What's the best drill bit for durock?

[brantmacga]

I've got to drill several 1/2" holes through durock (hard stucco) on top of OSB, through another sheet of OSB, then back through another layer of durock. What would be the best drill bit for this task? The cavity between the first durock/OSB layer and the second is 5 1/2".

 

[Dennis Alwon]

I've got to drill several 1/2" holes through durock (hard stucco) on top of OSB, through another sheet of OSB, then back through another layer of durock. What would be the best drill bit for this task? The cavity between the first durock/OSB layer and the second is 5 1/2".

A long masonry bit?

 

[nakulak]

a hammer .

 

[220/221]

How many is several?

If I had to do a crapload, I'd figure something else out. For several, I'd just use a paddle bit.

Run the drill backwards thru the first layer of Durock and it won't kill the blade. Drill forward thru the 1st layer of OSB and feel your way thru the second layer. Stop before you start to grind into the second layer of Durock and reverse the drill.

One problem will be aligning the holes perfectly. You can probably eyeball a few/several. If it's a lot, you will want to add a step to insure proper alignment.

Another thought. Use an 18" x 1/4" masonary bit for a pilot. Run it thru level (shouldn't be too difficult....put a level on it after the first hole). Then use the paddle/spade bit, reverse thru the Durock, forward thru the OSB. Go to the otehr side and do the same thing.

 

[ItsHot]

mason bit

mason bit

This is a piece of cake! Mason bit. You ever try drilling Trespa lab. counter top?

 

[220/221]

A 1/2 " mason bit will beat the heck out of the OSB.

Wait...1/2" holes or 1/2" IPS holes?? I was thinking IPS

A 1/2" bit will probably do it. A 7/8" is pretty big. It may work but it will blow the heck out of the back side.

 

[Pierre C Belarge]

I have not performed much field work in the last 7 years, but from way back in the deep recesses of my brain, I would answer...use someone elses drill bit(s).

 

[billdozier]

220 if you switch to a smaller bit like a 1/4 inch after drilling first hole. and use it as a pilot bit you can avoid major blow out. Then drill from other side

 

[brantmacga]

. . . . It may work but it will blow the heck out of the back side.

that is the issue i'm facing, and the reason for the question.


using a masonry bit will require me to force it through the osb, which could lead to a huge hole on the back.


does anyone know of a type of hole saw that works well on durock?


220/221, a paddle bit in reverse will make a clean hole through cement board? and will it do the job quickly?

 

[Dennis Alwon]

that is the issue i'm facing, and the reason for the question.


using a masonry bit will require me to force it through the osb, which could lead to a huge hole on the back.


does anyone know of a type of hole saw that works well on durock?


220/221, a paddle bit in reverse will make a clean hole through cement board? and will it do the job quickly?

Use a smaller masonry bit and don't put the drill on hammer- ease it thru gently.

 

[220/221]

220/221, a paddle bit in reverse will make a clean hole through cement board? and will it do the job quickly?

Yes and yes. The Durock is not very dense and will drill out easily but it will kill the bit in a heartbeat when drilling forward. A holesaw backwards will work nicely too and would make less of a mess since you are taking out less material.

 

[ItsHot]

carbide tip hole saw

carbide tip hole saw

Try a carbide tip hole saw. You can purchase various types for special cuts.

 

[nakulak]

sledge hammer

 

[Kdog76]

2 questions, is this durock a type of stucco? Also, never ran a hole saw or any drill backwards other then to get the bit out... What's the idea?

 

[ceb58]

does anyone know of a type of hole saw that works well on durock?

You can get the hole saw for tile, the type that has a carbide grit on it to drill the durock. You will then have the pilot hole marked for a regular bit for the osb.

 

[B4T]

I would first get a 1/4 x 12 inch masonary bit and drill a pilot hole through ALL layers. Then get a carbided tipped hole saw and drill V E R Y S L O W L Y throught all the layers. It works!!

 

[wawireguy]

Maybe something like this:

http://www.amazon.com/2pc-DIAMOND-HOLE-SAW-DRILL/dp/B000TYIWUW

??

 

[220/221]

is this durock a type of stucco? Also, never ran a hole saw or any drill backwards other then to get the bit out

Durock is a tile backer board made from cement type product bonded together by fiberglass mesh. It is generally 3x5 sheets, 1/2" thick and installs like drywall.

The teeth on bits of any kind are cut in one direction. When you run them backwards it will not dull them. It's a good trick for certain applications like asphalt shingles, drywall or Durock/Hardibacker. Anything than is easy to drill but full of abrasive material.

If you are driling thru the tile and the backer board, a carbide holesaw would be necessary but a few holes thru the board only will not require a special bit. If it doesn't have to be a clean hole you could make it with your least favorite screwdriver.

 

[brantmacga]

thanks for all those tips.


i know what i need now.

 

[iaov]

I have not performed much field work in the last 7 years, but from way back in the deep recesses of my brain, I would answer...use someone elses drill bit(s).

Excellent Pierre!!