
What Are House Jacks?
House jacks are adjustable steel support posts designed to stabilize sagging floors by reinforcing weakened floor joists and beams from beneath your home. Installed in a crawl space or basement, they transfer structural loads to a stable foundation beneath your home.
Unlike temporary jack posts or wood supports, engineered house jacks serve as a long-term structural repair. They help reduce floor movement, improve stability and, in many cases, lift sagging floors closer to their original position.
Every home is different, which is why the right repair starts with a thorough inspection. We'll assess your floor framing, crawl space conditions and structural supports to determine whether house jacks are the best solution for your home.

What Causes Crawl Space Structural Damage?
Crawl space structural damage usually develops gradually as moisture, shifting soils and aging materials weaken the floor support system beneath your home. Excess humidity, poor drainage, freeze-thaw cycles and older vented crawl spaces can all contribute to wood deterioration, settling support posts and unstable soil. Over time, these conditions may leave floor joists and beams without adequate support, resulting in sagging, uneven or bouncy floors.

Our Crawl Space Support Solution
Every sagging floor has an underlying cause, so every repair begins with a thorough structural inspection. If weakened floor supports are the source of the problem, we’ll recommend a permanent solution designed to stabilize your home’s floor system for the long term.
For stabilizing crawl spaces and sagging floors
SmartJack® House Jack System
The SmartJack® House Jack System is NV Waterproofing and Foundation Repair‘s engineered solution for stabilizing sagging floors and strengthening weakened crawl space support systems. Adjustable galvanized steel support posts are installed on a stable base to deliver permanent support beneath floor joists and beams, helping reduce floor movement while improving floor levelness.
Every home is unique, which is why every SmartJack® installation starts with a comprehensive structural inspection. We’ll evaluate your crawl space, floor framing and support system to determine the right placement and number of supports needed for lasting performance. The result is a repair that’s designed specifically for your home’s needs, not a one-size-fits-all fix.

Symptoms
Signs Your Home Could Need a SmartJack® System
Sagging floors rarely get better on their own. If you’re noticing changes in how your floors feel or other signs of structural movement, your crawl space support system may need attention. A professional inspection identifies the underlying cause and determines whether SmartJack® is the right solution.
Common Signs Include:
- Floors that sag or slope
- Floors that feel bouncy underfoot
- Floors that feel soft or unstable
- Squeaky floors that are getting worse
- Gaps forming between floors and baseboards
- Crawl space support posts that are leaning, rotting or failing

What To Expect
Ready to get started?
Schedule a free estimate to start your repair journey with Thrasher.
Schedule your inspection
Fill out our form or give us a call to book your inspection. Share what you’ve noticed so we can send the right expert to your home.
Full home
inspection
An expert will inspect the problem area and surrounding conditions, including soil movement, drainage, structural integrity, and any related concerns.
Clear explanation
of findings
We’ll walk you through what we’re seeing in easy-to-understand language so you know the root cause of the issue, not just the symptoms.
Review recommendations
If repairs are needed, we’ll outline your options, pricing, and timeline so you can make the best decision for your home.
Schedule your free inspection—
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Meet with a trusted expert, and get
clear answers about your home.












