Sound Proofing/Insulating between first floor ceiling joists

krustytheclown

i recently got a quote to pump warmcel sound proofing/insulating material up between my ceiling joists in my new dormer style house.it is newspaper mulch and the rep assures me it is ideal for soundproofing which i feel is vital. it also insulates but i'm just wondering will too much insulation here prevent heat from rising up to my upstairs rooms from below.the price is also substantial so i am just wondering do people have any experience of this product and is it worth the expense?

shane6977

What types of sound do you want to reduce, airbourne, impact or both?

Insulating between the joists will only reduce airbourne sound and will do nothing for impact sounds. Also, you will still get some transmission of airbourne sound down through the ceiling structure. You really need to address both types of sound transmission to achieve an effective solution by isolating the floorboards from the joists below. There are several systems available for doing this and I can PM them to you if you are interested.

In regard to the heating issue, any insulation you install between floors will reduce the amount of heat transfer to the upper floor, it just means your heating system may have to work a little harder to heat the upstairs rooms!

joeirish

I just found this and wonder if I can resurrect.

I have rolls of insulation supplied by the timber frame company. How should this be fitted in between the ceiling joists. Does the plasterboard need to go up immediately to stop the batts falling down or will they support their own weight by friction? Also should I pack it in very tightly or loosely (depth wise I mean).

Thanks.

joeirish

Oh and another thing. Would it be a good idea to put on some sound insulation above the flooring that has been laid (OSB sheets). Planning to have carpets upstairs but maybe that won't be enough to dampen the sound.

Thanks again

mfceiling

joeirish wrote: »

Oh and another thing. Would it be a good idea to put on some sound insulation above the flooring that has been laid (OSB sheets). Planning to have carpets upstairs but maybe that won't be enough to dampen the sound.

Thanks again

Carpet isn't worth a fiddlers. Thin strips of rubber or cork might have been an option below the OSB - that is to have put it on the joists first.

http://www.gyproc.ie/products/plasterboards/gyproc-plank

^^ This on top of the OSB board might be an option? I saw it being used on a house we slabbed a couple of years ago.

joeirish

mfceiling wrote: »

Carpet isn't worth a fiddlers. Thin strips of rubber or cork might have been an option below the OSB - that is to have put it on the joists first.

http://www.gyproc.ie/products/plasterboards/gyproc-plank

^^ This on top of the OSB board might be an option? I saw it being used on a house we slabbed a couple of years ago.

What I mean is that we are carpeting the upstairs anyway. So do we need more sound insulation or will carpet and underlay do the job on dampening sound when we are walking around upstairs.

mfceiling

joeirish wrote: »

What I mean is that we are carpeting the upstairs anyway. So do we need more sound insulation or will carpet and underlay do the job on dampening sound when we are walking around upstairs.

Carpet and underlay will help slightly but don't expect miracles!! If you have kids banging around upstairs you will still hear them. We have timber joists with heavy underlay and carpet down...it's ok but not great, infact at the edge of our balcony the plaster at the corner bead is cracking where the kids have been bouncing above it.

joeirish

mfceiling wrote: »

Carpet and underlay will help slightly but don't expect miracles!! If you have kids banging around upstairs you will still hear them. We have timber joists with heavy underlay and carpet down...it's ok but not great, infact at the edge of our balcony the plaster at the corner bead is cracking where the kids have been bouncing above it.

No kids, just two older adults. So maybe not the type of problems you have. I don;t see us jumping up and down much

mfceiling

joeirish wrote: »

No kids, just two older adults. So maybe not the type of problems you have. I don;t see us jumping up and down much

Shouldn't be a problem for 2 older adults. Go easy on the jumping up and down!!

Calibos

DIY non expert here.

Inter-Joist Insulation material is necessary but in the grand scheme of things contributes very little to the sound reduction. Mass and filling all gaps or isolation and filling all gaps are the only truely effective solutions or so i've read. We bought my grand parents Victorian era house a few years ago and renovated. The back of the house which was an independence era addition had all floors removed to lower the ceiling heights to fit in an attic conversion. ie. Modern steel frame effectively with 9x2 timber joists. Plasterboard ceiling, rockwool between the joists, 20mm ply sub floors then carpet underlay and carpet on top. My bedroom is over the kitchen and I can hear everything and understand conversations etc.

Carpeted attic bedroom above me a few years later but before I did, I filled all plywood sub floor gaps and under skirting boards with caulk and expanding foam, tapped over and then laid the underlay and carpet. Amazing difference compared to my room over the kitchen, though can still hear voices or TV in the attic above on occasion, but cannot understand the conversation its muffled enough unlike from the kitchen below me.

Contrast the basically built from scratch modern internal interfloor structure of the back of the house with the front two thirds of the house with the old 10ft ceilings. Saw how they were constructed when old false ceilings were removed which hid old holed ceilings above which we restored. Looked like 1.5-2 inches of the old style plaster of paris on lathes nailed to the joists. ABove that was another inch or so of a 140 years of detritus that fell through the gaps in the floorboards. Then oak floorboards, underlay and carpet. Cannot hear a thing from the rooms below those rooms. I once blasted the THX Surround sound Intro at really high volume from our floorstanding speaker 5.1 system in the room below. Could barely hear it in the bedroom above and couldn't hear it at all when the TV in that bedroom was on at low volume.

