dnb Posted December 10, 2021 Share Posted December 10, 2021 I am trying to understand what to do for my ceilings. I have consulted the white book and have two options that seem practical. Double board with 12.5mm or single 12.5 board on to resilient bar. Both will be going on to steico joists and have 100mm (unless i can get away with 50mm) acoustic insulation. I would like to know how either scheme works in real life because so often lab tests aren't totally representative. Link to comment Share on other sites More sharing options...
Dudda Posted December 10, 2021 Share Posted December 10, 2021 Why not resilient bars with two layers of acoustic board? Additionally on the first floor side you can have the silent floor system with the floor chanels that sit on top of the joists. https://www.gyproc.ie/sites/default/files/GypFloor SILENT_1.pdf I've used this successfully in a Black Box Theatre in a listed building where we obviously had to have excellent acoustic properties. I've also used it to separate a plant room from the main church so silent prayer was still silent and you couldn't hear all the plant equipment. Link to comment Share on other sites More sharing options...
joe90 Posted December 10, 2021 Share Posted December 10, 2021 The only thing I got wrong on my build was this. Just 12.5mm board with 100mm insulation between joists (passed building regs) but can hear TV and voices from downstairs when in bedrooms ?, I wish I had double boarded and resilient bars at least ? Link to comment Share on other sites More sharing options...
dnb Posted December 10, 2021 Author Share Posted December 10, 2021 9 minutes ago, Dudda said: Why not resilient bars with two layers of acoustic board?... Ceiling height is a minor concern - some rooms will start to look letterboxy, and the other is loading on the joists. My preference is bar and single board if it will work. Neither are significant i admit I saw the silent floor in the book but can't do it since the floor is already bonded to the joists as part of the sips kit build. I can however use an acoustic underlay of some description over the floor, appreciating that it will not be as good. Link to comment Share on other sites More sharing options...
Dudda Posted December 10, 2021 Share Posted December 10, 2021 6 minutes ago, dnb said: Ceiling height is a minor concern - some rooms will start to look letterboxy, and the other is loading on the joists. My preference is bar and single board if it will work. Neither are significant i admit I saw the silent floor in the book but can't do it since the floor is already bonded to the joists as part of the sips kit build. I can however use an acoustic underlay of some description over the floor, appreciating that it will not be as good. Unless it makes the room non compliant in terms of head height the additional 12.5mm won't be noticed in the overall height of the room. 1 Link to comment Share on other sites More sharing options...
dnb Posted December 10, 2021 Author Share Posted December 10, 2021 7 minutes ago, Dudda said: won't be noticed in the overall height of the room I will notice! And as far as it goes, that is enough. What, practically, is the performance difference between 1 and 2 sheets of board with resilient bar? 1dB or 3dB or more? And from what point? 1dB more attenuation from 30dB is worth having. But 1dB extra from say 55 or 60dB hardly seems worth it in a house. (BTW I do understand dBs.) Link to comment Share on other sites More sharing options...
Dudda Posted December 10, 2021 Share Posted December 10, 2021 1 hour ago, dnb said: I will notice! And as far as it goes, that is enough. What, practically, is the performance difference between 1 and 2 sheets of board with resilient bar? 1dB or 3dB or more? And from what point? 1dB more attenuation from 30dB is worth having. But 1dB extra from say 55 or 60dB hardly seems worth it in a house. (BTW I do understand dBs.) I'm sorry, but I have to disagree in that over a height of circa 2.5 meters you won't notice 12.5mm. It's only half of one percent in height. Adding a rug to the floor would make more of a difference. What is the exact height from the underside of the joists to your finished floor level currently? Look at the 'White Book' and the options it gives. They go through every possible combination from a single layer of 12.5mm standard board, 15mm board, 12.5mm acoustic board, and multiple layers of these. You might find one layer of 12.5mm acoustic board will be enough as that has a much better acoustic rating than 12.5mm of standard board which it sounds like you were originally planning. Link to comment Share on other sites More sharing options...
