
NWFA Certified · Metro Detroit
Subfloor Leveling and Repair Built for Michigan Homes
A premium floor is only as good as its foundation. We engineer the invisible work that most contractors skip. Laser-precision flatness, structural correction, and moisture mitigation for Metro Detroit homes.
The NWFA Standard
The Critical Difference Between Flat and Level.
There is a massive difference between a floor being level and a floor being flat. An older home may slope slightly and that's okay. But to successfully install hardwood or premium LVP, the subfloor must be perfectly flat. According to NWFA guidelines, that means within 1/8 of an inch over a 6-foot span, or 3/16 of an inch over 10 feet.
If your subfloor has dips, crowns, or peaks outside those tolerances, your new flooring will flex, squeak, and eventually fail. We use precision 10-foot straight edges and advanced lasers to verify every square foot before a single plank is laid.
Structural Engineering
More Than Surface Level: Structural Integrity & Deflection.
A perfectly flat floor requires a structurally sound foundation. Before any leveling begins, we evaluate joist spacing and subfloor thickness to ensure they meet NWFA deflection standards. We also calculate point loads the physical weight your structure can safely handle.
⚠ Engineering Warning
Pouring self-leveling underlayment adds massive "dead load" to your home's framing. Standard contractors often pour thousands of pounds of cement without checking joist capacity risking severe structural sagging. We calculate the exact weight loads, and for complex projects, we collaborate directly with licensed Structural Engineers to guarantee your home remains safe and stable.
Our Arsenal
Four Methods of Subfloor Correction.
We approach every subfloor as master carpenters and engineers. We diagnose the issue first, then prescribe the exact correction method your home needs:

Carpentry & Joist Repair
Sometimes the problem starts at the bones. We remove the subfloor to plane or sister uneven joists. Resolving severe structural dips and crowns at the source, not just masking them.
Mechanical Grinding
Swollen OSB seams, high plywood joints, concrete peaks. We aggressively sand them down to tolerance. It's unglamorous work, but it's the difference between a floor that lasts and one that squeaks within a year.

The Hard Shim Method
A highly specialized carpentry technique we use to permanently build up low spots with layered plywood, wood shims, and elastomeric glue. Without adding the massive water weight of cementitious patches.
Advanced SLU (Self-Leveling)
Precision-poured, high-tech self-leveling compounds that create a perfectly flat, glass-like foundation. This is our go-to for large-scale corrections. When executed properly, it's the gold standard.
Material Science
The Science of SLU: Why Standard Contractors Fail.
Pouring self-leveling underlayment is a chemical science, not a DIY project. Wood subfloors naturally flex, and if you use the wrong patch, it will crack and destroy your new floor. We strictly use premium, polymer-modified compounds from industry leaders like Schönox, Ardex, MAPEI, Bostik, and Uzin. The chemistry has to be right.
The Primer Rule
Proper bonding requires exact primer chemistry. We specify primers based on the porosity of your concrete or the type of plywood. Ensuring the underlayment has the right emulsifiers to flex and bond permanently with your home's specific structure.
From the Field
Primer → Pour → Perfection.
A complete subfloor correction sequence: specialized bonding primer over existing mastic, precision SLU pour, and the finished 8-inch hickory hardwood.

Bonding Primer Over Mastic
Livonia, Michigan

Engineered SLU Pour Glass Finish
Livonia, Michigan

Custom 8″ Hickory Michigan Plank Fireside
Livonia, Michigan

Bare Subfloor Evaluation
Northville, Michigan

Specialized Blue Bonding Primer
Northville, Michigan

Needle Rolling SLU The Money Shot
Northville, Michigan
Licensed Residential Builder
Subfloor work often requires a completely cleared workspace — more so than any other phase of a flooring project. We coordinate professional furniture removal and appliance disconnection by licensed plumbers before a single bag of SLU is mixed. The subfloor gets the access it needs. The work gets done correctly.
Case Studies
Project Spotlights: Subfloor Engineering in Action.

1.5-Inch Structural Correction & Silica Dust Control
How our 8-man crew safely executed a massive 1.5-inch correction using HEPA-filtered mixing stations.
View Project Details
Precision Flatness for 8-Inch Walnut
Engineering a flawless, glass-like subfloor to meet strict NWFA tolerances for custom wide-plank walnut.
View Project Details
Smart Encapsulation & Custom Hickory
Bypassing hazardous mastic grinding with specialized bonding primers and engineered underlayment.
View Project DetailsDon't let a bad subfloor ruin
a $20,000 investment.
Connect directly with Michigan's NWFA Certified Masters to evaluate and correct your subfloor before your next flooring project.
Related Services
The subfloor is step one. Here's step two.
Google Reviews
What your neighbors are saying
"We had a great experience with our flooring install. Our installer Aaron was very professional, he set the standard by which everyone will be judged against. He cleaned up everyday and the way he put the extra effort in to level and prep our floor the right way made us very glad that we got our flooring here. They make the floors themselves and the product speaks for itself. We looked around at many places and couldn't find anything comparable to their product."
"Our 1960s ranch had serious subfloor issues that two other companies said couldn't be fixed without a full tear-out. Ed's team leveled everything with self-leveling underlayment and the new floor is perfectly flat. Incredible technical work."
"After a national franchise gave us a quote over the phone without even seeing the house, we called 1 Wood Floors. Ed spent two hours evaluating our subfloor, testing moisture levels, and explaining why our Old West Side bungalow needed vapor barriers before any hardwood went down. Night and day difference."
"Our lakefront home near Island Lake had moisture issues that two other companies couldn't solve. Ed's team did a full forensic evaluation, installed vapor barriers, and leveled the subfloor before placing our Olde Wood wide-plank. Two years in and the floors are perfect. Worth every penny."
Subfloor Leveling FAQs
Subfloor questions answered.
An improperly prepared subfloor is the single leading cause of hardwood floor failures. Squeaks, hollow spots, cracked locking systems, and finish separation all trace back to subfloor problems. We engineer your foundation using laser topography and premium self-leveling compounds to meet strict NWFA flatness tolerances.
Common signs include squeaky floors, visible unevenness, hollow spots when you walk, or doors that don't close properly. Many subfloor problems are invisible to the untrained eye. We perform a full diagnostic evaluation on every project before installation begins.
SLU is a cementitious compound that we pour over your existing subfloor to create a perfectly flat surface. It flows like water and self-levels using gravity, but requires precise mixing ratios, temperature control, and expert application. We use premium Schönox products for all our SLU work.
Standard pours range from 1/8 inch to 1 inch. For deeper corrections, we've completed pours up to 1.5 inches using specialized techniques and multi-layer applications. Our Ann Arbor project involved a massive 1.5-inch correction across a full home.
Mixing cementitious materials creates hazardous silica dust. We utilize on site HEPA-filtered Collomix mixing stations to guarantee zero airborne silica reaches your living space. This is a critical health and safety measure that most contractors skip entirely.
