[Greenbuilding] sealing plywood floor?

Tue Apr 3 15:13:45 CDT 2012

Mr. Gennaro Brooks-Church,

Too many elements generate problems for wood materials in areas below grade.
Moisture being the most pervasive.
Treating wood to combat the effects of moisture may create more problems
than they solves.
Off Gassing by the compounds in the materials used to coat the wood and
prevent moisture from damaging it comes to mind.
Appropriate ventilation will be required just to handle this condition.

To offset the amount of moisture below grade in an enclosed space may
require a dehumidifier. 
Then the issue becomes contradictory.
That is to say that the wood may become so dried out due to the
dehumidifying effects that it wrought in both directions.
Moisture leaching into the wood by proximity to the foundation walls and
moisture extracted from the wood by virtue of the dehumidification causing
it to warp.
The sealant issue between the foundation and the wood cannot guarantee the
prevention of moisture leaching into the wood.

The balancing act to maintain equilibrium between the all methods would be
quite a feat.
This is why I believe it is thus a silly idea to put wood in close proximity
with the basement floor slab.
Regardless of the added sand and insulation and surface coating protection.

Sleepers may solve the problem as long as air can flow between the concrete
and the wood.
Then if you want the spongy feel of insulation and sand between the layers
of plywood under your feet.
This may work. 
But keeping the whole floor assembly away form the foundation walls is still
a main concern form my vantage point.
If I am mistaken in my appraisal of this issue please advise.

Regards,
Doug Lamb
douglaslamb at columbus.rr.com

-----Original Message-----
From: greenbuilding-bounces at lists.bioenergylists.org
[mailto:greenbuilding-bounces at lists.bioenergylists.org] On Behalf Of Gennaro
Brooks-Church - Eco Brooklyn
Sent: Tuesday, April 03, 2012 2:48 PM
To: Green Building
Subject: Re: [Greenbuilding] sealing plywood floor?

Why is it a silly project. I makes a lot of sense to me.

Gennaro Brooks-Church
Director, Eco Brooklyn Inc.
Cell: 1 347 244 3016 USA
www.EcoBrooklyn.com
22 2nd St; Brooklyn, NY 11231

