Starting a new build- Need insulation, for noise and heat.

[HarryInHudds]

Hi all, I’ve been lurking for a while and looking at old posts on here, but now we’ve taken the plunge and bought the replacement for our aging, much modified T5.
So with 5 year old Ducato delivery van sat on the drive I’m going to be asking many nube questions about the finer points of converting it.
I should disclose I have been doing reasonable level DIY in vehicles and houses for 40 plus years, as well as working as a mechanical design engineer for much of it...
And 10 years in VW size vans and decades camping.
However I think I might learn more here than from the hoards of first-timers on other sites!

Van concept spec

Our van is intended to be for travelling holidays for a couple: (possibly 3 seasons in all European climates, but no full timing or ski seasons). > insulation needed, but not OTT.
We do a lot of wilds & aires so need to be fully self-contained.
So far we rarely stay parked for more than 2 nights, and our only significant electrical use is a chest fridge. Thus minimal charging system and no solar (yet).

We like the VW campervan concept, but want a bit more: (full size N-S bed, showering capability, more storage with better access, easier cooking etc). I’ve got quite a well developed plan, to give us this in a MWB low roof Fiat. (Only 100mm longer than a LWB T5...)
Yes- low roof: we’re both fairly short and prefer the lower visual impact in the countryside, especially for wilding, and anticipate better sidewind resistance and mpg.

But we’re keeping the open side, single space ethos. As it’s more camping vehicle than mobile hotel, plastic crates are preferred to veneered cupboards etc, (looking down into our storage makes this easier too).

My Questions

• Noise. Our initial test drives proved the van to be stupidly noisy, and I get low level tinnitus after an hour in the T5… so
• Rear Sound deadening in the rear. I’m hoping to get a local company in Sheffield to spray foam the roof and walls. Is there any point in adding deadening pads first?
• Sound deadening the floor. I’m not bothered about thermal insulation in the floor. Ply plus lino plus rug should do; however I am concerned about noise.. Any suggestions? Deadening pads/ flashband? Soft rubber? Celotex? (but I’d rather not lose the height).
• Ditto any tips for quietening the cab? Door skins, engine bulkhead, floor, head liner etc.
  
  
• Spray foam insulation: It seems a no-brainer when starting with a clean van,
• Will 25-30mm will be plenty? I expect after that most heat will be lost be conduction through the ribs or ventilation.
• So how far to you go up the ribs? Would you carpet the rest?
• Do you use the voids for anything, eg hanging storage. Or
• Do you always do internal boarding?, with sealing, too?
• Can it be applied in winter?
• Anyone tried DIY spray cans? eg https://www.abbuildingproducts.co.u...ator-gun-1x-illbruck-foam-1x-gun-cleaner.html in case I can’t get a pro interested.
  
  Thanks for reading this far!

 

[SquirrellCook]

If you want a comfortable van, I think insulation if the key. Avoid any soft absorbent material. The manufacturers may claim it repels water, but that is when it's not covered in road dirt.
I'd be tempted to treat any potential rust areas first also. Aerosol spray foams are horrible in my experience. They never seem to do what you expect. Having to use them upside down doesn't help either. An experienced person using the two chemical method of spray foam would be the way to go I think.
At least one of our member took this route. i think he had some helpful tips about preparation too. Either hut him out, or hope he reads this.
I'd also be tempted to go full depth with it too, unless your worried about weight. At least do something with the floor too, even if it's only using sticky back foam in the low spots.
This should dramatically reduce the horrible empty van noise. Remember screw heads conduct cold. I've seen condensation on them. Try and use plastic push fasteners to hold panelling on if you can.
That's a couple of months of your life gone, have fun. Don't worry about asking any questions on here, though you may get conflicting answers.

 

[Squiffy]

I concur with Squirrell, insulation is key to noise and comfort both cold & heat my view on spray foam from what I have learnt over the years and from honest posts about it from folk who have had it done is, a) it's expensive b) You must find a really competent sprayer of foam c) it's very very messy, unless you do all the major masking up before the sprayer arrives, because they will do the basic minimum. d) Finding someone locally to come to you or even finding someone to go to is also difficult, unless you are lucky enough to be living close to a competent dealer. e) The benefits over 60 and 25mm foam wall insulation is debatable.
In my view the only real advantage is that it covers the strengtheners but that is a very small advantage for the price and clean up time. Phil

I'm sure others who have had it done will come back and say I'm all wrong, I can only say google the pros and cons of it and make your own mind up.

 

[wildebus]

There are quite a few Youtube videos that show Expanding/Spray foam insulation installations. Worth having a search to see both the good and the bad of them to get an idea of what it entails - and also what kind of prep work is needed (assuming even if you engage a professional to do this you may want to save time/money or just be involved in the process).
Most of the videos are of DIY installs but I do recall seeing a couple of apparently Professional ones which were pretty poor in their execution.

