Generator Bay insulation/soundproofing material for my Prevost Coach

[Achates_Bostons]

We have our PowerTech 17.5 KW generator out of our generator compartment so we can replace the starter.  The old insulation was de-laminating so we have all that removed and down to bare walls.  I need some recommendations on the correct material to use to re-insulate/soundproof this compartment.  I sleep right above the generator so I need something really good. The bay is 33" H X 54" L by 50" D.   Any help will be greatly appreciated.  I drive a '95 Prevost conversion by Royale.

[kaypsmith]

I too have a bus conversion, I don't usually recommend spray foam in these situations because there is some flame non resistance, but that is what I used because of ease of installing it. I shot about 1.5 inches, then leveled it after it dried, then glued air conditioning duct insulation to that, it's a half inch thick and very dense with a foil glued to it from the factory, has worked very well for 7 plus years. If you don't want to go to that extreme, you can use foam insulation up to two inches at the top (under the floor) then cover that with the AC duct insulation and over the walls as well, the thicker foam mounted under the floor and covered will dampen the generator sound very well.

[rsbilledwards]

look into the sound mitigation used in the building industry when the do theater and music rooms in expensive homes.

[rayin]

54 minutes ago, RSBILLEDWARDS said:

look into the sound mitigation used in the building industry when the do theater and music rooms in expensive homes.

Like this? https://www.megasorber.com/soundproofing-products/sound-absorbers/fireproof-acoustic-material

and for the ceiling: https://www.soundproofcow.com/product-category/soundproofing-foam/fire-rated-acoustic-foam/

[jleamont]

I bought the rolled product on here and installed it on my engine hatches since the original product was deteriorating. The product I purchased had adhesive on once side, but I added short screws with fender washers to make sure it stayed in place. 

https://www.summitracing.com/search/part-type/heat-barrier-and-sound-deadening-mats

 

[Achates_Bostons]

9 hours ago, RayIN said:

 

Thanks for this info.  I was on the Megasorber web site several weeks ago and wrote to them using their form but no one ever wrote back.  I wanted to know if this was sold in the US or if I had to buy it from them.  It looks like a wonderful product.  I just need to know where I can find it.

 

2 hours ago, jleamont said:

 

https://www.summitracing.com/search/part-type/heat-barrier-and-sound-deadening-mats

 

Thanks for your information as well. I'll check it out today.

 

Thanks to all that replied.

[wildebill308]

The Boom mats from Summit look good and you could double the thickness if you wanted. Did you say you slept over the generator? Ok triple the layers.

Bill

[rayin]

9 hours ago, WILDEBILL308 said:

The Boom mats from Summit look good and you could double the thickness if you wanted. Did you say you slept over the generator? Ok triple the layers.

Bill

I donno, I had a 1976 Allegro with genset under the bedroom. The sound put me to sleep.

[richard5933]

This is the stuff Custom Coach used in our generator bay. I replaced it recently since after 45+ years it tends to break down. It works great. Not cheap, but works great.

https://www.soundproofcow.com/product/quiet-barrier-specialty-composite-2/

The stuff from Summit designed for under the hood will not hold up the same or work nearly as well. I've tried that in the past.

[hermanmullins]

Looks like good material. How do you secure it, contact adhesives, two sided tape, or screws and flat washers? Might take 4 sheets to do his job at $120.00, your right it could be expensive but if it works would be well worth it. It didn't say anything about heat resistance. 

Herman

[richard5933]

I used the variety with the self-adhesive on the back. It won't hold it permanently, but it does hold things long enough for installation of fasteners. To hold things long term, mine has two types of fasteners. On the side walls there are large fender washers screwed to the walls - no enough to flatten the material, just tight enough to compress it slightly. On the ceiling of the bay, there is a piece of expanded aluminum sheet metal which is held on with the fender washers/screws. This is the same type of stuff you see used on the bottom of old screen doors. The concept here is to prevent any possibility of it sagging on the horizontal surface. I also think that the material itself also adds some additional sound insulation since it's an irregular surface.

[Achates_Bostons]

I called Megasorber in Melbourne, Australia today and they are e-mailing me information on their Megasorber FM50, which is what they recommend for generator enclosures, plus a shipping quote.  They do not sell their products in the US so I'll have to order it from them if that is the route I go. 

 

Thanks for everyones input.  I'll let you all know what I end up doing.

 

Sue

[Achates_Bostons]

I received my information from Megasorber in Melbourne, Australia and was shocked at their prices.  It would be $1,989 plus international freight, customs and import fees.  Soooooooo, on to the next company.  

[wildebill308]

https://www.homedepot.com/p/SilveRboard-24-in-x-1-in-x-48-in-R5-Radiant-Acoustic-Insulation-Kit-STC-19-5-Piece-SB12AKIT/205975329

try this

https://www.homedepot.com/p/3M-17-6-oz-Hi-Strength-90-Spray-Adhesive-90-24/100151277

Bill

Edited July 31, 2020 by WILDEBILL308

[richard5933]

The stuff from soundproofcow is commonly seen in bus conversions and high-end coaches. I've never seen the rigid board from HD used in anything other than DIY conversions or homebuilt rigs.

Given the prices for shipping from down under, the stuff from soundproofcow is looking cheaper and cheaper.

[wildebill308]

Interesting sound deadening material. Go watch the video.

https://www.acoustiblok.com/acoustiblok-video-gallery-page/

Call and see what the direct price is.

Possible source.

https://www.amazon.com/Soundsulate-Loaded-Acoustic-Barrier-Soundproofing/dp/B077DKR8JZ/ref=asc_df_B077DKR8JZ/?tag=hyprod-20&linkCode=df0&hvadid=312193478571&hvpos=&hvnetw=g&hvrand=3522986160684528301&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9027284&hvtargid=pla-571478936141&psc=1&tag=&ref=&adgrpid=61623488145&hvpone=&hvptwo=&hvadid=312193478571&hvpos=&hvnetw=g&hvrand=3522986160684528301&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9027284&hvtargid=pla-571478936141

There are lots of sound deadening materials out there.

Bill

[manholt]

IMHO.  I would go with a soundproof/fireproof material from America!

[Achates_Bostons]

Just wanted to add that Megasorber is working on a distributor in the States selling their products.

[Achates_Bostons]

I am now looking at a product made by Willtes Foam.  It can be purchased on-line from either  www.pinta-accoustic.com or http://www.stopthesound.com.