Flooring Questions

[Jolly Roger bus 223]

i did 1/4 foam underlayment 3/8 birch that gave me a clean slate for marking the framing layout and to frame on top of.
inside of the wet areas like under the shower or kitchen sink/counter area under the bathroom sink shower area all got full size sheets of rubber flooring that turned up the framing 3-4 inches to make a pan to contain the water. the walking and other under areas on top of the 5/8" already installed got a layer of (helped a friend that did flooring move his business) 3/8"recycled fibre underlayment and then a mix of 3/8" bamboo and teak solid wood flooring but went together like a floating floor..
good luck

[demoman]

According to the people at Capitol plywood in Sacramento marine plywood does not have any waterproof qualities to it. The glue and the wood is the same as regular plywood. The only difference is it is guaranteed to have no voids in it. No unfilled knots or any place where it can sag or move under a load. It is not pressure treated. I have talked to several people who confirmed it but it seems to be an enduring myth.

[o1marc]

Originally Posted by demoman

According to the people at Capitol plywood in Sacramento marine plywood does not have any waterproof qualities to it. The glue and the wood is the same as regular plywood. The only difference is it is guaranteed to have no voids in it. No unfilled knots or any place where it can sag or move under a load. It is not pressure treated. I have talked to several people who confirmed it but it seems to be an enduring myth.

Mostly true if Capitol uses a waterproof glue, unlike most ply manufacturers. The biggest difference is the marine plywood usually consists of hard wood layers, instead of the soft woods used in standard ply. The hard wood and water proof glue are the only difference.

[banman]

Originally Posted by demoman

According to the people at Capitol plywood in Sacramento marine plywood does not have any waterproof qualities to it. The glue and the wood is the same as regular plywood. The only difference is it is guaranteed to have no voids in it. No unfilled knots or any place where it can sag or move under a load. It is not pressure treated. I have talked to several people who confirmed it but it seems to be an enduring myth.

You could always go to the source -- not all info on the web is bs...
(see chap 10, pg7.)

https://www.fpl.fs.fed.us/documnts/f.../fplgtr113.htm

[demoman]

Originally Posted by banman

You could always go to the source -- not all info on the web is bs...
(see chap 10, pg7.)

https://www.fpl.fs.fed.us/documnts/f.../fplgtr113.htm

Thanks for the clarification. I was assuming the waterproof glue used in marine plywood was the same as used in an exterior grade ply. It is definitely a better product than regular ply for an application that needs it. And I just found there are some made with chemical treated wood too. Either way it doesn't look like op would need it.

I gonna learn something about wood today. Thanks for the link.

[demoman]

And I should not have said the "only" difference. There are also better qualities of face wood, sanding, filled voids etc.

[Gdog 5651]

I used 1.5" Foamular covered with 3/4" Dri-Max which is I believe is Georgia Pacific's version of Adventech it has a 500 day exposure warranty if the inside of my bus is exposed to water for 500 days my problems are way more than the floor! I used the 3/4" without any framing or cribbing the floor is as flat and as solid as a bowling alley. Gene

[Ross]

Marine ply is overkill. Use a good t&g plywood. AC or better, A side up. I would not use Kills. Use a good metal primer, oil based.

[BigPaul367]

I hate Eucalyptus Trees, they are not indigenous, they stink after a rain, provide a haven for pill/stink bugs and kill everything around them. After I stripped out the bus, tore up the flooring, replaced all the metal that was ate away and covered everything with three types of rust control every day! Then I installed the in floor radiant heating! Then I laid down the flooring, YUP, you guessed it, Eucalyptus! Now I can stomp on it every day.
Tougher than Bamboo and Water does not bother it.

[Jon-Jon]

Originally Posted by family wagon

For a point of reference the pink Owens Corning Foamular 150 foam board found on shelves at The Orange Home Center is specified to have a minimum compressive strength of 15 psi "at yield or 10% deflection, whichever occurs first." The weight of a 150 pound individual standing directly on this foam, if spread perfectly evenly over 10 square inches, could cause a 1" foam board to crush almost 1/8".

People's feet are larger than 10 square inches, though they don't strike the floor exactly evenly and don't spread weight perfectly evenly either so dents in the foam would still happen.

What it comes down to is this: how rigid is the finished floor covering, in other words how well does it spread load? A roll product like linoleum will do little. Laminate flooring will do much better, but I wouldn't be surprised if the small bit of flexion below the joints made the flooring fail early. Of course if the bus isn't a full-time residence then "fail early" is still very far down the road!

A layer of 3/4" plywood is going to spread load very well and prevent any damage to the foam from concentrated loading. It's probably overkill, and it does deduct from the ceiling height that several of us are sensitive about.. but it's also easy and relatively cheap insurance. It also provides an anchor for relatively light-weight things to be secured to the floor.

Personally, I'm not going to put plywood over my foam. Instead I'm thinking aluminum plate somewhere between 0.060" and 0.120" thickness (it'll double as a heat spreader for in-floor radiant heat, but that's another story!).

family wagon, can you explain the aluminum plate sub floor idea a bit more? That sounds like a very thin piece of aluminum, is that enough to distribute the load so as not to damage the XPS underneath? Has anyone tried this? I like the idea, as the conductivity of the aluminum would spread the radiant heat nicely.

