Ask NADRA: Is Fungus Destroying CCA Wood?

April 30, 2011 | Wallace from Midway, GA asks:

“[What do I] need to know about fungus destroying CCA lumber?”\

Huck DeVenzio of Arch Wood Protection Reponds:

From your question and e-mail address, I’d guess that you have heard reports from a guy (Sam Brooks) saying that there is a strange fungus destroying CCA-treated wood in coastal areas. He says his company has a solution.

I’m amazed that this non-story is getting as much attention as it has. From all we have been able to piece together, there is no strange and destructive fungus. The photos he shows involve an occasional condition called tracheid separation or salt-killed wood. It does not involve a fungus and it is not a failure of CCA preservative. It is caused by wicking of salt into some pieces of wood. A document (link provided below) published by experts at Mississippi State University is attached; it explains the phenomenon. This was written in March, largely to counteract the assertions appearing in the Charleston-Savannah area. I have another technical paper if you need more information.

This “salt kill” can cause problems for marine piling, but it tends to be scattered and it is not caused by fungi. I do not know anything about the solution offered by Mr. Brooks, but you have to be suspicious when he doesn’t even understand the cause of the problem.

Click here to read the report from Mississippi State University.

Ask NADRA: Preserved Wood For Wet Climate

April 26, 2011 | A concerned homeowner in British Columbia asks:

I have a 3-foot crawlspace which has a damp concrete floor whenever we get heavy rain. Consequently, the exterior pony walls carrying the fiberglass insulation are beginning to decay. Can I replace the pony walls with preserved wood and not put a finish cladding on it? Is there a toxicity factor here if the wall is not properly sealed? Timing and budget are not big factors here as much as having the job done right. Thank you.

Huck DeVenzio of Arch Wood Protection Reponds:

If you purchase properly treated wood (we, of course, recommend the Wolmanized brand) intended for ground contact, you can be confident that the wood will resist fungal decay for many decades, and you don’t have to be concerned with sealing or cladding. Treated wood has been used for years in Permanent Wood Foundations (made of treated studs and treated plywood), framing for all homes in Hawaii (where termites necessitate this), and for the sill plate of nearly all homes in North America. In all of those applications, many left unfinished, there is not a single known adverse health or environmental incident from the preservative in the wood.

Because of the dampness and your past problem, I would try to get wood treated for ground contact, even if most of the lumber will be above ground. That gives you an extra measure of security.

You can probably find properly treated wood at a lumber dealer near you. I hope this helps.

Ask NADRA: Deck Stair Lighting Codes

March 21, 2011 | Lainie Sleppin of Mid-State Lumber asks:

“I am getting a number of calls regarding the code on deck stair
lighting, no pun but can you shed any light on this code so I can
advise correctly. We are talking about guys in the NJ market.

Thanks for your help and have a great weekend.”

Glenn Mathewson, NADRA’s Technical Advisor, responds:

Hello Lainie,

Thanks for your confidence in NADRA, the voice of the decking industry, to be your “go to” when you need quality information on the decking and railing industry. I understand your contractor customers in the New York and New Jersey area have been asking questions lately about lighting at deck stairways. I am happy to provide you assistance in better understanding the requirements of the 2009 IRC in this regard. Many people I discuss this with are surprised that when you read Section R303.6 there are two requirements…one for the location of a lighting fixture, and one for the illumination of the stairway. They are not one in the same.

I have copied below the discussion from ICC’s deck code book, Deck Construction based on the 2009 IRC. Continue reading “Ask NADRA: Deck Stair Lighting Codes”