How to drill a hole in a overhead feature beam?

[Zippo01]

Hi Members, I have a cathedral ceiling in the games room of my house, I wish to add extra lighting by way of two hanging pendant lights. One at each end of the beam. The beam is large measuring 38cm in depth(height) by 8cm in width.  I need to drill a 10mm hole using a electric hand held drill, standing under the beam and drilling overhead. I purchased what I believe to be the correct drilling auger bit, but how am I to drill precisely 38 cm directly through the beam without drilling askew and ruining the beam?  The beam already has a lighted ceiling fan at the midpoint of the beam .I want to feed the wires up through the beam hiding them along the top  edge of the beam and using the existing fan for  the electrical connection. I have attached an image of the beam. Any help or ideas would be much appreciated. Cheers Greg

[Dave-1]

Good Evening @Zippo01 

I have had the same sort of issue when I was drilling posts for my privacy screen, There is an easy way to do it

First lay your hands on a piece of timber the same width as your beam (8cm) Maybe an old fence post or something along those lines.

Then drill through the center of it where you want the hole to be in your beam (as if the spare piece of wood is sitting against the beam.

Now source a fence pailing or a pice of timber that is thin but wide. Cut it at around the 36cm mark. Make two of them

Screw these two pieces either side of your spare "block with hole" making sure the screws doint go through your drilled hole.

This is your "Jig" that will slip under the beam, the predrilled hole will be straight and will keep the drill bit straight as you drill up through your beam. Once you have sunk the drill as far as it will go, remove the jig and continue as the hole will now hold the drill in place. Take your time, no need to force the drill bit as it will want to eat away at the hole. Remove the drill bit freaquently from the hole so the chafe can come out also. It stops the drill bit getting too hot.

Please wear saftey goggles, take it from me a piece of sawdust is faster then a blink and hurts! Make sure they are the ones that seal against your face as you will be drilling upwards. Also make sure what you are standing on is solid and gives your body height to about your shoulder height level with the bottom of your beam. Lats one is to watch out for grabbing. The drill will want to catch and twist the body of the drill around, that also hurts. 

I was looking for my decking projects for the jig picture (think large upside down U) but couldnt find one. If you cant picture it I can draw a pic for you.

Dave

[MitchellMc]

Welcome to the Bunnings Workshop community @Zippo01. It's fantastic to have you join us, and many thanks for your question about drilling through a beam.

I see @Dave-1 has already provided a great suggestion on keeping that drill bit straight. I thought I'd point out that drilling vertically through a timber roof beam presents significant risks that must be carefully considered. Vertical drilling compromises the beam's structural integrity more severely than horizontal drilling by removing material across its entire thickness. This weakening can reduce the beam's load-bearing capacity and increase the risk of splitting along the grain, particularly if not aligned precisely. 

To mitigate these risks, it's crucial to consult a structural engineer or timber construction professional to assess the proposed drilling and implement appropriate measures, such as pilot holes or reinforcement techniques, to maintain the beam's structural integrity and ensure the safety of the structure.

Please let me know us you have any questions.

Mitchell
 

[Zippo01]

Hi, 

 I didn't think a 10mm, hole in such a large beam would compromise the integrity of the beam. The beam already has a ceiling fan attached ,long before we purchased the house, its wiring goes up through the center of the beam . I haven't investigated the hole size that the wire are fed through I guess its probably not too large. If you believe there is some risk, maybe my electrician friend who I am using to wire the new lights may have an opinion.  

    Thanks for your input. Regards Greg.

[Zippo01]

Hi Dave, 

             Can you post an image or photo of the drilling jig you mentioned, to give me a better idea.  

                                                                             Regards Greg.

[EricL]

Hi @Zippo01 

Just to add to the suggestions made, I propose installing installation boxes onto the side of the beam instead of drilling into it. From where you are standing it will not be visible and will only be seen from the other side. But if the boxes are painted in the same finish as the beam, then it will not be very obvious.

My only other thoughts regarding your beam is that it might be hardwood and it would be like drilling into steel. Attaching an installation box would be infinitely easier and save you from having to drill into the structure of the beam.

If you need further assistance, please let us know.

Eric

 

[Dave-1]

Afternoon @Zippo01 

Will see if I can find them this weekend. It is definently worth noting what @EricL has said about the structual effect. I do like the workaround solution he has suggested. In my garage I drilled horizontaly through my beams and placed teh cabling on the far side where it wasnt obvious to the eye. If you went to the other side of the room and looked up you can see it but it works with the look I was going for.

Will check my scrap heap or lay out an example of what I mean for you this weekend.

Dave

[Dave-1]

Howdy @Zippo01 (aka Greg)

I forgot a couple of days Sorry 😕  

So here they are  

Top down my hole drill guide for beams (this one is prob fairly old)

The horizontal piece of timber is just a example to show how the guide sits over a beam

End on view. The Upside down U is sitting straddling the beam.

The two sides slip up eaither side of your beam, holding the guide in place as you drill.

I had three guides (cant rem why lol) This little jig really helped me out drilling straight holes through hardwood beams. 

I would keep in mind @MitchellMc's valid concens. 

And wrap around goggles are a must (Says I after a trip to the docs and wearing a patch for a day)

Dave