Family circumstances changed and I plan to reconfigure the rooms and stud walls at the back of the house. It'd be too expensive to utilise the best sound isolation method which is double layer plasterboard with acoustic glue between layers hung from resilient channel from the joists. But I will be relaying the sub floor on the joist isolators and filling ever single gap on that floor before I carpet the new layout. Still haven't ruled out an inch or two of kiln dried sand between the joists though. The floors at that end of the house were over engineered from a loading perspective going on what I've read. Steel I beams all around perimeter and across the middle of the spans. Then 3 metre max 9x2 wooden joists at 16" centres between. My rationale is that if 7x1.5" joists spanning 4.5m in the old part of the house can hold a ceiling of 2 inch thick plaster of paris and detritus and huge old heavy hardwood wardrobes for 140 years, I can,t see a problem with 2 inches of sand at the back of the house. Obviously I'd consult an engineer first. Likely battening the sides of the joists and with a few noggins along the length with a 20mm marine ply resting on the battens/noggins between the joists. Then a water proof sheet membrane, 2 inches of kiln dried sand and sealed with another sheet, then joist isolators and subfloor and carpet on top. The mass of the sand plus the fact that each grain vibrates and converts sound vibration into heat would likely be very effective I imagine.

New build?? Concrete Floors

joeirish

Thanks Calibos, plenty to think about in your post. Unfortunately it is too late for us to put in concrete floors. Also we have a large double height void between the open plan downstairs and the largely open plan upstairs. So I'm just wondering how important sound insulation is between the joists? Also does anybody know if there are specific building regs on this and how sound insulation is measured.

Thanks

writhen

http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,1646,en.pdf

BryanF

http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,39956,en.pdf

joeirish

Eventually installed knauf omnifit insulation between joists. Incredible difference to the sound. As the job was partially done you could walk around the first floor and hear the difference between those areas that were insulated and those that were not. I would strongly recommend that anybody wanted sound insulation does the inter joist insulation regardless of whatever other sound insulation is being planned.

THE DON FANUCCI

joeirish wrote: »

Eventually installed knauf omnifit insulation between joists. Incredible difference to the sound. As the job was partially done you could walk around the first floor and hear the difference between those areas that were insulated and those that were not. I would strongly recommend that anybody wanted sound insulation does the inter joist insulation regardless of whatever other sound insulation is being planned.

is that insulation just sound insulation or for heat AND sound insulation??
what type floor have you on your timber joist for ur second floor

builder007

hello everyone. Has anyone actually put gyproc in their house. How does it feed on a day to day basis. Does it really make difference or is it a hype

BryanF

builder007 wrote: »

hello everyone. Has anyone actually put gyproc in their house. How does it feed on a day to day basis. Does it really make difference or is it a hype

Can you be more specific. 99% of the Country has some kind of gyproc in their house.

builder007

Hi Brian,

Thanks for your interest in this HUGE problem of mine.

Here's the detail.

1. The house has no sound insulation at the moment.
1.1 Solid pine wood T&N was laid on bare joists (no rubber strip)
1.2 There is no rockwool in the cavity between the joists

If possible at all I would like to avoid ripping solid pine planks (to put rubber and rockwool) but I'm worried that I will waste money and time if I don't do that.

My current thinking is to leave everything as and ADD the following:

1. Put some sound proof rubber membrane (6mm) and seal with acoustic tape the connections.
2. Put a layer of plywood or something similar
3. Put rubbery tiling underlay (acoustic)
4. Tile wood effect tiles

JOB DONE

Now, my worry is if this would be enough or not because there is no going back i.e. ripping the floor and putting rubber on joists and stuffing rockwool.


What do you think

builder007

here are the exact products that I have in mind

1. Sonic Gold Underlay 65kg 15x1mx5mm (15sqm roll)
2. 18MM Hardwood Faced Plywood 2440 X 1220MM
3. Sylcer for Ceramic Tiles
4. Wood Effect Tiles

Will this floor be silent enough?

builder007

Hi,

I've searched and read all threads on this topic (and there are many) but I'm still not sure about the validity of my approach with the challenge I have at the moment. Any help would be highly appreciated...

Here's the detail.

- The house has no sound insulation at the moment.
- Solid pine wood T&N was laid on bare joists (no rubber strip)
- There is no rockwool in the cavity between the joists

If possible at all I would like to avoid ripping solid pine planks (to put rubber and rockwool) but I'm worried that I will waste money and time if I don't do that.

My current thinking is to leave everything as is and ADD the following:

1. Put some sound proof rubber mat (6mm) and seal with acoustic tape the connections.
2. Put a layer of plywood or something similar on top of it (please suggest alternative)
3. Put another rubbery underlay for tiling (acoustic)
4. Tile with wood effect tiles

JOB DONE

Am I going to in the right direction with this approach?

listermint

What's wrong with carpet and underlay

builder007

Wood effect tiles must be the top layer. The other layers are there to minimise impact noise.

Lumen

This site is useful:

https://www.soundstop.co.uk/soundproofing_floors.php

I don't think Rockwool is going to do very much, but every bit helps I guess.

builder007

Yeah. That's what is hope for. It would be a waste of time and money if I had to rid of solid pine planks just to put something that will make no or little difference. It's the impact noise that I want to eliminate not airborne. And I think wool has nothing to do with impact nosie reduction

builder007

thanks for the link. very useful tips.