PT Lumber

Question - when pressure treated lumber is cut, what is the proper way to seal the cut end? :-k


All these years,
I was not aware that there was a proper or improper way to cut dimensional lumber

Bill, most lumber yards and DIY stores sell products, usually in quart sized cans. Sorry, but I can’t think of the brand name at this moment.

In looking at the 2009 Deck Guide, the only mention is for posts. Nothing else was mentioned for joists or other framing members.

“Cut ends of posts shall be field treated with an approved preservative (such as copper naphthenate).”


Liquid preservatives can be brushed on the cut end, or the end can be dipped into them. Spraying is not recommended. If dipping is used, a minimum of three minutes immersion is recommended. If brushing, use two coats. Only the cut end need be dipped or brushed. Workers should wear proper protective gear (rubber gloves and eye protection) when using these preservatives, primarily because of the organic solvent. Borate rods and pastes are inserted into pre-drilled holes and plugged tightly with a piece of dowel, a plastic plug or some other suitable material to keep water out of the hole.

And I’m sure they always are. :wink:

Excellent replies - thanks guys!

Found it Bill. This is what I used on my deck a few years ago.

Brush-on Preservatives for Field Cuts

According to American Wood Preservers’ Standard M4-02, lumber and timber which are used in above ground applications and are of sapwood species such as southern, red or ponderosa pine, generally do not require treatment to provide a good service life. This category includes the majority of the treated products Universal Forest Products provides. Other heartwood species, typically found in the Western US, should be field treated when cut or drilled. If you are concerned about wood exposed due to cutting or drilling, you can use a brush-applied preservative.

Home centers and lumberyards often carry brush-applied preservative systems based on two different active chemicals: either copper naphthenate or IPBC (3-iodo 2-propynyl butyl carbamate). These systems should be applied, in accordance with their labels, to any surface exposed by damage or field fabrication. Users should carefully read and follow the instructions and precautions listed on the preservative system label when using them.

The wolmanized product Jeff mentioned is used to preserve the warranty of the wood product. Wolmanized supposedly has a lifetime against rott and termites if contsructed per directions useing end cut solution.

**Product: **
**EPA Registration Number: **

This pesticide is used as a:


This pesticide is registered for unrestricted use.
This pesticide’s toxicity code is 1, which corresponds to a toxicity category of Danger.
Active Ingredients in this Product](
[RIGHT][RIGHT]Percentage by Mass[/RIGHT][/RIGHT]

Wolmanized treated lumber recommend a product Wolmanized End Cut Solution called Cunapsol-1. It is a pesticide, but contains the ingredient COPPER NAPHTHENATE](
It is a regulated pesticide.

Regulated Pesticide

**What maintenance is needed for the product?
**No maintenance is needed to renew resistance to fungi and termites. Wolmanized wood has a lifetime limited warranty against these organisms. However, protection is required to maintain the wood’s appearance against weather. Sun and rain cycles cause stresses in lumber and result in swelling, shrinking, warping, and cracking.

• To help protect your project against moisture damage, apply an effective brand of
water repellent as soon as your outdoor wood project is finished or, for large projects,
as sections are completed. Water repellent should be applied every year or two.

• To revitalize a dingy appearance caused by dirt and mildew, use deck brightener to clean
the outdoor wood.

To validate the warranty in some states and for some species, apply an end-cut solution.

There is no such thing in this State for providing and end cut sealant on pressure treated lumber and I don’t think there is any such thing as lifetime warranty. The product hasn’t been around for 80 years. :):wink:

This quote:


Not always possible or practical. (short post deck or patio where multiple posts are cut from one longer post).