Insulating basement ceiling

[supton]

Working on a room in the basement which will have a drop ceiling with acoustical tiles. Is there value in putting insulation into the ceiling joist above it, for noise absorption from the room above it? I don't see how I would have issues with moisture, just not sure on the value. [I would use the unfaced insulation meant for noise absorption, that is what I've been putting into the walls.] The insulation would be in the joists and not on the tiles.

Basement is pretty echo-y and noise travels from the first floor straight down (and vice versa).

 

[Donald]

You want to seal and insulate the rim joist. The insulation between floors will do little if anything. Maybe sound abatement.

 

[supton]

Seal as in how? Not sure what is being sealed.

But the whole point would be noise abatement. Soundproof may be impossible but every dB of noise reduction between floors would be nice.

 

[MrHorspwer]

Insulating floor joists for sound absorption is super common.

You'll want to use a mineral wool insulation batt, not fiberglass. Rockwool is a common brand.

 

[Donald]

There is air leakage and heat loss at the rim joist. Old times people would stuff in a 1 foot piece of fiberglass in the rim joist. That did not do a lot. So the newer and better way is to spray in 2" of foam which will seal and insulate or caulk the seams and use a piece of 2" foam board as insulation.

 

[supton]

Insulating floor joists for sound absorption is super common.

You'll want to use a mineral wool insulation batt, not fiberglass. Rockwool is a common brand.

not sure if it is rockwool but it's something like that.

For the want of one more foot in basement height... I wish I had made the walls taller, but the darn waste pipe got in my way.

 

[Donald]

not sure if it is rockwool but it's something like that.

For the want of one more foot in basement height... I wish I had made the walls taller, but the darn waste pipe got in my way.

View attachment 27414

Better to have the waste pipe in your way than some idiot plumber cut away sections of floor joists.

 

[supton]

Better to have the waste pipe in your way than some idiot plumber cut away sections of floor joists.

True. Once we got into this project, we were like, ???? For a few more dollars they could have run the PVC around the basement, avoided the center like this. Well maybe, we weren't there when decisions were made.

In the end, that wall in the pic, the pipe is at exactly 7'. And as the pipe goes to the left it's obviously lower. No way to finish the basement, so it gets used & enjoyed for what it is. Wife is tired of looking at my office upstairs, where I set up shop in the living room. Ergo, fast office in the basement, where I can heat it to office temps in the winter easily, and not care about not meeting any requirements for living space (>7' ceilings and all that).

 

[RhondaHonda]

Did you put carpet down in the “finished” part? That would help the most with any echo you get. If you are putting a drop ceiling on the room that you framed I don’t think insulating just that will do much. If you put open faced insulation in all the joists it will definitely cut down on the echo as you are eliminating reflective surfaces but you’ll still hear people walking on hardwood floors above you in hard soled shoes.

I have a basement home theater and I used Roxul in the walls and ceiling of the home theater. My kitchen and family room are directly above the home theater and have hardwood floors and you better believe I can hear my MIL stomping around in heels or boots when she’s over.

 

[JTK]

One of the issues I have on the finished side of our basement that has a drop ceiling is, if anything gets spilled on the floor above, it can leak through. If you have insulation stuffed between the joists, it could get wet.

Case in point, my little guy dropped a gallon jug of whole milk on the ceramic tile kitchen floor while helping mom unload groceries. The jug exploded onto the floor loosing better than half it contents. The tile stops at the base cabinets and peninsula, so what ever got over the edge poured onto the drop ceiling below in the basement and pooled on the plastic lense of a 2x4 light. Ugh..

 

[hemitom]

We have a bedroom in the basement and one directly above it the ceiling is dry walled with no insulation , if someone is in the room on either floor you hear everything , i would insulate that ceiling !! use the same stuff you have on the walls.

 

[supton]

Did you put carpet down in the “finished” part? That would help the most with any echo you get. If you are putting a drop ceiling on the room that you framed I don’t think insulating just that will do much. If you put open faced insulation in all the joists it will definitely cut down on the echo as you are eliminating reflective surfaces but you’ll still hear people walking on hardwood floors above you in hard soled shoes.

I have a basement home theater and I used Roxul in the walls and ceiling of the home theater. My kitchen and family room are directly above the home theater and have hardwood floors and you better believe I can hear my MIL stomping around in heels or boots when she’s over.

