| Author | Message | ||
| Pat Bartlett (Muddog16)
Rating: N/A |
My bus is 20 years old i noticed when tearing the old flooring plywood out that only the edges show moisture problems, anyone have some good suggestions or bad, i know pressure treated plywood would be good, but can i use that in a enclosed area like a bus, are there any health hazards? | ||
| TWO DOGS Rating: N/A |
paint the edges,make sure it's 3/4 plywood | ||
| Pat Bartlett (Muddog16)
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Thanks Dog, painting is a good idea, i'm planning on using two layers of 1/2 plywood, with a layer of 1/8 cork between them for sound. | ||
| Gary McFarland (Gearheadgary)
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Anybody ever consider this stuff?: http://www.dricore.com/en/eindex.htm They sell it at my local HD. Gary | ||
| TWO DOGS Rating: N/A |
stick with plywood... | ||
| Kyle Brandt (Kyle4501)
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2D, why? | ||
| TWO DOGS Rating: N/A |
Pat... make sure your second layer of plywood,has staggard joints...not in the same place as the joints of the first layer | ||
| Brian Brown (Fishbowlbrian)
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I'd avoid an OSB-based product, like Dri-core, if it were mine. While the bottom of the product is impervious, the OSB top could delaminate in a moist environment. If they made the stuff with a plywood top I'd be more apt to consider it. And I suspect a bus would have more moisture infiltration as well as heat-cold cycles in variable humidity, perhaps leading to a dew-point right where the wood part is. More so than any residence that's relatively even-temp. and has more stable humidity levels. My $0.02, FBB | ||
| Jack Gregg (Jackinkc)
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Now is the time to think about that hydroponic heat. They make a ¾ plywood with groves for the heating tubes. Just another $.02 | ||
| Gary McFarland (Gearheadgary)
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HI Brian, you ever work with OSB? Gary | ||
| niles steckbauer (Niles500)
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brian is correct - DO NOT USE OSB BOARD - ESPECIALLY if your using cork as you described - the trapped moisture will ruin it - Use marine grade tongue and groove plywood (moisture treated with marine grade glue) - tried and tested product - if your laying tile , concrete backer may be better for your 2nd layer of subfloor - Niles | ||
| TWO DOGS Rating: N/A |
I disagree..only one layer of 1/2 inch plywood ...would be too much 'flex' in the floor | ||
| Gary McFarland (Gearheadgary)
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My wife's dad is a millwright at one of those places where they make engineerred joist products. OSB is a primary component in these products. They had a bunch of "Leftover" OSB, so he brought me about 25 sheets. I didn't have a use for them right then, so I stacked them out behind the shed at my place in Oregon. I think about five years later when I checked On them, they still looked like the day he brought them to me. Now, Aesthetically, OSB is not my favorite. Frankly not my favorite product to work with either. But this product is made for basements. Now I don't know about you guys, but my bus stays pretty Dry. Way way way drier than my basement. Why on earth would you spend to money for Marine T&G? Are you guys going underwater? There are lots of waterproof plys available that use waterproof adhesive, Marine ply is certified void free and has other properties that are a waste on a bus subfloor. Non T&G Marine ply is ~$75/sheet for 3/4". I wish I had your budget for my bus. Jack, do you have a link for the hydroponic stuff? Gary | ||
| Brian Brown (Fishbowlbrian)
Rating: N/A |
Yup, Gary, I have some experience with OSB. As an architect, I have more than a tangental relationship with specifying materials for construction (albiet, of the non-moving variety). Without question, compared to plywood, OSB wicks liquid water much more readily but releases it more slowly. Thereby , IMHO, making it a poor candidate for applications calling on it to be a first or even second-line-of-defense barrier. In houses, we can often predict the "warm side" of a structure based upon heating and cooling degree data. Even then, there's obviously times when the inverse condition is true, and water can and does wick into the sheathing. I would say this is even more difficult to predict in a bus. On my houses, I specify plywood excusively for roofs, and usually for walls, depending on it's sectional construction. Floors over heated space below can receive OSB sheathing (it's cheaper), but never over unheated crawl spaces (mold is a BIG problem with OSB). I tell my clients that because of many factors, you can count on sheathing getting wet... and which would you rather have: something that dries out quickly and is dimensionally stable OR something that dries out slowly, if at all, and is forever swelled? I'm not alone, since many municipalities have outlawed OSB for roof and wall sheathing because of failures under severe conditions (huricanes, etc.). If you Google "OSB failure" there will be plenty of info, as well as plenty of rumor and innuendo to digest. Rather than "cherry pick" a link that supports my position, I'd recommend anyone to do their own research prior to selecting this or any product that strays from the "tried and true". Thanks, FBB | ||
