Rebates Clearance
Hills Flat Lumber Co.

(530) 273-6171

Grass Valley, CA 95945
Grass Valley

(530) 346-8685

Colfax, CA 95713

Top-Quality Lumber Supplies in Northern California

Pressure Treated Lumber

Hills Flat Lumber is the largest pressure treated lumber dealer in Northern CA. While other yards need to special order the material you need…we have it IN STOCK! All pressure treated materials are kept in covered storage, protected from the sun & rain with EASY drive thru access. We do not sell twisted, checked boards.

Naturally strong and durable, Allweather Wood pressure treated lumber is a proven building material for a wide range of commercial, industrial, and residential applications. No matter what you're building, it's going to have to face the natural elements – air, fire, earth, and water, insects, mold, and decay. Allweather Wood pressure treated lumber is ready for whatever nature brings your way.

For more information please contact our Pro Sales Department:

Grass Valley Store: (530) 273-6171 ext. 123

Colfax Store: (530) 346-8685 ext. 220


Pressure Treated Douglas Fir In Stock

Other Pressure Treated Inventory In Stock

Always In Stock and Ready for Pickup or Delivery

  • 25' Class 5 Power Poles
  • Temporary job site power poles with or without service panels. In stock and ready for pickup or delivery.
  • 6'x 8' Landscape Timbers
  • 2" x 8' Tree Stakes

Engineered Wood

Engineered wood products provide outstanding excellent performance for a reasonable cost, reduces the use of natural resources and minimizes waste on the job site. With engineered wood you will know the precise strength of every piece, taking all of the guesswork out of building a stronger, silent floor. It's that simple.

Find out everything you ever wanted to know about engineered lumber (but were afraid to ask) by talking with one of our knowledgeable, trained staff.


The primary cause of moisture damage in a commercial or residential building is water intrusion through the interface details around windows, doors, and other exterior penetrations. Water intrusion also represents the number-one reason for warranty callbacks and customer dissatisfaction in new home construction.

Flashing, properly installed and integrated with a weather-resistive barrier, is one of the most important factors in the successful performance of exterior walls.

Framing Lumber

At Hills Flat Lumber, we take pride in offering a choice of high quality lumber. Our framing lumber is the best available.

Our timbers are #1 & Better FOHC (Free Of Heart Center) anti-stain treated. This means straighter walls, doors and windows.

Truss joist MacMillan is our manufacturer of high-quality, engineered lumber. Our pressure treated material is Naturewood - 40 ground contact in everything from 2x4 through 2x12, and 4x4 through 4x12.