undervan insulation ?

kellyjohn

Guest
hi all when i was undersealing van a few weeks ago i noticed my swift kontiki has what i would call marine ply to the base floor do you think i could add 25-50 mm of kingspan to the underside if so how best to fix as dont really want to make loads holes i was thinking of gripfill or no nails of some sort what are your thoughts cheers john
 
wolly north yorkshire

hi
i used sticks like s--t from builder merchant sticks any thing and is fully
waterproof.
 
Thinking the same for my kontiki.

Couple of Questions:

If damp gets trapped between insulation and floor it will be detrimental over the long term

Do I put battens in to separate the insulation so there is an air gap with some ventilation so that vents will let limited airflow but not too much to let out the heat?

I propose roofing battens to give a 1/2" gap, sealed around each of the gas vent holes to ensure a thorough gas vent to inside.

Kingspan gives a better "U" value than expanded polystyrene therefore a better insulant, but would it make that much difference? Polystyrene is cheaper option.

As kingspan is not UV stable will it need to be covered?

I know that some static caravans are using SIPS panels as a floor for insulation (SIPS = Structural Insullated Panels, a sandwich of OSB3 board with a polyurethane centre for insullation) the OSB3 is waterproof.

Probably fit the battens with waterproof polyurethane adhesive as used in boats, this will prob be OK for kingspan. Could use low expansion foam used to fix plasterboard/dry lining to walls (Sticks like Sh*t to a blanket).

Fill in all holes with expanding gun type foam.

Obviously have to be careful around hot things like exhaust etc

Might even give better airflow under the vehicle, so less drag, better MPG etc. pay for itself in 500K miles??

Or do you know better???
 
wolly said:
hi
i used sticks like s--t from builder merchant sticks any thing and is fully
waterproof.
Click to expand...

I have used kingspan many times in house conversions, but can you really stick the stuff to the underside of your pride n joy and expect it to stay on whilst roaming the country?
Seriously would like to know, as I have pondered about a diy winterisation on the underside of our 'van, but thought the spray on expanding foam might be more permanent.
 
And remember that heat rises. I insulate my roof lights using pieces of closed-cell foam, the kind of stuff that climbers use to lie on in their tents. It's amazing, you can lie on snow and feel very warm. I cut up an old one and, if you make the pieces a couple of inches larger than the aperture, they'll bend and hold themselves in place. The difference in the cold was very noticeable when I first did this.

And of course some nice thick rugs on the floor are another simple way of adding worthwhile insulation. Sorry if I'm teaching granny to suck eggs!
 
Good idea about the roof lights, I was considering using an old swimming float, same idea.

Also means less heat being extracted when driving along, I keep the blind shut when driving, but you can see the bellying as the air is sucked out.
 
Bigpeetee said:
Good idea about the roof lights, I was considering using an old swimming float, same idea.

Also means less heat being extracted when driving along, I keep the blind shut when driving, but you can see the bellying as the air is sucked out.
Click to expand...

I forgot to mention that the closed-cell foam mats are quite cheap and available from good camping shops or on-line of course. With any left overs, cut up a piece just big enough to sit on and put in in your rucksack around the edge if you see what I mean so that it doesn't take up too much space. Brilliant if you have to sit on damp or cold ground.

Hi Gear Foam Sleeping Mat | GO Outdoors
 
Northerner said:
And remember that heat rises. I insulate my roof lights using pieces of closed-cell foam, the kind of stuff that climbers use to lie on in their tents. It's amazing, you can lie on snow and feel very warm. I cut up an old one and, if you make the pieces a couple of inches larger than the aperture, they'll bend and hold themselves in place. The difference in the cold was very noticeable when I first did this.

And of course some nice thick rugs on the floor are another simple way of adding worthwhile insulation. Sorry if I'm teaching granny to suck eggs!
Click to expand...

Whilst I fully understand your motivations for doing it, remember that most sky lights ventilate even when closed, and form part of the upper ventilation in respect of gas regulations in most vans.

Perhaps a good idea to pop out the foam when cooking particularly, Fires and boilers are normally room seamed so no problems.

I liike the idea though

Channa
 
I think my biggest concern is capturing moisture between the two layers maybe make something up for winter and remove spring time lots to think about thankyou for thoughts will keep racking my brain maybe secure with battens and which can be removed etc does anyone know how thick approx marine ply is thats used on motorhome floors just thinking how long for screws etc cheers all :)
 
Just for info
The floor of a Kontiki 2004 is a sandwich of plywood outer with polystrene inner and the top layer ie the inside floor again is plywood. It is not a thick layer of plywood much to my surprise.
 
Northerner said:
I forgot to mention that the closed-cell foam mats are quite cheap and available from good camping shops or on-line of course. With any left overs, cut up a piece just big enough to sit on and put in in your rucksack around the edge if you see what I mean so that it doesn't take up too much space. Brilliant if you have to sit on damp or cold ground.

Hi Gear Foam Sleeping Mat | GO Outdoors
Click to expand...

Also cheapo ones at poundshop in the summer. Ask and they may have some in stock. They make a good vapour barrier and an insulation base under kingspan.

Mr B.
 
i will bare that in mind ,mine is 1994 but presume same makeup cheers john
 
kellyjohn said:
I think my biggest concern is capturing moisture between the two layers maybe make something up for winter and remove spring time lots to think about thankyou for thoughts will keep racking my brain maybe secure with battens and which can be removed etc does anyone know how thick approx marine ply is thats used on motorhome floors just thinking how long for screws etc cheers all :)
Click to expand...

I'm just trying to do a bit of lateral thinking here as crawling underneath a motorhome to fit extra insulation won't be easy and you could end up causing some problems. Why don't you consider the easiest method, which must be insulating it from the inside? Put an extra layer of thick and inexpensive carpet on the floor and then throw some removable and cleanable rugs on top. You may even consider proper carpet underlay underneath your normal carpet, that must have pretty decent insulation qualities and is easy to remove when Spring comes.
 
I've added extra insulation to the non double floor part of my van, easy to fit. I used a 2m x 1.5m sheet of 30mm closed cell foam called Plastazote. I think I used an HD grade, perhaps HD24, it's not cheap but then I use LD24 in my business so guess what! I glued it in place with evostick timebond (which you can use upside down) and it's perfect.

My van was fairly new, clean and bone dry when fitted. 9 out of 10 people looking wouldn't see it as it is the same colour and finish as the original underfloor.

Do we notice the difference? Well it's still nowhere near as warm as the (heated) double floor bit but when it really is cold I would say the carpet is now cool on the feet rather than quite cold.

Why did I do it? Skiing.

Kev
 
Years ago for tent camping I bought some closed cell foam (sold by the metre off a roll) as a "tent carpet". I had two sizes one for 'car camping' (covering whole tent floor) and a smaller piece for back packing. Very light, very warm, easy to roll up and put away when not required. I'm still using the same pieces about 12 years later.

Looked on the web and the nearest I can find is

Closed Cell Foam Mats - Needle Sports
 
You must log in or register to reply here.

Users who viewed this discussion (Total:0)

Back
Top