[Greenbuilding] Alternatives to Pressure Treated Wood

[Rob Tom]

On Mon, 08 Oct 2007 11:56:47 -0400, <dantonioli at earthlink.net> wrote:

> roofdeck projectpressure treated wood "sleepers."

Dan;

I don't have enough details about what you're wanting to do so I'm  
shooting in the dark but...

Assuming that the sleepers are not being ripped down from the 1.5" (or  
0.75" ?) dimension,
could the decking be designed as modular duckboard panels whose dimensions  
are such that the stiffeners (or "sleepers") could be left whole  
(unripped) ?

The modular panels (let's say 2400 x 2400 mm just for the sake of  
discussion) could then be levelled by plonking down 9 gobs of mortar (ie  
in a 3x3 grid) for each panel, into which the panel could be set &  
levelled.

The perimeter gobs would do double duty to provide a setting bed for  
adjacent panels.

Some sort of capillary break would be provided between the mortar and the  
contact points with the panels stiffeners. (I'm thinking some sort or  
gridded affair made of recycled plast-echh! that would allow drainage  
(something like the bottoms of broken plastic milk crates for instance).

The result would be no wood directly in contact with the existing roof .

The Gobs o' Mortar could be made somewhat tidy looking (and hence provide  
the cachet of being "designed" rather than "plonked") by using a  
"formwork" into which the gob would be placed.
The form might be something like yoghurt tubs or milk jugs with the ends  
cut off and sliced (like a salami) to an appropriate height.

Another idea along somewhat the same lines might be to cast the "sleepers"  
using a fly ash concrete mix and cast in connections to enable fastening  
of the decking afterwards.

The cast-in connectors would be similar in principle to the deck fastening  
clips that one buys at the building supply but could be easily/cheaply  
site-made from bulk flat stock.

Happy (Canadian) Thanksgiving. Eh ?


-- 
=== * ===
Rob Tom
Kanata, Ontario, Canada
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