Things You'll Need
Plastic drop cloths
Heavy-duty fabric drop cloths
Tongue-and-groove ceilings are composed of interlocking lips intended to hide nails from sight. When it comes to finishing a tongue-and-groove ceiling, success has more to do with procedure than style. Because seasonal movements in the wood create slight movement, parts of the tongue tend to become exposed over time. That is why it is critical that you stain the wood of a tongue-and-groove ceiling before it is installed. Otherwise, the unstained portions of the tongue will eventually become exposed, creating lines of bare wood that will detract from its appearance.
Spread plastic drop cloths on the ground. Lay fabric drop cloths on top of them.
Lay the tongue-and-groove wood on top of the drop cloths. Determine which side of the wood will be exposed after installation and lay this side facing up.
Wipe the surface of the wood with a tack cloth.
Apply oil-based stain to the wood, using a 4-inch paintbrush. Brush along with the grain of the wood. Apply only a thin coat. Allow the surface to dry for three hours and apply another coat if you desire darker results.
Clean the paintbrush using mineral spirits. Do not use water as this will ruin the brush.
Stain will seep through fabric drop cloths and pool on top of plastic ones. These two types of drop cloths must be used in concert to prevent messes when staining.
If you need to refinish a tongue-and-groove ceiling that has already been installed, spread plastic drop cloths on the floor and overlap them with fabric drop cloths. Access the ceiling with a stepladder and apply a fresh coat of oil-based stain using a 4-inch paintbrush.
Tongue-and groove-ceilings must be stained before installation for best results. If, however, the builder hung the roof without staining it first, finish the ceiling in the method suggested in the tips section. Then you'll have to touch up the unstained portions of the tongue as they become exposed over time.
Follow the safety guide printed on the side of the ladder to avoid injury due to falls.