Unique Cast Iron Decor (using Industrial Items)

Cast iron plates decorate a brick wall in a black and white sketch of a living room

Unexpected home improvement projects with decorative cast iron

A sketch of an old gray iron cast tree grate with small plants growing through.
Tree grates are designed to let air and water get to roots while preventing soil compaction.

Most of our tree and trench grates are bought by municipalities or facilities managers, but we also fulfill smaller orders for homeowners and contractors. The majority of these are cast iron trench drains used in residential driveways. There, they are functional and decorative, and fulfill the same purpose they do in the municipality: provide long-lasting attractive water management. In contrast to trench, it’s rare for tree grates to be needed at a private home. Yet we’ve seen a recent trend in tree grates being repurposed by homeowners, artists, and contractors—as cast iron décor for use all around the home!

Iron has a long history in architecture. Traditionally, cast iron has been used for functions that require its compressive strength. Grates, bollards, railings, and columns would be made by pouring molten iron into green sand molds. The patterns are clean and of similar depth and size, so that liquid iron will easily fill all spaces in the pattern. A good casting pattern also ensures that the cast object will cool at the same rate throughout. This means no segment will contract much more quickly than surrounding segments.

A lattice of white-painted aged gray iron creates a repeating fence pattern
Cast iron décor was traditionally made of wrought iron.

If functional iron is often cast, decorative iron is often wrought. Wrought iron starts life as rods, billets, pipes, or bars, or other regular shapes, and is heated but not liquified while being processed. It’s worked through the application of heat and pressure. It is in this ironworking that we get the classic image of the blacksmith, pounding and twisting glowing metal into forms.

Wrought iron is used to create lattices filled with curling spirals; the ornamental scrolls and filigrees that have been popular cast iron décor since medieval times. Trends in iron shaping have come and gone, but the wrought iron lattice has proven an extremely long-lasting architectural look. A common detail on fences, gates, screens, and windows, the wrought iron lattice can also stand alone. Wrought iron filigree is commonly hung against a wall, sometimes with a mirror behind it to create a false window, sometimes as a decorative detail all its own.

Cast iron plates decorate a brick wall in a black and white sketch of a living room
Geometrical cast iron can provide decorative elements with an industrial, modern, or deco feel.

Cast iron wall décor

The modernist and industrial styles of the 20th century eschewed fussy decorations like filigree and scrollwork. Instead, the movement embraced plain lines form following function. Where iron was seen, it was generally in exposed girders and beams.

New trends are combining the simpler lines of the modernist look with the historical richness of traditional building materials. Decorative elements that tell a story are back. Yet grandeur is not just captured by baroque curlicues or ornate Victorian trim; instead, modernist approaches have inspired a new way of creating visual impact, with clean lines and industrial elements that offer geometry, texture, and weight.

In these approaches, iron is again being used decoratively: but now the look of cast iron, with its distinctive and regular geometry, provides the right look. Here, iron finds expression in clean lines, and provides eye-catching substance to a room.

A 48 inch by 72 inch tree grate that looks like a sun with rays

R-8851-1 Metropolitan Tree Grate
Length: 48 in
Width: 72 in
Tree Opening: 18 in
Slot Openings: 1/4 in
Weight: 480 lbs

With proper framing, these grates can be used as an indoor screen to help partition a large space, adding a visual element with an industrial feel. Light and air will pass through them, but the screen itself provides structure and weight—it’s neither light nor airy! Panels are available in various sizes to fill the needed space: the Metropolitan, above, is available as 48×48 in, 60×60 in, or 48×72 in.

On either a wall or as a screen, cast iron tree grates can provide a lattice to climbing plants, like ivy.

If using raw cast iron and hoping for the patinaed look, it is wise to let the metal weather outdoors past the first stage of rust, where red rust is more likely to rub off on fingers or clothing. Iron can also be painted or varnished depending on the wished-for look.

A square tree grate stands like a picture frame with plants on one side and the horizon on the other
In the garden, a tree grate can act like both sculpture and frame.

Tree grates as garden screens

Tree grates can also be used as free-standing screens in the garden.

Stained glass artists Karen and Carl found a used tree grate and repurposed it into a garden frame. This inspirational project makes a sculpture of a standard tree grate. The grate is used as a frame for a planter, creating a starburst around the central plant that draws the eye. The natural red-brown patina of the raw casting echoes the earth-tones of their garden. As a sculptural piece the iron becomes part of the landscape, rather than standing too far outside it.

A square tree grate has a woven border and slats toward the middle.

R-8781 Riverwalk Tree Grate
Length: 48 in
Width: 48 in
Tree Opening: 18 in
Slot Openings: 3/8 in
Weight: 254 lbs

Tree grates frame trees on the sidewalk and are often chosen for visual interest or to offer consistent style to a neighborhood. They can be something of a “vernacular” style, in that they’re a simple repeated element in the landscape necessary because of climate and conditions. It is an interesting inversion to use them in a garden to frame a view or a planting. Whether the grate draws attention or blends into will depend on the choice of grate and finish.

Three grates with cable-knit-like pattern make part of the surface of a backyard patio
When used as pavers, tree grates can be placed like a patchwork, a runner, a rug, or repeating element.

Tree grates in a patchwork cast iron décor

Using tree grates outside as pavers can lend textural interest to a patio or backyard. Many different styles can be created by varying size, shape, or placement.

We first learned that tree-grates were being used as pavers when we were sent an image showing grates used in a patchwork. In the backyard design, these grates-as-pavers are offset one against another, and gaps between filled with stone or brick. The tree grates in the image are raw cast iron, weathering to their distinctive rich red-brown patina. Raw iron colors complement the red brick sections of the design, while honey-colored frames around each square pick up the colors of the wooden deck. The result resembles a quilt, providing texture and interest as well as functional hardscape amidst the trees.

A singular large tree grate can be placed centrally, creating a rug-like effect. Again, weathering provides a depth and texture. A series can be used to create the look of a runner, or to echo segments of fence or other details.

Of course, in a garden, a tree grate can be used to help construct hardscape around a tree! A patio can be built around a shade-giving tree. Trees cool and condition the air through respiration providing a more refreshing sunshade than a deck umbrella alone. A tree grate helps water and air get to the soil and prevents soil compaction.

A large square tree grate with a knitting-like pattern

R-8754-1 Greenwich Tree Grate
Length: 60 in
Width: 60 in
Tree Opening: 14 in
Slot Openings: 3/8 in
Weight: 410 lbs

Tree grates in unusual settings

Tree grates are a functional piece of hardscape, generally installed to keep air and water moving to the roots of urban trees. They’re also an opportunity to create an attractive and eye-catching casting. Municipalities and facilities have long chosen these frames to create a sense of place. Tree grates have become a product allowing creative expression in industrial design.

It’s not surprising then that some creative homeowners, architects, and contractors have decided to repurpose these pieces. Since they are designed for the heavy traffic of the city sidewalk, they are high quality, built to last. High quality raw cast iron offers unique weathering, a natural patina that changes over time.

We’re curious to see what other projects come from inventive repurposing of cast iron tree grates. Reach out to us if you’ve got a project you’d like to highlight!