screw down floor or float floor

[Virgil Jones]

Planning the build for the van I just bought.  I have watched tons of videos and read forums. I have narrowed down the insulation to polyiso, no reflectix, and probably some sound deadening material is certain places.
I like the idea of 1"x2"s as a framework on the floor, 1" polyiso in between and 3/4" plywood on top as the floor (maybe a floor covering in the non-bed and non-cabinet areas)
The question I have is:
1... do I just let the floor "float" OR 
2...screw it down to the van's metal floor (not liking this idea) OR
3... glue each layer down with Liquid Nails or some other appropriate glue.
Any experience or thoughts?
Thanks

 

[Headache]

I'm going to use a floating floor because everything I put on top of it is going to hold it down as well as most of what I put on it being secured to the walls in some way.

Also, if you ever wanted to remove the floor or repair a section of it, it's going to be MUCH easier if it isn't secured to the floor metal. I also don't want anymore holes in the floor because they are exposed to harsher conditions underneath making for more ways for the floor metal to corrode.

 

[DrJean]

I'm using prodex under the Ford flooring rubber floor (fills grooves). Prodex will provide some sound buffering as well...I have to maybe put two layers on the wheel wells though. It's probably 1/3 the cost of reflectix. At the bottom of the index page here, Bob has a link for the newest stuff. I'll use non-skid floor protectors under any "furniture" I put in and they will be attached to the walls so they don't slide around and the floor shouldn't either. I am thinking of putting outdoor rugs (I have 2 matching nice ones I hope fit well) down on top of the rubber floor.

I guess it depends upon how heavy you are when you walk, and how heavy the things you're putting on that floor as to whether you want it moving, squeaking or whatnot?

If you screw it down, use furring strips attached at the sides, and still as you probably saw on those videos, you must seal those holes and screw or you will rust!

 

[MrNoodly]

Polyiso will act as sound deadener. So fill the grooves in the van floor with lath strips in order to even things out, put down the polyiso, then cover it with plywood. Three-quarter inch is WAY overkill. You're not putting it over joists. Polyiso won't compress. All you need to do is protect it from punctures and gouges. Something like luan or masonite is plenty thick for your purposes.

 

[Almost There]

I floated 3/4" plywood on the bare floor.

No matter what insulation method I've used on the walls and ceilings of vans, I've never insulated the floor. If it's cold out, there is no amount of insulation I could use that would keep the floor warm anyways.

BUT, I laid out the plywood such that all the seams were going to be under cabinetry. The only full sheet of plywood starts at the passenger side just behind the passenger seat(about equal to the side door opening. It was carved along the passenger side so that it fit snugly against the passenger side wall. A 2' x 8' piece, similarly carved on the drivers side was almost forced in to place...(snug fit!). Then the balance of the rear of the van was done, again matching against both walls and is snug to the closed rear doors.

I used 3/4" so that I had something thick enough to ensure a good hold from the screws that are holding all the cabinets/bed frame, etc. down to the floor.

 

[GotSmart]

There is no need to use lath strips.  The Poliso will compress.  I used 3/8 Advantek, and screwed it down with these.  Stainless steel self tapping flat head.  I did not want things jumping out of place if I was in an accident. 


https://www.grainger.com/category/s...steners/ecatalog/N-8n3Z1z0ny6t?sst=subsetTest

 

[Reducto]

Let it float. It's not going anywhere.

 

[MrNoodly]

I used 3/8 Advantek...

A few years ago I did the advertising for Advantek and other Huber Engineered Woods products.  If you wanted to use it properly, you would've glued it as well as screwing it. 

Mighty spendy stuff, and heavy (since it's mostly polymer adhesive) , but I supposed its water-resistant properties might be useful—especially with screw holes in the van floor.

 

[GotSmart]

A few years ago I did the advertising for Advantek and other Huber Engineered Woods products.  If you wanted to use it properly, you would've glued it as well as screwing it. 

Mighty spendy stuff, and heavy (since it's mostly polymer adhesive) , but I supposed its water-resistant properties might be useful—especially with screw holes in the van floor.

