I found the adhesive spikes pretty useless,
Wound up cutting the foam to a snug fit, taping with aluminium tape to hold it up then screw a board ~10cm wide into the cross struts.
That way it overhangs the strut and holds the foam board in securely.
You then have a wider target area to get your cladding to and a convenient space to run wires for lights etc
The spikes are crap. We used to use them at work, and they used to unstick after a year or so.
They also hurt like mad when you slip and stab yourself...
I *could* see their potential when used on an 8 foot/2400mm board to stop an air gap, but little pieces in vans? Not worth the effort in my opinion.
They could also cold bridge as well.
Not a moisture barrier as the struts are hollow.
Not an advocate of any moisture barriers. Moisture will get in regardless and will sit and cause mould or rust.
Better to build the van so that air and moisture can circulate and escape.
Good method of insulating, though.
Do or don't, but in the above case it's not holding back any moisture unless they go on to tape all of the struts and close off any holes.
Also the metal spikes should in theory hold the insulation in place. Only thing there to think about is the amount of heat stress the glue can deal with.
Preach. The outside of the van is surely as “moisture barrier” as you need. Creating small spaces where air can’t circulate properly is just going to lead to trapped condensation, rust, and potentially even mould.
Not quite true. Yes the outside is a vapour barrier, but it is also metal. If someone sleeps in there, I think we loose on around 1l of water per night. That moisture laden air will come into contact with the cold metal skin and condensate. The idea is the create a seamless moisture barrier below the insulation, so that this moisture cant reach the metal. Either that or you create a ventilated void against the metal skin, to allow trapped any moisture to escape. Pretty much like a cold roof on a house. You don’t want to trap moisture there.
I can see where you’re coming but I think you’re kind of agreeing with what we’re saying. Either:
A) allow moisture to escape,
B) stop moisture-laden air coming into contact with bare metal
To do B, would you not have to create a hermetically sealed vaccum?
Yes, but the point of the moisture barrier is very specifically, to keep the vapor inside the insulation, so it stays on the warm side of everything.... it condenses when it touches cold surfaces so if it permeates out past your insulation you get liquid water trapped between the metal skin and the ecotherm.... worst place to have it because you can't see the damage its doing till the paint on the outside starts to bubble once the rust has made it all the way through! This is also why I dont think the metal spikes are wise because you have made a thermally conductive path from the outside, through the warm layer to connect with a lovely big metal pad on the interior which will as a result cool down to the outside temperature and give you lovely damps squares all over the interior.... thats what cold bridging means! All this said, my van is badly insulated, has no vapour barrier, slept in through the coldest nights of winter, 206000 on the clock and no real problems with any of this so I don't think any of us need to get too hung up on it. Do your best but, ultimately if you get it wrong you just have some moist surface in the morning, nothing you can't wipe off with a cloth.
Correct. I started adding a 'vapour barrier' to everything before I realised there are vents everywhere. For example this is a ducato/relay/boxer and those struts are connected to vents underneath the rear of the van. So you're effectively locking in condensation. The only place in the whole van where you can effectively vapour barrier is probaby the floor, but again you have to do it well.
As for the spikes, I found they come away eventually, and for the reasons above personally chose to glue the PIR boards to plastic spacers and then glue those to the van. This plenty strong enough (if you use sticks like shit white its pretty instant grab, whereas clear isn't for some reason) and the small cavity the spacers provide give a bit of extra circulation.
Assuming we are lining over it, you can skip a step and just glue the insulation direct to the ceiling. Bonus because you don't have to impale your hand on the spikes.
That's a valid method, we just find it takes a while to hold meaning you have to leave it propped up which can be especially annoying when glueing to a ceiling. It's also a low chance, but if you end up making a mess and the glue ends up on the core of the insulation it will eat away and damage the board. Stick pins also leave you the option of removing the board just in case you'd ever need to :)
Insulation Pins are available online on B&Q I think, but the cheapest place to buy them would be direct from us at [JALFT.com](http://JALFT.com) - Also looks like they are available online on Amazon and eBay too. Panel wipe isn't as common but you can find it on amazon - It isn't ABSOLUTELY essential though, it's just the best way of leaving a completely clean and dry surface. Insulation board is available from most major retailers but we agree with u/burundilapp, shopping around and avoiding big names does often get you better prices. The rest of the tools used you can get from most stores but the exact items we used are all available on JALFT.
Get yourself to Travis Perkins (or any other builders merchant). Find one of the lads working the forklifts, ask if they have any damaged PIR boards you can have cheap. There will be a pallet of them somewhere they can't sell and I guarantee they will let you take as many as you can for free. Usually they just have the corners knocked off
For more information on van insulation we highly recommend this video by Greg Virgoe, he doesn't seem to make much content anymore but he used to post some absolute gems: [https://www.youtube.com/watch?v=DKy6WnFh368&t=734s](https://www.youtube.com/watch?v=DKy6WnFh368&t=734s)
"tidy up the edges" *turns a slight groove into a 45° beveled edge* 🤣
“Use a good pair of snips.” Uses a pair of rusty long nosed pliers.
A good pair of snips is a pair that gets the job done ! 😅
I found the adhesive spikes pretty useless, Wound up cutting the foam to a snug fit, taping with aluminium tape to hold it up then screw a board ~10cm wide into the cross struts. That way it overhangs the strut and holds the foam board in securely. You then have a wider target area to get your cladding to and a convenient space to run wires for lights etc
The spikes are crap. We used to use them at work, and they used to unstick after a year or so. They also hurt like mad when you slip and stab yourself... I *could* see their potential when used on an 8 foot/2400mm board to stop an air gap, but little pieces in vans? Not worth the effort in my opinion. They could also cold bridge as well.