No carpet, in or out outside of the finished bits. The bulk of the floor has been getting some cheapo laminate though. With throw rugs being tossed on here and there.

It's weird, my old house had a layer of planking, then I think plywood, then hardwood flooring--and noise just didn't go through the floor. This house is just plywood and boy does everything go through!

One of the issues I have on the finished side of our basement that has a drop ceiling is, if anything gets spilled on the floor above, it can leak through. If you have insulation stuffed between the joists, it could get wet.

Case in point, my little guy dropped a gallon jug of whole milk on the ceramic tile kitchen floor while helping mom unload groceries. The jug exploded onto the floor loosing better than half it contents. The tile stops at the base cabinets and peninsula, so what ever got over the edge poured onto the drop ceiling below in the basement and pooled on the plastic lense of a 2x4 light. Ugh..

That is a great point. This office is right under the kitchen, close to a bath, so there is a good argument for not closing it up like that. That was part of the reason why I didn't want to finish the basement in the first place (that and it's too shallow, and no second door for ingress/egress). I've been trying to avoid any and all utilities. Just in case. The unfinished areas are turning into hallways and storage areas.

 

[JC1]

not sure if it is rockwool but it's something like that.

For the want of one more foot in basement height... I wish I had made the walls taller, but the darn waste pipe got in my way.

View attachment 27414

Yes Rockwool is what you should use. Roxul is the most common brand. That brand of insulation can get wet and will not fall apart. I used Roxul, Safe and sound in my basement along with resilient channel on my basement ceiling that was drywalled. You can make a lot of noise in the basement and not much travels upstairs. More sound comes from the door to the basement in my house.

That waste pipe is a real eyesore. Are you putting something around that part? I might go for the Faux beam look and paint it to look like an old wood beam. I think they even have faux beams that are made of foam and are like a U which could cover 2x4s. In your case you'd make some sort of cleat/bracket attached to the joists which could be used to hide that pipe with the faux beam attached to that structure.

As Donald mentioned, sealing of the rim joist is to keep the cool air out of your house. Most leaks in houses are from this area where the foundation meetings the sill plate of the first floor of the house. In my house, I used low expansion spray foam and sprayed it into that spot around the entire basement. I also sprayed some of the joist bays to keep the leaks out. Makes a huge difference.

 

[supton]

The office is not attached to any wall. The open space between the room and wall will be used for storage. Rim joists are already insulated. No worries there.

We'd love to do something with that pipe, but the major area that it sits is out in the dance studio portion--wife and daughter are big into dance, and what with everything closed, daughter is doing online classes. Wife says she keeps hitting that pipe as it is, so doing anything to change its intrusion is out of the question. Out in the dance studio portion. [The room in this picture is the wife's sewing room, which as at the other end of the basement.]

But inside my office I will put in a drop ceiling to hide it, and to make it look more like an office. 6'8" (80") is kinda short in the scheme of things, but it's just a home office. Only so much one can do, with the space and constraints given.

Wasn't until we had it framed that I realized I wish I had made it a foot shorter. It intrudes a bit too much into my wood workshop area I think. Oh well, live and learn. If I use the office 8-10-12 hours a day going forward for the 4 months (the expected duration of WFH) or indefinitely (anybody got a crystal ball?) then I might prefer the bigger office. [This wall on the right I think will get plywood, or pegboard, not sure which yet.]

 

[philipp10]

No carpet, in or out outside of the finished bits. The bulk of the floor has been getting some cheapo laminate though. With throw rugs being tossed on here and there.

It's weird, my old house had a layer of planking, then I think plywood, then hardwood flooring--and noise just didn't go through the floor. This house is just plywood and boy does everything go through!


That is a great point. This office is right under the kitchen, close to a bath, so there is a good argument for not closing it up like that. That was part of the reason why I didn't want to finish the basement in the first place (that and it's too shallow, and no second door for ingress/egress). I've been trying to avoid any and all utilities. Just in case. The unfinished areas are turning into hallways and storage areas.

I have an older home in which I added a bath in the basement, no insulation. I don't hear a sound from that room ever. Must be a new house thing and how they are built....

 

[alarmguy]

Absolutely, putting unfaced fiberglass insulation between any floor or interior walls is a great method for reducing noise.
Many high end homes automatically have this done by good builders.