 

[Millie Master]

My 'Millie' had all 3 sides professionally spray foam lined, however I ran front to back load bearing 25 x 50 mm roofing lats across the floor with a 25mm thickness of Cellotex between them and then topped off with a 15mm thick marine ply floor that had various cross channels in it into which I ran various cables, gas and water pipes. Over the years we have been out in temps. as low as -17C and as high as +40C and the insulation has worked superbly!

My van is of course a Renault Master, however my plans were all drawn up over the years for a Sevel van but when at the last moment I decided to go for a Master, altering the plans only took me about an hour.

As for the spray foam, it is at a minimum 25mm thick and all the ribs are injected with it as well, oh and the main sliding door was also liberally injected with it as well.

Phil

 

[wildebus]

I concur with Squirrell, insulation is key to noise and comfort both cold & heat my view on spray foam from what I have learnt over the years and from honest posts about it from folk who have had it done is, a) it's expensive b) You must find a really competent sprayer of foam c) it's very very messy, unless you do all the major masking up before the sprayer arrives, because they will do the basic minimum. d) Finding someone locally to come to you or even finding someone to go to is also difficult, unless you are lucky enough to be living close to a competent dealer. e) The benefits over 60 and 25mm foam wall insulation is debatable.
In my view the only real advantage is that it covers the strengtheners but that is a very small advantage for the price and clean up time. Phil

I'm sure others who have had it done will come back and say I'm all wrong, I can only say google the pros and cons of it and make your own mind up.

I understand that if any panel repair work is needed that involves welding, the sprayed foam in the surrounding area of the repair has to be removed? that would be quite a hassle

 

[SquirrellCook]

I understand that if any panel repair work is needed that involves welding, the sprayed foam in the surrounding area of the repair has to be removed? that would be quite a hassle

Don't worry about it for later welding, I think it was 70's alfa's had in in the sills. Even welding with oxyacetylene, it just gets out of the way. If combined with some oily deposit it will burn. Though nothing your fire watcher shouldn't be able to deal with.
Hence I recommend treating for rust before you get it. I expect you'll need a good vacuum cleaner and air line to clean the cavities first. Or if it's empty, cover the dash with a plastic sheet and used traffic film remover and a pressure washer. You will get wet!

 

[MarkJ]

I can't add much to the spray debate (other than to say I chickened out of doing it) but I might pick up on not bothering with insulation on the floor. My current self build has two floor levels: the lower has 25mm insulation, then ply, then Altro. The higher bit (where we sit and sleep) has a 100mm raised floor over that lower floor build, with more insulation in that bit. It is very much warmer and we don't feel the need for a rug or mat or anything in that area. Your call, of course, but I personally would insulate the floor.

 

[Squiffy]

I can't add much to the spray debate (other than to say I chickened out of doing it) but I might pick up on not bothering with insulation on the floor. My current self build has two floor levels: the lower has 25mm insulation, then ply, then Altro. The higher bit (where we sit and sleep) has a 100mm raised floor over that lower floor build, with more insulation in that bit. It is very much warmer and we don't feel the need for a rug or mat or anything in that area. Your call, of course, but I personally would insulate the floor.

This is good advice, I also have 25mm insulation under a 19mm ply floor with Carnian flooring over the ply, and in the depths of winter we can walk bare foot on the floor and not feel the cold. Phil

I did at one point put my total build pictures up through photo bucket, but I think they have changed their policy and the link may now not work? Pity because it showed the complete floor structure and build.

 

[SquirrellCook]

One thing I would mention is not to use ply for the floor. Use Buffalo board or some other phenolic resin board. If you ever have a problem with damp, it will not delaminate. Also 12mm thick should be enough using this stiffer material. Betty is getting it even on the shower walls.

 

[HarryInHudds]

Thanks for all the replies. I'm still not sure what to do with the floor, the van is only intended for "camping weather" - and if we do more the ubiquitous diesel heater may be cheaper. The few days a year we'd need heat wouldn't show in power use.
Phenolic ply is an interesting option I'd not considered, though I'm drawn to idea of not packing the floor solid, to allow air flow underneath. I suppose I'd have to ensure it was sealed from the interior to avoid sucking condensation out of the air. Phenolic may give a belt and braces on that, despite the cost.
In normal Sevel style, there'll be belted passenger seats behind the front pair, meaning that a) I have to bolt a structural frame though the van floor, and b) there is a raised step for our feet when sitting, whilst this also hides a small shower tray it should be warmer.
I'm using Citroen Picasso seats as they clip on with a simple interface (suitable for DIY welding), fold flat, or are quickly removable. [And no, I don't intend to crash test it!]

One of the features of doing a campervan, rather than a motorhome, is that there are no internal walls, and in my plan, few internal panels. Bed and kitchen will be off an ally frame. If I'm careful I can imagine removing the all interior panels in a couple of hours, leaving the technical bits (pipes and wires) in the walls. As such the van is capable of evolving if experience proves it necessary.

