Spigot Types Explained: Floor Mount vs. Side Mount vs. Core Drill

If you are shopping for a frameless glass railing system, you will quickly encounter the word spigot. Spigots are the hardware that holds each tempered glass panel in place, and the type you choose determines how your railing attaches to your deck, balcony, or pool surround. In this guide we break down the three main spigot categories -- floor mount, side mount, and core drill -- so you can pick the right one for your project.

What Is a Glass Railing Spigot?

A spigot is a compact clamp assembly that grips the bottom edge of a tempered glass panel and anchors it to a structural surface. Despite variations in shape and mounting style, every spigot shares the same core anatomy:

• Base plate -- the flat or L-shaped bracket that bolts to your substrate (concrete, wood, or steel).
• Glass clamp body -- the slotted housing that receives the glass panel.
• Rubber gaskets -- EPDM or silicone inserts that cushion the glass inside the clamp, prevent metal-to-glass contact, and allow for thermal expansion.
• Set screws -- Allen-head bolts that tighten the clamp around the glass. These must be torqued carefully; over-tightening can crack the panel.

Spigots are typically sold in pairs (one for each side of a glass panel) and are rated for specific glass thicknesses -- most commonly 3/8" (10 mm) or 1/2" (12 mm) tempered glass. For a broader look at choosing the right panels for your spigots, see our guide to glass railing panels.

Floor-Mount (Top-Mount) Spigots

Floor-mount spigots -- also called top-mount or surface-mount spigots -- bolt directly to the top surface of your deck, concrete slab, or steel beam. They are the most common type used in residential glass railing projects.

How They Work

Each spigot base plate has four pre-drilled holes. You drill into the substrate, insert concrete wedge anchors (for concrete) or lag bolts (for wood), and torque the plate down. The glass panel then slides into the clamp slot from above and is secured with set screws.

Best Applications

• New deck builds where you can plan the substrate and framing to accept anchor bolts.
• Concrete patios and balconies with at least 4 inches of slab thickness.
• Steel beams and mezzanines where you can through-bolt or weld mounting plates.

Pros and Cons

• Pros: Easiest to install for DIY homeowners, widest selection of styles, straightforward layout on a flat surface.
• Cons: The base plate sits on top of your deck surface, which slightly reduces usable floor space and creates a small trip point if not flush-mounted.

If you are planning a DIY installation with floor-mount spigots, our step-by-step installation guide walks you through the entire process.

Side-Mount (Fascia) Spigots

Side-mount spigots attach to the vertical face (fascia) of your deck edge, balcony slab, or staircase stringer rather than the top surface. This shifts the glass panels outward, past the edge of the walking surface.

How They Work

The spigot features an L-shaped or extended bracket that bolts horizontally into the side of the structure. Anchor bolts pass through the fascia board or concrete edge beam into solid backing. The glass clamp extends above the deck surface level, holding the panel alongside the deck rather than on top of it.

Best Applications

• Balconies and elevated decks where you want to preserve every inch of usable floor space.
• Retrofit projects where the existing deck surface cannot accept top-mount anchors (e.g., tile or thin concrete topping).
• Staircase railings where mounting to the stringer keeps the walking surface clear.

Pros and Cons

• Pros: Maximizes deck area, nothing protrudes above the floor surface, clean look from the deck side.
• Cons: Requires a structurally sound fascia at least 6 inches tall; slightly more complex installation since you are drilling horizontally into the deck edge.

Side-mount spigots are especially popular on urban condo balconies where space is at a premium. If your project involves a balcony or elevated deck, be sure to review local building codes for guard height requirements -- most jurisdictions require 42 inches for residential balconies above 30 inches off grade.

Core-Drill Spigots

Core-drill installations eliminate the visible spigot hardware almost entirely. Instead of clamping the glass from the outside, the bottom edge of the glass panel is set into a channel or slot cut directly into the concrete substrate.

How They Work

A contractor uses a core drill or slot-cutting saw to create a narrow channel (typically 1" to 1-1/4" wide and 4" deep) in the concrete slab. The glass panel is lowered into the slot, shimmed plumb with plastic wedges, and then locked in place with a structural grout or a metal wedge-and-gasket system. No external base plate or clamp is visible.

Best Applications

• Pool fences and surrounds where a seamless, hardware-minimal look is desired and code may require self-closing gates.
• High-end residential and commercial lobbies where aesthetics demand an almost invisible mounting system.
• Concrete balconies and terraces with sufficient slab depth (minimum 6 inches recommended).

Pros and Cons

• Pros: Cleanest, most minimal appearance; no exposed hardware at the base; excellent wind resistance when properly grouted.
• Cons: Requires professional core drilling equipment, cannot be used on wood decks, difficult to adjust or replace panels after grouting, higher labor cost.

Material and Finish Options

Regardless of mounting style, spigot material matters for longevity:

• 316 stainless steel -- marine-grade alloy with superior corrosion resistance. Required for pool areas, coastal properties, and any location exposed to salt air or chlorinated water.
• 304 stainless steel -- standard grade suitable for most inland residential and commercial applications.

Both grades are available in brushed stainless for a classic contemporary look or matte black powder coat for a bold modern contrast. Browse our full hardware selection at our product catalog.

How to Choose the Right Spigot Type

Use this decision framework to narrow down your choice:

1. Identify your substrate. Wood deck? Concrete slab? Steel beam? Core-drill is only viable on concrete. Wood and steel structures will use floor-mount or side-mount.
2. Evaluate your deck edge. If the fascia is structurally sound and at least 6 inches tall, side-mount is an option. If your deck surface is clear and accessible from above, floor-mount is the simplest path.
3. Consider your priorities. Maximum floor space favors side-mount. Minimal visible hardware favors core-drill. Easiest DIY installation favors floor-mount.
4. Check local codes. Some municipalities have specific requirements for railing attachment methods, especially for pool barriers. Review our state-by-state building code guide for details.
5. Factor in budget. Floor-mount spigots are the most affordable. Core-drill installations carry the highest labor cost. For a full cost breakdown, see our glass railing cost guide.

Still unsure which spigot type is right for your project? Request a free quote and our team will review your measurements, photos, and substrate details to recommend the ideal mounting solution. You can also browse our complete glass railing kits -- each kit includes the spigots, glass panels, connectors, and optional cap rails you need for a complete installation.

Frequently Asked Questions

How many spigots do I need per glass panel?

Each glass panel requires a minimum of two spigots, one on each side. For standard 35.4-inch wide panels, spigots are placed at each edge. Wider panels may require an additional center spigot depending on wind load requirements.

Can I use floor-mount spigots on a wood deck?

Yes. Floor-mount spigots can be installed on wood decks using lag bolts. The deck framing beneath the mounting point should be solid lumber, not just decking boards. Our installation guide covers wood substrate mounting in detail.

What is the spacing between glass railing spigots?

Spigot spacing depends on your panel width. For 35.4-inch panels (used in 3ft and 6ft kits), spigots are placed approximately 36 inches apart center-to-center. For 47.2-inch panels (used in 8ft kits), spacing is approximately 48 inches.

Should I choose stainless steel or matte black spigots?

Both finishes use the same marine-grade stainless steel base. Brushed stainless is the most cost-effective and blends with modern or coastal designs. Matte black pairs well with dark-framed windows and contemporary exteriors. Browse both finishes in our product catalog.