Putting down timber floors on the first floor - sound and heat insulation

message from Dermot O'Loughlin on 21 May 2004

Hi all,

I am about to undertake the first fix carpentry on my new build. My
carpenter tells me the best way to put down the floors upstairs is to
put plywood on top of the joists - then put down battens and
insulation between the battens - then put down the timber floors on
top of the battens. We would put insulation under the plywood (between
the joists) when putting on the ceiling slabs downstairs.

Do you think this is a good approach in terms if heat and sound
insulation?
Can anyone recommend the type of insulation to use?

Thanks,
Dermot.

Christian McArdle replied to Dermot O'Loughlin on 21 May 2004

If you're going to do all that, then make sure you choose where to run pipes
and cables carefully, as you'll probably need access to them in the future.

Just guessing here, but I would be inclined to use sand instead of
insulation between the battens. The between joist insulation will have
easily satisfied the heat insulation requirement, given that it is an
internal floor and probably only for better heating subzone performance.

I would expect the sand to provide better low frequency sound insulation
resistance due to the extra mass. It'll also provide useful (but probably
not certifiably so) fire spread resistance. Ensure that you allow for the
extra weight of all this wood and material when calculating the required
joist sizes.

Christian.

BigWallop replied to Christian McArdle on 21 May 2004

Also another little aside. Good sound insulation can be achieved by laying felt padding,
like the thick felt underlay you get for expensive carpets, under a top layer of normal
flooring boards. It's called a floating floor and is commonly used in sound recording
studios and theatres I think.

And, as Christian says, the insulation you apply to the joist spaces should be more than
enough for the thermal retention side of things.

A simple floating floor is less expensive as well.

N. Thornton replied to Dermot O'Loughlin on 23 May 2004

sounds like a pointless way to spend your money and time to me.

Regards, NT

Michael Mcneil replied to N. Thornton on 23 May 2004

"N. Thornton" <bigcat@meeow.co.uk> wrote in message
news:a7076635.0405230119.488bd9ce@posting.google.com

My first thoughts too but if he's building flats...

N. Thornton replied to Michael Mcneil on 23 May 2004

Yeah, I hadnt thought of that. But if he is he cant just pick and
choose what he feels like, there will be fire regs to meet.

Regards, NT

Michael Mcneil replied to N. Thornton on 23 May 2004

"N. Thornton" <bigcat@meeow.co.uk> wrote in message
news:a7076635.0405230645.203bbfb8@posting.google.com

Plus he'd be looking for the cheapest out.

Dermot O'Loughlin replied to N. Thornton on 24 May 2004

I'm not building flats. This is my new home so I want to get it right.
I'm not in the building trade so I just wanted to get advice on the
best approach to take for sound and heat insulation. I'd like to know
if my carpenters approach is way off the mark. Do you think it is?

I'll look into using the felt like stuff for sound insulation - does
anyone know where i'd source it and any internet resources that
explain how to do it.

Many thanks for your suggestions so far.

Dermot.

Pete C replied to Dermot O'Loughlin on 21 May 2004

Hi,

I doubt you'd need much heat insulation between floors, a Google
search for the building regs for flat conversion will give some idea
of what is needed. If you want better than that have a look at some
specialist sound insulating websites.

cheers,
Pete.

Hugh replied to Dermot O'Loughlin on 21 May 2004

from the point of view of sound insulation, with your builders suggestion,
sound will be transmitted throught the floorboards, battens, ply, and
joists - there has to be a gap, and bigwallops ideas 'sounds' better.
Timber is a quite good transmitter of sound - very useful to get a length of
timber and use it as a stethoscope for e.g.testing if a boiler pump is
working, it's also a useful primitive diagnostic tool for finding out where
'funny' noises are coming from in car engines or any home appliances.
I tried to 'google' for 'The Building Research Council' but they must have
changed their name - they provided me a long time ago with specifications
for soundproofing.
Anyone know what they are called now?
Hugh

"Dermot O'Loughlin" <dermot_o_loughlin@yahoo.com> wrote in message
news:44aa40ff.0405210313.cd5bcb5@posting.google.com...

Coherers replied to Hugh on 21 May 2004

Sounds like the sort of thing produced by the Buildings Research
Establishment....

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