How to Apply Boric Acid to Foundation Wood

Using a Brush

• 1

  Put on a dust mask to avoid breathing the fumes. Mix the boric acid according to the directions on the can or bottle. Start by adding enough water to the pail in which you are mixing the powder. Slowly add the powder, stirring gently so that little of the boric acid mixes with the air.

• 2

  Put down a drop cloth if you are applying the boric acid mixture outside near landscaped areas. Boric acid can be toxic to vegetation in sufficient quantities.

• 3

  Brush the solution onto the surface. Since the treatment is water-based, it penetrates quickly into the wood's surface. Once you have finished the project, dispose of small amounts of the boric acid solution by pouring it down a sink and run the tap to dilute the solution. Thoroughly rinse the bucket and brush you used for the project.

Using a Sprayer

• 4

  Put on a dust mask, place the boric acid inside a yard sprayer and slowly add water to the canister.

• 5

  Place the cover on the sprayer and shake gently to mix the solution.

• 6

  Pump up the pressure in the sprayer.

• 7

  Spray the solution on the foundation wood you want to treat. Drain any excess down a sink, following with plenty of water to dilute it.