M-F. 8AM-5PM | SAT. 8am-12pm
 685 Berne Rd. Columbia Falls, MT 59912
 (406) 892-4208

Solid Wood Beams

Beams and timbers can add an impressive accent to almost any project and are frequently an integral component of the structure itself. When possible why not add the natural beauty and character of a real solid wood beam? At RBM we have been supplying posts and beams to local contractors for over 30 years.

The balance between visual appearance, structural quality and price can make obtaining beams for a project a real challenge. We help our customers get past this hurdle by being as flexible and versatile as possible. We understand these concerns and have developed our product line with them in mind. When we don’t think we have the right product for you we will try to steer you in the right direction.



RBM Lumber - Columbia Falls Wood Beam Sizes

Beams and Timbers: Sizes

  • We can cut up to a 28” x 28” and lengths up to 32 feet long. However, bear in mind that logs that qualify for such large and long beams are rare in this part of the country.
  • Unless otherwise specified we cut all our beams at full dimension meaning a 6x12 is a full 6" by a full 12" etc.
  • IMPORTANT NOTE: Sizes and lengths of various grades are always dependent on log availability.
  • Inventory: we try to inventory some of the most commonly requested smaller beams like 6x6's and we always have some inventory of random larger beams but the majority of our beams are cut to order.

RBM Lumber - Columbia Falls Wood Beam Grades

Wood Beams and Timbers: Grades

  • #2 green is the base of our grading system. It is primarily concerned with structural quality and may have some wane, checking and other defects that don’t affect structural quality.
  • Choice is our own grade which is a #2 beam high-graded for appearance purposes. This will have square corners, no loose or dripping pitch, limited checking, and other visual defects will be limited. Be aware that each person will have his/her own perception of what is acceptable in appearance, so this grade is not a commitment to satisfying all individuals tastes but rather a commitment to high grade out the cleaner looking peices.  
  • #3 has defects such as excessive checking, twist or rot that are not allowed in the #2 but are still useful in some applications.
  • Green beams are cut from green timber which has a higher moisture content and will shrink and check some and possibly twist as they acclimate to the environment, they are in.
  • Dry or dead standing beams are cut from dead standing timber. They have a much lower moisture content and therefore are more stable. We do not guarantee a certain moisture content in any of our beams or that they will not move or twist in the acclimating process.





Rough Lumber and Decking

Our Rough Lumber History

RBM Lumber started the lumber business with a portable mill called a Mini Mite sawmill which cut very accurate dimensions in rough lumber - if the operator was attentive. Since then our product line has evolved and continues to evolve based on our customer’s needs. We have the ability to produce very customized products and when there is a consistent need for any particular product we try to make it an inventory product so it doesn’t always have to be a special order. Due to the wide variety of applications we dry many rough products and sell some green. If you are uncertain as to whether you need dry or green you may ask any our customer service who will be happy to assist you. We literally have tens of thousands of products so it is impossible to always have all of them in stock so we advise calling ahead to be sure we will have it when you need it.

We carry rough products in F&L, White Woods and Cedar but not all products will come in all species.


Rough Grades for 2"

Note: at RBM Lumber we have tailored our grading system as best we could to the needs of our customers so our grades may be different than what you would see in others' product lines. We recomemnd you inspect our product before deciding it is what you need. If it is not, many times we can offer you a grade above or below that will work in your application. We have also invented many grades specific to particular applications. Any of these products in dry will be dried to exterior moisture.   

  •  #2&Better; The baseline grade for our rough lumber is a #2&better which is primarily a structural grade. It may have defects such as wane, checks, splits, stain, etc that don't affect the structural quality of the piece. To some these characteristics enhance the rustic appearance of the product.
  • Choice Green; This is our own grade which is basically a #2 that has been high-graded for appearance purposes. It will be free of wane, excessive checking, pitch and other visual defects. This is not an inventory item so it must be special ordered.
  • Select; In some products we can supply a select grade which has very limited knot content.
  • #3; This grade has defects that are not allowed in a #2 such as excessive checking, wane, rot or warp but it is still useful in some applications.
  • 2" Decking grade is graded to have a choice face but with unlimited defects on the back side. This grade may or may not be on hand.
  • 6/4 x 6 Decking is the same as 2" decking except is 1 1/2" thick. This is an inventory product.
  • #1 Rough Dry is a high graded #2 and dried to exterior moisture. This is not necessarily graded for visual purposes and can have some minor defects.
  • 2" Exterior Trim is graded specifically for visual applications and dried to exterior. 
  • 5/4 Exterior Trim is graded for visual and comes in Cedar and Spruce. This product is specifically made to go with bevel and 1" siding products.
  • Weathered Wood is product that has been in the sun and weather long enough to be naturally gray. 


Rough Grades for 1"

Note: the rough dry grades described here are dried to exterior moisture - 12%

  • Sheeting is an economy low grade of 1" boards with excessive defects which won't allow it in any of our regular grades but is still useful in some applications.
  • #3 rough dry has some small knot holes, wane, limited checking, stain, limited crook and warp
  • #2 & Better rough dry is your typical "knotty pine" grade and has almost unlimited knots and other limited defects usually on the back.
  • Select is very limited in knots up to completely clear. This is not commonly a stock item for us. 


Rough Lumber Dimensions

At RBM we cut all our rough full dimension which means a 2×4 is a full 2″ by a full 4″ unlike surfaced which is 1 1/2″x 3 1/2″. This means our 2×4 has more wood in it than a surfaced 2×6 and so on up the scale. 1" boards are 15/16" thick by the full width. Keep in mind that any of these widths will shrink during the drying process. We can also cut almost any special dimension you may need and depending on the product we can cut up to 32' in length.

We try to inventory as much of the more commonly requested products as possible such as 2×4 through 2×12 in rough green and in dry exterior trim stock, rough dry 1x4 through 1x12 and 5/4 trim for different siding products. The term 5/4 means it is 1 1/4" thick by the nominal width. We also stock a lot of specialty items like decking, live edge siding, 2x2 spindle stock, etc. There are so many possibilities don't assume anything is out of the question without asking.

Not all products come in all grades and all species, but we can usually find a product that will fit your needs. If not, we may know where you can find it.

RMB Lumber Montana Wood Products and Lumber Mill


RBM Lumber Columbia Falls MT | Montana Lumber Products