EverJack® in Bay Area Crawl Spaces: Why It’s Not a Good Substitute for Concrete Piers in High Seismic Zones

 

Adjustable supports like EverJack® look tempting: lighter, “engineered,” ICC‑approved, and sold as an upgrade over “old‑fashioned” concrete piers. Some local contractors are even telling owners to remove existing concrete piers and replace them with these products.

In a high seismic zone like the Bay Area, that is a big mistake.

This article explains, in plain language, why EverJack‑type products are gravity devices, not seismic foundations; what the building code actually requires; and why you should keep your embedded concrete piers and wood posts (and repair/replace/ retrofit them correctly when needed) instead of swapping them out for surface‑set jacks.

If you want a professional opinion on what’s already under your house, start here:
Seismic, Foundation & Drainage Services

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1. What EverJack® Really Is, Per Its Own ICC Report

EverJack has an ICC‑ES Evaluation Report, ESR‑4900, which means it has been evaluated for specific uses under the IBC/IRC. It is not a random, untested product.

But look at how ICC‑ES describes the use:

“The Original EverJack … [is] used as individual, isolated footings supporting post columns for downward vertical loads only.” (icc-es.org)

Key points:

• Individual, isolated footings
• Downward vertical loads only

That’s gravity support. It is not evaluated as:

• A seismic pier
• An uplift anchor
• A lateral restraint device
• A complete load‑path element from soil → footing → post → beam

So yes, EverJack can be code‑evaluated for supporting weight. That does not mean it is automatically appropriate as a replacement for embedded concrete piers and post bases in Seismic Design Categories D, E, and F (Bay Area reality).

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2. What the Code Actually Requires at Posts and Footings

Two pieces of the residential code matter a lot here.

a) Columns must be restrained at the bottom

IRC/CRC R407.3 (Structural requirements for columns):

“The columns shall be restrained to prevent lateral displacement at the bottom end.” (codes.iccsafe.org)

In high seismic areas (D and above), the exception for unrestrained short posts generally doesn’t apply. The intent is clear:

• A post cannot just sit on something.
• The bottom needs lateral restraint so the column doesn’t kick out under load or shaking.

b) Deck post analogy: restraint or embedment

For decks, IRC R507.4.1 requires:

Where posts bear on footings, lateral restraint must be provided by manufactured connectors or minimum 12‑inch embedment in surrounding soil or concrete piers. (codes.iccsafe.org)

Why does this matter for crawl‑space posts? Because the same physics apply to anything that behaves like a post on a footing: without embedment or mechanical connection, it can slide, tilt, or walk off under lateral load.

In other words, the code is consistently saying:

• “Post just sitting on a pad” is not a restrained post.
• You need anchorage or embedment to keep the load path intact in real lateral events (wind, quakes).

EverJack, as sold, is a surface‑set composite pad with an adjustable cap. It has:

• No embedment into the soil
• No cast‑in reinforcement into concrete
• No built‑in mechanical connector to the wood post

Unless an engineer adds specific hardware and details, it does not meet the spirit of “restrained to prevent lateral displacement” in a high seismic zone.

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3. Why Embedded Concrete Piers With Post Bases Are Different

A properly built concrete pier / footing under a crawl‑space post gives you things EverJack simply does not:

1. Embedded bearing below disturbed surface soil
2. Lateral confinement from surrounding soil or continuous foundation
3. Real resistance to sliding and rotation
4. The ability to cast in an anchor or drill‑and‑epoxy an anchor for a steel post base
5. A continuous load path from soil → footing → post base → wood post → beam/joist

California’s own programs highlight that post‑and‑pier houses with unconnected posts and piers are especially vulnerable in earthquakes; the piers shift, posts fall off, and the house can move or collapse. (californiaresidentialmitigationprogram.com)

The whole point of modern retrofit standards is to:

• Bolt the house to the foundation
• Brace cripple walls
• Improve the load path and post connections

Replacing embedded piers and anchored wood posts with surface‑set composite jacks moves you backwards on that load path.

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4. Where EverJack Might Be Fine – And Where It Isn’t

Based on the ICC report and what we see in the field, there are two very different use cases:

A. Reasonable uses (gravity only)

• Supplemental floor leveling in non‑seismic applications
• Temporary or secondary support for sagging floors
• Repairing localized settlement where an engineer specifies EverJack as a gravity support under an existing beam

In other words: non‑seismic gravity support, when an engineer has looked at the situation and is intentionally using it just for vertical load.

