How to Cut a Cinder Block Wall

Cutting through cinder block is a dirty, messy and dusty job, but it's necessary for creating doorway, window or access openings in basements. Cinder blocks are made of concrete that has been molded in a factory. Cinder blocks have been used for many years for house and building foundations, especially crawlspaces. Cinder blocks range in size, but are typically 16 inches long, 6, 8, 10 or 12 inches wide and 8 inches tall.

Things You'll Need

• Tape measure
• Level
• Pencil
• Respirator mask
• Hose
• 14-inch concrete saw
• Sledge hammer
• Shop vacuum with dust filter

Instructions

1. 

   Level

   Mark the opening's length and width using a level to find a true and plumb area for the opening.

2. 

   Saw blade

   Put on your respirator mask and hook up the hose to the nearest faucet. Turn on the 14-inch-blade concrete saw and lightly move the blade along the pencil lines to score the pencil marks.

3. Turn on the hose to a light trickle and have a friend with a respirator on also hold the hose above one of the lines you are going to cut. Turn on a shop vacuum with a filter in it to pull dust out of the air while cutting. Turn on the saw and cut along the score marks you made, keeping the hose above the saw trickling along the wall to prevent dust from accumulating in the air. Cut as deep as the saw will cut. Make sure you turn the hose off when finished cutting. Keep the shop vacuum running for a few minutes after cutting.

4. 

   Large hammer

   Take your sledge hammer and hit the corners of the blocks you are removing. The blocks will break along the line you cut. pound out the remaining cinder block until you are left with the opening through the cinder block.

5. 

   Shop vacuum

   Clean up all of the cinder block pieces and discard them. Use the shop vacuum to suck up any settled dust from cutting the opening.

Tips & Warnings

• If you are cutting in an opening for a window or doorway, you might need to dig out the soil in this area before cutting the opening. The dirt in front and to the sides of the window or door will have to be supported by retaining walls.

• Cinder block walls often are load-bearing walls. You will need to install a header and jack studs to support the weight of this section of the structure. The larger the opening, the bigger the header will have to be. Headers should never be less than two 2-by-8 inch lumber nailed together.

• This project kicks out a lot of dust and can be very dangerous if respirator masks are not worn. If you feel at all dizzy or light-headed, stop working immediately and go outside for fresh air. Do not continue working until you are confident that your motor skills have not been compromised.

• Use caution when operating the concrete saw.

References

• Cinder block cutting
• Arcat
• Sunbelt Rentals

Resources

• National Concrete Masonry Association