Insulating the RV Doghouse

My wife and I insulated the floor of the cab in our 2019-20 Jayco 26Y last summer. We were quite pleased with the results. Much quieter and most importantly got rid of the "hot feet" on the passenger side. She is happy!

Some users reported that their doghouse got hot and even melted candy that was laying on its surface. We did not experience this problem with our RV.

We had plenty of the materials left over (Killomat) and decided to insulate the "doghouse".

This post summarizes that project.

The cab insulation project is here: https://www.jaycoowners.com/forums/f5/yet-another-post-about-sound-and-heat-abatement-2020-greyhawk-86233.html#post957747

Materials:

Killomat 50 mil: https://amzn.to/3iRFiRB. This was used on the cab floor and the leftover used on the doghouse.

Noico RED 150 mil: https://amzn.to/3hYAbPW. Used on the cab floor but not the Doghouse. I felt that the stock material and the Killomat would be enough sound and heat insulation for our needs. I also worried that three layers of material would be to thick and make reinstalling the doghouse difficult.

Tools

• Application Roller: https://amzn.to/3eKHxoq I bought this when we did the cab and found it to be a very useful tool to form and ensure the insulation fully adhered to the substrate
• Philips screwdriver
• Utility knife with a fresh blade
• Scissors
• Beer

Removal of the doghouse

The doghouse was removed by:

Remove the storage compartment that is on the front of the doghouse. I had no idea this compartment was removable. Getting it out of the way made getting the doghouse out from between the two seats much easier.

The compartment is affixed with two keyholes at the top and a clip at the bottom. When the clip is released the unit can be pulled upward and off.

To remove pull upward on the compartment while depressing the clip on the bottom of the assy. It's a bit "fiddly" but the key is to get the bottom clip to release the compartment so it can be lifted off.

Then release the locking arms at the upper and lower left and right of the doghouse and pull toward the rear of the RV and upward.

Notice the front storage compartment is removed

Remove the stock insulation

The stock insulation can be removed by freeing one edge and then systematically pulling the edges out from under the seal on the outer rim of the doghouse. The stock insulation is not glued in place but rather just held in place due to its form and the seal.

The stock insulation can be removed in one piece. Set it aside as we will replace it on top of the Killomat.

Do not remove the seal that is on the perimeter of the doghouse.

Install the Killomat Insulation

Clean the inner surface with alcohol or something that will remove any oils etc. Then systematically install the Killomat inside of the doghouse. You can fit each piece by placing it on the surface, with the backing on, and then press it in place to get it formed. Then cut it to shape. The Killomat cuts easily with a utility knife and scissors. 

Note: I left a 1-2" area at the edge of the seal free of Killomat. I did not want the thickness of the Killomat to inhibit installing the stock insulation back under the seal. This insured that the stock material was its original thickness as it is reinstalled under the seal.

The basic installation process is easy:

• Place the Killomat in its intended location and form it to the surface.
• Cut it to size. 
• Remove the backing. 
• Apply it to the surface. 
• Roll it on with the roller.

Killomat installed up to within 1-2" of the seal

Replace the Stock Insulation

After the Killomat is installed place the stock material over the top and fit the seal around the edges.

I used a Phillips head screwdriver to pull the seal up and over the edge of the stock insulation. Proceed around the perimeter of the doghouse until the entire edge of the stock insulation is under the seal.

The doghouse is now ready to re-install.

Reinstall the Doghouse Into the RV

Re-install the doghouse back into the RV

Reinstall the storage compartment onto the front of the doghouse. 

Enjoy the COOL & QUIET

Testing & Conclusions

I took 2 measurements with the sound meter on my phone. The first is at idle and the second is with the engine at 3000 RPM. The third measurement was previously made after the cab was insulated and running at idle. The apples-apples comparison is between the 1st and 3rd measurements.

The noise level measurement shows an improvement. I am not convinced that these measurements are consistent and accurate enough to make a conclusion about the value of insulating the doghouse. 

I have found that the real test is climbing up Parley's Canyon while the engine is groaning at 4000+ RPM and trying to have a conversation with the wife.

I don't know yet if this addition further reduced sound but it was easy to do and I had plenty of materials leftover from the cab insulation to do it.

I still have more material left. I plan to insulate the interface between the cab and the house. You will notice a step up from the cab to the house. This is a piece of fiberboard that is open to the road. Although I insulated it on the inside I plan to add insulation underneath and on the outside of this area.

Enjoy the Quiet

Don