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tonyc56
Is pre drilling cement board siding required

do you have to pre drill cement board siding prior to installing a lag screw. If you don't pre drill what would happen.

MLB Construction
Re: Is pre drilling cement board siding required

installing a lag screw in almost anything requires predrilling. if you're "nailing" up cement board siding the answer is no, it does not have to be predrilled.

jkirk
Re: Is pre drilling cement board siding required

if your gun nailing no it doesnt need to be pre drilled.. if your hand nailing you have to pre drill at the ends otherwise it will shatter

Fencepost
Re: Is pre drilling cement board siding required

Since you're installing lag screws, you really want the screws to be biting into the wood behind the siding, since the siding itself isn't going to have the structural integrity to hold any weight by itself. So yes, you should predrill through the siding. The pilot hole through the siding should be equal to the outer diameter of the screw threads; the pilot hole in the wood behind should be equal to the inner diameter of the threads (or slightly smaller). Failing to at least predrill the siding could cause a blowout of the fiber cement product.

tonyc56
Re: Is pre drilling cement board siding required

All,

Thank you...One more question should i use a masonry drill bit.

MLB Construction
Re: Is pre drilling cement board siding required

yes, into the cement board.....no for the house sheathing

jkirk
Re: Is pre drilling cement board siding required

if you can find a store that sells cheap bulk drill bits those will work fine too. 1/8 " is what i use

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