[Bormanko]

Hi, I need to cut a 6*4 hole in one of my 2*10 metal joists, to be able to run a vent duct from my bathroom light/fan to the main duct. Do I need to reinforce the joist? if yes - how? Can I do it at all?
Thank you very much, I appreciate your help
Bormanko

 

[Termite]

The biggest hole you can cut in a 2x10 joist is about 3", and it has to be pretty much centered. 1/3 the depth of the joist is the maximum hole diameter. Anything more will structurally compromise the joist and would need to be designed by an engineer. There is no legal or prescriptive method for cutting such a big hole in a joist without engineering support and documentation. :no:

EDIT!!!!!!!!!!! Didn't realize we were talking about metal joists. Sorry for the confusion...Disregard this post.

 

[gregzoll]

You basically go either above the support beam, or below it with the duct. You can't cut it, or it will fail.

 

[Gary in WA]

Picture would help....

Gary

 

[proremodel]

What you can do is not run that big of a hole for a vent in a bathroom lol. You can run a 4in (hardpipe) to a 3in (hardpipe) threw the 2x10 then back to 4in to the main. A 6x4 is like a HVAC line. Is that what you mean?

 

[Joe Carola]

Hi, I need to cut a 6*4 hole in one of my 2*10 metal joists, to be able to run a vent duct from my bathroom light/fan to the main duct. Do I need to reinforce the joist? if yes - how? Can I do it at all?
Thank you very much, I appreciate your help
Bormanko

What's are metal joists?

 

[proremodel]

Joe I have seen in one house in my life in California they did everything out of metal. Walls 2nd floor joists and roof rafters in metal. Was interesting to say the least. It was the most quite job site I have ever been too lol. The joist I saw were just like wood, same size and full box but hollow core.

 

[Bormanko]

Im trying to instal light/fan component on my ceiling, and the fan has 6in exhaust pipe coming out. the space is limited. my main duct is behind one metal joist, so i'd like to cut that joist 6*4 to pull a flex duct through the joist. i would go under, but i can not. can i cut it and reinforce the joist? thanks

What you can do is not run that big of a hole for a vent in a bathroom lol. You can run a 4in (hardpipe) to a 3in (hardpipe) threw the 2x10 then back to 4in to the main. A 6x4 is like a HVAC line. Is that what you mean?

 

[Bormanko]

hi ,
the ceiling joist I have in my ceiling are 2*10 metal U joist

Joe I have seen in one house in my life in California they did everything out of metal. Walls 2nd floor joists and roof rafters in metal. Was interesting to say the least. It was the most quite job site I have ever been too lol. The joist I saw were just like wood, same size and full box but hollow core.

 

[proremodel]

Ok so I would really say get a reducer and make it a 3in pipe. No need for a 6in pipe on a vent fan unless your bathroom is the size of a 2 car garage. Then you can cut threw the joist. Also do not cut a square hole what ever you do. Make it round even if that means you go by the 15 dollar hole saw bit.

 

[Bormanko]

thank you very much. i will get the reducer. i might still reinforce the joist. thanks a lot

Ok so I would really say get a reducer and make it a 3in pipe. No need for a 6in pipe on a vent fan unless your bathroom is the size of a 2 car garage. Then you can cut threw the joist. Also do not cut a square hole what ever you do. Make it round even if that means you go by the 15 dollar hole saw bit.

 

[proremodel]

If you can post pics for us to see this setup before you drill please.

 

[Bormanko]

well the hole is there premade, its used to run electrical wires, the hole is size of 4*3. so i'm going to use the same hole, i just off center the light/fan instalation, use the reducer and i might not cut the hole at hole. I just hope it will be sufficient. thanks

If you can post pics for us to see this setup before you drill please.

 

[proremodel]

you don't have to off center anything grab a elbow or 2 of hardpipe or even flex pipe and bend it from the start point threw the hole you will be fine. Set the fan up were ya want.

 

[Termite]

WHOA! I read your post incorrectly and missed the part about the joists being light gauge steel. I hate those darn things!

We rarely see them around here so I don't have the boring allowances committed to memory but I'm thinking that you cannot do much more than you can do to wood to them, if anything at all. There is a manufacturers association for light gauge steel framing member manufacturers and I'm betting they have their prescriptive methods for cutting holes posted online. Can't think of their name off the top of my head unfortunately. The last time I inspected them in a home, the manufacturer did not allow any cutting of holes, as there was a fairly large rolled opening every three or four feet.

 

[Bormanko]

I am going to use one of those holes to go with. I think, if I use reducer and elbow it should work. Thank you very much, I appreciate it

WHOA! I read your post incorrectly and missed the part about the joists being light gauge steel. I hate those darn things!

We rarely see them around here so I don't have the boring allowances committed to memory but I'm thinking that you cannot do much more than you can do to wood to them, if anything at all. There is a manufacturers association for light gauge steel framing member manufacturers and I'm betting they have their prescriptive methods for cutting holes posted online. Can't think of their name off the top of my head unfortunately. The last time I inspected them in a home, the manufacturer did not allow any cutting of holes, as there was a fairly large rolled opening every three or four feet.

 

[Bormanko]

I will do it like that, Thank you very much for your help

you don't have to off center anything grab a elbow or 2 of hardpipe or even flex pipe and bend it from the start point threw the hole you will be fine. Set the fan up were ya want.