|
01-19-2012, 06:02 PM
|
#1
|
Eric Johansen
1976 31' Sovereign
San Francisco
, California
Join Date: Feb 2011
Posts: 12
|
How to waterproof new sub-floor?
What product do you recommend to waterproof a new plywood sub-floor?
Thanks, Eric
|
|
|
01-19-2012, 06:17 PM
|
#2
|
Rivet Master
2005 30' Classic
...
, ...
Join Date: Nov 2004
Posts: 512
|
Not that any water-proofing is considered long term, but I used marine epoxy on my marine grade ply.
|
|
|
01-19-2012, 07:34 PM
|
#4
|
Tool Hoarder
Currently Looking...
West
, California
Join Date: May 2010
Posts: 907
|
I used West systems epoxy around the edges of my MGP sub floor then used spar varnish on the rest
|
|
|
01-19-2012, 09:32 PM
|
#5
|
Rivet Master
2006 25' Safari FB SE
St. Cloud
, Minnesota
Join Date: Aug 2003
Posts: 13,280
|
Hardware store epoxies may not be waterproof. Look for boatbuilder/marine epoxies. System Three and MAS are good; West System probably is a more expensive option.
When I re-did areas of floor on my Argosy, I used System Three on the plywood edges and six inches on top of the floor perimeter. And then I treated the rest of the floor-top (eg, under the water tank) with RotDoctor - a high-solvent penetrating epoxy (ventilate nothin' -- gotta do this with a lot of outside air circulation!). Don't count on System Three, MAS or West to penetrate. Encapsulating wood really is a vain pursuit -- moisture will still penetrate somewhere and then nothing can evaporate (resulting in accelerated rot). I left the underside of my floor untreated.
Marine epoxies can be dealt with in enclosed spaces. Nothing more than a slight ammonia smell. But be very good on glove wearing and wash any skin contact with un-set resins. Use respiratory protection if you power finish or power sand any epoxy treated area.
Time spent looking at window gaskets, roof penetrations & skin lap seams will be more important than going overboard on sealing the floor. Gotta take care of the 'they all leak' problem.
|
|
|
01-19-2012, 10:38 PM
|
#6
|
Rivet Master
1956 22' Safari
2015 27' Flying Cloud
Vintage Kin Owner
Conifer/Evergreen
, Colorado
Join Date: Feb 2002
Posts: 12,702
|
Thinking ahead...
What kind of floorcovering will you be putting down? Some "glues" will not stick to the :waterproof" surfaces. If you are just laying carpet or something that isn't glue-down, no problem. If you plan on installing linoleum or tiles, you may want to think twice before applying a waterproofing material wall-to-wall.
Shari
|
|
|
01-20-2012, 06:59 AM
|
#7
|
Rivet Master
1981 31' Excella II
New Market
, Alabama
Join Date: Sep 2011
Posts: 6,145
|
Polyurathane wood coating works well and it is relatively cheap. It is also waterproof assuming there are no holes in the coating or gaps. Edges are especially important that they are sealed. You want to seal any penetrations through the wood as well. If the floor stays wet long enough eventually water will penetrate through some pinhole or crack in the coating etc. Many so called fiberglass boats are just fiberglass coated wood. The wood rots in 10 or so years and you have a fiberglass egg shell where your boat use to be. The advice of coating the top and the edges and leaving the bottom bare is probably not a bad idea if there is nothing like pink fiberglass that is holding moisture against it. The bottom edges should be sealed for 2 or 3 inches from the edge though.
Perry
|
|
|
01-20-2012, 07:13 AM
|
#8
|
Rivet Master
1982 34' Limited
Brunswick
, Georgia
Join Date: Feb 2009
Posts: 1,084
|
Another thought:
Look at Tnemic coatings. ( Tnemec Industrial Coatings and Architectural Coatings ) I have used this on concrete to waterproof the interior of an indoor water feature. I believe they have a product that will work on wood as well. It will be pricey but bulletproof.
A different option would be a peel-and-stick membrane variety. I have used a product called Proflex. Is a waterproofing membrane as well as a sound reducing mat. The primary application is for tile underlayment, however I have used it under wood floors in multiple applications with great success. PROFLEX? Products - Crack Suppression - Waterproofing - Sound Control - Membranes Underlayments
Casey
__________________
1982 34' Limited
2000 Excursion V10 4x4
WBCCI #3321
TAC #GA-24
|
|
|
01-20-2012, 10:15 AM
|
#9
|
Rivet Master
1973 27' Overlander
Currently Looking...
