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Discussion Starter · #1 ·
Ok, I will be floor mounting my new G70. Problem is, the floor in my theater is concrete and I don't have the ceiling height to construct a raised floor.


So that I can hide the cables, I want to run PVC tubing in the concrete floor.

So... How do I go about cutting a 12' long 3" wide 3" deep channel in the concrete floor? Is there any way I can accomplish this without using a water cooled diamond tipped blade? Once I get the channel cut and pvc installed, what type of cement should I use to fill in the gaps?


thx!

Mark
 

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I would do a wet concrete saw for that distance. Your other choice is a jackhammer and you won't be staying 3" wide.
 

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FYI


I watched one of my contractors cut my cement slab in my bathroom with a diamond blade in a worm drive skill saw. The two cuts were side by side over 15 feet long, about 6 inches apart. He then used a sledge hammer to break up the cement between the cuts. This was done to re-route my drain pipes.


It blew me away how fast he made the cuts (no water used). Be sure and wear a mask and eye protection (lots of dust).


I was so impressed by the worm drive saw I bought one and used it to do much of the internal construction in my HT (e.g. raised floor, stage, columns, etc.).


Good luck
 

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yipes, what about power? you may need two channels 6-8" apart running parallel.


for an easier cut, although I'm not sure they have or do this. You might consider rigging the wetsaw for two 45 degree cuts that form a v bottom groove. otherwise your going to have to chip or take multiple passes at the channel. Also, I wouldn't cover it with concrete once done, I would see about a wooden or metal slat that has two opposing 45's that wedge into the v and leave some space at the bottom. That way you will have access in the future...
 

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You can get a 7" dry cut blade for a regular circular saw about $100 but it may not get you the depth you need to cut through your concrete slab. You can rent a 10" dry cutoff saw. It will give you the depth you need. Big problem with the dry cut saws is the dust.

To fill the hole you can use a regular concrete mix if you have over 3" over the conduit or better use a concrete repair mortar.

Ps.

You are cutting concrete not cement. Cement is the powder you mix with the sand and aggregate to make concrete.
 

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Discussion Starter · #6 ·
Thanks to everyone for the replys so far. Sound like the worm drive saw might be the way to go. There are a few people around my work that had the same repsonse.


Mark
 

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Quote:
Originally posted by mhaaksma
Thanks to everyone for the replys so far. Sound like the worm drive saw might be the way to go. There are a few people around my work that had the same repsonse.

Mark
I cut my driveway in half to remove a broken section. I went to Home Depot and bought the cheapest Skil saw there $39, and a $40 diamond blade. I figured the saw would be disposable, and there was no way I would abuse my nice Porter-Cable saw on concrete.

I filled a squirt bottle with water and used that to keep the dust under control, and the blade somewhat cool. It was still a dusty dirty job, but the blade held up.

I started with a score cut about 1/4 deep along the 10 feet or so, mainly just to follow the snap chalk line. I passed through about 2 or 3 more times until I had the saw at max depth of about 3 inches. I didn't make it all the way through, but that was plenty. A bobcat mounted jackahammer did the rest.

For you I would recommend a rental jackhammer, about $50/day. If you are in shape, and I mean athletic shape, you can try the sledge, but I couldn't hack it for more than 30 minutes. That's hard labor! ;)

The blade and saw are still in service, and have since cut through probably 100' of stucco when it came time to demo the back half of my house. (hint, a 4' x 4' slab of stucco from the side of a house is heavier than you think)

Also, you should really find out what is inside or under that floor before doing anything. It would not be fun finding a drain pipe via jackhammer.

Good Luck

-Bill
 

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Well, from a guy who has been involved in a LOT of concrete cutting for his theater I can tell you there is NO beter way than a wet saw. The water's benefit is in keeping the dust down. You think drywall dust is bad?? Try conctere dust. Far more caustic and dangerous.


Why in the world would anyone allow that amount of dust in their house?? Use a wet saw...tiny amount of water and be done with it.


Ted
 

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Discussion Starter · #9 ·
Ok, well the dust I'm not really worried about, my theater is located under the garage in a concrete bunker (walls, floor, ceiling). All I have to do is seal off the door and that'll keep any dust out of the house.


Since there is no drain in this room, I was more concerned about cleaning up the water. It sounds like there won't be much perhaps it would just be best to rent a water cooled concrete saw and have a friend standing by with the shop vac sucking up the water. Anyone have any approx idea how much it costs to rent one of these things?


I've verified there isn't any drains under the floor (the people who built my house left me with all the blueprints, plans, etc!). So I guess the next thing to do is lug my G70 downstairs and make sure I've got the right distance from screen.


thx!

Mark
 

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Not to sound like Bob Villa here, but in addition to your eye protection, buy a good $10-$20 dust mask (not the cheap all paper one, but one with a rubber gasket that seals your face). Concrete dust is very fine and has alot of lime in it, and it is caustic (alkaline). If you work with it all day, your hands will be dry and raw, so imagine what your lungs will look like.

Good Luck,

-Bill
 

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I've cut alot of concrete in my time and can say that the wet saw is the way to go. I rented the big one from HD, cost about $70 CND in total. Took me about 30 minutes to cut a 4' square hole. The concrete should be 3 to 4" thick and will break up with a sledgehammer once you've cut through.


Another thing, the amount of water that comes out of the saw is less than you think. A few towels on the floor should be all you need to keep it in check.


Check out the construction pics in my sig, I have pics of the saw I used.


Wes
 
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