[ThemadTurk]

I used 3/4 inch plywood, cut it into 6 inch strips and nailed it down and stained it. Looks like hardwood flooring

[family wagon]

Originally Posted by Jon-Jon

family wagon, can you explain the aluminum plate sub floor idea a bit more? That sounds like a very thin piece of aluminum, is that enough to distribute the load so as not to damage the XPS underneath? Has anyone tried this? I like the idea, as the conductivity of the aluminum would spread the radiant heat nicely.

It's still just a concept in my head; I haven't actually built anything to try it out. There could easily be a fatal flaw I didn't think about yet. I haven't seen anybody else try it yet but if somebody gets to it before me and works out the kinks, I'll be very appreciative! I haven't worked with aluminum sheet enough to have intuition telling me how thick the top sheet should be, but gut feel is that 0.120" (1/8") should surely be overkill.



The idea is to cut grooves in the foam, lay down aluminum heat transfer plates, insert PEX tube, then lay another aluminum sheet over the top. Fasten the aluminum sandwich.. somehow. Maybe countersunk rivets or just adhesive to hold them together. Maybe it'll look nice enough to just leave as the finished floor, but probably I'd cover it with something like LVT.

[cofrari]

Our bus doesn't have any leaking from the window or roofs. Although as I was pulling the plywood up, there appears to be condensation between the wood and the metal floor. The bus is 11 years old and the current plywood isn't rotted: dry and firm on top, but damp underneath.



What do you do, or what can be done, to deal with the condensation? Am I OK just putting down a layer of the foam board on top of a surface that will get moist? I do plan to put some sort of rust prevention paint on top of the metal, so now I'm more worried of dealing with mildew, mold or just a damp smell.



On the positive side, this is the worst rust spot I have come across so far in the back half of the bus (haven't gotten to the front yet). So I'm thinking I'm getting off kind of lucky with floor rust compared to other photos I have seen.

[musigenesis]

Originally Posted by cofrari

Our bus doesn't have any leaking from the window or roofs. Although as I was pulling the plywood up, there appears to be condensation between the wood and the metal floor. The bus is 11 years old and the current plywood isn't rotted: dry and firm on top, but damp underneath.

You're right that this is really not bad at all for wheel well damage. It's not from condensation - most likely when you remove your wall panels you will see signs of leaking from some of the windows.

This degree of rust you can just treat with Ospho and paint.

[cofrari]

Originally Posted by musigenesis

You're right that this is really not bad at all for wheel well damage. It's not from condensation - most likely when you remove your wall panels you will see signs of leaking from some of the windows.

This degree of rust you can just treat with Ospho and paint.

Thanks for that tip - I'll take the walls off now in that area and see if there looks like leaking. The moisture was so spread out under the plywood (but not soaked) that I assumed it was condensation.

[musigenesis]

Originally Posted by cofrari

Thanks for that tip - I'll take the walls off now in that area and see if there looks like leaking. The moisture was so spread out under the plywood (but not soaked) that I assumed it was condensation.

Apparently bus operators sometimes hose down the inside of a bus to clean it, letting the water (or most of it) drain out the back door, and that might be the source of some wheel well damage.

As far as "in that area" goes, water from leaks can sometimes travel a good ways forward or backward, so the source of your leaks isn't necessarily right above the wheel wells. In my case it was, though - literal rivers of rust visible from the windows right above the wells. And the leaks were extremely small, just a trickle, but plenty to cause massive damage.

Generally, everybody finds that they need to remove all their windows, clean them, and reinstall them with proper seam sealant and/or butyl tape.

[Native]

Originally Posted by musigenesis

Apparently bus operators sometimes hose down the inside of a bus to clean it, letting the water (or most of it) drain out the back door, and that might be the source of some wheel well damage.

As far as "in that area" goes, water from leaks can sometimes travel a good ways forward or backward, so the source of your leaks isn't necessarily right above the wheel wells. In my case it was, though - literal rivers of rust visible from the windows right above the wells. And the leaks were extremely small, just a trickle, but plenty to cause massive damage.

Generally, everybody finds that they need to remove all their windows, clean them, and reinstall them with proper seam sealant and/or butyl tape.

Like yours, our bus had leaks above the rear wheel wells from the window. The amount that dribbled through was not a lot, but it does not take much to cause damage. As an experiment, pour 8 ounces of water on a large metal surface and see how much it travels and covers You might be surprised.

[banman]

Originally Posted by musigenesis

SNIP...

Generally, everybody finds that they need to remove all their windows, clean them, and reinstall them with proper seam sealant and/or butyl tape.

This seems like a great idea even if one is not overly worried about floor preservation --

I just wouldn't want the risk of mold/mildew once I started sealing things up...

[brokedown]

I wonder, has anyone ever used faced plywood subfloor and just stained it and coated with polyurethane or epoxy rather than adding flooring above it?

[Native]

Originally Posted by brokedown

I wonder, has anyone ever used faced plywood subfloor and just stained it and coated with polyurethane or epoxy rather than adding flooring above it?

I do not have the pictures or the links, but I have seen such. They used a blow torch to "brown" the plywood and ive it a very rustic look.