Floor insulation ideas?

CH28

New Member
Joined
Jul 3, 2020
Next on the list is the flooring. How has everyone done there's? Sound deadening? Insulation? Ply thickness? I'm planning on visiting the snow, so I want it cosy.

Any tips would be greatly appreciated.
 
Joined
Sep 28, 2020
Location
Lancashire
I built a 25mm thick wood framework with 25mm Cellotex (foam sheets) tightly fitted in all the spaces or gaps. Sealed all edges with wide aluminium tape (vapour barrier) then boarded with 15mm light weight ply sheets. I didn’t use any sound reading on the floor as I felt it unnecessary but I did use sound deadening material elsewhere in the vehicle.
 

CH28

New Member
Joined
Jul 3, 2020
I built a 25mm thick wood framework with 25mm Cellotex (foam sheets) tightly fitted in all the spaces or gaps. Sealed all edges with wide aluminium tape (vapour barrier) then boarded with 15mm light weight ply sheets. I didn’t use any sound reading on the floor as I felt it unnecessary but I did use sound deadening material elsewhere in the vehicle.
Thank you, was the framework screwed together? As I've read about gluing the battons to the floor with screws? When you say seal the edges, do you mean the edges between the foam and wood framework?
 

Sandbagsid

Active Member
Joined
Sep 16, 2019
I laid 1” rectocel (same as kingspan only a lot cheaper) then taped all the joints overlaid with 12.5mm ply screwed down in just a few places as the weight of all the furniture sat on it and screwed to the 10mm ply on the walls keeps it all in place. As the insulation is solid foam there isn’t a need for battens on the floor.
 

jjturner

Active Member
Joined
Nov 7, 2016
I did 25mm frame method, styxall'd to the floor, shaped to make the floor flat, with 25mm cellotex also styxall'd which is also then aluminium tape on the gaps. Overlayed with 12mm ply.
 
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Coire

Member
Joined
May 8, 2018
I have a low roof van. I previously had the floor insulated but wanted to make the most of the limited headroom and removed it when I rebuilt it. I didn't notice much of a difference to be honest. I had more impact creating thermal blinds for the cab and fitting a Chinese diesel heater. Big windows seem to be the worst areas for heat loss. Just something to consider.

Most of my camping is done in the north of Scotland in winter. May not be as cold as where you are heading.
 

Rixster

New Member
Joined
May 5, 2018
I did my Peugeot Boxer floor similar to egg-fried-rice. You would think that the van floor is flat. It is not ! Across the van, it is concave : rising at the edges. I used the plastic spacers to ensure that the battens were flat. I read that it is best to start from a flat surface when building furniture. I'm not fully convinced that it affects the build much much...The centre of the van was approx 5-6mm lower than the edges. Behind the wheel arches, it was much worse. As this in not a big area, it did not cause too many problems.

I did use 25mm PIR & 12mm ply but I have seen that 9mm ply can be used if the spacing of the floor battens is less. I wonder: more battens, thinner ply versus, less battens thicker ply. Weight difference : I would like to know!

Nobody ever talks about PIR insulation under the van. The areas are quite 'flat' and it is something I may do. But then again, the metal work is so conductive to the cold, I wonder if it would make much difference.
 

tacr2man

Active Member
Joined
Dec 13, 2017
Location
Near J10 M40
I have always thought that there are so many thermal bridges with a pcv that insulating the floor beneath the ply is pretty much a waste of time , better to fit big heater . Anyone tried this ?
 

mrmoosehead

Member
Joined
Sep 28, 2020
Location
Ilkley, West Yorkshire
I have always thought that there are so many thermal bridges with a pcv that insulating the floor beneath the ply is pretty much a waste of time , better to fit big heater . Anyone tried this ?
You'd probably lose loads of the heat through the underside without insulation under the heating mat :D
 

Roadrunner

Well-Known Member
Joined
May 29, 2016
Location
Glengormley
Put a layer of silver bubble insulation below the floor, it also cuts down the noise, wood in its self insulates also.
i would glass fiber any wood on the floor with one thin layer, stops water and rot, i found out the hard way and had to redo rear section.
 

jmatosp

Member
Joined
Oct 19, 2020
I'm tempted to go 20-25mm PIR, battens between groves if possible and 9mm (or 12mm) ply. Alu tape to close so I guess similar.
 

Rixster

New Member
Joined
May 5, 2018
The common thought is that marine plywood is far too heavy to use in our vans. I have tried some ('normal') 9mm ply in my raised step. It is actually ok, but I guess the distance between the supports is something like 200-300mm and there a quite a few of them.

I often wonder what is the best compromise : 9mm ply and smaller batten spacing (ie more wood) vs 12mm ply and larger batten spacing (ie less wood).

In some areas where I have had an after thought and require just a bit more support, instead of running long lengths of battens, I have just used small blocks (say 50mm square) and put these at strategic places....This was to provide extra support without having to greatly disturb the PIR board.
 
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