I would like to cut a 4 ft hole into my basements center support wall. This wall is cement block, and spans 40 ft down the center of my house. Above it are perpendicular floor beams that are 25 ft long. There is one doorway already cut towards the center of the wall, and that is 4 ft wide. I would like to cut another doorway closer to one of the sides, so I can access the other half of the basement easier. Will I need to put in floor jacks or a header of some kind? What is the best way to knock this block out? Are there any dangers to be aware of?

Thank You!

DC

The best way to make the opening if this is an unfinished basement is rent an electric concrete saw. Plastic in area. Use a pump sprayer with a buddy here and spray saw blade while you are cutting. Just enough water to keep dust down but not drown saw.

Or rent a demo/chipping hammer to make the openings. You need to temporally support the joist in front of the openings. Now remove the opening all the way to the house joist. In that area you should use concrete lintels for the door header then block up to plate.

No real dangers here as long as you temp brace/post the joist where the door is going.

I cut doors and windows opening all the time through out the year.

You can use a wooden header but I like to keep it masonry to masonry. Wood shrinks and you really can't mortar wood in to attach to block for a header. Plus it may be the fact I'm a mason and its just as easy to set a concrete lintel.