Thread: Waterproofing floor (with covering?) & Mac's (VersaTie) Track installation Q's

Before you go and do the equivalent of turning your wallet upside down and shaking it onto the counter of your nearest van accessories store, here's my cheapa$$ solution...

Visit a local auto trimmers and buy several square meters of that wadded up cotton belly button lint underfelt stuff that's used under every car carpet ever. Buy some marine carpet in the colour of your choice while you are there.

Visit Bunnies and buy a few sheets of that black film faced ply that's used for formwork, and some sheets of 9 and 12mm ply.

Line the van floor with underfelt, cutting round things as needed; a bit of gaffer tape here and there can hold it in position. Cut the ply to fit inside all the major obstacles in the van and throw it on top.

Secure the plywood floor using either convenient bolts or boltholes that were already in the floor or a half dozen small bolts you install. Try for nice clear areas of the underbody so you don't have to work around pipes or double walled sections; hide the bolt heads by recessing them into the ply and use a LARGE washer on the metal side as reinforcing, and slather bare metal liberally in cold gal paint and a layer of bituminous underbody paint. Nyloc nuts are also good.

You should now have a waterproof, strong, flat and reasonably sound-reducing floor, that hasn't stolen too much headroom and is also easy to attach things to, and it's probably cost you less than $200.

Now spend a day or so figuring out what is going in there, and how you will get it in, and build in storage to suit (9 or 12mm ply is a good option for building supports).

Things like tie down anchors for holding bikes will probably mean popping the ply up and attaching via bolts from the underside of the ply (again, large washers to spread the load and and you can even recess the fittings).

With that done, flop the marine carpet in, cut to shape, and use double sided carpet tape to secure it.

If you've been clever, you've also put two or three coats of marine epoxy on the bottom 150mm of any plywood that touches the floor (and maybe made some sides for the floor that you can also waterproof) so it is quite hoseable when dirty. (see some of the boatbuilding threads, and a few of the camper trailer threads for ideas).

When constructing storage inside, remember to allow a bit of room between the van wall and anything that is secured to the floor, so there's clearance if the van body deforms slightly when cornering.

NOTE - I've never tried using epoxy on film faced ply...depending on your floor waterproofing desires it might be better to use standard ply (waterproofed with several coats of epoxy) if you are going to use epoxy to bond things to the floor. See the West Epoxy guide for more ideas. See the How to Use and Projects headings here - Epoxy by the Leading Epoxy Manufacturer | WEST SYSTEM Epoxy

I just gotta ask. Why? Do you snore loudly? Are you setting up a stealth surveillance vehicle? Do you want it to float? Is your girlfriend a screamer, preacher, sycophant or orator?

The mind boggles and enquiring minds need to know why.

See also: Ron Paulk's Mobile Wood Shop - YouTube

Ahh sensei! Thanks Master Splinter for your comments. Cheapa$$ is fine by me, no point in needlessly throwing money away. But I've gotta wonder how effective it would be... having to re-do it would be a major pain, in the soundproofing I'd rather spend more and know it's done right (or as best as possible).

On that subject, just reading around on some other sites and it seems that I may not need so much material for that anyway. I was following the lead of a van build thread I saw on Sprinter-Source.com, the guy was covering every inch of his interior with those vinyls! But it turns out that you really don't need to use that much (of course that's not what the manufacturers want you to think).

Good tips and ideas there though, I will check out this black lined ply.

Do you think the bitumenous paint is really a permanent solution? I just looked it up online and one info sheet said that it's not suitable for waterproofing??
Edit >> I must have been looking at a household/garden variety bitumen paint. Just found a automotive specific one and it looks better. There's also a Septone Body Deadener. Though it looks like the bitumen based ones have a max temp of around 35ºC? May be okay under a vehicle, but inside, if parked in the sun on a hot day..?

Originally Posted by Master Splinter

When constructing storage inside, remember to allow a bit of room between the van wall and anything that is secured to the floor, so there's clearance if the van body deforms slightly when cornering.

Yikes, hadn't though of that! I was going to mount a bench and cupboard right back against the wall (once the wall is lined) so that nothing can slip down behind... I'll have to look into this...

Also when you mention putting a large washer under the ply, for tiedown points, you mean you would just use the ply as the securing point? You wouldn't go right through to the metal floor?


Haha . Yes, the enquiring minds are the ones I've always gotta watch out for...

Really there's no reason other than comfort. When I learnt that you could achieve luxury car comfort and silence in any car just by adding damping and soundproofing vinyls, I knew it was something I wanted to do. Planning to keep this van for a long time, and if I don't do this right I know it's going to bug me every single time I drive it! At a minimum I think the doors in a van would all benefit greatly, always so "tinny" sounding. I love a good solid sounding door.


