Soundproofing ceiling/internal floors from the top instead.

[Patrick]

Had this idea and wondering if anybody did this.

To insulate the first floor from the top instead of struggling with overhead pushing rock wool between joists and then putting plasterboard on.

 

The problem most of the times is that there is a ready installed subfloor (e. G. Tongue and groove chipwood boards) in place which is nailed/screwed and glued down long before any sound insulation is done inbetween floors.

 

So it's not practical to go from the top.

 

However

 

The installation of insulation (maybe even loose, like cellulose) from the top, after the 1st fix electrics, plumbing.... Is done and plasterboard is installed to the ceilings, would be a lot less messy quicker and therefore maybe cheaper then fiddling rock wool or similar from the bottom.

 

If you would put down large 2400x1200 plywood or osb sheets as a 1st floor subfloor without attaching them too much (just 3-6screws/board)  in order to have a working platform while building.

 

When all mvhr/electric/plumbing in the floor is done and it s sealed from the bottom with plasterboard, unscrew the boards, lift Row by row and stuff cellulose or loose eps (or whatever you fancy) down the void.

Maybe even go a few mm higher then the Joists so by putting the osb/plywood  back down you're compressing the insualtion a fair bit.

Then attach the osb/plywood as usual with nails/screws and glue to the joists to finish the subfloor.

 

A bit more work in laying the first floor  boards, specially can see that as an issue if using the small chipwood t&g subfloor boards.

But should be a lot quicker and easier to put insulation in.

 

As always... Overcomplicating things.

 

Or has anyone tried anything like this?

Experience with it?

 

 

[nod]

We are fitting out a new build that’s been stood for tens years 48 apartments and houses We’ve done all the soundproofing to the ceilings 

But as an extra measure we are laying 1200 x 400 timber boards with 15 mil of insulation on the back 

On top of the existing caba board 

Absolutely brilliant for foot traffic 

Simply gluing the joints and the underside 

[joe90]

I like the idea, as someone who wishes they had more sound insulation between floors ? I may have considered it but we have some stud partition walls that went on top of the chipboard!!!. Ours was done by a building contractor so not involved at that time, mores the pity. I would deffo recommend more sound insulation than standard regs. 

[Patrick]

1 minute ago, joe90 said:

I like the idea, as someone who wishes they had more sound insulation between floors ? I may have considered it but we have some stud partition walls that went on top of the chipboard!!!. . 

A really good point. This would stop a few people doing it.

[joe90]

I wish I had double boarded the dealings and/or used sound resilient bars.

Edited December 14, 2019 by joe90

[Cpd]

I put up a vcl under my floor joists and then two layers of normal plaster board ......... and then another of acoustic plasterboard ! I then from above put in 3 layers of insulation with various acoustic properties and left a 50mm air gap between the top of the insulation and the 22mm chip board flooring which was glued and screwed. The plasterboard joints were all sealed with acoustic mastic and all laid with off set joints.  I still have final floor coverings to add and the stairs to build so can’t comment on how it’s going to perform but feel I have done enough ! Once the stairs are in and various doors installed I will be able to see how it works and then add additional soundproofing on top of the chip board if required. 

[Mr Punter]

I have used acoustic overlay boards called ScreedBoard 28 for a flat conversion.  They were a cement type t&g with a soft backing. Worked very well but were very expensive.

[Patrick]

36 minutes ago, Cpd said:

 ! I then from above put in 3 layers of insulation with various acoustic properties and left a 50mm air gap between the top of the insulation and the 22mm chip board flooring which was glued and screwed

How was that all done. Did you have a temporary floor to work on the 1st floor or did you lay the chipboard and removed it again in order to access to Insulate?

[Cpd]

1 minute ago, Patrick said:

How was that all done.

First laid old shuttering ply and whatever I could find until watertight and then laid loose chip board until I was ready to insulate. Floor down now and stud work for room division to be done next. All services  and joist centres marked on floor surface to prevent and accidents.

[Moonshine]

2 hours ago, joe90 said:

I ?would deffo recommend more sound insulation than standard regs. 

 

So would I, building regs minimum arent good at all. 

For internal walls volume builders for minimum, but are going for something more substantial for party walls and floors.

[Moonshine]

On 14/12/2019 at 17:47, Mr Punter said:

I have used acoustic overlay boards called ScreedBoard 28 for a flat conversion.  They were a cement type t&g with a soft backing. Worked very well but were very expensive.

 

Maybe have a look at a chipboard alternative, such JCW acoustic deck or similar 

The acoustic performance (impact) isn't as good as screedboard but still gives a step change in performance.

I tested a conversion with party floors on Thursday (which I provided advice for) using that type of product with insulation, res bars and 2 X 15mm SoundBloc, that got airborne (DnTw + Ctr) 50 dB and impact (Lntw) 51 dB.

Needless to say client was very happy with that.

[willbish]

Continuing on with @Patrick idea of sound insulation from above the joists.
How about cutting ~100m holes into the chipboard and filling with EPS beads?
How frequent would the holes have to be to get a decent fill?
But can you imagine how annoying that would be when you inevitably have to cut a hole in the ceiling a few years down the line... 

[joe90]

12 hours ago, willbish said:

filling with EPS beads?

 

Would electric cables in the floor void be a problem with the insulation?

[ADLIan]

Also EPS, board or beads, is not used for acoustic insulation.