permaculture

["Lawrence F. London, Jr." <lflondon@mindspring.com>]

On 11 Dec 2001 04:22:03 -0800, Michael Dean
<mikedean.com@altavista.com> wrote:

>Can somebody explain to me why --"Never use lead head nails as fasteners on 
>such a roof; alternatives: stainless steel screws, also galvanized screws 
>and nails with neoprene washers" 

Lead-head nails are galvanized ring-shank roofing nails with lead caps
surrounding the smaller galvanized steel heads on the nails. When you
nail your 5-V roofing panels to your skip sheathing or plywood decking
you'll nail into the inner of the two outside ridges of the panels.
The lead head is forced onto and into the hole made by the nail thus
preventing water from getting in. Over time the lead will leach out
into the water running off the roof and into your cistern. Doubt you'd
want to drink that under any circumstances, though many have over the
years.



L.F.London ICQ#27930345 lflondon@mindspring.com
http://www.ibiblio.org/ecolandtech  london@ibiblio.org