Selecting The Right Material For Your Fence Project

Choosing wood for your next fencing project can be a headache for beginners and at home D.I.Y’ers who haven’t yet gotten their feet wet when it come to selecting not only the species of wood but also the grade. Hopefully we can help break that down for you today and get you pointed in the right direction.

For questions and concerns directed specifically towards materials needed for posts, please refer to choosing the right fence post.

For this article, we are going to be looking specifically at the 2×4, fence board, and trim options commonly (and a few uncommonly) used in residential fencing.

2×4:

To start, we will dive into arguably the most common set of dimensional lumber.

The 2×4. Most commercial grade 2×4’s found at big box store’s all across the nation are going to come from one of three trees: Pine, Hemlock and Fir. These trees have a place in almost every project taken on in carpentry and in construction in general.

As far as fencing is concerned, these offer an inexpensive and easy to find solution. The one downfall these all have in common is longevity.

Hemlock has been known to outlast the other two but not exactly by leaps and bounds. More like a step ahead of the pack.

However the fix to its downfalls has come in the form of pressure treated lumber. This is a process that chemically treats raw wood to give it a leg up against rot and insects. The chemical turns the wood from a pale brownish pink in its raw form, to a unnatural greenish grey typically seen in marine grade wood products.

After their treatment they are stained to even out the appearance for the end consumer. The treated wood is rated for “ground contact”.

It will allow for a slower more prolonged period of strength and durability it decays but it will decay none the less.

The kings crown for fencing has to go to Cedar. Cedar have natural rot and insect resistant properties that allow it to stand up against even the most inclement weather.

Also, without the need for pressure treatment you can enjoy the beauty that Cedar has to offer. It is a durable, long lasting wood that will take on the test of time.

Cedars downfall come in the form of availability and with that comes price. It may last 2-3x as long but it will come at an equally multiplied cost.

Where as a Fir 2×4 will come in around the 2$-3.50$ range Cedar can range from 6$-10$ per board depending on the grade.

All of these options will benefit from a well applied stain or similar treatment either before or after installation. Typically 2-4 coats for the initial application and then follow the manufactures guidelines for future coatings.

Pro tips:

Try not to have any knots within 2-3 inches of the ends of your 2x4s when going to install. This will help in avoiding splits or blow outs from screws or nails when attaching the fence rails to the 4×4’s
Stains slightly darken with each coat so if your looking for a deeper or darker finish try bumping up the number of coats until your satisfied (5-6 max)

Fence Boards:

Fence boards follow nearly all of the common highs and lows of their 2×4 counterparts as far as wood type is concerned. The Pine, Fir and Hemlock options come at a lower cost but with a lower resistance to rot and damage from sun, rain and insects.

Big box stores will also have pre stained options for these wood types for added protection straight out of the gate.

Cedar fence boards come at a slightly higher cost but I personally believe they hold up their end of the transaction in the long run.

The big differences you will find in fence boards will come in the form of their grade. Grades are assigned to wood of all species and classes.

These grades are to allow workers and end consumers to accurately select for durability, strength and beauty once it has left the saw mill without needing to sorting through mountains of lumber.

Fence boards are typically arranged in classes 4-1 and clear.

(These grades or systems may vary state to state or even person to person but it is the most common grading scale we see specifically for fence boards)

Grade 4 – Low grade:

You will typically find boards cut closer to the exterior of the tree, both sides may have significant defects such as chipping, raised grain, splits, wane and blade burn. Maybe the biggest issue that will land a board in grade 4 is loose knots.

Loose knots are knots that may be soft, loosely fitting in the wood (likely to fall out and leave a hole) or missing all together leaving a hole in its place.

Grade 3 – Mid/Low grade:

These boards will have many of the same defects as grade 4 aside from loose or missing knots. Large knots will be common for grade 3 with no limitations for the number of knots per board.

Grade 2 – Mid grade:

Boards in this grade should not have significant defects. You may find minor wane but out of 100 boards you should expect 90% of that stack should be free of wane, splits and blowouts.

Few large knots should make it to this grade and a lesser number of small knots.

Grade 1 – High grade:

This grade will yield the lowest number and the smallest size of knots. You shouldn’t expect nearly any defects.

Clear:

This class of boards if held for boards that will pass the grade one specs without a single knot on the board.

Something to keep in mind is the reality of “gradeout”. Gradeout is when a board either passes by an inspector and a defect is not caught or it is damaged in transit and handling.

You should expect between 5-10% of grade out when purchasing in bulk. If you need 500 fence boards, buy 575.

Common 2×4 and trim grades come with a different vernacular. (These grades may vary and we will not cover all of them but we will hit on all of the major grades)

These range from rough sawn to S4S and so on.

“Rough sawn” lumber comes right off the saw and straight to the shelf. Without going through the full proses these boards keep their raw form as far as being dimensional lumber.

Whereas a S4S 2×4 will be milled down to a final product of 1 1/2 x 3 1/2-3 3/4 a rough 2×4 will typically be a 1/4 wider and thicker.

S2S: Refers to Lumber that is surfaced on 2 faces. The two widest faces of the board will be planed to a smooth finish.
S3S: Refers to lumber that is surfaced on 2 faces and ripped down on edge square to the surfaced faces.
S4S: You guessed it, surfaced on all 4 sides. Leaving the lumber smooth on all faces and all 4 corners rounded.

All of these boards have their place in fencing. Each step in the milling proses adds labor, ultimately raising the cost of the end product.

Typically with solid fences you will only see one or maybe 2 sides of a 2×4 so you may not need to fork out the extra cash for a fully surfaced board.

Other times you want those clean and crisp lines from any angle so you may need to bump up to a S4S graded piece of lumber.

Pro tips:

Rough lumber is typically thicker and wider then more common boards so it may not fit into common brackets designed for connecting two prices of wood.
Most mills and lumber yards will have a “2 and better” grade for fence boards. You may pay slightly more per board than simply buying #2’s but you will also have a mix of #1’s and clear fence boards in your lumber package.
A cost effective alternative for 2×4’s are commonly referred to as “back rail” these boards will have substantially more defects but will come at a much lower cost. Typically one face will with defects to allow a clean look on the exposed side of the 2×4.
A 2×4 carries its load best on its 4” face not its 2” face. When installing the rails for your fencing we recommend they are attached so that the fence boards are being attached to the 4” face.

If you still have questions or looking for professional fence installers to handle the job, we are just a phone call away. Feel free to reach out to us and our team of fence install experts will gladly assist. Contact South Sound Fencing today.