| Kyle Brandt (Kyle4501)
Rating: N/A |
8 years ago, I installed 12" sq tiles in my church rest rooms. The tile mfgr's told me to use 1" thick ply-wood under the tile (and latex modified thinset & grout), anything less would cause the grout to crack. I did & it still looks new and no cracks. I also put in 1/2" concrete backer board although it was not required by the tile mfgr. The tile mfgr's said to not use wafer board as it is 'unstable'. | ||
| Gary McFarland (Gearheadgary)
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Hi Brian, It was a real question, Thanks for a real answer. I was afraid you might take it as a jab, especially on this board  I really don't like the stuff, truthfully. I was amazed when I checked on the stack out back expecting to have to chain-saw it for the burn-pile. It seriously looks the same as it did when it was brought to me. It's Magic. I am surrounded where I live with the McMansion phenomenon, these slightly-lesss-than-million-dollar homes (this is in Michigan, I moved from CA) are completely built with the stuff. I'm sure they don't use it here for roofs though, due to snowloads. I guess I'll skip on Dricore, but MY concern was the small tile-size and potential flex. Gary | ||
| Brian Brown (Fishbowlbrian)
Rating: N/A |
Gary, I'd hazard a guess that your experience with the product is consistent with its properties, as long as the edges were reasonably sealed (full sheets). Since the environment was the same on all six sides, water wasn't necessarily drawn into the product. Most of the moisture transfer in structures is due to vapor and condensation, rather than rain, snow, spills, etc. Now that buildings are being built "tighter", providing trapped moisture a means to escape is much more critical. OSB is a fine product, and more cost-effective alternative to plywood, where the relative difference in temp and/or humidity can be kept in check. It's also more environmentally-sensitive, using what was one waste from the mills to make millions of sheets a year for the building industry. My current beef with OSB, and all sheet goods in general, is that the military bought so much of it right at the time when the mills were shutting down (because of lack of demand)... and now it's all so freaking expensive. FBB | ||
| Robert Wood (Bobwoodsocal)
Rating: N/A |
Boy, you are not kidding Brian. It has almost tripled around here. OUCH! Bob | ||
| jimmci9 #2 Rating: N/A |
what about using the OSB as an overlay... like over the original bus floor... just to make a new clean, flat surface???? any suggestions for that???? | ||
| Marc Bourget Rating: N/A |
Jimmci9, FishBowlBrian stated above: Without question, compared to plywood, OSB wicks liquid water much more readily but releases it more slowly. Thereby , IMHO, making it a poor candidate for applications calling on it to be a first or even second-line-of-defense barrier. In houses, we can often predict the "warm side" of a structure based upon heating and cooling degree data. Even then, there's obviously times when the inverse condition is true, and water can and does wick into the sheathing. I would say this is even more difficult to predict in a bus." The following two paragraphs were also relevant. I'm not sure if you're heating your basement but on top of the original plywood would make the OSB a "first line" material. I'd opt for the 5-7 ply stuff (depending on thickness). I doubt you're a sloppy housekeeper or a drunk, etc. and your behavior wouldn't cause a problem, but what would the result be if you had a line leak or something equivalent? My Father was in Oregon, as they left the RV park they noted the kid next door playing "catch" with himself. They returned, after a heavy rainstorm, the side window busted and their neighbors, scheduled to remain for 4 days, had left suddenly (first day) while they were away. Onward and Upward | ||
| Pat Bartlett (Muddog16)
Rating: N/A |
