sound insulation under the salon carpet?

vas

vas

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hello,

although I've rebuilt the salon flooring and added again at least 50mm rockwool and a perforated 3-4mm MDF or something underneath, there's a fair amount of noise from the engines in the salon, most annoying is generator noise passing through.
The carpet some natural thing that's hardwearing and almost torturous to the bare wet feet (no backing/underlay) is placed straight on top of the plywood floor.

I'm thinking of adding something (could be easily up to 10-20mm thick and even more!) to cut the noise.

Any ideas of materials that I could use?
If it's thick, it has to be not compressible else it's going to be a bit like walking on snow/mud/you name it, wont be good.
It also has to be easily (...) removable for the annual lift of floors for maintenance. I do all the regular tests from the e/r.

cheers

V.
 
I doubt the rockwool is doing a lot to stop sound passing through the floor. A better solution would be to replace it with barrier mat https://www.asap-supplies.com/soundproofing/soundproofing-sheets. All fixed and removable panels that are part of the engine compartment should be covered where practicable. Use a good quality, solvent based contact adhesive.
To go under the carpet you could try https://www.asap-supplies.com/soundproofing/soundproofing-damping-barrier.
The rockwool will absorb some sound but is poor at preventing sound passing through it as it is not thick enough to absorb low frequencies. Increasing mass or density is the most effective way to stop sound transmission and unfortunately one is avoiding that because of fuel consumption increases!
The barrier mat on the floor and under the carpet would be incompressible and give you a heavy layer.
The rockwool could be deployed elsewhere in the engine room to generally soak up some of the reverberant sound which would help.
You mention 3-4mm perforated MDF this sounds like a frequency selective absorber rather like pegboard but I would not think it is preventing transmission.
You could also try a separate compartment around the generator with air vents that are ducts but with a bend in them as bends help suppress noise transmission. Try lead lining the enclosure. If this is not possible try to screen it somehow.
 
My friends boat has over carpets . He intended to throw them out and have the original carpets replaced . However he since realised the over carpets are handy for cleaning (he has dogs). From within the saloon the engines are remarkably quiet..
 
If you do put basic carpet underlay beneath carpet ensure it is the heavy rubberised type which will stay in place.
The light foam type will slip/slide and require constant relocation back to its original position.
 
On one of the boats I used to service the owner taped over all the access panel joins with gaffa tape, it made a suprising difference as we noticed when we first put the carpets back without the tape, doesn’t cost much to apply new tape on the few occasions that you have to lift the floor.
 
vas said:
hello,

although I've rebuilt the salon flooring and added again at least 50mm rockwool and a perforated 3-4mm MDF or something underneath, there's a fair amount of noise from the engines in the salon, most annoying is generator noise passing through.
The carpet some natural thing that's hardwearing and almost torturous to the bare wet feet (no backing/underlay) is placed straight on top of the plywood floor.

I'm thinking of adding something (could be easily up to 10-20mm thick and even more!) to cut the noise.

Any ideas of materials that I could use?
If it's thick, it has to be not compressible else it's going to be a bit like walking on snow/mud/you name it, wont be good.
It also has to be easily (...) removable for the annual lift of floors for maintenance. I do all the regular tests from the e/r.

cheers

V.
Click to expand...
I agree with earlier posting that rockwool is a very poor sound absorber. Recommend you replace it with proper 50mm engine compartment sound deadener and also ensure all lifting hatches have a foam seal and every single hole or gap between the engine bay and saloon is blocked. You will not then need to add carpet underlay.

Www.solocoastalsailing.co.uk
 
thank you all for your suggestions which generally are interlinked and along the same lines (that I've not followed during the rebuilt...)

OK, first, what I have under the salon floor beams is indeed pegboard (sorry had to google that) and the reason I think was just to keep the rockwool in place back in 75 when MiToS was built.
So I'm planning to follow your instructions and go for some suitable material in the 50mm height of the salon floor beams.
This means I remove and discard the pegboard and keep the rockwool and stuff it elsewhere.
For the record, I do have some rubber self adhesive seal on the bottom of the lip where the hatches rest, there's a gap on the sides 3-4mm though.

