Monument Signs With No Foundation

This article is by Rusty Gibbs, co-owner of Gibbs Graphics (Leavenworth, WA).

LATELY, WE’VE BEEN doing a lot of our monument signs with no foundation. Instead they just float on the ground. It started because of a job where we had too many underground obstacles, but we’ve continued with the method because it’s faster and lower-cost for the client. Occasionally we put treated posts in the ground but often the entire sign is floating. I’ve had a 100% success rate so far with obtaining permits (in a few different jurisdictions).

I should probably start by saying that this technique is definitely not for everyone, and many shops may never have a reason to use it. But in certain situations it can save a project entirely — especially when underground utilities, existing hardscape, irrigation or other site limitations make traditional excavation difficult or extremely expensive.

Most of the time when we use this technique, it’s for permanent commercial monument signs, but of course, the general concept would be useful for temporary or event signage as well. Structurally, the base is usually built with either a steel or aluminum armature wrapped in galvanized lath and covered with fiber-reinforced mortar. Many of them are designed to resemble carved stone or faux rock bases.

Here is the Cascade Veterinary Clinics sign showing the internal frame with a mix of steel and aluminum. The mortar work was done onsite.

Overview of the Process

Rather than relying on deep, concrete footings, when we use this method we focus on creating a sign with a broad footprint, substantial weight and a low center of gravity. Typical signs range anywhere from roughly 30 to 200 sq. ft. in footprint and may weigh between 500 and 3,000 lbs. depending on materials and size.

Usually we prepare and compact a gravel base first. From there, the support method varies depending on the site conditions. Sometimes the sign is completely free-floating. Other times we incorporate shallow hidden steel “feet” slightly below grade, use occasional treated posts, or tie into an existing footing if one is already onsite.

One method we’ve used successfully is an upside-down “T” style steel or aluminum foot beneath the sign. Two stabilized posts with wide hidden feet can support the structure well, especially when the sign itself acts as a shear panel.

Because many of our mortar-based signs are sculpted to resemble rock or masonry, we often fabricate the armature and lath in the shop, transport it in lightweight sections and complete the mortar work onsite. That avoids cranes and large equipment in many cases.

Weight Requirements, If Any

There’s no exact number for a required weight, because footprint, wind exposure, center of gravity and overall shape matter more than weight alone.

What seems to matter most are the following:

• Wide footprint
• Low center of gravity
• Minimal “sail” effect from roofs or tall vertical surfaces
• Overall rigidity of the structure

We generally avoid this method for tall, narrow or top-heavy signs.

This installation only took one trip and two hours on site since there was no need to pour a concrete foundation. This foundation-less installation method is especially useful when the job is far away.

Advantages and Disadvantages

The advantages seem to be faster and less-expensive installations. Are there disadvantages?

Absolutely. This method is not appropriate for every situation.

We would generally avoid it for very tall or top-heavy structures, in soft or saturated soils or with customers who would look at us weird if we even suggested such an odd idea. 🙂

Permitting Suggestions

There’s also a level of engineering judgment involved. Even though we’ve had a 100% success rate obtaining permits so far in several jurisdictions, some reviewers understandably pause when they first hear the concept. A good relationship with local jurisdictions definitely helps.

Some permit reviewers recognize that the structures are substantially overbuilt for their size and do not require engineering stamps, while others want additional structural review. So far we’ve found that once they understand the low center of gravity and overall mass of the structures, the conversations go fairly smoothly.

Final Thoughts

One thing I’d emphasize is that this isn’t about cutting corners. In many cases, the structures themselves are actually stronger and heavier than traditional monument signs.

The main goal is avoiding unnecessary excavation, concrete work, utility conflicts and footing inspection delays.

In areas of Washington state, such as Chelan and Douglas Counties, where we often deal with a frost depth of three feet, simplifying installation can sometimes make the difference between a practical project and an impractical one.

For more information, see 14 Looks at Foundationless Monument Signs by Rusty Gibbs.