Cohousing-L Mailing List: Re: question about resurfacing decks

[James Kacki (jimkacki]

As an architect, my first impression is that Marks suggestions are  
correct, but you are also correct Kay in that the detailing is  
critical.  The theory is simple.  The sheet roofing, rubber, EPDM or  
similar waterproof membrane will last for years (decades even) but  
must incorporate a slight slope (1/4" to  1'-0" is recommended  
minimum), leading the water away from any walls roofs etc. to a place  
where it can drain away.  Then another part of the simple theory is  
that there must be no penetrations of the membrane.  The floating  
wood decking that Mark refers to must not be nailed  through the  
membrane, have sharp edges or block the water from flowing to a  
drainage point.  Its a tricky thing to design properly and the best  
advice while planning is to avoid these situations.  But if the  
design warrants a flat deck over a living space, it can be done but  
be super vigilant about the detailing. A coating over the plywood  
helps if it is the right product, but should never be counted on as  
the line of defence to keep water out (due to joints in the plywood  
eventually opening up, cracking etc.)  Marks suggestions are the more  
appropriate method IMHO.
James

On 21-Aug-08, at 4:18 PM, Kay Argyle wrote:

> > ... butyl rubber sheets, a.k.a. "rubber roofing," glued in place to
> > form a continuous weather barrier (and) covered with floating
> > wood decking consisting of sleepers and deck boards.
> > ... expected lifespan much greater.  ... a deck might last decades  
> > without
> further attention. > > Mark
>
> We wish. Our decks have rubber underneath.  Ask your architect and
> contractor how much experience they have with it.  Based on our  
> experience,
> I'd guess there's something tricky about design and installation,  
> making
> sure water drains off the edge you want it to instead of seeping  
> around
> edges you don't. (You'll recall my mentioning walls being ripped  
> out ....)
>
> Kay
>
> _________________________________________________________________
> Cohousing-L mailing list -- Unsubscribe, archives and other info at:
> http://www.cohousing.org/cohousing-L/