Mod: Insulated Floor

Laying an insulated floor in an RV serves two purposes. The insulation minimizes the heat (or cold) transfer between the interior and the exterior of the van, while the subfloor creates a solid base upon which all the cabinets can be attached to.

Temperature control or more precisely control of the humidity inside the van, is the most important issue when converting a van.

This project is subdivided into seven smaller projects, that are each documented with videos, photos and a step-by-step guides. When the project is completed, the entire guide will be made available as a FREE download below.

wheel wellSTEP ONE: Tie Downs & Wheel Wells
Noise reduction in cargo vans is sometimes important and the wheel wells are the obvious place to tackle the main source of noise production.
paper templateSTEP TWO: Paper Plywood Templates
To cut out the wheel wells and the C pillars from the plywood sub-floor, paper templates are made to accurately transfer the shape of the floor in the workshop.
floor insulationSTEP THREE: Floor Insulation
Insulating the floor, will help control temperature variations within the RV and add some sound reduction as an additional benefit.
glueSTEP FOUR: Fasten Insulation With Glue
To reduce squeaking and prevent unwanted movement of the insulation, spray glue will hold it to the metal floor.
spray foamSTEP FIVE: Spray Foam Application
The remaining spaces between the insulation panels are filled with an application of spray foam.
plywood-floorSTEP SIX: Plywood Installation
The plywood sheets are fitted and installed on top of the insulation.
fastenersSTEP SEVEN: Hardware & Soft-Ware
The hardware is installed, caulk applied and the finishing touches are being made.

  • Download This Free Guideinsulated-floor-small-1pdf [ .pdf Download ] – Size: 3.4 Mb
  • 56 Pages.
  • 8 Videos
  • 115 Images

Other projects of this Van Conversion:

I’m just a DIY’er with a lot of common sense, but with some of the projects, I use some tools and materials, that require you to really know, what you’re doing. Always read the manual and consult an expert if you’re in doubt.

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  1. I liked all your videos. It seems you know what you are doing. Besides the filming was great even in difficult and narrow passages.

  2. I’m enjoying your floor insulation guide, it’s very clear, useful, and easy to follow. I have a question as to why you place the insulation board silver side up vs silver side down? My plan was to place the silver-side down to protect from any moisture from the bottom of the van. Thanks. Any you advice you can provide.

    1. Hi Keith:
      First, I’m not an expert at this, but have researched it extensively.
      The reflective layer on insulation boards has more to do with insulation than moisture protection. A separate moisture barrier would do more in that case.
      From a practical standpoint, I approached this issue by looking at insulation, ventilation and moisture prevention. I find that proper insulation is virtually impossible in a van. Just opening a door to enter or leave, will affect the entire living area. The many door and window cracks and other openings around the vehicle make it even worse, both in winter and summer. As a warm weather traveler, I’m fortunate to be able to moderate the insulation; if you use the van in cold climates, extra insulation is always a necessity.
      Then there is the issue of keeping the heat inside (in winter) or out (in summer). You place the reflective layer on the side of the heat. I regard the metal skin of the vehicle as the moisture barrier, others place an extra barrier on the interior side of the walls. The Ford Transit already has an issues with moisture retention inside the wall cavities, so I decided against the extra barrier and opted in for more ventilation.
      While I also started my design with propane appliances, I have converted to an all-electric system. Otherwise, propane would have produced a lot of moisture inside the vehicle. Another measure that reduces moisture in the van, was the floor vent, that I installed inside the wall, just behind the drivers seat. In combination with the roof vent, which is located at the opposite end of the living area, natural convection is induced. It also allows for cooler temperatures from underneath the vehicle to enter.
      Many more things can be done to improve temperature and moisture, but insulation and on which side the reflective material should be, is a lower priority to me. Ventilation (and sometimes heating) is in my opinion much more important.
      Van Williams

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