Jupiter
, Florida
Join Date: Apr 2006
Posts: 2,062
|
I replaced the back sheet and then realized the whole floor had to go. I know, poor prior planning but I kept hoping to find where one gawd awful smell was coming from but even with bath, tanks, and all plumbing out it persisted.
I wasn't happy but I learned a couple of things that I'll share..
I used marine-grade plywood and put 4+ coats of vinyl-ester resin on before installing it. The first two coats were thinned and the wood was saturated to the point of rejection, I just kept washing it on until the soaking in slowed way down. Two more un-thinned coats and I though I was set.
Vinyl Ester resin is superior in every property as compared to all polyester resins. This product is used in high performance applications in which high-strength and maximum heat tolerance is necessary. This resin is extremely chemical resistant when cured. Similar in strength to epoxies with much increased stiffness.
Vinyl-ester is brittle - although it armored the surface the underlying wood yields and the VE cracks like rock-candy. When the wood grain shifted from moisture content the VE failed. See picture, the MGP on top of the pulled 40-year-old flooring.
The 8-ply the private lumberyard sold me was more furniture grade than construction grade. If you go MGP research the grades and symbol stamps and review the offerings available before you commit. The $85 sheet I got had a soft exterior ply and even softer internal plies - I had floor screws pull halfway through with little effort.
The new floor I just put in is a hardwood construction grade plywood (MDO) and I followed directions meant for outdoor advertising billboards: Fill any flaws w/ caulk and two (three in my case) coats water-based primer, then two top coats of outdoor porch paint. If you want to rubber-neck along with my slow-motion train wreck restoration look for a post "Hey y'all, watch this..."
If I were doing a back-sheet restoration again I'd seriously be tempted to use an epoxy resin that would allow thick build up, kinda like a surf board but that is just me.
__________________
The days are short and the night is long and the stars go tumbling by.. . ~Airstream~
|
|
|
04-08-2018, 03:09 PM
|
#10
|
New Member
the dalles
, Oregon
Join Date: Oct 2017
Posts: 1
|
subfloor and bilge paint
i am replacing the rear-end subfloor. i am planning on using marine plywood. my next thought was to paint it with bilge paint. any thoughts? any problems with reactivity or corrosion due to aluminum and that type of paint? i see many use an epoxy or spar urethane.... thanks
|
|
|
04-08-2018, 03:16 PM
|
#11
|
Rivet Master
2016 28' International
Sioux Falls
, SD
Join Date: Oct 2017
Posts: 576
|
Quote:
Originally Posted by pilar
i am replacing the rear-end subfloor. i am planning on using marine plywood. my next thought was to paint it with bilge paint. any thoughts? any problems with reactivity or corrosion due to aluminum and that type of paint? i see many use an epoxy or spar urethane.... thanks
|
Welcome to the forum.
Stick with a good epoxy on the marine plywood. It will last longer than we will
__________________
2016 Int. Signature 28' w/ ProPride 3P-1400 Hitch
Mich. LTX w/ 16" Sendels, Centramatics
2017 Ram 2500 4x4 Diesel, CG1800 Bed slide, Leer topper
Better to live one day a lion than a lifetime a sheep. Camp hard, camp often
|
|
|
04-08-2018, 03:21 PM
|
#12
|
Dazed and Confused
Currently Looking...
1983 31' Airstream310
Hillsburgh
, Ontario
Join Date: Sep 2012
Posts: 3,805
|
Or you can just use Coosa board, not have to treat it with an expensive epoxy and not care about leaks into your subfloor. It won't rot, mildew, grow mold; 40-45% lighter than plywood, stronger than plywood and just as easy to machine.
Pricey, maybe, so is marine plywood and West epoxy; peace of mind that nothing will rot your sub-floor.....priceless.
Cheers
Sidekick Tony
__________________
Per Mare, Per Terram and may all your campaigns be successful.
“It’s a recession when your neighbor loses his job; it’s a depression when you lose your own.” "Harry S Truman"
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|