Oak beams are large, solid-wood structural elements that are typically used in houses with open ceilings to create a rustic design theme. If you prefer a different look for your beams, or if the beams have become faded and grey, consider a fresh coat of paint to transform the structures.
Clean the oak beams. Dip an old rag in soapy water and wash all sides of the beams. Make sure to remove all dust, dirt, spider webs and any insects.
Place a dust sheet over the sections of floor that are underneath the beams. Remove all furniture from the area or cover it with plastic sheeting or more dust sheets.
Wear safety equipment as you work, including a hat. Coverings will protect you from paint spatter, which can be difficult to remove from skin and hair.
Use the paint sprayer or roller to prime each side of the oak beams. Take care when using a ladder to reach the beams. Use a paintbrush to apply the primer in narrow sections that the roller can't reach, such as in areas at the ends of the beams and around any objects hanging from the beams.
Wait one to two hours for the primer to dry, depending on the label's directions. Apply another coat of primer and wait for it to dry.
Apply the paint with the roller or sprayer. Allow each coat to dry for at least one hour before adding the next coat. Because oak wood can be dark in hue, it is likely that you will have to apply three coats of paint. Allow the paint to dry for 24 hours.
Plan to work in small blocks, in about 1.2 m by 1.2 m (4 feet by 4 feet) areas. This way, when your hands get tired, you can take a break and the paint job will not look uneven.