Sound Proofing First Floor

Brave Harvey

Hi, I'm looking into soundproofing an intermediate floor of a two storey house. I've been told to discard with the concrete flooring as it will break and complicate the airtightness layer. I have been looking at options using mineral wool and an impact mat. Does anyone have any advice on this and do the mats really work? And isn't mineral wool a thermal insulation? Anyway I'd be glad to hear from anyone with an opinion and what type of systems are available. Please PM me any recommended products. Thanks very grateful.

mfceiling

The amount of work trying to install a timber floor with noise reducing mats, insulation etc would be a waste when compared to dropping in a concrete slab.

I wouldn't worry about airtightness as this can be done properly when you follow the correct detail.

PM Sas or check back his post history in the "live builds" thread.....he went with the concrete floor slab and went all in doing the air tight membrane properly.


Sorry OP - am i reading correctly in that you are renovating a house and not building a new one?

Brave Harvey

Sorry OP - am i reading correctly in that you are renovating a house and not building a new one?

Building a new one..

MicktheMan

Brave Harvey wrote: »

I've been told to discard with the concrete flooring as it will break and complicate the airtightness layer.

Hoh! Who told you that?

sydthebeat

Brave Harvey wrote: »

Hi, I'm looking into soundproofing an intermediate floor of a two storey house. I've been told to discard with the concrete flooring as it will break and complicate the airtightness layer. I have been looking at options using mineral wool and an impact mat. Does anyone have any advice on this and do the mats really work? And isn't mineral wool a thermal insulation? Anyway I'd be glad to hear from anyone with an opinion and what type of systems are available. Please PM me any recommended products. Thanks very grateful.

if you think making a timber floor air tight is easier than making a concrete slab floor air tight, then youre in for a rude awakening.

cork2

I'm a carpenter currently working on a new build in Cork with a timber floor upstairs. The engineers spec was 9x3 joists sheeted with 18mm wbp ply, on top of that we rolled out a 5mm rubber underlay called Isoglomma. We taped all the joints of the underlay with an airtight tape and then taped the underlay to the airtight membrane on the walls. Then we sheeted the whole floor again with 18mm t and g osb,we rolled out a standard timberfloor underlay and floored the house with 18mm t and g white deal prefinished flooring. The client didn't like the thought of concrete floors upstairs but still wanted an airtight, soundproof floor. There is a huge amount of time and material in this floor and is fairly pricey but the airtightness test came out with a great result and you cant hear a thing when people are upstairs.

mfceiling

cork2 wrote: »

I'm a carpenter currently working on a new build in Cork with a timber floor upstairs. The engineers spec was 9x3 joists sheeted with 18mm wbp ply, on top of that we rolled out a 5mm rubber underlay called Isoglomma. We taped all the joints of the underlay with an airtight tape and then taped the underlay to the airtight membrane on the walls. Then we sheeted the whole floor again with 18mm t and g osb,we rolled out a standard timberfloor underlay and floored the house with 18mm t and g white deal prefinished flooring. The client didn't like the thought of concrete floors upstairs but still wanted an airtight, soundproof floor. There is a huge amount of time and material in this floor and is fairly pricey but the airtightness test came out with a great result and you cant hear a thing when people are upstairs.

I don't want to sound cheeky here, but what was the cost and time frame of doing this, compared with the normal 6-8 hours of dropping in concrete slabs?

I'd imagine there were no savings and that it took longer than a days work.

saltandpepper10

mfceiling wrote: »

I don't want to sound cheeky here, but what was the cost and time frame of doing this, compared with the normal 6-8 hours of dropping in concrete slabs?

I'd imagine there were no savings and that it took longer than a days work.

i am actually a big fan of concrete slab floors myself mf but it is far from 6 -8 hours all in diference in time and materials.a finnish floor screed still has to be poured which is still some steps behind a turnkey finnish which some posters are talking about

mfceiling

saltandpepper10 wrote: »

i am actually a big fan of concrete slab floors myself mf but it is far from 6 -8 hours all in diference in time and materials.a finnish floor screed still has to be poured which is still some steps behind a turnkey finnish which some posters are talking about

True enough but the time savings are still there with a concrete floor.

I've seen builders starting the first rows of blocks upstairs the following day after installing the slab.

Count the time building the joist hangers in, the installation of the joists, cross braces, rubber mats, plying the floors, insulation and plasterboard and there's a fair amount of work involved.

homewardbound11

saltandpepper10 wrote: »

i am actually a big fan of concrete slab floors myself mf but it is far from 6 -8 hours all in diference in time and materials.a finnish floor screed still has to be poured which is still some steps behind a turnkey finnish which some posters are talking about

Did you check with pumping cellulose into the joists. Mineral wool on its own won't deaden the sound enough. I put in mineral wool and it was o.k. but if I had the money I would have done it.A concrete floor would obvious but not always possible.

cork2

It took 2 men Around about 3 days but at that you wouldn't be idle, to joist, bridge and floor it. I wouldn't hazard a guess at the cost of material because Id only be taking a wild guess. Concrete slabs would be in place after 6-8 hours but that's just the tip of the iceberg. My way is no slower than the slabs Id be willing to bet. A day to put in slabs, a day to put a handrail around it for pouring and a day to pour it. Still 3 days but it would take more then 2 men in the majority of houses.

Brave Harvey

if you think making a timber floor air tight is easier than making a concrete slab floor air tight, then youre in for a rude awakening.

Yeah i seen where in a passive house what the builder did was attach a timber sole plate to the wall at first floor avoiding the use of joist hangers, beforehand an airtightness sheet was fitted behind the soleplate timber and then the timber is fixed to the wall. Then the floor joists are just nailed to this timber. This sounds a whole lot more simple than fixing a airtightness sheet to the wall with a dpc laid over which is recommended so the airtightness doesn't tear, and then drop the slabs. The slabs in my case will require thicker walls to support it in some places with that added expense. So I think at the moment the timber option sounds far better than the concrete floor option and less expensive.

sydthebeat

Brave Harvey wrote: »

Yeah i seen where in a passive house what the builder did was attach a timber sole plate to the wall at first floor avoiding the use of joist hangers, beforehand an airtightness sheet was fitted behind the soleplate timber and then the timber is fixed to the wall. Then the floor joists are just nailed to this timber. This sounds a whole lot more simple than fixing a airtightness sheet to the wall with a dpc laid over which is recommended so the airtightness doesn't tear, and then drop the slabs. The slabs in my case will require thicker walls to support it in some places with that added expense. So I think at the moment the timber option sounds far better than the concrete floor option and less expensive.

definitely get that arrangement signed off by your structural engineer, its not as straight forward as you may think.
It also doesn't exactly answer the air tightnes question, it may make application easier but in my opinion that detail isn't as air tight or as robust as membrane and slabs. Remember timber shrinks

Brave Harvey

definitely get that arrangement signed off by your structural engineer, its not as straight forward as you may think.
It also doesn't exactly answer the air tightnes question, it may make application easier but in my opinion that detail isn't as air tight or as robust as membrane and slabs. Remember timber shrinks

http://www.building.co.uk/passivhaus-diaries-part-nine-floor-junctions/3148204.article

Hey Syd have a look at this detail from the denby dale passive house and see what you think, It notes sand cement parging to wall where junction with first floor is connecting. At this point a Versalam engineered timber wall plate is fixed. This timber sounds specific for such purpose and maybe has limited shrinkage as a property?. I quite like the plywood I beam Floor joists in the detail and should take the ducts of a MHRV quite well?. Obviously there are points at the resin wall plugs, however these should be packed with resin shouldn't they? and therefore airtight those connections.