Interesting mobile workshop video there as well. There's definitely no shortage of ideas or inspirations for van layout & setup.

I'd use bolts to fix the ply to the floor (similar to how you mount child restraints in cars without child restraint mounting points) and then do a similar mounting arrangement (steel plate or large washer under the ply) for any fastenings (such as bike tie down points) that have real heavy things attached to them.

As for the paint...when they say 'not to be used as a waterproofing membrane', they mean as a waterproofing membrane to Australian Standard 3740 for waterproofing defined wet areas in class 1 and 10 buildings...so unless you are thinking of taking showers in there everyday and don't want tiles coming off the walls....it works fine in a car application!!!

When I was doing car stereo installs, it was the go-to solution to use when not paying $150 (at the time) a square meter for dynamat, and it also doubled as an adhesive that you could stick the underlay to.

Realistically, using that as a sound damping solution along with heavy, barium doped vinyl panels in the doors gets you to about 80% of what you can achieve. Chasing that last 20% is ridiculously expensive and time consuming.

And keeping anything solid and floor mounted away from the walls helps avoid the after-nasty-pothole shock of seeing a sharp dent on the outside of your van. You can use a foam rubber strip to hide the gap.

Hmmm... so 9-12mm ply - would that be strong enough if tying down a 200-250kg bike? I wouldn't want to have to use a bunch of points, only two straps at the front and one holding the rear down. I just don't have any experience with ply, so I'm a bit hesitant I suppose.

Thanks for the clarification on the bitumen paint. But I think I'm going to go with Raptor (by U-Pol). I can get it for $200, enough to do a LWB van and it can be tinted as well. Will basically just look like paint when done, needn't be highly textured depending on the application method. Then it still looks good if the floor has to come out for any reason.

I also found a site that does the sound/vibration vinyls at a much cheaper price than Luxury Liner et al.
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His theory is not to make any permanent alterations to the vehicle, so he glues the vinyl layers to each other with contact cement, then uses velcro to hold them down. No difference between using velcro of adhesive as far as performance goes. It will still cost more than it could be done, but I think I just have a fetish with "doing things properly".

As far as floor mounted things... would they seriously put a dent in the body panels?? Does that only apply for tall items like full height shelving? Do you think a workbench type height would be okay? Surely if it was braced against a strut/spar/ribbing there's no way it could contact the outer sheet metal?

As for strength, formply is 17mm and you'll find that lots of van floors use that sort of thickness. If you want stronger, go for marine ply (that'll be about 2-3 times the price). Check your local bike/off road place for suitable tie down points, or simply use a longer strap that wraps all the way around the panel (like a big seatbelt that holds the bike to the ply...needs no fasteners on the top, this way).

Modern car panels are pretty thin, so yes, firmly mounted fittings could easily dent it. All depends on the flex of your van. It might be no flex whatsoever, or it might distort like a shoebox with no lid.

And you can buy mass loaded (barium) vinyl panels from Jaycar Electronics.

Thanks for that info. I didn't know that JayCar did those kind of vinyls either... I reckon I must have learnt at least one new thing every day for the past month or two.

Okay, well I actually have the van now and I've measured up and worked out what kind of area I have if I want to cover all the floor and half way up the walls. I then took that and looked at prices for MLV to cover that area... and now I got an idea of why you suggested the cheapa$$ method. Woe is me... That stuff really ain't cheap if you have a big area is it?!

Makes me wonder about doing just the cabin area, or cabin area plus floor? Doing the whole thing (CLD on 25% of the area, and MLV/CCF half way up the walls) would cost over $2k going the JayCar option. I wouldn't mind spending $300, even $400 on a car, but when the area is about 3-4 times the size of a car (or more?)...

My thoughts now are to at least do the CLD on the doors and walls (looks like the roof is already done from the factory), and MLV/CCF on the doors and in the cabin area. Not sure if there is much point to CLD/MLV on the floor of the cargo area since there will be stuff permanently bolted down in there? That weight on the floor ought to help with any vibrations and noise? And there may already be CLD down there.

I'd still prefer to stay away from the underlay option, don't really want to use anything that could absorb water. I'll have a look in Clark Rubber and see what they have... at least a cheaper CCF surely...

Also looking at the option of buying from the U.S. but I'm thinking that freight will kill that idea.

Any ideas for other cheaper local options? I'm scouring the depths of the internet hoping, and seem to have come up with a few interesting ideas...

• Apparently Bostik 8158 is good for CLD. Not sure on price though, couldn't find that online...
• Resomat - $50/m². For use as CLD.
• AccoustiFlex - not sure on price, but seems to be for use as an MLV
• One suggestion was to use butyl roof flashing from Bunnings (in place of CLD?), but that doesn't look like a cheap option from what I'm seeing...
• Audimute Peacemaker 3.2mm - $19/m². Recycled rubber insulation - seems to be used instead of MLV for blocking sound. I'll check if Clark Rubber has anything like this... Seems cheap enough, but shipping from the States my kill this idea.
• Go direct to the source & buy from AliExpress/Alibaba etc.?