So list of actions:

  • circa 50mm heavy (as in weight) material will be sourced locally and used.
  • hatch tape where the hatches rest
  • gaffa tape on top of the hatch seam
  • block all other minor (and not so minor...) gaps where the el. cabling duct (60X150mm hole) goes from e/r to salon .
  • I can also buy thinner material, say 20-25mm for the hull sides (down to about wl level) and stick that around and between the iroko hull frames.

So this sounds like a plan.

If it still is noisy, then I can get the roll on mat for under the carpet and know for sure I've done my best!

Question is this:

soundproofing with barrier mat, in terms of VFM, what should I get?
Polymeric barrier or lead barrier?
cloth or silver foil?

thinner with lead or thicker with polymers? Consider I do have the 50mm height of the floor beams at 200-250mm intervals, so nothing to loose filling the whole space with material (other than money that is!)

The only thing I can easily find down here is single density polyurethene foam based material typically with an ondulated or prismatic outer skin and no foil cloth or whatever lining. These sheets are single material/density jobs and to my understanding rely on shape for some diffusion and single material for some absorption of sound. No serious or detailed specs given on line... Mostly used for airduct lining and sound studio properties alterations/improvements.
I've seen them used on boats down here and soon become rather filthy (OK they are dark so they don't look filthy but they are!) plus on a smallish and low ceiling dark e/r I'd rather have something light and reflective to see my way through and not feel totally depressed down there...

Searching around from home (will visit 2-3 building material places later on today) I came across this which is a typical example of what they use:

http://balamoti.gr/domisi/domika-ylika/ixomonotika-ylika/isolfon-pu/

ISOLfon - PU is produced on flat panels made of high quality polyurethane foam, special in dark gray color. It addresses simple, fast and cost-effective problems of acoustic regulation and noise control in construction and industry. It also offers thermal insulation. It is produced in various thicknesses to meet different sound absorption needs. In order to achieve a high sound absorption coefficient, the foam produced has the optimal percentage of closed cells that absorb the kinetic energy from sound waves. It is applied very easily and quickly without requiring any special tools or specialized technical knowledge.

Plate dimensions 100 × 100cm. They can also be rolled up.
Total Thickness 5 - 10 - 20 - 50 mm. They can also be produced in different thicknesses.
Density: 29 Kg / m3.
Behavior in fire: SE ( MVSS 302) self-extinguishing.
Properties: Good sound absorption depending on thickness. Uniform cell structure.
Sound absorbing interior lining on covers of air conditioners and fans, speakers, air compressor chambers, air ducts, etc. Sound absorption in sound studio (in large thicknesses).
Click to expand...

1sqm slab 10mm thick is 7.9euro, guess 50mm will be 30-35euro, no lining though.

I guess I should discard that, correct?

cheers

V.
 
I would not use that sponge stuff in the link ^^ .
Cheap as it is it will fall apart with time and poss soak up moisture as well ?
Here’s the best stuff for inside between the beams .Also if you click around “ products “ there’s actual barrier mat for on top as well .
http://www.quietstone.co.uk/product/quietpad-soundproofing-panels/

Did you say in a previous thread ( fire extinguishers) that there was an air vent inside the cockpit area ( as well as the external hull vents ) ?
 
PCUK said:
Have you sealed every opening from the engine compartment and used thick hatch seal tape under the hatches. If not nothing will stop the noise.
Click to expand...

Our engines are under the wheelhouse floor. There are six teak faced ply lifting panels resting on alloy beams. These have heavy insulating material secured to the underside, but the wood rests directly on the beams with slight gaps between the panels. I had thought of using some form of sealing strip on these mating faces, but it would need to withstand frequent lifting of at least three of the panels for regular engine checks. Do you think the neoprene strip would survive, or would solid rubber be better, but might not work as well as a sound barrier?
 
Portofino said:
I would not use that sponge stuff in the link ^^ .
Cheap as it is it will fall apart with time and poss soak up moisture as well ?
Here’s the best stuff for inside between the beams .Also if you click around “ products “ there’s actual barrier mat for on top as well .
http://www.quietstone.co.uk/product/quietpad-soundproofing-panels/

Did you say in a previous thread ( fire extinguishers) that there was an air vent inside the cockpit area ( as well as the external hull vents ) ?
Click to expand...

agree hence my question.

