Drill through cinder block or mortar?
- Thread starter dlundblad
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Block
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Definitely drill through the block
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Why?
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Originally Posted by E150GT
Why?
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Block. Drilling through a block with I assume the correct bit so as not to cause a blowout on the backside; should leave the block structurally sounder than if you were to take a 3/4" hole or thereabouts out of the mortar ans surrounding block. I don't know for sure but highly doubt your block has anything more than 1/2 joints. Guessing your piping is 1/2" so you'd be drilling through some of the cornerstone of the block as opposed to a more center portion.
Think of a hole in the center of a 2x4 or a hole taking out a piece of the edge of a 2x4. What would be stronger under load? The 2x4 drilled in the center by far.
Drill thru block. These days it is common to fill block with concrete. Be advised this will take a few extra min to drill with hammer drill.
Do not drill thu mortar, the mortar is softer than the block. You can lift a block and break the mortar. Also some code require rewire in the mortar That will add to the fun of drilling.
Rod
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And don't drill through the middle of the block! That is where the WEB is. Most block are partitioned in the middle with solid concrete web, go off center from that, by about a third, there will be two voids, one on either side of the center web. Try to hit that area and your job will be easier.
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Originally Posted by JohnG
And don't drill through the middle of the block! That is where the WEB is. Most block are partitioned in the middle with solid concrete web, go off center from that, by about a third, there will be two voids, one on either side of the center web. Try to hit that area and your job will be easier.
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Originally Posted by JohnG
And don't drill through the middle of the block! That is where the WEB is. Most block are partitioned in the middle with solid concrete web, go off center from that, by about a third, there will be two voids, one on either side of the center web. Try to hit that area and your job will be easier.
Thanks for the replies everyone. I have done the job before for a gas line, but this area had no block. The stoner at the rental place told me $15 for 4 hrs. Well, that was for the bit ONLY. Renting the actual hammer drill was an additional $35. I was done with it in less than 1 hr.
Had I known that, I would've entertained buying one seeing how I have all the jobs lined up for it. Like right now, I'll be spending another $50 so that's $100 that could've went to buying the tool.
Oh well.
https://www.harborfreight.com/power...e-speed-pro-rotary-hammer-kit-64288.html
Something like with. Home Depot has a 1-1/8"x18" masonry bit for $60. I'm assuming it's compatible? I'll have to see stuff in person.
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Block is typically solid filled at certain locations. These would be on either side of the windows and doors or above the lintel. These areas will also have a number 5 bar in the cell. Long walls without windows will have cells filled at intervals based on engineering for structural support. The cleanest and neatest drill through block to prevent blowout is both sides. Sometimes that doesn't work either. If you do it from one side be prepared to patch.