One other question - would it be worth using only a MLV layer? Or is that almost pointless without a CCF layer to decouple from the factory CLD and exposed body panels?

Part of me wants to just forget about it, but the other part knows that I would drive myself crazy if I don't do something to reduce the noise. Can't even speak to another person sitting right beside me without yelling. And any extended highway driving... well let's not go there!

The biggest problem with a van is the suspension is stiffer than a passenger vehicle, leading to more transmission of vibration and noise.

My recommendation (in order) would be:
Engine firewall and front footwell (both sides of firewall if possible) and bonnet (if none there already or replace the batt style stuff with a proper soundproofing compound)
Wheel wells (mix of underbody deadener outside and underfelt inside)
Mass loaded vinyl in door panels
Underbody deadener and underfelt everywhere else.
Use plywood for floors/internal fitout as it's better at reducing vibration and noise than metal structures.

After that, you have to start looking at softer bushings and springs...but this reduces your load carrying capacity and will probably cost you as much as using expensive soundproofing stuff anyway.

Cheers for that. I'll look into the underbody sound deadener... but don't all vehicles have an underbody coating from the factory? Or is that just for rust protection and not sound deadening so much? Or it's more effective if you add more?

Some more options for the vinyls/foam:

• Clark Rubber has 5mm CCF for $10/m² (with a discount for larger quantities)
• House/building soundproofing seems to be the most cost effective option for sourcing MLV. Sonicbar 4kg MLV, $29/m². I'm waiting to hear back from a couple of places that have CCF/MLV composite and will phone around as well, but I think that kind of price is the best there will be. That's a pickup price.
• Fatmat 9.2m² pack on eBay seems to be the most cost effective option for CLD so far, coming in at $27/m². Although looking at reviews it seems like it may only be a good product for the price. Actually, looking into it even more and it may not even be good for that... Looks like it's actually a asphalt based product - which is no where near as good as a butyl product. Although it's a lot cheaper, you could spend the same amount on a butyl product (and get much less coverage) and still have the same end result. Good info here. Reading around some more and it seems that it's just relabelled roof sealant! And asphalt products will fail when they're exposed to heat, not to mention stinking. The things you learn on Google, eh?!

Ahwell, looks like Fatmat isn't as good as it first looks. At least I'm weeding out all the bad options... It seems like there's no way but to spend the money for CLD. But the CCF and MLV can be had a fair bit cheaper.

I will definitely remove the floor around the firewall and footwells etc. and check it out, and under the hood as well.

Thinking about this a bit more, I am starting to realise that maybe I am over thinking all of this. I've got to drive a bit more and see if I really need the CLD. From memory there weren't actually too many rattles (just from the floor over rough patches of road, and the van was empty which would be many times worse). So seems like the factory damping could be good enough... I'll find out when I strip the interior.

Its more effective if you add more. And you'll find that many areas that transmit sound (good old wheel wells) often don't have any except at seams.

No kidding about it being more effective if there's more of it! I spoke with a local reseller for soundmat (a MLV and CCF composite) and he said that they only stock the 8kg/m² version because that's what most people use in their vehicles! Yikes! Anyway, $75/m² for the 4kg/m² if anyone is interested (or about $10/m² more for the 8kg version).

I also found out some info about Acoustiblok. That's a bit of a strange one, not quite sure what it is, but it's described as a viscoelastic polymer (usually only CLD media gets to list that). It's also isn't exactly a mass loaded vinyl, it doesn't use barium like MLV. It's recyclable. And it's only 3mm thin at 4.89kg/m². This one would cost $39.90/m². Not much info on their site about vehicle application, I asked and was told that most of their customers are happy with just the Acoustiblok in their utes (not sure if that refers to the cabin or the trays). Since it's viscoelastic I wondered if it would require a CCF decoupling layer, seems like it's almost an all-in-one solution. Apparently it will give a marginally better result with CCF installed.

So the choice so far boils down to:

• Sonicbar MLV & glue Clark Rubber CCF to it - equalling $39/m² (and a bit of time gluing)
• Acoustiblok by itself - also equals a total of $39/m²

Not sure on the thickness of the Sonicbar, but the CCF would be 5mm. I want for the Acoustiblok to be amazingly effective, but I wonder if MLV + CCF would be noticeably better?

Just keep in mind that the name-brand stuff really is the 'price no object' option, and you could be paying a lot for very little improvement on the overall performance. If you want to go that far, you really should look at softer springs, softer shock absorbers, and less stiff bushings in the suspension.