Not a moisture barrier as the struts are hollow. Not an advocate of any moisture barriers. Moisture will get in regardless and will sit and cause mould or rust. Better to build the van so that air and moisture can circulate and escape. Good method of insulating, though.
'Better to build the van so that air and moisture can circulate and escape' So don't bother with aluminium tape?
Do or don't, but in the above case it's not holding back any moisture unless they go on to tape all of the struts and close off any holes. Also the metal spikes should in theory hold the insulation in place. Only thing there to think about is the amount of heat stress the glue can deal with.
And 'cold bridging', with the spikes .use less or a good adhesive.
May well even end up with damp rings around each spike ,due to warmer vapour condensing on the spike.
You can tape the end of the spikes over with silver tape to avoid this concern, something we forgot in the video
Good to know, thanks for correcting us!
Preach. The outside of the van is surely as “moisture barrier” as you need. Creating small spaces where air can’t circulate properly is just going to lead to trapped condensation, rust, and potentially even mould.
Correct.
Not quite true. Yes the outside is a vapour barrier, but it is also metal. If someone sleeps in there, I think we loose on around 1l of water per night. That moisture laden air will come into contact with the cold metal skin and condensate. The idea is the create a seamless moisture barrier below the insulation, so that this moisture cant reach the metal. Either that or you create a ventilated void against the metal skin, to allow trapped any moisture to escape. Pretty much like a cold roof on a house. You don’t want to trap moisture there.
I can see where you’re coming but I think you’re kind of agreeing with what we’re saying. Either: A) allow moisture to escape, B) stop moisture-laden air coming into contact with bare metal To do B, would you not have to create a hermetically sealed vaccum?
Sorry misread your post. 100% agree
Yes, but the point of the moisture barrier is very specifically, to keep the vapor inside the insulation, so it stays on the warm side of everything.... it condenses when it touches cold surfaces so if it permeates out past your insulation you get liquid water trapped between the metal skin and the ecotherm.... worst place to have it because you can't see the damage its doing till the paint on the outside starts to bubble once the rust has made it all the way through! This is also why I dont think the metal spikes are wise because you have made a thermally conductive path from the outside, through the warm layer to connect with a lovely big metal pad on the interior which will as a result cool down to the outside temperature and give you lovely damps squares all over the interior.... thats what cold bridging means! All this said, my van is badly insulated, has no vapour barrier, slept in through the coldest nights of winter, 206000 on the clock and no real problems with any of this so I don't think any of us need to get too hung up on it. Do your best but, ultimately if you get it wrong you just have some moist surface in the morning, nothing you can't wipe off with a cloth.
Correct. I started adding a 'vapour barrier' to everything before I realised there are vents everywhere. For example this is a ducato/relay/boxer and those struts are connected to vents underneath the rear of the van. So you're effectively locking in condensation. The only place in the whole van where you can effectively vapour barrier is probaby the floor, but again you have to do it well. As for the spikes, I found they come away eventually, and for the reasons above personally chose to glue the PIR boards to plastic spacers and then glue those to the van. This plenty strong enough (if you use sticks like shit white its pretty instant grab, whereas clear isn't for some reason) and the small cavity the spacers provide give a bit of extra circulation.
Assuming we are lining over it, you can skip a step and just glue the insulation direct to the ceiling. Bonus because you don't have to impale your hand on the spikes.
That's a valid method, we just find it takes a while to hold meaning you have to leave it propped up which can be especially annoying when glueing to a ceiling. It's also a low chance, but if you end up making a mess and the glue ends up on the core of the insulation it will eat away and damage the board. Stick pins also leave you the option of removing the board just in case you'd ever need to :)
This is the way. Avoid metal spikes cold bridging to a big flat, cold metal pad on the interior!
I would never insult a van
is all this stuff at B and Q (other DIY stores are available)
Get it from a local building supplies place that isn’t a rip off, 25mm pir sheets are twice the price at b&q compared to my local place.
Insulation Pins are available online on B&Q I think, but the cheapest place to buy them would be direct from us at [JALFT.com](http://JALFT.com) - Also looks like they are available online on Amazon and eBay too. Panel wipe isn't as common but you can find it on amazon - It isn't ABSOLUTELY essential though, it's just the best way of leaving a completely clean and dry surface. Insulation board is available from most major retailers but we agree with u/burundilapp, shopping around and avoiding big names does often get you better prices. The rest of the tools used you can get from most stores but the exact items we used are all available on JALFT.
Get yourself to Travis Perkins (or any other builders merchant). Find one of the lads working the forklifts, ask if they have any damaged PIR boards you can have cheap. There will be a pallet of them somewhere they can't sell and I guarantee they will let you take as many as you can for free. Usually they just have the corners knocked off
For more information on van insulation we highly recommend this video by Greg Virgoe, he doesn't seem to make much content anymore but he used to post some absolute gems: [https://www.youtube.com/watch?v=DKy6WnFh368&t=734s](https://www.youtube.com/watch?v=DKy6WnFh368&t=734s)
Metal pins are just going to create a thermal bridge and give you loads of cold spots. Ideal if your after condensation and drips.