Insulating a Sprinter Van
A bare-walled Sprinter can get very cold in the winter even with a heater running full-blast., or very hot in the summer. Especially a deep-black colored Sprinter.
Tyvek Thermawrap 5.0
The insulating material of choice for this build was Tyvek Thermawrap 5.0 - a material used in the commercial house building industry. A breathable product for air, water and thermal protection. We chose this due to cost and local product availability at the time.
There are no local 3M Thinsulate distributers in our area. The local Home Depot was clearing out the last two batches of Tyvek ThermaWrap at $100 for each roll. We bought two rolls, and that was more than enough for our needs as we still had most of the second roll left over. To bring in the “proper stuff” - 3M Thinsulate, it would have cost us nearly $1,000 with customs and shipping costs from across the USA border into Canada.
3M Super 90 Spray Adhesive
3M Super 90 Spray Adhesive used to mount the Thermawrap to the metal walls of the Sprinter, white Tyvek scrim against the metal, and the white fluffy material facing inside the Sprinter.
To use the product, spray the metal walls of the Sprinter with the adhesive, and separately spray the white Tyvek material with the adhesive. Do not spray the white fluffy side with adhesive. Wait about 3 to 5 minutes until the adhesive is almost dry to the touch. Then carefully mount the insulation, Tyvek-side up against the metal, and press the insulation in place with your hands.
On the Sprinter, there are plastic bumpers guard along the sides of the van, and are held on via plastic clips which penetrate through the metal wall. There are also small drain holes which allow any water that enters through the clips to drain out of the van. Careful that this adhesive is not sprayed on the plastic clips on the inside of the van, only around them. Once the Tyvek material is attached, any water that enters from the outside via washing or rain will not be absorbed by the Tyvek and will simply exit the vehicle via the lower drain holes.
To date, this method has prevented retention of water inside the van and works very well. Other types of insulation like wool, fibreglass or rockwool will actually absorb the water since they do not have the white Tyvek scrim up against the exterior holes.
Initially the 3M Super 77 Spray Adhesive product was used to mount the insulation, but in the heat of summer the adhesive would almost melt away and the insulation would begin to fall off the metal walls of the van. 3M Super 90 Spray Adhesive prevents this problem from occurring.