Sound insulating my doghouse

[Wayward1]

I own a 2007 Mirada class A motorhome. And in my coach the only thing between me and a howling V10 was fiberglass and carpet. I was looking for a way to significantly reduce the noise and heat transmission through the doghouse or tunnel. Here is what I did.



Shopping list:



6 X 2" elevator bolts in 1/4"

6 X 1/4 nylon lock nuts

6 X 1/4" fender washer

1 sheet of metal lathe with ridges.

1 package of Roxul Safe and sound insulation. (Comes with 12 pieces)



You can buy everything at Lowes except the Roxul which Home Depot carries. Some Lowes are starting to carry Roxul as well.



I removed the doghouse and laid it upside down and laid to pieces of Roxul side by side in the Dog house. that filled the doghouse perfectly. I then trimed it to fit with a serrated bread knife or a saws all blade. On top of the 3" thick Roxul I laid the metal lathe I believe that it was 28" wide. I trimmed the lathe to length and clipped the corners to fit. I used tin snips and a metal cutoff tool using an abrasive disk. I then drilled the 6 holes through the top of the doghouse. I inserted the elevator bolts though the carpet, fiberglass, insulation, and metal lathe. As the bolts are 2" you will need to press down on the lathe firmly to attach the washers and nuts. That's it! I still had space between the lathe and the engine intake. I had to press down more to re-insert the doghouse bolts and that's good.



Test drive impressions were amazing. I hoped for some relief from the noise and I got more than I could have hoped for. Conversation and movies are much easier to hear now. I believe that the heat should be lessened significantly also. Total price was just under $50. I am so pleased with the results and so is my wife.



Roxul is made from basalt and slag and is pure rock. Melting point is over 2200 degrees Fahrenheit. Google it it has a lot of amazing properties but remember that Roxul comes in two forms. One is for temperature insulation and one is for sound. I recommend the Safe and Sound which is designed to stop noise.



Jonathan



(Sent from my phone so forgive any typos please)

[stink]

So cool!! Can I copy that for my engine cover? Yup a DP but on a warm evening and a late arrival the bedrooms like a sauna!

[Wayward1]

You will have enough lathe and Roxul for probably three covers. I'm putting some of the extra in in the generator bay and in the front upper cap.

[Wayward1]

Oh and copy and improve on my design please.

[Giant Jeff]

Sounds like a good fix. So did you mold the metal lath to the conture of the doghouse under side? Any pics of the under side of the doghouse cover?

[_nelsonc]

If there are no pictures, it didn't happen. :-) Show us how it looks.

I have a 2013 Mirada 35DL I would like to quiet. Sounds like a good approach.

[spritz]

X's 2 I found some materials if interested
I'm going to try on my doghouse unless someone else has a better idea.

Description

Thermozite Thermal-Acoustic Insulation 48" is an excellent heat and sound barrier! Thermozite is a lightweight thermal-acoustic insulation composite made with Eco-fi™ polyester fiber (100% post consumer recycled plastic bottles). This insulation material has a laminated scrim reinforced foil on one side and jute carpet padding on the other. The tough aluminum foil side provides a radiant heat shield which can increase thermal resistance up to a factor of four (depending on distance from heat source).
Use Thermozite insulation to insulate floors, doors, side panels, and engine compartments in cars, RV's, trucks, and boats as well as firewalls, machinery enclosures, and noisy pipes and valves. Install foil side down when used to insulate flooring. Install foil side up when used in a headliner application.
Specifications

Width: 48 inch Thickness: 1/4 inch Sale Unit: Sold per linear yard. Please Note: Maximum continuous piece for shipping is 15 yards.
Thermozite Features:

• Superior sound deflector (sound deadening)
• Excellent heat barrier
• Minimizes vibrations
• Lightweight and durable
• Contains no irritants or carcinogens
• Cut with scissors or knife

Thermozite Specifications:

• Noise Reduction Coefficient (Hz): 0.30
• Thermal Conductivity (K): 0.280
• Thermal Resistance (R): 1.3
• Passes FMVSS 302
• Maximum Temperature: 500°F

Thermozite Applications:

• Auto, RVs and Trucks
• Boats and personal watercraft
• Mass transit vehicles
• Hot rods
• Headliners and hull liners
• Engine hatch covers
• Door panels
• Interior firewalls
• Machinery enclosures
• Noisy pipes and valves
• Catalytic convertor shielding
• Construction equipment

[homeless]

Ya pictures!!!!

[Wayward1]

I'm on the road with work. So I'll try to get some photos when I return. The metal lathe I used I laid down the middle of the two pieces of Roxul. It did not come all the way to each side. It left a little on either side unsupported. Molding the lathe was not required. It does have enough support and the Roxul is firm enough that I don't expect any problem with those small areas I didn't cover with lathe. The pictures will help.

[DegoRed]

I just used Dyanmat on my doghouse, cut the noise in half and reduced the heat considerably. Took just a few minutes to apply, actually took longer to get dog house off and out of the coach.

[cochise1949]

I really like this idea for my F53. My problem is....noise from these chassis' has been an issue for years. I would hope that one of the RV manufacturers, of the many that use this base, would have incorporated noise suppression into their design/fabrication. Has anyone checked with Ford or Winnebago or whomever to see if adding the insulation affects cooling of the engine etc.?

[BA-in-Mich]

I have been wanting to do this for years on mine. My concern is how much weight does it add to the dog house? My cover is 5/8" plywood with some sort of aluminum reflector on the engine side and the carpet on the top side. Heat has never really been an issue but the engine fan kicking in gets to be old real quick. I would say my cover right now weighs about 30 lbs.

[Wayward1]

I would guess that you would add 3 to 5 pounds.

[Wayward1]

If you were cool and had friends with class A's. You could drop the cost a lot. You will have enough lathe and Roxul for 3 MH. Actually if you bought 2 sheets of lathe and the hardware you could do 6 MH.



Roxul one package. $42. (12 pieces). You need 2 per MH



Lathe $7. Will probably do 3



Hardware. $8 ish



So split the cost and everybody wins.