In the past I've often chuckled at American vans from youtube etc for leaving steel doorframes bare, yet I'm now considering this suspect practice... I know steel has something like 1600 times the conduction of typical insulation, so even when it's thin wall it's bad news. Maybe some VW style stretchy carpet will sneak in. I imagine controlled ventilation to be more important. I remember seeing a promotion for passive ventilation ducts with passive heat recovery for houses (outgoing air warming incoming air etc) : anyone tried this on a van?

 

[Millie Master]

One thing I would mention is not to use ply for the floor. Use Buffalo board or some other phenolic resin board. If you ever have a problem with damp, it will not delaminate. Also 12mm thick should be enough using this stiffer material. Betty is getting it even on the shower walls.

And this is why I used Marine Ply as it doesn't delaminate most especially as in my case when it is liberally varnished on both sides and all the edges before being put down.

Oh and as for treating everywhere before spray foaming to prevent rust, all Renault Masters were fully dip galvanised post 2004 and all Sevel vans had exactly the same treatment post 2007, so unless they have been badly abused, rust quite literally isn't a problem.

 

[SquirrellCook]

And this is why I used Marine Ply as it doesn't delaminate most especially as in my case when it is liberally varnished on both sides and all the edges before being put down.

Oh and as for treating everywhere before spray foaming to prevent rust, all Renault Masters were fully dip galvanised post 2004 and all Sevel vans had exactly the same treatment post 2007, so unless they have been badly abused, rust quite literally isn't a problem.

I’m sorry I will have to disagree with you about the marine ply. I purchased some from Bristol with all the correct markings. It was no more water and moisture tolerant than shutting ply. It cost me a lot of time and money to refit Murky’s wet room after it failed.
Varnishing is an excellent idea, especially the sawn edges. It’s recommended with phenolic resin board too. The one thing that worries me about varnishing ply, is it burns like there is no tomorrow.
I wanted to use double skinned ply in the Betty build, but it was unavailable. So I’m varnishing the backs and edges.

 

[HarryInHudds]

Sevel vans had exactly the same treatment post 2007, so unless they have been badly abused

the only rust I've found so far is where first users screwed ply lining straight through the wheel well. Thus is manageable, though I've yet to lift a floor panel... but I'm hoping they won't have got quite as wet.
Re marine ply: I never got it wet untreated, but I had some 4mm left over from building a canoe, and it was incredible: despite it's thinness it was incredibly hard to snap, and of course, beautifully flexible. On a boat, you epoxy coat it with grp taped seams.

 

[Millie Master]

I’m sorry I will have to disagree with you about the marine ply. I purchased some from Bristol with all the correct markings. It was no more water and moisture tolerant than shutting ply. It cost me a lot of time and money to refit Murky’s wet room after it failed.
Varnishing is an excellent idea, especially the sawn edges. It’s recommended with phenolic resin board too. The one thing that worries me about varnishing ply, is it burns like there is no tomorrow.
I wanted to use double skinned ply in the Betty build, but it was unavailable. So I’m varnishing the backs and edges.

I am afraid it is those damned damnable Chinese (or possibly Russians) again, they make rubbish and they sell rubbish and they hold the World to ransom!

European marine ply lasts and lasts, so check for the origin of any ply before buying it, the stuff I used was made in the UK and is as good now as it was when I made 'Millie'.

 

[SquirrellCook]

I am afraid it is those damned damnable Chinese (or possibly Russians) again, they make rubbish and they sell rubbish and they hold the World to ransom!

European marine ply lasts and lasts, so check for the origin of any ply before buying it, the stuff I used was made in the UK and is as good now as it was when I made 'Millie'.

And this was purchased from a Boat building company.

 

[trevskoda]

Floor ply is best coated in fibre glass both sides and edges, resin board is much better.
Do remember to have all wiring runs sorted and in place at the start, think solar is a must.

 

[HarryInHudds]

I think I'm generally aiming for a lower spec build... static caravan rather than bespoke arctic cabin... I've got enough custom assemblies to build, so I'm trying to avoid non-essential extra steps, eg adding a grp process (plus sourcing all the specialist materials).
But thanks for the suggestions, they will get remembered in case I get more time or needs change.

btw I happened to be in the woodyard this morning, and asked about Phenolic Ply. Wow! 12mm at £80 a sheet,
and with an alternative brand Celotex from Wickes at £30... x 2 sheets...
My wife thinks £220 is excessive to be able to walk round the van in socks, for a few cool nights. I didn't even prompt her! But we've never considered it a problem in the VW.

 

[wildebus]

something which may be relevant depending on the vehicle .... the more insulation on the floor, the less the headroom you have.

 

[wildebus]

Floor ply is best coated in fibre glass both sides and edges, resin board is much better.
Do remember to have all wiring runs sorted and in place at the start, think solar is a must.

whilst it is neater, I would avoid underfloor cabling if possible. (not sure if you had that in mind?)
Usually enough furniture runs going on on the side to be able to run cables along the floor/wall edge and have it accessible for service but hidden from view.