noise trough roller blind pelmet

Hi to all, I've been carefully reading the forum for a few days before posting and made sure that this particular issue hasn't been discussed already, if I missed a post it's my bad and I apologize. I'm just starting the planning of a control room for mixing, composing etc, but I won't go too much in detail with that yet because before making any room plans I'm trying to see how much airborne noise I can block coming through the ROLLER BLIND PELMET just above the windows. I think I should deal with structure-borne noise later on by treating the room itself... The room (552 x 413 x 288cm) is in a partly below ground level apartment in the center of Rome, just in front of a busy street . The noise volume is the average noise of a fast passing-by vehicle traffic some 5 meters from the external window roughly. The building (built in the 30's) has sturdy walls made of brick and concrete. I've placed two thick double glazed windows with a 12cm air gap between them and now the main noise source is the cavity that hosts the pvc roller blind above the windows. Pictures 1 and 2 are a 3D view of the pelmet and windows: Picture 3 is a 2D side view with some names and measurements (sorry guys, all in mm... :( ). Of course the roller blind is all pulled up in the picture so 187mm (the diameter) is its maximum encumbrance. The window's and pelmet's width is 236cm, the windows height is 150cm, I've also attached the sketchup file so to make things clearer. The roller blind cavity is built inside the wall so both sides are closed as you can see in picture 4. So my question is the following: - What sort of material and how do you think it should be placed inside the pelmet in order to block as much external noise as possible? I suppose the only areas that can be treated are in front of the roller (that 176mm gap) and underneath (the 85mm gap). I also was thinking of placing some insulation attached beneath the plywood structure in the gap between the two windows... My first attempt would be a neoprene/lead/noeprene (5mm thick) sheet on the inside surface of the plywood pelmet and one layer of sheetrock on top of it, but mine is just a guess, would you suggest some other solution? Concerning budget whatever has to be done to block noise from coming in I'll pay for it. I hope I've taken adeguate care of all the requirements for posting on this forum, if not please do tell me... Thanks for your help, cheers! :) Pat

Can you get access to inside the pelmet? I suppose you could treat it as a AC silencer and fully line the inside of the box will compressed isulation 203. Seal all cracks with acoustic sealant and maybe look at adding a draught/door seal (flap type) too miniumise the gap where the blind drops in.

Pat - you need to sisolate the window frames from each other like this

Dear John, I apologize :oops: with you for not including in the former pictures the actual path of the blind as it closes down, as you can see in the following pic it rolls down just between the timber frame and the external wall so I cannot seal it: Also I did not point out that the plywood structure on the top of the windows is part of the frame that holds the internal window up, as you can see in the pic below it rests on a pinewood structure, its sides are screwed in the walls and the top is screwed in the plywood which is then screwed on to the top of the external window. So unfortunately dividing the plywood structure is an option that I cannot consider at the moment...right? I've renamed A, B and C the areas that could (?) be treated with insulation: 1- as you've suggested A will be filled with 40mm rockwool sheets plus 1 more outer layer of plywood (bottom and left). I also added another layer of plywood on the right (to prevent external moisture damaging the rockwool in the long period), good or bad idea? 2- same thing in C, rockwool and plywood underneath. 3- In position B I'm considering to use 20mm Ecorubber (vulcanized elastomer rubber), or should I go for rockwool and plywood here too? I hope you'll have the patience of giving me some further advice on this. thanks again... Pat -------------------------------------------------------------------------------------- Dear Lilith, thanks for your advice, I'll seal it all up when the insulation will all be fixed in place, I'll also add the draught door which I'm sure will improve things, please give me some more advice if you can... :) thanks, Pat -------------------------------------------------------------------------------------- P.S. I've also attached one more skp file..

I suppose the question is do you need the blind?? Curtains inside would serve the same purpose and enable you to seal the window off.