TonyT Posted December 10, 2021 Share Posted December 10, 2021 I double sheeted my old kitchen that changed into a downstairs loo. upstairs loo direct above, all the noises were previously heard. fired rock wool between joists and double sheeted with standard plasterboard, direct onto joists. first layer was sealed around perimeter and between sheets prior to second sheet going on. then wet plastered. no noises now. Link to comment Share on other sites More sharing options...
nod Posted December 10, 2021 Share Posted December 10, 2021 (edited) 3 hours ago, dnb said: I am trying to understand what to do for my ceilings. I have consulted the white book and have two options that seem practical. Double board with 12.5mm or single 12.5 board on to resilient bar. Both will be going on to steico joists and have 100mm (unless i can get away with 50mm) acoustic insulation. I would like to know how either scheme works in real life because so often lab tests aren't totally representative. 3 hours ago, dnb said: I am trying to understand what to do for my ceilings. I have consulted the white book and have two options that seem practical. Double board with 12.5mm or single 12.5 board on to resilient bar. Both will be going on to steico joists and have 100mm (unless i can get away with 50mm) acoustic insulation. I would like to know how either scheme works in real life because so often lab tests aren't totally representative. I normally use a gypliner system on click brackets Quick and easy to install Better than res bar Only loose 40 mil of ceiling height Or a standard Mf if your not to bothered over loosing 150 height Edited December 10, 2021 by nod Link to comment Share on other sites More sharing options...
eandg Posted January 4, 2023 Share Posted January 4, 2023 On 10/12/2021 at 13:00, nod said: I normally use a gypliner system on click brackets Quick and easy to install Better than res bar Only loose 40 mil of ceiling height Or a standard Mf if your not to bothered over loosing 150 height Is this just installed like resilient bars? Link to comment Share on other sites More sharing options...
saveasteading Posted January 4, 2023 Share Posted January 4, 2023 40 minutes ago, eandg said: Is this just installed like resilient bars? Just remember that the White Book and its equivalents give lab tests which are unreasonably optimistic. It is easy set up a small panel then test only the middle of it. In real life there are edges and interfaces. I was advised by an acoustician always to allow the 'next up' (about 3dB) if it was a fundamental requirement., esp if going to be tested. Double boarding provides overlaps at joints, and easier cutting to edges (and fewer flanking issues). Link to comment Share on other sites More sharing options...
bob the builder 2 Posted January 4, 2023 Share Posted January 4, 2023 Hi All I am just about to spec ceilings on my Timber frame At this point i am planning the following build up Soundbloc plasterboard Resilient bar 100mm acoustic rockwool 22mm caber deck acoustic matting or underlay carpet. I would be really grateful for comments on how well you think this will perform In addition any tips on the acoustic underlay / matting would be appreciated thanks Bob Link to comment Share on other sites More sharing options...
Russdl Posted January 4, 2023 Share Posted January 4, 2023 @bob the builder 2 that build up is very similar to ours apart from the kitchen where the ceiling is fermacell (that stuff is a bitch for a non skilled DIY’er). The remainder of the ceilings are acoustic PB. No normal sounds make it through the ceilings, unloading the dishwasher, listening to music, watching TV etc. If the doors are closed I can have music on in the kitchen at a good volume and it can’t be heard in the bedroom above. Link to comment Share on other sites More sharing options...
saveasteading Posted January 4, 2023 Share Posted January 4, 2023 19 minutes ago, bob the builder 2 said: how well you think this will perform It will be good. Normal but quality carpet underlay might suffice rather than anything fancy, unless upstairs is a music room or dance studio. The fancy acoustic underlays are more important for separating flats, classrooms etc, where foot traffic in outdoor shoes may be a big problem. I would poss use 2 layers normal plasterboard rather than 1 of soundbloc. same sort of cost and probably better results due to overlapping joints. Link to comment Share on other sites More sharing options...
eandg Posted January 4, 2023 Share Posted January 4, 2023 1 hour ago, saveasteading said: Just remember that the White Book and its equivalents give lab tests which are unreasonably optimistic. It is easy set up a small panel then test only the middle of it. In real life there are edges and interfaces. I was advised by an acoustician always to allow the 'next up' (about 3dB) if it was a fundamental requirement., esp if going to be tested. Double boarding provides overlaps at joints, and easier cutting to edges (and fewer flanking issues). Also requires (almost) twice the time and a bit more cost. Trade-offs everywhere in this self-build lark! Link to comment Share on other sites More sharing options...
eandg Posted January 4, 2023 Share Posted January 4, 2023 24 minutes ago, saveasteading said: It will be good. Normal but quality carpet underlay might suffice rather than anything fancy, unless upstairs is a music room or dance studio. The fancy acoustic underlays are more important for separating flats, classrooms etc, where foot traffic in outdoor shoes may be a big problem. I would poss use 2 layers normal plasterboard rather than 1 of soundbloc. same sort of cost and probably better results due to overlapping joints. Any recommendations for LVT underlay? Link to comment Share on other sites More sharing options...
