Flooring-to insulate or not

gotgoodkarma

New member
I keep going back and forth about pulling up the factory flooring and putting down some insulation and then plywood floors. Its a lot of extra work, but is it necessary? I lose so much heat through windows and I'm putting in an espar heater.

Here's what I want to know...will it help that much with keeping it warm? Will it quiet my ride? Any thoughts on putting a layer of plywood over the factory flooring? Will a wool rug on the floor help? If I do pull up the floor and insulate, what's a really simple and inexpensive way to do it?
 

john61ct

Active member
For winter heating, less is needed on the floor than ceiling.

Yes windows need covering too in extreme cold.

Floor insulation needs to be thicker than ceiling for aircon.

If using both then equal R-value all round.

A tight envelope is just as important.
 

220629

Well-known member
If you want to avoid pulling up the factory floor, Glasseye suggests that horse stall mats help with noise. The stall mats should also help with insulation by providing more space between your tootsies and the cold solid floor.

A search from the blue bar above will get more info.

There is a relatively recent discussion here.
https://sprinter-source.com/forum/showthread.php?t=73667

:cheers: vic
 

Kevsuda

Active member
I pulled the factory floor up and only put down a layer of underlayment foam. The thin stuff that goes under laminate. Then I put the factory floor back down laid another layer of underlayment and then put my snap together vinyl flooring in. I'm not sure how beneficial any of it was. One thing to consider is how much square footing will be exposed? In my living area, I really don't have much exposed flooring. Under cabinets, benches, etc. I really don't see any benefit. I don't think I would even put additional flooring over the factory floor again. The thing I do notice is nice is the rubber backed area rug I cut to fit in the area.
 

Matt Foley

Down by The River
Thinsulate is the best way to go, but not the cheapest for sure. I also just wanted to add that horse stall mats are soooo freaking heavy.
 

hein

Van Guru
We have been dialing in our methodology for using 3M Thinsulate(TM) AU4002-5 under flooring. We are using plastic lumber as furring strips and attaching those to the metal with VHB 4611. Here are some photos of our transit which has had Thinsulate under the floor for 6 months. I recently removed the plywood for rework and added the furring strips around the perimeter to improve support. The Transit does not have as many raised ribs and there are none along the walls.





All the best,
Hein
 

Onefin

Well-known member
We have been dialing in our methodology for using 3M Thinsulate(TM) AU4002-5 under flooring. We are using plastic lumber as furring strips and attaching those to the metal with VHB 4611. Here are some photos of our transit which has had Thinsulate under the floor for 6 months. I recently removed the plywood for rework and added the furring strips around the perimeter to improve support. The Transit does not have as many raised ribs and there are none along the walls.





All the best,
Hein
What is the R-value in that application?
 

hein

Van Guru
What is the R-value in that application?
The published R value for 3M Thinsulate is 3.7/inch. R-values for building insulation materials often include air gaps and the outside and inside sheeting so I don't believe they directly correlate or perform the same in vehicle applications. It's quiet and comfortable so we know it works. We have many customers using Thinsulate(TM) in hot and cold climates and they give us two thumbs up on the performance.

All the best,
Hein
 

john61ct

Active member
Polyiso wherever flat is OK. Just needs puncture resistance over the top, spread the load a bit.

More expensive / lower R-value stuff only "needed" to accommodate curves, or for those who think they are sensitive to off-gassing
 

GSWatson

2013 144
Also, rigid insulation like polyiso isn’t as good at noice attenuation due to the rigid nature. So I’m not sure how polyiso for the floor does for road noise; I used 1/2” closed cell neoprene for mine (harbor freight anti-fatigue mat) for both filler strips and insulation, with factory floor back over. Then outdoor carpet over that. Feels solid and is very quiet.


Greg
 
Floor insulation needs to be thicker than ceiling for aircon.

t.
I disagree. For air conditioning you will likely be dealing with massive heating from the sun. If the inside of the van is 80 degrees and the outside is 100 degrees you will have a 20 degree gradient at the floor. However, the roof and sides of the van are mostly affected by radiant heat which is much different than the conductive heat gain from the floor. Radiant heat is what causes vehicles to hit 140 degrees inside on a 90 degree day. That is why parking in the shade is so effective. It takes a lot of insulation to counter the sun's heat.
 

Aggie

2010 Roadtrek SS Ideal
So far discussion relates to winter insulation and noise. I wonder if floor insulation would also help with reducing inside temps in the summer after / during a long day drive. I sense heat continuing to rise from the floor for a long time after stopping, possibly as the exhaust system emits heat as it and surrounding components cool ?
 

bcman

Active member
Hein,

My understanding of your post is that the plastic strips are needed to space the floor off the sheet metal and keep the Thinsulate from getting crushed. Is this correct?
 

Shawn182

Well-known member
I disagree. For air conditioning you will likely be dealing with massive heating from the sun.
In that scenario you also have to factor in the immense heat that is trapped in the asphalt and concrete that is under the van from the sun. All that trapped heat rises right into he floor of the van as well as the rays from above.


I too was debating on floor insulation as my objective was more to keep cool in summer vs warm in winter and once that was pointed out to me and I did my homework I realized how important a good floor insulation was.
 

hein

Van Guru
Hein,

My understanding of your post is that the plastic strips are needed to space the floor off the sheet metal and keep the Thinsulate from getting crushed. Is this correct?
Thank you for asking for clarification.

It's necessary in the Transit because there are no ribs close enough to the wall so the floor is essentially cantilevered in those areas. The Thinsulate AU4002-5 does appear to resist compression and support weight quite well. Any structures sitting on the floor should have furring strips underneath. It will be fine to let the Thinsulate carry the load of people, pets and gear over the rest of the floor. I was skeptical at first but our experience with the Transit has shown us that Thinsulate(TM) AU4002-5 is a viable solution for floor insulation. Definitely very quiet.

If you are worried about too much deflection then we would recommend using minicell foam which we have been using for years. We just ordered a huge stack of it to replenish our stock.

All the best,
Hein
 

Top Bottom