Treatment Levels

Code Requirements:
IBC 2302.1.8
IBC 1809.1.2
IRC R319.1
IRC R320.3.1


Pressure Treatment Process
The process of pressure treating foundation posts involves kiln drying, then placing the members in a cylinder, applying a vacuum, and pressure to force treatment into the post.

Retention Levels
The amount of chemical absorbed by the member in pounds per cubic foot is used as a rating or retention level for pressure treated lumber.

CCA-C
Chromated Copper Arsenate or CCA-C is not available for residential use due to the fact it contains arsenic. Our laminated posts use CCA exclusively. The Forest Products Laboratory provides more information about different types of wood treatment.

Decay
Preservatives are necessary to prevent decay of members due to insects and fungus. In many parts of the country common belief is that allowing concrete to "touch" foundation posts will cause decay. This is caused by purchasing the WRONG foundation post. Properly treated foundation posts will not rot due to contact with concrete, and some areas of the country embedment in concrete is required.

American Wood Protection Association
The AWPA is ANSI accredited and provides standards for wood chemical usage evaluating through rigorous testing of treatment methods and treatment levels for southern yellow pine and douglas fir species.

UC4A - GROUND CONTACT

UC4B - FOUNDATION POSTS

Code	Preservative Name	UC1/2	UC3B	UC4A	UC4B
CCA-C	Chromated Copper Arsenate			0.40	0.60
ACC	Acid Copper Chromate	0.25	0.25	0.50	---
ACQ	Alkaline Copper Quaternary (Types A,B,C)	0.25	0.25	0.40	0.60
ACQ	Alkaline Copper Quaternary (Type D)	0.15	0.15	0.40	0.60
ACZA	Ammoniacal Copper Zinc Arsenate	0.25	0.25	0.40	0.60
CA-B	Copper Azole, Type B	0.10	0.10	0.21	0.31
CA-C	Copper Azole, Type C	0.060	0.060	0.15	0.31
CuN-W	Waterborne Copper Naphthenate	0.070	0.070	0.11	---
CX-A	Copper HDO	0.206	0.206	---	---
EL2	DCOI-Imidicloprid-Stabilizer	0.019	0.019	---	---
PTI	Propiconazole-Tebuconazole-Imidicloprid	0.013	0.018	---	---
PTI	PTI plus Stabilizer	0.013	0.013	---	---
SBX	Inorganic Boron (Formosan termites)	0.28	---	---	---
SBX	Inorganic Boron (non-Formosan termites)	0.17	---	---	---