stone

We all know that reusing what already exists can be much more eco-friendly than starting anew--not always, but frequently. So what do you do with an old stone house? While mud and clay are most popular in dryer states, stone houses are common in areas like the North East. In New England in particular there are a lot of stone house.   Townies call it the 'library look', because so many local libraries and state buildings were old, old stone buildings.  Stone houses are different from "rock" houses--you'll fnd some interesting houses carved out of existing large rocks if you do a search. 

While stone homes are prevalent in cold areas, the weight of stone homes add to the consideration of 'frost heaves' when building your foundation (that's when a thawing action allows the foundation to slip).  The foundation is generally built twice as wide as the walls, and the cement has only a few rocks in it, sometimes metal is mixed in if you have it.  Walls vary as much as 6 inches to two feet. 

As for the obvious insulation challenges, some just build two rock walls for thermal mass insulation.  The web-site, www.kohlerandlewis.com also addresses a special 'concrete foam insulation'.  

The technique of choice for most involves slipforms.  Slipforms are just plywood secured on both sides before pouring, and then slipping the plywood up when things begin to get solid.   'Bubble-stone' is the appearance it creates.  www.hollowtop.com  It was mentioned that slipform was considered an 'art', which translates to me, that there is a possibility you might stink at it.  So practice, practice, practice.  That includes building bar-b-ques, walls, etc as well as most things in life, right?

What tips and insights do you have about shoring up and greening a stone structure?