Posted by Admin on 12/10/2020
Choosing the right screw for your projects is key to a successful installation. One challenge is on outdoor construction with the chemicals in pressure-treated wood. One of the most common is ACQ, which is used for both above ground uses and in contact with soil, etc. ACQ is a corrosive chemical which will attack both fasteners and hardware, so it is very important to use materials that can withstand the environment that they are installed in. The term “ACQ compatible” is no longer accepted by building officials in terms of whether or not a coating will perform correctly. The new terminology to look for is AC257 compliant. This rating will ensure the performance of the coating in the corrosive material.
A variety of coatings are used in protecting fasteners and hardware against the corrosive conditions of these chemicals. Quality coatings will have a test rating which is usually accomplished with an accelerated salt spray test. These are done in a controlled environment and assimilate long term conditions under which the fasteners and hardware are subjected to. Any reputable manufacturer should have these ratings available to share with customers. Our exterior star-drive fastener coatings, SKT11, are rated at 1200 hours, one of the highest ratings on fasteners!
Another option is stainless steel screws, the main drawback is cost. The screws will not be affected by the chemicals, maintain their appearance and function for the life of the installation.
Enjoy the Holidays!!