Soundproofing between floors

H

Hawthorn

Registered User
Messages
15
I am taking up the floorboards in my upstairs bedrooms and am replacing them with new red deal boards. At the moment things are quite noisy downstairs when somebody is walking around upstairs. I am hoping to try and eliminate alot of this noise by putting sound insulation in between the joists before putting down the new boards. What would people recommend? Sheepwool? Moy isover do an acoustic insulation roll. Anyone have any experience of this? I have also heard that you can get special material to lay along the top of the joists before nailing down the new floor boards. Anyone heard of this or know what it is called?
Any help much appreciated.
 
Hawthorn,
I dont know about the insulation side of things, however I would not go about nailing down the floor boards, as this will crack the plasterboard underneath. (ceilings). I would look into screwing them down.
 
The heavier the material the better it soundproofs. Ideally you put some lightweight concrete between the joists, but ask a civil engineer about the loadbearing capacity of the joists before you or your builder start the job.
The felt strips between the floor and the joists will help as well.
 
You can get layers of dam-tec, its a cork based material (I think!) that has sound dampening qualities, although going by what your doing I'm not quite sure how you could lay it for it to be effective or whether it could be used on top of the joists like you mentioned.

But that might be what your thinking of - it comes in 3mm and 6mm thicknesses and a roll of dam-tec costs approx 100e per roll for 20sqm of 3mm thickness.

Its used in alot of new commercial developements and apartment blocks, have only just bought some as laying it down in new house we are moving to.
 
Dam-tec is usually used as an under lay when tiling a concrete floor with an occupied space below. The sound from floor boards is usually from clip clopping of shoes on the boards themselves so if it was me I'd pack as much insulation (Roc wool or the Moy stuff you mentioned) into the void as possible. Don't over do it as you don't want to put too much pressure on the ceiling below when the boards go down
 
BTW if nailing use a nail gun or you will damage the ceiling below as mentioned by hyabusa
 
Go with concrete if you can. It's very hard to reduce the impact noise for it's borne through the structure which is wood
 
Hi, we used a system supplied by a company in Athboy, Co. Meath. The product is a sort of anti-fire/insect etc. woodchip wool-like substance that is 150mm tick and lays in between the floorboards (its also an insulator). Then if you want the full bells and whistles, they also supply a material that sits in the joists of the roof (about 25mm in rolls, could be cork) that you then put your ply/flooring on..I'm only new here so I don't know if I can give the name of the company...
 
Just wondering when people say "in between the joists", do they mean resting on the downstairs ceiling? Surely this can't hold too much weight?
 
the insulation can be packed tight between the joists for the more solid sheets or just left lying on the ciling for the lighter rolls of insulation. either way there isnt that much wiehgt on the ceilign boards
 
Checkout

www.unifloor.nl

There products are probably the only ones with proper certification for impact (footfall) sound reduction. Some products can be up to 20dB - which is an awful lot.

I think they have a distributor here.

S.B.
 
In soundproofing the floor I assume this insulation would mean there would be little heat transfer from the ground floor to the second storey. I have u/f heating in groundfloor with rads upstairs and red deal flooring. Yes there is a noise element of movement upstairs. I would have noticed this a lot when we moved into the house first but now I barely notice it . We never need to put rads on in the upstairs rooms because of the heat transfer. I wonder if the floor was insulated might we need less heat downstairs without this heat loss to the next level.So might it be in fact better to have heat on when required in the bedrooms rather than depending on the heat transfer ? I have just been looking at our oil usage over the last twelve months and we have used nearly 4,000 litres for a 2,200 square ft house which seems high.
 
To Joe Nonety:
"In between the joists" means that that in between the joists a second ceiling is build, similar to the bottom of a box, and this will hold the concrete or any other insulating material.
The existing (plaster board) ceiling wouldn't be touched this way. Which helps to reduce sound transmissions even more.
 
Having talked to a few people it seems that lifting the existing floor could involve alot of work and cost. One carpenter reccomended leaving the existing white deal floor in place. He said that you could put tuplex http://www.snt-group.net/tuplex/usa/ominai.htm on the existing floor and lay the new red deal floor over this. Has anyone heard of this product or something similar? Sounds like a good solution but not sure as to how effective it would be at reducing impact noise.
 
You must log in or register to reply here.
Back
Top