Learn what's possible with the art and science of preserving our architectural past
An overview of carbon fiber uses for strengthening individual timbers or floor systems. Epoxy tape can be used to support weakened timbers, but with vacuum-forming carbon fiber cloth can be form-fit to the core of hollow timbers as well.
Stabilization with carbon fiber is a very cost-effective and preservation-oriented option for deteriorated building elements.
Mortar matching is often seen as difficult to do, but once you understand that historic mortars primarily came from local sources, one need only look to the local geology including at roadside cuts to recognize the aggregates of a sand in their former condition. This is the wonder of the fractal nature of stone reduced to sand. And often the sand you seek is right beneath your feet!
The basic idea behind determining the void space in a sand is to determine the ratio of lime needed to adequately bind the sand without pushing the sand grains apart. In other words, how to make the strongest possible mortar by optimizing the lime portion.
The right qualities of sand are crucial in lime mortar making and differ some from brickwork versus plaster and stucco. The increasing inclusion of crushed rock in sand mixes presents particular problems.
Google Maps for mortar matching?! Go local when seeking to match historic mortars as the sand you seek may well be under your feet. If you need to go off site, look nearby. When the mortar analysis checkbox is clicked by sending away for a report that does not give you an exactly matching source (without relying on tweaks from pigments that may not be stable and will change the lime-sand ratio of a mortar and its working properties), your money is being wasted and your building is not getting the best treatment.
A skilled mechanic can make almost any aggregate work for most uses on historic buildings. But learning how to locate (or assemble from several sources) a better aggregate will make for better working characteristics and a more durable product.
The type of paint to be used affects the time until painting after installing lime mortar. Switching to an historic paint like casein can get you painting right away despite the high pH of freshly-installed lime mortar
Sand is not sand is not sand. Often when people are having stucco or plaster application problems (although the same can happen with bricklaying mortar), it turns out the aggregate is to blame. In short, it is not as simple as accepting whatever is at the local masonry supply house. Nor for that matter if… Continue reading What you need to learn from a mortar analysis about aggregates and ratios
Covering the differences between hydraulic limes or cement and lime putty, this is a summary of the importance of pre-mixed mortar, proper hydration before and after installation, and compaction of lime putty-and-sand mortars.
The Preservation Science Blog 
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