I thought about leaving the orginal sheeting down but i wanted to look at the chassis and see if it needed any work, so far the rust proofing paint that Prevost used looks pretty darn good for an eastern rust bucket, i was very surprised, Dog i will stagger the seams for sure, Kyle i installed a tile floor in my kitchen probably 18 years ago, i used 2X12 on 12inch centers with two layers of 3/4 inch tongue and groove plywood, in that period of time the only damage i've seen is from the cleaning lady tossing her pots and pans around.........(the wife) if she could catch i'd send her to the Reds, lord knows they need help! | ||
| Stephen Fessenden (Sffess)
Rating: N/A |
Wafer wood makes great roof sheathing, but most of it is irregular in thickness and it often has loose wafers. I would think it would be a poor subfloor. I noticed that signs made of waferwood last longer in the elements than plywood so I have it for my roof sheathing. I tried it for cabinets, and it is a lousy material for that. I would not use treated plywood for bus flooring. It is wet, warps and delaminates. I use it for ground contact under my wheels, but I would not use it in the bus, even for bay floors. Home Depot has had a hardwood plywood of some kind for about $29 a sheet for 3/4 inch that looks real good, better than the fir plywood for a bus floor, I think. I know the floor in a 4905 is not ordinary fir plywood. It looks like hardwood plywood. | ||
| Marc Bourget Rating: N/A |
Luke told us at Bussin' 2002 that the floor of a GM is a shear member and is important to the structural integrity of the coach. There's good reason for higher quality wood in a GM! Good observation, Steve! | ||
| Jayrjay Rating: N/A |
Steve, the floor in my 4905 is 5 plies (3/4") of red oak plywood, assembled with two plies biased at 45 deg., and a waterproof urea adhesive. (from GM's manual). Probably a hunnert bucks a sheet nowadays- if you could even find it. Harder than an old maids heart. ...JJ | ||
| Jack Gregg (Jackinkc)
Rating: N/A |
Gary - Here is the web site for warmboard, a sub floor system for hot water heat. It looks like 1.125” plywood with slots cut for ½” pex. The slots are lined with aluminum sheeting so the heat is transmitted to the surface (great idea!). It appears to be special order product. | ||
| FAST FRED Rating: N/A |
Steve is on the right track, "Home Depot has had a hardwood plywood of some kind for about $29 a sheet for 3/4 inch that looks real good, better than the fir plywood for a bus floor, I think. I know the floor in a 4905 is not ordinary fir plywood. It looks like hardwood plywood" The hardwood ply with many layers is much stiffer and deflects less when you walk on it. Unfortunatly HD doesn't know if this Canadian import has waterproof glue. If you put a hunk in a pot and boil it for 2 hours , then leave it in the water for a day , you will know. IF it still intact the glue is fine. Works for me, when I dont want to pay for Marine $$$ Ply. FAST FRED | ||
| don (Bottomacher)
Rating: N/A |
I bought ten sheets of the HD hardwood plywood for my interior cabinets (only), but I doubt that it is made with waterproof glue, since cabinet grade plywood almost never is. The finest floor system I have personally ever seen is two layers of 1/2" 5- ply exterior fir plywood, staggered 50%, glued with exterior glue (liquid) and screwed. The wood should be treated on the edges with Woodlife or other preservative according to directions before installation, and sealed on both faces as well after installation. You can bounce a cannonball on it, and it is far stronger than what the factory used. | ||
| TWO DOGS Rating: N/A |
LOTS of 1" deck screws on the second layer...probably 1000 or more...I would prefer one 3/4" piece...but everybody has their own way | ||
| Gary McFarland (Gearheadgary)
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Away from this discussion for about 24 hours-- Pat--For me, I am replacing the floor to remove any trace of the smells from it's previous duty and the steelfab process. Stephen--What can possibly be better than fir? Jack--Thanks for the link. Gary | ||
| Jack Gregg (Jackinkc)
Rating: N/A |
Gary - Get rid of smells in the wood by coating with Kilz brand primer, available in the paint department everywhere. The oil base includes shellac for extra stain blocking but you will not need that; the water cleanup is sufficient. We use white primer when we rehab mobile homes to seal pet urine smell into OSB floors or smoke (from fire) into porous ceilings. This stuff works!!!!! | ||
| niles steckbauer (Niles500)
Rating: N/A |
