Fire Retardants and the Lumber Shortage

Right now there is a building boom going on, and a corresponding lumber shortage. That translates into prices that are triple what they were a year ago. It also creates a shortage of Fire Retardant-Treated Lumber (FRT) - plywood and dimensional lumber that is pressure-impregnated with flame retardant, so it meets fire code right from the start.

What can you do if you can't get FRT? In many cases, you can treat regular lumber on-site, and it will pass code. After all, they use exactly the same chemicals to treat it either way. And there are actual benefits to using FRT that hasn't been pressure-impregnated - it's easier on fasteners, doesn't become as brittle, and doesn't affect the glues.

There are a couple areas that are prime candidates for on-site treatment - floor/ceiling assemblies and plywood/OSB sheathing.

Floor/ceiling assemblies are typically either 2x10 joists or engineered i-joists, with plywood decking above. These normally require a one-hour rating. There are several paints and one saturant we offer that can meet that standard. It also depends on if the assembly will be covered with sheetrock, or left exposed. In a lot of remodels, people want the exposed natural wood of the joists

Plywood and OSB sheathing can be either Class A or B, or require a time rating, depending on the code requirements.

Applying the retardant on-site is pretty straight forward. Saturants can be applied with a simple Hudson garden sprayer or backpack sprayer, and the paints with brush, roller or airless. Airless is usually going to be most efficient, but FR paint is usually pretty thick, and we recommend a stout 3300 psi hydraulic airless if possible.

Here are some of the retardants we offer that can help you meet fire code for these assemblies:

• Contego
• FX Lumber Guard
• DC 5040
• FF88
• FP100

So if you are having trouble getting FRT lumber, give us a call at 405-306-3062, and we might be able to keep your project rolling!