Anyway, spent an hour at the only decent shop we have in Volos, saw various samples, heard prices (which I mostly DIDNT like) and I'm much wiser now. so bear with me:

Undercarpet they have a material called PIOMBOLEN 4006R here are the specs: https://www.noisecontrol.gr/images/eshop/catalog/products/0002/files/PIOBOLEN 4006R_en.pdf

It's 6mm, 4kg/m2, 1X3m roll and costs 60+ euro per roll. This to be used under the carpet, saw it, liked it two layers of polyethelene sandwitch with a lead film in the middle.
So say 150euro for my salon floor.

However, for the e/r ceiling, they suggest some stuff similar to what Montemar recommends in post #2:
FIREND ARF CPX 25P, a 28mm, 5kg/m2 sandwitch of two slightly different (?) polyethene layers, with a barrier in the middle and aluminum foil cover outside. specs here:
https://www.noisecontrol.gr/images/eshop/catalog/products/0004/files/CPX_EPDM_en.pdf
If I want to use it in the ceiling and god forbid sides of the hull, we are talking about a grand worth of material, plus I have to epoxy special bases on the ply (probably screw them tbh) and use the "button" like pins to secure the insulation in place.

Finally, in theory I also do have all the 25X50mm beams (every 250mm or so) being soundbridges around the floor, which is not that nice, don't know to what extend they affect sound, will ask.

PF, yes there are two main inlets say 100X500mm above deck to suck fresh air in, and 4 smallish outlets on each side but that's getting complicated as there are vertical shafts out of plywood stuck on the hull (between to adjacent frames so say 250mm wide by 600mm high as a chimney to lead the hot air up and then out to the sides from the backwards facing black scoops (hole area say 150X150mm or thereabouts). Will probably line the area around them with something, but doubt it's vital as there are already furniture infront blocking access and hopefully sound transmission.


So, plan (unless someone comes with a clever and cheap idea!) is to buy the undercarpet mat now, seal the el.ducts and other small holes now, see how it goes during the summer and decide if I go for the full ceiling lining with the fancy stuff next year when I recover from all the projects running right now.

cheers

V.
 
Leighb said:
Our engines are under the wheelhouse floor. There are six teak faced ply lifting panels resting on alloy beams. These have heavy insulating material secured to the underside, but the wood rests directly on the beams with slight gaps between the panels. I had thought of using some form of sealing strip on these mating faces, but it would need to withstand frequent lifting of at least three of the panels for regular engine checks. Do you think the neoprene strip would survive, or would solid rubber be better, but might not work as well as a sound barrier?
Click to expand...

On my previous boat the hatch seal tape lasted for several years around the access hatches that were used every day when on board. In any case it is not dear and with the self adhesive backing is quick to replace. You will certainly notice a difference!
 
PCUK said:
On my previous boat the hatch seal tape lasted for several years around the access hatches that were used every day when on board. In any case it is not dear and with the self adhesive backing is quick to replace. You will certainly notice a difference!
Click to expand...
Thanks I will go for it. Hope the Boss will be pleased.
PS I have a choice of thickness 3 or 5 mm. would the thicker be more effective? I will have to check that the saloon doors don’t foul though.
 
Last edited:
vas said:
Undercarpet they have a material called PIOMBOLEN 4006R here are the specs: https://www.noisecontrol.gr/images/eshop/catalog/products/0002/files/PIOBOLEN 4006R_en.pdf

It's 6mm, 4kg/m2, 1X3m roll and costs 60+ euro per roll. This to be used under the carpet, saw it, liked it two layers of polyethelene sandwitch with a lead film in the middle.
So say 150euro for my salon floor.