Let me clarify my problems with OSB used in buses - first I must say that OSB is fine in certain climates as roof decking and sub-floor if properly installed and ventilated - Buses, by the nature of their owners wants, travel through many climates under some adverse conditions - I recently had a meeting with state officials and all the subcontractors at one of our homeowners/customers in Florida in response to a service request to replace approximately 200 sq ft of floor in this 1 year old home - the decking was OSB - the problem floor area was located within a 15 foot radius , partly in bath, utility room, and dining room - after a considerable time investigating the cause of the floor failure - The Mechanical contractor found a cold spot in the attic using his thermal imaging equipment - turns out there was an open leg of the A/C duct system blowing into the attic - this caused the home to go negative and suck air in through the crawl space and floor decking - In the carpeted areas the moist air simply was exhausted by the system - but in the roll goods areas (bath,utility,dining) the moisture was trapped between the vinyl and the decking - if the Mechanical system had been correct they never would have had the problem, but this kind of thing happens all the time, and even plywood won't last forever under these conditions thats why I suggest marine ply - think of all the things going on inside and outside your bus, is your rig 100% leakproof ?, is your mechanical system at 100% nuetral pressure ?, do you have an air exchanger to remove moisture from your living area and one for the bays below ? - so when Pat mentioned sandwiching a layer of cork between the OSB, it sounded a warning to me (DANGER - WILL ROBINSON), that the cork would not provide for proper ventilation and could cause a disaster as described above - hope I clarified my post - BTW I'd rather pay $3 a sq. ft. for a good sub floor than have to tear it and the finished floor up later to R/R it. Niles | ||
| Marc Bourget Rating: N/A |
Niles just made a good argument for split A/C systems, Evap in living quarters is the definition of neutral pressure effects. Thanks Niles for the analysis. I learned from it! | ||
| Stephen Fessenden (Sffess)
Rating: N/A |
Many plywoods today are made with the same glues as marine plywood. They may be just as good or almost as good. The boil test Fred described is the way to find out how the glues hold up. A boat builder I know also cuts up one or two sheets in a lot of plywood into very small pieces looking for voids. If you have the same glue proven by a good boil test, and no voids, I would be very comfortable with the material for bus floors. Price and certification are not a guarantee of quality. Test it yourself. We tested certified foam materials for aircraft uphostery once and found they burned easily with excessive smoke. Continued doing our own burn tests and chose materials that passed our test. Yes, seal the edges, as Don suggested. The edges are where delamination seems to start. | ||
| Pat Bartlett (Muddog16)
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Niles thanks for the excellent information, and Will Robinson did take note........ | ||
| David Dulmage (Daved)
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The plywood should be marked somewhere with the Cerification mark from the Enginneered Wood Association (the APA mark) or the Canadian Plywood Associatoion (the CANPLY mark). Bothe organizations do extensive testing on the durability of the glue used in plywoods thjey certify, this generally includes boiling samples and conducting tests for delamination. More information on which products are certified should be available on their websites. FWIW Dave Dulmage | ||
| Stephen Fessenden (Sffess)
Rating: N/A |
But you pay more for boilproof marine plywood. There is plywood out there that is under-rated if you are smart enough to figure it out. Certification means liability so it is natural to not note that a plywood is fit for marine use when marine use is not being charged for. | ||
| Adame Rating: N/A |
Neoplan USA uses an 8 layer 3/4" plywood which has a rubbery layer between the 3rd and 4th plys. See www.greenwoodproducts.com I don't know how it's attached. | ||
| Marc Bourget Rating: N/A |
Adame, I was curious and went through all the product descriptions. None of their products on the site discuss an internal lamination process, just exterior with metal or plastic. There was one RV reference and the following that I came across: "BUS PANELS The Alternative to expensive panels. "Marine Grade" plywood. Bus Panel is a specialty plywood designed to be used for floors and bulkheads in buses and light rail cars. It is carefully manufactured to maximize strength and flatness for ease of installation and long-lived performance. The added benefit of XL Bus is the same tough panel with preservative treatment. XL Bus carries a limited lifetime warranty against rot." Can you show me where you got the info? I'm still curious. Thanks Marc | ||
| Adame Rating: N/A |
Marc, it's called db-ply. Used to damp structure-borne noise and vibration. It's available in either soft or hard wood outer plys. |