You're right John, that's what I tought about in the first place but I have to keep it due to some restrictions I have on maintaining the external look of the facade of the palace unchanged. :( Also my new windows are PVC and during the hot season I need to have some shelter from eccessive exposition to sun rays. That's why I'm trying to do the best with what I have... What do you think of areas A, B and C? Thanks again... Pat --------------------------------------------------------------------------------------- Lilith, do you know anything about Ecorubber? Ever used it? let me know, thanks :) Pat

Dear John, it took me some time to answer ‘cause I’ve been making some more attempts but could not get the traffic rumble noise from the outside street lower than 50db :( … In order to isolate the two window frames from each other as previously suggested by you I've come out with a few ideas which I'd like you or any other to criticize if you could be so kind of doing so... What kept me from breaking the plywood connection between the tops of the two window frames was the fact that the top of the internal window frame was supported by it. So this is what I tought I’d do: 1- Eliminate (as you said) the plywood connection between the two tops of the windows. 2- Break the wall on both upper sides of the internal window (at the top) and place a metal beam (see picture) from side to side and secure it in the wall sides with quick concrete. Then screw the top of the internal window frame to the metal beam. Would it make any sense to paint with some sort of liquid rubber the extremes of the beam, I mean the part that goes inside the wall? 3- Place a NEOPRENE (any other suggestion?) layer between the internal window frame and: (1)the metal beam, the (2)left and (3)right concrete wall, (4)the wooden internal window support underneath (see earlier pic in this post), (5) the vertical 15mm plywood layers. The internal's window frame will be screwed in these 4 areas.I was thinking of placing a rubber ring between the screw's heads and the pvc window frame. 4- In place of the old plywood horizontal structure between the two window frame tops I was thinking of using some decoupling material such as Ecorubber (ever heard about that? it's quite popular here, not sure if it's any good though...got lots of it) and filling the rest with rockwool. Would you suggest some other material for closing the gap between the to windows while keeping them decoupled? I’ve read a few posts about decoupling double windows but those refer to the CR-to-tracking room windows which are on two separate stud walls while here it’s a completely different setup. As you have noted I still didn’t eliminate the roller blind, I’d like one last attempt to save it before getting rid of it… --- But the main question is: does all this make any sense considering that in any case both internal and external windows (even if the internal one will have neoprene to decouple) are screwed to the same walls (see earlier pics above…) at their left and right sides? What would you guys suggest? Let me know and thanks again:) Pat

How about this?

I usually go direct to the source to stop the sound. That would take me outside of the building to seal the area above the window, even if I had to get a ladder to do it ;) Is that too easy? Get a beer and call it a day :)

Thanks John that's great:) never tought about that! I'll set it up this week! I will have to put the metal beam anyway in order to hold the internal window up. Could you please answer two quick questions so that I can proceed further? 1- considering that in any case both internal and external windows are screwed to the same walls at their left and right sides, would this make any sense at all? (see pics and attached skp file) 2- So would it help DECOUPLING to put a layer of neoprene between the pvc window frame and the concrete side-walls before drilling the screws in? I also was thinking of placing a rubber ring between the screw's heads and the pvc window frame where they hold on to it. Or would you suggest some other solution? Thanks again for your time, cheers Pat ----------------------------------- xSpace nice to meet you too and thanks for your advice, in fact I'll do exactly as you said if anything else shouldn't work, I'm trying to make one last attempt to keep using the roller blind so I still cannot seal the opening... Luckily the room is on ground level :D Please keep helping Pat

What I was getting at is this. Doing what you and John are working on is a requirement based on the pictures you have here. But if there is an opening on the exterior of the building around the shade, I would make certain this hole was closed up as well, because it is a direct access to the interior of the room/wall.

yeah - but I think he needs to be able to pull the rollerdoor up and down.

What about a sealable trap door/ pelment plug thats on hinges!

John Sayers wrote:

yeah - but I think he needs to be able to pull the rollerdoor up and down.

exactly, thanks anyway xSpace, in case some noise will still be leaking in I'll seal the opening and eliminate the roller blind as you kindly suggested:)

lilith_envy wrote:

What about a sealable trap door/ pelment plug thats on hinges!

That's an interesting idea Lilith, would make things easyer in case I have to reach and fix something inside later on. Do you mean to place a plug/panel on the CR (internal) side of the pelmet right? Thanks for helping:)