However, for the e/r ceiling, they suggest some stuff similar to what Montemar recommends in post #2:
FIREND ARF CPX 25P, a 28mm, 5kg/m2 sandwitch of two slightly different (?) polyethene layers, with a barrier in the middle and aluminum foil cover outside. specs here:
https://www.noisecontrol.gr/images/eshop/catalog/products/0004/files/CPX_EPDM_en.pdf
If I want to use it in the ceiling and god forbid sides of the hull, we are talking about a grand worth of material, plus I have to epoxy special bases on the ply (probably screw them tbh) and use the "button" like pins to secure the insulation in place.
So, plan (unless someone comes with a clever and cheap idea!) is to buy the undercarpet mat now, seal the el.ducts and other small holes now, see how it goes during the summer and decide if I go for the full ceiling lining with the fancy stuff next year when I recover from all the projects running right now.

cheers

V.
Click to expand...
Good plan. Underlay for the carpet sounds very good and may be sufficient.
I would not think about lining the hull as it radiates sound outside the boat and is further away than the floor.
Better to stick it as it will work better if up against a hard surface.
Good luck.
 
Montemar said:
Good plan. Underlay for the carpet sounds very good and may be sufficient.
I would not think about lining the hull as it radiates sound outside the boat and is further away than the floor.
Better to stick it as it will work better if up against a hard surface.
Good luck.
Click to expand...

thanks!

ordering the underlay on Monday.
Went to measure at the boat and realised that when I made new engine hatches (approx 4/5 of the current salon floor area!) I didn't add any lining to the 15mm ply :rolleyes:
oops!
wasn't sure what to do as didn't have any more hardboard to cover it with so left it as is and promptly forgot it...
so I'll order enough of this expensive material to cram in the hatches between the frames and see where I stand.
another 400euro gone then...


Montemar: you mean use self adhesive (probably a spray can) to keep these 28mm panels in place, right?

cheers

V.
 
A good quality, solvent based contact adhesive that you apply to both clean surfaces and let dry until tacky then put them together with weight or something to ensure they are fully stuck. Double check the edges are stuck well because if they were to come apart it will start at an edge. Spray adhesive not strong enough.
 
Hi Vas,
for the carpet underlay you can use "any" high density (slightly) flexible "dead" material, such as rubber, linoleum, roofing, ... the heavyer the better.
dead means: not having a resonant frequency in the audible frequency range
We typically use rubber or- synthetic (as in car doors) sheets of 6...10kg/m2
more weight gives more isolation !

a rubber lip seal on the hatch rebate,
and fill the gap with a fairly "solid" material fe a rope with the correct thickness

for the E/R ceiling, if you want to do the effort, make a sandwitch of rockwool or foam, then a layer of heavy foil as above, and again a layer of rockwool / foom.

as mentioned above, PU foam tends to pulverise in time with high temps,
and doesn't have fire resitant property's,
better use rockwool, or mineral wool, or pet wool, ..
any foamy product of about 80kg/m3 is good for making the spring weight spring sandwitch, and does absorbtion of reflections inside the E/R (makes the ER room more quite inside )

you could glue heavy foil on the ER ceiling beams, to damp their vibrations, but thats much work for only a slall improvement (gut feeling)
 
BartW said:
Hi Vas,
for the carpet underlay you can use "any" high density (slightly) flexible "dead" material, such as rubber, linoleum, roofing, ... the heavyer the better.
dead means: not having a resonant frequency in the audible frequency range
We typically use rubber or- synthetic (as in car doors) sheets of 6...10kg/m2
more weight gives more isolation !

a rubber lip seal on the hatch rebate,
and fill the gap with a fairly "solid" material fe a rope with the correct thickness

for the E/R ceiling, if you want to do the effort, make a sandwitch of rockwool or foam, then a layer of heavy foil as above, and again a layer of rockwool / foom.

as mentioned above, PU foam tends to pulverise in time with high temps,
and doesn't have fire resitant property's,
better use rockwool, or mineral wool, or pet wool, ..
any foamy product of about 80kg/m3 is good for making the spring weight spring sandwitch, and does absorbtion of reflections inside the E/R (makes the ER room more quite inside )

you could glue heavy foil on the ER ceiling beams, to damp their vibrations, but thats much work for only a slall improvement (gut feeling)
Click to expand...

I was wondering whether our resident sound engineer was going to offer advice, thanks for the input Bart, it gives Vas some lower cost options, cheers
 
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