steel screws are usually more flexible than case hardened steel screws. Stainless steel screws are more expensive than case-hardened screws and are also softer than case-hardened steel screws. Stainless steel screws should be used in the entire deck where it is near the ocean or a source of salt, where composite or PVC deck boards are supported by sleepers, and where air circulation beneath the deck board is poor. Stainless steel screws are recommended when attaching composite or PVC decking over a single piece of wood. This is commonly done on fascia boards that are attached to the outside of joists and where composite decking is applied directly over wood decking. The combination of using very durable deck screws made from case hardened SAE 1022 steel to fasten down the composite deck boards to joists and flexible stainless steel screw in areas where it is needed will help build an economical and long-lasting deck.

What are GuardDog screws used for?

FastenMaster's GuardDog Exterior Wood Screws have been trusted by pros for over 20 years. These versatile screws are commonly used for cedar, redwood, or pressure-treated decks, railings, fencing, and more.

The following clip shows the new updates made to GuardDog screws in 2021.

Specialty Products

What is PAMFast?

FastenMaster PAMFast is an auto-feed screw system that uses an auto-feed screw gun and compatible screws to easily install subfloor, decking, drywall, and more. The PAMFast screw gun is fully assembled for use while standing, but also adjusts to being handheld for wall applications. The PAMFast gun is meant for use with PAMFast screws or FastenMaster Trapease 3 screws.

What can PAMFast screws be used for?

PAMFast auto-feed fasteners are designed for various wood and steel frame applications. There are PAMFast screws designed for installing subfloor, wood decking, composite decking, drywall, tile roofing, cement board, steel framing, and crating or pallets.

How many screws does the PAMFast screw gun hold?

The PAMFast AutoFeed Screw Gun holds 50 screws per collated strip, which makes installation fast and eliminates the struggle handling loose screws.