October 26, 2021

How To Fix The HOT Floor Problem in Your Gas RV

How to Fix Hot Floor in Class C Motorhome

The cab area floor and dog house (engine cover) of in Class C motorhomes can get very hot if not properly insulated. It can be very uncomfortable for the passenger and driver especially when traveling during hot summer months.

What causes the hot floor? The hot engine and engine exhaust located directly under the cab is the main cause of the excess heat.

Here’s how I fixed the hot floor problem in our Class C motorhome by adding more insulation both in the floor and around the engine exhaust. These simple and inexpensive DIY projects will make the drive much more comfortable next time you hit the road.

Add Heat Shield Insulation Under Your Cab Flooring

We have carpet on the floor of our Class C motorhome, but the manufacturer mounted it directly on the metal frame with no protective barrier. I’m guessing your flooring is similar if your experiencing excess heat in the floor. Here’s how to add some insulation to keep the floor from getting hot.

Step 1: Buy some heat shield material and some foil tape

One roll of this heat shield material should be enough for one side of your cab area. I purchased two rolls and covered both the passenger side and driver’s side floor with material to spare. I also picked up a roll of aluminum foil tape to secure it.

Step 2: Remove the dog house cover and set it aside

The cover should have a few tabs that secure it to the frame. Release the tabs and work the cover off. You should see the engine and edges of the flooring once it’s off.

Step 3: Cut the heat shield to size

Place the heat shield material “foil down” on the area of carpet you will be insulating. Using a pen or sharpie, trace a pattern on the heat shield. Use a scissors to cut the heat shield material.

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Draw line with a marker around the opening

Step 4: Place The Heat Shield Under the Carpet

Lift the carpet and slide the heat shield under it with the shiny side down. Use strips of metal tape to hold the heat shield in place. Repeat this process for as much of the flooring you want to insulate.

Step 5: Replace the dog house cover and enjoy a cooler floor

That’s it! You’re RV floor will stay much cooler than before. Just insulating the floor will be a dramatic improvement. However, you may consider adding insulation to the inside of the dog house as well.

TIP: When replacing the engine cover inside the cab area (a.k.a “Dog House”), make sure it is snugly in place and all engine cover seals are closed. Wires or other materials under your dashboard may have gotten caught up in the opening creating a gap for air/heat to get in.

Wrap the Engine Exhaust Manifold and Exhaust Pipe

Adding insulation in the cab floor may still not stop all heat from entering the cab. If the engine cover inside the cab still gets really hot to the touch, then add more insulation inside the cover. If that doesn’t make a significant difference, then try covering your exhaust manifold and nearby exhaust pipe with an exhaust wrap.

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Wrapped passenger side exhaust manifold (left) and trailing exhaust pipe (about 2-3 ft)

First pick up a roll of exhaust wrap material. I used this titanium wrap for my manifold and exhaust. A 50 foot roll will be plenty. It also comes with several stainless steel zip ties to secure the ends of the wrap.

The instructions in the package should tell you what to do. Here are the steps I took and it seemed to work out well.

Step 1: Fold and tape the end of the wrap material

This is a tip I picked up online that worked very well. I used a couple pieces of Gorilla Tape to create a smaller end to fish through openings and prevent the wrap from unraveling.

Just fold each side of the wrap towards the middle and put tape around it. This keeps the wrap from fraying and makes it much easier to get around exhaust components.

Step 2: Measure and Cut The Length You’ll Need

Here’s a simple way to figure out how much material you’ll need for each section.

  1. Pull out a section of heat wrap equal to one loop around your pipe or manifold
  2. Count how many loops you’ll need
  3. Fold over the initial section as many times as there are loops
  4. Add a couple extra loops just in case you need more
  5. Cut the wrap

Step 3: Start wrapping the section of exhaust

You’ll want to start wrapping from the end that you didn’t tape.

  1. Start by folding the end over by about an inch
  2. With the rough frayed end down wrap it around once to secure the folded end
  3. Continue wrapping each loop pulling the extra material through each time
  4. Overlap each loop by roughly 1/4″ based on the manufacturer recommendation and pull it snug each time
  5. Feed the taped end through openings and around the pipe until the final loop
  6. Wrap it one last time and cut any excess material

Step 4: Secure each end of the wrapped section with stainless steel zip ties

Wrap one of the stainless steel zip around the end of each section. Use a needle nose pliers to twist and tighten the zip tie. Then bend it under and cut away any excess.

Note: There is a special tool for this, but I’ve found that a needle nose pliers works just fine.

Conclusion

I’ve made both of these mods to significantly reduce the floor and dog house temperature in our rig. The dog house used to get very hot, now it just stays warm (much better than before). If you’re still hot after doing these upgrades, driving with the air conditioner on seems to cool everything right down. Good luck and stay cool!

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