How to pre-drill?

[GJO]

Hello!
I have two questions regarding pre-drilling in wood and other materials. What are the dimensions for how large the drill hole should be compared to the screw you then want to attach in the wood? Is there a good rule of thumb?

I am planning a small project where I need to fasten wood to a concrete wall. Can I drill straight into the wood and then into the concrete wall (meaning: do both at the same time) or should I do each separately?

Thankful for your response.

 

[SBH]

what are you going to attach?
if it is a framework with nail plug or similar, you drill everything at the same time

 

[GJO]

OK, yes, it's a rule that needs to be put up.

 

[SBH]

then I would just drill and drive in spikplugg.

 

[fahlis]

then I would just drill and insert nail plug.

Or an expansion nail …

 

[GJO]

OK, Thank you for the answers!

But how does it work with pre-drilling if you need to attach one beam to another beam? How much smaller should the drill hole be compared to the screw that will attach the two beams?

 

[SBH]

OK, Thanks for the answers!

But how does pre-drilling work if you want to attach one beam to another? How much smaller should the drill hole be compared to the screw that will fasten the two beams together?

If they are at least 45*45, I wouldn't pre-drill there. (depending on what type of screw you have)


some reading
http://www.dinbyggare.se/communicate/artiklar/article.aspx?id=5271
http://www.bosch-do-it.com/se/sv/go...ndningstips/skruva-och-borra-i-trae-98726.jsp
http://www.svenskttra.se/om_tra_1/forbandstyper/spik-och-skruv

 

[Tune]

But how does pre-drilling work if you are going to attach one beam to another beam? How much smaller should the drill hole be compared to the screw that will fasten the two beams?

Then you use screws with some form of drill tip that don't need pre-drilling.
If you want to be more sure that it doesn't crack, then pre-drill with a diameter that matches the screw without threads.