General Build questions

srdb20

Hi lads,

I have a few questions im hoping to get some help with....

Currently joisting out the first floor using 9'' by 3'' s, im looking for the best way to soundproof them first floor, have been given a few ideas, such as foam that sits on top of the joist and the ply is nailed onto it, or screwing the plywood every 2-3 inches to ensure it remains tight rather than just nailing it down, and finally laying the first layer of plywood, then a standard sized plaster slab followed by another sheet of ply. Can anyone comment on the above, what have people been doing to soundproof there first floors (Besides concrete first floors)

secondly, have an electrician coming on board soon and im looking for peoples electrician specs, will be hoping for a decent setup with internet, surround sound, ipod docks, hdmi, cctv, alarm, anybody got any good setups or particularly good ideas, i would be grateful thanks very much.

Certain parts of the house will have spots in the ceiling, whats the best way to keep them airtight without the air literally pissing out through them?

Has anyone gotten triple glazed pvc windows? any reviews or major issues with them? i have quotes from munster joinery and senator windows.

Any opinions welcome, thanks for reading.

Mellor

srdb20 wrote: »

Currently joisting out the first floor using 9'' by 3'' s,

Very big joists, 75x225 would normally be used around the stairs. Have you got very big spans?

im looking for the best way to soundproof them first floor, have been given a few ideas, such as foam that sits on top of the joist and the ply is nailed onto it, or screwing the plywood every 2-3 inches to ensure it remains tight rather than just nailing it down, and finally laying the first layer of plywood, then a standard sized plaster slab followed by another sheet of ply.

The plaster slab sounds a little strange.
A floating floor works well to isolate sound passing through the floor.

Certain parts of the house will have spots in the ceiling, whats the best way to keep them airtight without the air literally pissing out through them?

Just keep them downstairs where it's not an issue.

MicktheMan

Mellor wrote: »

Just keep them downstairs where it's not an issue.

Mellor, not sure this is correct!
Very often you get air infiltration through down stairs recessed spots because the ceiling to floor void is not sealed from the outside. It depends on the construction type and what the airtightness strategy is (if there is one!).

Poor Uncle Tom

Surface mounted would take care of this, or design them in from the start. They're usually only a problem where they are incorporated as an afterthought.

srdb20

Mellor wrote: »

Very big joists, 75x225 would normally be used around the stairs. Have you got very big spans?


The plaster slab sounds a little strange.
A floating floor works well to isolate sound passing through the floor.


Just keep them downstairs where it's not an issue.

Hi Mellor thanks for getting back to me so quick, no not unusually large spans, just want as little noise and squeaks as possible, and was advised to go with the 9 x 3's rather than 9 x 2's....

Again the plasterboard between two sheets of ply was another way of reducing noise caused by footfalls etc advised to me.... Can you explain what is meant by a floating floor please?

MicktheMan wrote: »

Mellor, not sure this is correct!
Very often you get air infiltration through down stairs recessed spots because the ceiling to floor void is not sealed from the outside. It depends on the construction type and what the airtightness strategy is (if there is one!).

We are hoping to get as airtight as possible within reason, can you tell me how i can ensure if the ceiling to floor void is securely sealed to the outside, and i will ensure it is completed before going any further, cheers.

Poor Uncle Tom wrote: »

Surface mounted would take care of this, or design them in from the start. They're usually only a problem where they are incorporated as an afterthought.

Would you have any examples of the surface mounted lights that i could take a look at Poor Uncle Tom????


Thanks for all the replys so far lads, really appreciate it

MicktheMan

srdb20 wrote: »

We are hoping to get as airtight as possible within reason, can you tell me how i can ensure if the ceiling to floor void is securely sealed to the outside, and i will ensure it is completed before going any further, cheers.

I don't intend to be factitious but what level of airthighness are you hoping to achieve? (get as airtight as possible within reason is not a specification!)
What is your airtight strategy to achieve this? How to deal with the void between ceiling and floor should be dealt with in this strategy as would all other junctions etc!
Your question cannot be answered without knowledge of your plans and construction type.
You need someone to look over your design and construction type to determine the best overall strategy for airtightness.

Poor Uncle Tom

PM sent

Mellor

MicktheMan wrote: »

Mellor, not sure this is correct!
Very often you get air infiltration through down stairs recessed spots because the ceiling to floor void is not sealed from the outside. It depends on the construction type and what the airtightness strategy is (if there is one!).

I don'r see how that's relevant, in a new build the first floor void should be sealed. Esp if you want downlights.

srdb20 wrote: »

Hi Mellor thanks for getting back to me so quick, no not unusually large spans, just want as little noise and squeaks as possible, and was advised to go with the 9 x 3's rather than 9 x 2's....

Who adivsed you. I don't know if it will help much tbh. Moise of the noise is airbourne passing straight through or simply feet on floor boards, not the floor moving its self.

Again the plasterboard between two sheets of ply was another way of reducing noise caused by footfalls etc advised to me.... Can you explain what is meant by a floating floor please?

I understood what you were suggest, just not sure who gave you this idea.
A floating floor is where the floor boards are fixed to a separate struct to the joists, often with acoustic pads inbetween. It reduces the direct line of conact and therefore some of the sound transmission.

MicktheMan

Mellor wrote: »

I don'r see how that's relevant, in a new build the first floor void should be sealed. Esp if you want downlights.

Mellor,
You are right, it "should be sealed". In my experience, more often than not it's not (or badly done) and as a result air pisses through the recessed lights when the house is depressurised during the air tightness test.

FesterBeatty

The width of the joist wont affect soundproofing whatsoever. As stated above the noist emanates from contact between shoe and timber. The noise then travels through the material...so joist width is not a factor. Naturally most of the noise will travel through the voids between joists.

Have seen a lot of people go for easyscreed (on ply/battens) between joists to accomodate underfloor heating and this seems to significantly contribute to the overall soundproofing...you would of course have your engineer check that the floor can cater for the additional weight of concrete...Personally however I'm not fond of the concrete/timber detail as it WILL and does lead to cracking due to different rates of expansion. Ultimately, its a timber floor, so its gonna sound like one...you can add on all sorts of bells and whistles as mentioned above - but its still a timber floor.

...pull em out and go for precast!!

Mellor

MicktheMan wrote: »

Mellor,
You are right, it "should be sealed". In my experience, more often than not it's not (or badly done) and as a result air pisses through the recessed lights when the house is depressurised during the air tightness test.

We are talking about a specific one off house where the owner is aware of air-tightness, the issue around downlighters and is planning on eliminatign any issues (hence thus thread), so its pretty safe to say that it'll be done here.

Then again, no downlighters, or DLs in a service void will always be better than the best sealed floor void.

srdb20

Lads thanks for all the replies, think I have most areas boxed off now. Appreciate all the replies, vie posted a new thread just querieing about air tight plaster?