B. High‑risk misuses we’re seeing in the Bay Area

• Removing concrete piers and replacing them with EverJacks as primary supports
• Using EverJacks as main supports under long lines of beams in raised foundations
• Treating EverJack as a direct replacement for concrete piers with post bases that are part of the lateral system
• Swapping out piers during a seismic retrofit in place of properly detailed post‑and‑pier upgrades

These cases worry us. In Seismic Design Category D/E/F, your post‑to‑footing connections are part of the lateral‑force‑resisting system. A gravity‑only jack simply is not the same thing.

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5. Why “Engineered” and “ICC‑Approved” Still Isn’t Enough

The EverJack brochure and website emphasize:

• ICC‑ES Evaluation Service Report ESR‑4900
• IBC / IRC compliance
• Testing and load ratings up to 8,400 lbs

Again: none of that is fake. But you have to read the scope:

• It is evaluated as a special foundation/load‑bearing element for downward vertical loads in under‑floor spaces. (icc-es.org)
• ICC‑ES explicitly says their reports are not endorsements or recommendations for any use not addressed in the report. (icc-es.org)

Being “code compliant” in a gravity‑only role is not the same as being appropriate as a seismic pier/post system in the Bay Area.

The marketing language about “uniform load distribution” and “no point loading” is about serviceability and long‑term floor performance, not about surviving lateral shaking where posts can walk, tilt, or punch through.

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6. Steel Screw Jacks: Same Gravity Problem, Different Material

We see a similar pattern with steel screw jacks in crawl spaces:

• Great for temporary shoring
• Useful for fine‑tuning elevations

But as permanent primary posts in a lateral system, unless:

• The base is anchored
• The top is mechanically connected
• The diameter is properly sized
• The whole thing is engineered

…you still have a column that can kick out or buckle under combined vertical + lateral load.

Swapping out wood posts on good concrete piers for bare steel jacks without real bases/caps is the same category of error as swapping in EverJack: you’re trading known, fixable details for an unrestrained gravity device.

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7. Our Position for Bay Area High Seismic Work

For raised‑foundation homes and crawl spaces in the Bay Area:

• Keep your concrete piers. Repair or replace them with properly embedded footings where necessary.
• Keep wood posts as the primary vertical elements. Replace rotted or undersized posts with new 4x or 6x posts as needed.
• Use post bases, post caps, and manufacturer‑listed hardware to connect posts to concrete and to beams.
• If you need leveling or supplemental support, it may be appropriate to add engineered adjustable devices – but they should not become the primary seismic posts unless an engineer specifically designs it that way.

If a contractor is recommending that you remove all existing concrete piers and replace them with EverJacks or screw jacks, especially as part of a seismic retrofit, you should treat that as a red flag and get an independent opinion.

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8. What To Do If You’re Being Sold an EverJack “Upgrade”

If you’re in the Greater San Francisco Bay Area and someone has proposed removing your piers and/or posts and swapping in EverJacks, steel jacks, or other “easy” systems, here’s a smart sequence:

1. Document what you have now
   • Take photos of posts, piers, connections, and any proposed changes.
2. Get an independent under‑house evaluation
   • Our Seismic Truth Audit™ is designed exactly for checking existing and proposed retrofit work.
3. If needed, talk to a structural engineer
   • Have them look at our photos and notes and explicitly answer:
     • “Is this acceptable as a primary support in Seismic Design Category D?”
     • “Would you seal drawings that show EverJacks as the main posts?”
4. Design corrections around proper piers and posts
   • If your concrete piers are bad, design better embedded piers with hardware – not short‑cuts.
   • If your posts are bad, replace them with properly detailed wood posts and connectors.

You can see how we typically evaluate crawl spaces, foundations, and posts here:

• Under Your Home: The Bay Area Crawl‑Space & Foundation Guide
• Foundation Repair & Replacement
• Crawl Space & Cripple Wall Retrofits

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9. Bottom Line

EverJack is not “garbage.” It’s a gravity support system with a real ICC report for specific uses.

The problem is when people in a high seismic zone:

• Treat it as a drop‑in replacement for embedded concrete piers with anchored wood posts
• Use it as part of the primary lateral system without engineering
• Sell it as an “upgrade” to unsuspecting homeowners because it’s faster, cheaper, and easier

If you own a Bay Area home, your best seismic money is still spent on:

• Solid, embedded concrete foundations and piers
• Properly sized and anchored wood posts
• Code‑compliant seismic retrofits that respect the entire load path, not just vertical capacity

If you want help sorting through your specific situation – including whether adjustable products already installed under your home make sense or should be corrected – we can take a look and give you a real, crawl‑space‑level answer:

Seismic, Foundation & Drainage Services