How to Attach a Wooden Roof to a Cinder Block Building

Cinder block building are fitted with anchor bolts to allow for attachment of a wood roof.

However, the do-it-yourselfer can attach a wooden roof to cinder block, with little or no training, in one to two days, depending on the size and scope of the project.

1. Order cement grout from any cement supply company or mix your own. You will need enough grout to fill four blocks full, and 1/2 bag of Portland cement will pour approximately eight blocks. Mix cement grout by adding eight shovels of clean brick sand and 1/2 bag of Portland cement to a wheelbarrow. Combine the dry mix with a hoe and add three gallons of clean water. Combine the mixture until you have a pancake batter consistency. Shovel the mixture into a five-gallon bucket and pour the grout down into the cinder block core from the top of the wall.

2. Insert the 16-inch anchor bolts upright in the cement grout, beginning at one corner and spacing the bolts four feet apart along the top of the wall, leaving only two inches remaining above the grout and cinder block surface. Make sure that the anchor bolts are directly in the center of the cinder block core.

3. Cut a 2-by-8 six inches long to use as a template for the anchor bolt. Once the bolt has been inserted into the cement, slide the scrap 2-by-8 next to the anchor bolt to ensure that the bolt is straight and that it extends no more or no less than two inches above the cinder block surface.

4. Allow the cement to dry for 24 hours. Measure from one end of a treated 2-by-8 and place marks in the center every four feet. Drill one-inch holes through the 2-by-8 at the four-foot marks. Since the anchor bolts are 1/2-inch, the one-inch holes will give you some room to adjust the 2-by-8 if necessary. Place the 2-by-8 lumber flat on the top of the cinder block wall and onto the anchor bolts, inserting the bolts through the drilled holes.

5. Attach washers and nuts to the anchor bolts and tighten the bolts with an adjustable wrench. Attach the wooden roof to the anchored 2-by-8s by placing the pre-fabricated roofing members onto the 2-by-8 lumber.

6. Measure from one end of the 2-by-8 lumber and place pencil marks every 24 inches. Place the pre-fabricated roofing members on these center marks and drive 3-inch wood screws through the roof wood and into the 2-by-8 lumber that has been anchored to the cinder block wall.