OSB subfloor advice

Kildare787

Hi guys,

We have carpet on top of OSB board in our bedroom. The OSB appears to be screwed down to the joists below. Our living room is below our bedroom. We have significant sound transfer downstairs. Talking, walking opening drawers etc. All can be heard clearly from below. We also hear cracking/creaking noises from the OSB board when someone is walking in the bedroom. It's very distracting and annoying.

There is no sound insulation in the cavity between the joists. Have researched a specific rockwool sound insulation and want to go with that. Also want to add noggins between the joists for more support.

We have a skirting and large built in wardrobes so it's not practical to pull up the OSB boards from the very edges of the room.

We have had people look at it and it was suggested that it would be possible to cut around the perimeter of the room very close to the skirting/ in front of the built in wardrobes and essentially pull up a large section of the OSB to allow the carpenter to put the insulation in and push it in to the very edges also. He can then add noggins also.

He said he can then put the OSB back down like a jicksaw and secure it with more screws than were previously there.

We are wondering if anyone has experience of doing something like this? We are worried that when any part of the perimeter is stepped on it is going to move surely as it's been cut. Even if it's screwed down surely sagging is going to be inevitable in places? We can't see it turning out well, but then again we are not experienced with this type of thing.

Can anyone give some advice here if possible. Very much appreciated.

Calahonda52

a bit more work but if the cut edged are supported by say 3 by 2 between the joists and both edges of the cut screwed to it....
they dont need to be screwed to the joists, just have the OSB predrilled for the screws to make sure its good and tight

sky6

I done a job like this years ago to stop sound going both ways between Offices above and below.
I lifted the Floor Boards upstairs and I used proper sound insulation Batts 4 x 2 which came in a Bale of 6, I Cut them to size to suit the Rafters.
I had also used them previously. So new they would work.
I got them from Capco in Ballymount. They done a brilliant Job and you couldn't hear anything afterwards.
Before I'd put the OSB Boards back down I'd lay a Thin Felt underlay on top of the Rafters, to cut out squeaks between the Rafters and osb Boards.
Not Cheap but problem solved and everyone was very pleased working their.

Kildare787

sky6 wrote: »

I done a job like this years ago to stop sound going both ways between Offices above and below.
I lifted the Floor Boards upstairs and I used proper sound insulation Batts 4 x 2 which came in a Bale of 6, I Cut them to size to suit the Rafters.
I had also used them previously. So new they would work.
I got them from Capco in Ballymount. They done a brilliant Job and you couldn't hear anything afterwards.
Before I'd put the OSB Boards back down I'd lay a Thin Felt underlay on top of the Rafters, to cut out squeaks between the Rafters and osb Boards.
Not Cheap but problem solved and everyone was very pleased working their.

Are you available to do a job for me?

Kildare787

Calahonda52 wrote: »

a bit more work but if the cut edged are supported by say 3 by 2 between the joists and both edges of the cut screwed to it....
they dont need to be screwed to the joists, just have the OSB predrilled for the screws to make sure its good and tight

The 3x2s work have to go around the entire perimeter to fill in the gaps between the joists ye? Thanks for your input

Kildare787

sky6 wrote: »

I done a job like this years ago to stop sound going both ways between Offices above and below.
I lifted the Floor Boards upstairs and I used proper sound insulation Batts 4 x 2 which came in a Bale of 6, I Cut them to size to suit the Rafters.
I had also used them previously. So new they would work.
I got them from Capco in Ballymount. They done a brilliant Job and you couldn't hear anything afterwards.
Before I'd put the OSB Boards back down I'd lay a Thin Felt underlay on top of the Rafters, to cut out squeaks between the Rafters and osb Boards.
Not Cheap but problem solved and everyone was very pleased working their.

So would something like this do? Says for roof but a lot cheaper than flooring ones.Not sure if it would be useless haha. Thanks in advance.

https://www.screwfix.ie/p/protect-protect-a1-roofing-underlay-15-x-1m/31617?gclid=Cj0KCQiAmfmABhCHARIsACwPRACyodNhHMZ1L17ZZHajurXNxWCFVf5cQ67-la0mcarVeh4ns8bazEIaAlC0EALw_wcB&gclsrc=aw.ds

whizbang

No Good.

There is a black foam underlay for wood flooring available somewhere; (sorry i cant do better than that!)
I used strips of Torch-on roofing felt once. Bloody great job.

Sam Collie

https://www.boards.ie/discussion/comment/116189264#Comment_116189264

Just two questions if you see this thread;

Our floor boards are individual planks nailed to joists - would it be possible do you think to cut the batts in such a way that they could be pushed in through smaller sections cut strategically in the floor boards rather than lifting all the boards?

Also, in your job, were there water pipes or electrical wires between the two floors and if so how did you work around them to leave them accessible?

Thanks

GreeBo

I'd fix the insulation from the ceiling below if it was me. Much easier to reboard/skim than taking up floors etc.