Conor Posted January 4, 2023 Share Posted January 4, 2023 1 hour ago, eandg said: Any recommendations for LVT underlay? We used 5mm woodfibre underlay. Great stuff. Gives the floor a bit of "give" and it's certainly not noisy. Not so good at heat transmission tho if you're having UFH Link to comment Share on other sites More sharing options...
eandg Posted January 4, 2023 Share Posted January 4, 2023 1 hour ago, Conor said: We used 5mm woodfibre underlay. Great stuff. Gives the floor a bit of "give" and it's certainly not noisy. Not so good at heat transmission tho if you're having UFH Great, will have a look. For upstairs so no UFH. Link to comment Share on other sites More sharing options...
markharro Posted January 7, 2023 Share Posted January 7, 2023 Basic point I know but what is the "White Book"? Building Regs or something else? Link to comment Share on other sites More sharing options...
saveasteading Posted January 7, 2023 Share Posted January 7, 2023 2 hours ago, markharro said: White Book"? British Gypsum's technical manual. The book, if you can get it, is very much easier to use than online resources. The same applies to Knauff, whatever the new name is. Link to comment Share on other sites More sharing options...
Sparrowhawk Posted January 7, 2023 Share Posted January 7, 2023 1 hour ago, saveasteading said: British Gypsum's technical manual. The book, if you can get it, is very much easier to use than online resources. The same applies to Knauff, whatever the new name is. I found this 2020 PDF: https://www.gyproc.ie/sites/default/files/The White Book Oct 2020.pdf For the 2022 version it looks like you have to download it in chunks rather than as a single PDF, starting from https://www.british-gypsum.com/specification/white-book-specification-selector/white-book-overview 1 Link to comment Share on other sites More sharing options...
saveasteading Posted January 7, 2023 Share Posted January 7, 2023 Thanks Sparrowhawk. I couldn't find this. Back to the original discussion about resilient bar: page 40 has graphs showing how effective the 'decoupling' of a resilient bar or staggered studs is. 10 dB (and more) is lots. A real wall or floor will not work as well, but the comparisons should stand. The usual downfall of any compartment is at edges, or with sound travelling through the adjoining walls or floors (flanking) Link to comment Share on other sites More sharing options...
markharro Posted January 8, 2023 Share Posted January 8, 2023 Thanks - looks like the White Book is a good resource for soundproofing etc. For what its worth on at least a couple of passivhaus projects I have been to see resilient bars were used for the GF ceilings for soundproofing. Seems to be an easy and hopefully cheap option. On a separate point when our house is built later this year we will need the best solution to soundproof the "TV room" that will be an offshoot from our main living space. The issue is that we will have a wide sliding pocket door between the two spaces - 1.5m from memory when closed. I think its too wide to use a generic door panel but in any event I want the best acoustic option. Can anyone suggest a good option for what we could use? Link to comment Share on other sites More sharing options...
Russdl Posted January 8, 2023 Share Posted January 8, 2023 25 minutes ago, markharro said: The issue is that we will have a wide sliding pocket door between the two spaces - 1.5m from memory That is wide. We have two largeish sliders, 900mm openings, we used 1000mm fire door blanks which are very good at blocking sound. (One thing to consider with your sliding doors which we didn’t until the deed was done. Redecorating them could be nigh on impossible. We had the blanks sprayed, beautiful finish but once the doors in it’s in forever. Some sliding kits allow you to remove the door - ours doesn’t. Not ever). Link to comment Share on other sites More sharing options...
Iceverge Posted January 8, 2023 Share Posted January 8, 2023 On 04/01/2023 at 19:21, bob the builder 2 said: Hi All I am just about to spec ceilings on my Timber frame At this point i am planning the following build up Soundbloc plasterboard Resilient bar 100mm acoustic rockwool 22mm caber deck acoustic matting or underlay carpet. I would be really grateful for comments on how well you think this will perform In addition any tips on the acoustic underlay / matting would be appreciated thanks Bob What kind of joists are you using? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now