On Tue, Apr 3, 2012 at 2:19 PM, Douglas E Lamb <douglaslamb at columbus.rr.com>
wrote:
> Mr. Deumling,
>
> Be more succinct in your request next time.
> You ask for reference to surface finishes on wood mentioned from a 
> previous thread for wood you are putting in you basement. (God only 
> knows why) I provided you a site that offers coating for wood as well 
> as other surfaces that was mentioned from a previous thread and as you 
> requested. (I hate being redundant!) You project isn't worthy of 
> succinctness.
> It is down right silly.
> Left it @ that.
>
> Regards,
> Doug Lamb
> douglaslamb at columbus.rr.com
>
>
>
> ________________________________
> From: greenbuilding-bounces at lists.bioenergylists.org
> [mailto:greenbuilding-bounces at lists.bioenergylists.org] On Behalf Of 
> Reuben Deumling
> Sent: Tuesday, April 03, 2012 1:40 PM
> To: Green Building
> Subject: Re: [Greenbuilding] sealing plywood floor?
>
> This is one of the succinct summaries of this sandwich:
>
> ---------- Forwarded message ----------
> From: JOHN SALMEN <terrain at shaw.ca>
> Date: Wed, Apr 20, 2011 at 9:18 PM
> Subject: Re: [Greenbuilding] building floor on top of rigid foam...
> (basement/garage retrofit)
> To: ArchiLogic at chaffyahoo.ca, Green Building 
> <greenbuilding at lists.bioenergylists.org>, satjiwan at alumni.brandeis.edu
>
>
> I missed this thread somehow. I can testify that putting a floor 
> directly on eps foam is a great system. I have done this in a number 
> of renovations, new homes and a school.  The basic spec. is rigid eps 
> board (minimum 4”)  on a level surface w/ t&g ply sheathing laminated 
> directly to the foam with a suitable adhesive. That is it.  The level 
> surface does not have to be concrete – it can be a granular base (sand).
>
>
>
> The real point of this approach is to avoid the use of concrete or in 
> the case of insulating on existing concrete to isolate from moisture 
> and to minimize the use of unnecessary materials.
>
>
>
> As for materials the ‘suitable adhesive’ is generally specified as a 
> polyurethane foam adhesive (enerbond or equiv.). If the finished floor 
> is to be ¾” solid wood nailed -  I specify a min. 5/8” t&g ply 
> sheathing. If it is tile I generally specify either a thickset mortar 
> directly on the foam
> (w/reinf.) or an additional layer of ½” ply laminated and fastened @ 3”
> o.c.  I’ve found that most contractors get the concept pretty quickly 
> but the trick is that in putting down the ply it needs to be flattened 
> and weighted down while the adhesive sets (concrete block, buckets 
> with sand,
> etc...)
>
>
>
> For your application I would eliminate any subfloor wood framing
(sleepers).
> Waste of time and material. eps boards can be ordered cut to the 
> thickness needed for the finished product. Using foam on an existing 
> slab it is nice to have additional thickness – 5-6” foam can span any 
> deflections or defects in the concrete. I would spot adhere the foam to
the concrete.
>
>
>
> Essentially the finished floor (eps and ply) is a weight bearing 
> floating floor that can carry standard interior partition loads well. 
> It is a pretty nice floor.
>
>
>
> On Tue, Apr 3, 2012 at 10:32 AM, Benjamin Pratt 
> <benjamin.g.pratt at gmail.com>
> wrote:
>>
>> wouldn't 1/2 plywood warp over time? I don't knwo the procedure.
>>
>> On Tue, Apr 3, 2012 at 12:28 PM, Michael O'Brien <obrien at hevanet.com>
>> wrote:
>> > Hi, Reuben--
>> >
>> > To clarify what is being finished--I'm sure it's obvious, but the 
>> > plywood should be exterior grade. Practically speaking, moisture 
>> > won't be able to pass through the phenolic adhesive between the 
>> > plys. Are the two layers free-floating over the sand? Is that 
>> > OK--they won't move when there's traffic on them?
>> >
>> > It seems like a hardwood would work better than a softwood like 
>> > fir, costlier but might hold up to traffic better, especially on 
>> > half-inch sheets. (I wonder if 5/8" might be worth it for extra 
>> > stiffness?)
>> >
>> > I'd suggest coating both sides and all edges with a water-resistant 
>> > finish, while the plywood is dry. Have you looked at Miller's 
>> > Evolution satin exterior paint? It's reasonably priced for its 
>> > performance. Miller staff can help decide if a wood filler is 
>> > needed. The satin finish would make it easier to clean.
>> >
>> > Might be good to leave a little space between edges for expansion 
>> > and to stagger the joints between the two layers, to slow any 
>> > moisture from the sand layer.
>> >
>> > Is that about what you already figured out? :^ )
>> >
>> > Best,
>> >
>> > Mike O'Brien
>> >
>> >
>> >
>> > On Apr 3, 2012, at 9:32 AM, Reuben Deumling wrote:
>> >
>> > I'm planning on assembling a floating double layer of 1/2" plywood 
>> > over foam over sand that JOHN SALMEN described here in the past, 
>> > and as this is for a basement wood shop I'm wondering if anyone has 
>> > suggestions about what to seal or paint the plywood with to 
>> > maximize its longevity?
>> >
>> > Thanks.
>> >
>> > Reuben
>> > _______________________________________________
>> > Greenbuilding mailing list
>> > to Send a Message to the list, use the email address 
>> > Greenbuilding at bioenergylists.org
>> >
>> > to UNSUBSCRIBE or Change your List Settings use the web page
>> >
>> > http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_list
>> > s.bioenergylists.org
>> >
>> >
>> >
>> > _______________________________________________
>> > Greenbuilding mailing list
>> > to Send a Message to the list, use the email address 
>> > Greenbuilding at bioenergylists.org
>> >
>> > to UNSUBSCRIBE or Change your List Settings use the web page
>> >
>> > http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_list
>> > s.bioenergylists.org
>>
>>
>>
>> --
>>
>>
>> b e n j a m i n p r a t t
>>
>> professor art+design
>> the university of wisconsin stout
>>
>> _______________________________________________
>> Greenbuilding mailing list
>> to Send a Message to the list, use the email address 
>> Greenbuilding at bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web page
>>
>> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.
>> bioenergylists.org
>
>
>
> _______________________________________________
> Greenbuilding mailing list
> to Send a Message to the list, use the email address 
> Greenbuilding at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page 
> http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.b
> ioenergylists.org

_______________________________________________
Greenbuilding mailing list
to Send a Message to the list, use the email address
Greenbuilding at bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioener
gylists.org