When I rebuilt the floor in the jewelry store, the owner wanted 3 layers of Advantek, (Glued and screwed) Then the 3,000 lb safe came in.  Then Durarock and tile.  It may have been excessive, but after the raccoon came through a hole and trashed his showroom, he was not about to go cheap. With the safe tiled in place, nobody could move it.  

Anyway, 3 + years, and no problems.

 

[MikeRuth]

Just my case, 2007 Ford Van. I laid in 5/8" wood floor and screwed it down. It's solid, I can attach things to it and it has not been a problem at all.

 

[Gary68]

depends on what you have planned,if your going to be on pavement with little excursion off,a floating tongue and groove will do,myself,if it isnt secured down it will be bouncing off the ceiling

 

[ArtW]

So was that YOUR camper i saw lying off the side of that level 6 trail back in 98?

 

[vanman2300]

I would let it float. Every time you put a screw in its another chance for rust to form. Bolting the furnishings will be plenty enough to keep the floor in place and don't forget that a floating floor adjusts better to temperature swings.

 

[Gary68]

So was that YOUR camper i saw lying off the side of that level 6 trail back in 98?

nope,but i am a firm believer that things are meant to be used and that includes skid plates :angel:

 

[Vagabound]

Now that I have a breather to add a note ...

What about a quasi-floating floor?  Mostly floating, with only one or two screws to keep it from sliding.  Might be best of all worlds ... or worst of them.

I initially agreed with whomever said that 3/4 inch plywood on the floor was overkill.  Then later, somebody made the point that they used 3/4" to provide a thick enough base to screw into while attaching furniture to the floor.  That made sense to me.

Vagabound

 

[Virgil Jones]

So some vote for screws and some float.  Does anyone have a vote or experience with gluing the floor?  My current thoughts are lathe strips in the metal floor grooves, then a frame work structure 1" High with polyiso in-between for sound and insulation. Then 5/8 inch plywood.  I would like to glue the floor joists to the metal floor and the plywood to the floor joists.  I am researching adhesives for both situations   Any thoughts on this?

I'm very tall so my bed will be along the drivers side wall.  I will be putting AGM batteries under the bed.  On the passenger side wall I will have the kitchen...sink w/pump...propane stove...Dometic frig... lights...plug-in outlets for a/c and d/c.    I plan on running a pair of SHEATHED 4 gauge cables in a groove under the 5/8inch plywood (in the area where the framework and insulation will be). One cable for d/c from the battery and one cable for a/c from the inverter.  They will be going to fuse panels under the kitchen counter and then spread smaller wires where necessary.  Has anyone done this?  This seems easier than running the wires around or through the ceiling. I also plan on having a second fuse panel on the battery side to take care of that side of the van.  I'm not sure whether to run one cable off the batteries and then split it at a junction box to the two sides or run two seperate cables off the batteries.  Virgil

 

[Vagabound]

So some vote for screws and some float.  Does anyone have a vote or experience with gluing the floor? ...

Could be wrong, but my gut feeling is that the amount of flexing and moving of a vehicle floor would end up either defeating glue or reducing its lifespan considerably.  Even special glues. Or by the time you found one that would really work well and last, it would no longer be cost-effective. Just an impression.

Vagabound

 

[highdesertranger]

I always let the floor float in a van. any cabinets you build are attached to the floor and the walls, which hold the floor down. highdesertranger

 

[Fluffhead]

Sikaflex 221 or 227 would make a great flexible bond in a floor build.

http://usa.sika.com/en/automotive/a...5/01a005sa11/01a005sa11100/01a005sa11102.html

 

[Vagabound]

Sikaflex 221 or 227 would make a great flexible bond in a floor build.

http://usa.sika.com/en/automotive/a...5/01a005sa11/01a005sa11100/01a005sa11102.html

Is somebody a closet boatbuilder? ;-)

That's the only place I've heard of Sikaflex before.  ... Now that I've typed that, I see in your link that Sika has an automotive category. 

Learn something new everyday.

Vagabound