Both NHL and OPC are made from limestone, although not necessarily the same kinds of stone and are fired in a kiln. NHL is produced in Vertical shaft kilns, which is like a big chimney, with natural gas or clean coal at a low temperature. While OPC is burned in a rotary kiln fired at nearly 2,500 F. The amount fuel used to maintain such a high temperature is by far greater than the relatively low firing temperature of NHL.  Often hazardous waste is used as a fuel, which can emit toxins into the atmosphere. During either process CO₂ is driven off into the atmosphere. Even though NHL production drives off less CO₂, the benefits don’t stop there.

When the NHL is ready to be mixed as a mortar right out of the bag, it’s hungry. NHL wants the CO₂ that was pumped into the atmosphere back all for its self, in its natural process to turn back into a limestone. As different grades of NHL are produced their whiteness and density change. On a scale from lightest to heaviest and from whiteness to grayness, NHL 2 is Light and white while OPC in heavy and grey. Since mortar is mixed by volume in the field, less lime is used per pound to make up the same volume of mortar using OPC.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

We’re very excited to extend an invitation to you to join us at the Greater Philadelphia Historic Home Show Show March 10-11 in Oaks, PA. Visit our display booth where we will be giving demonstrations and providing a complete package of resources for your historic building.

LimeWorks.us produces appropriate historic masonry repair materials for respective applications to ensure a long-term service life for the conservation of our region’s cultural heritage as represented by its vintage architecture.

Andy deGruchy, owner of LimeWorks.us will presenting on the importance of proper repairs for vintage masonry.

How to repair vintage masonry successfully the first time with in-kind repairs that don’t offend.

 Many historic homes that have had no restoration work are in better condition than others that have been repaired improperly. Learn from the fatal mistakes homeowners and professionals often make regarding historic buildings. Understand how damaging Portland Cement has caused headaches and sometimes irreversible destruction to countless historic homes built during the 18th, 19th and early 20th Centuries. Educated homeowners are able to properly repair their historic homes the first time. Come to this one hour presentation and learn how to embark on a successful repair campaign on your historic home.

Also, take a few minutes to listen to a recent interview Andy had with the National Center for Preservation Technology & Training. A few of the topics discussed include confusion surrounding lime terminology, the application of lime mortars, master stonemason Ian Cramb and our efforts here at LimeWorks.us to educate others on the importance of using lime.

The New York Life Building was completed in 1928 at a cost of $21 Million. It’s currently undergoing a repair campaign using Lithomex for stone repairs and patchwork.

The Irish Hunger Memorial stands as a tribute and reminder of the Great Irish Famine and the tragedy of world hunger. Stones were donated from each county of Ireland and even an entire cottage was transported and reassembled on site at Battery Park in Manhattan. Historically accurate lime mortar was used in the construction of this memorial which ensures that it will remain standing tall.

The Eldridge Street Synagogue is an incredibly gorgeous testament to the architecture and influence that once spanned across the Lower East Side from the Eastern European Jewish community. This was the first Synagogue constructed by the Eastern European Jews emigrating from Russian, Romania, and Poland. It was built in the late 1800s and flourished into the mid 20th Century. As the neighborhood changed and new immigrants arrived, membership dropped and the synagogue was left virtually abandoned through the rest of the 20th Century. The rescue effort of the Eldridge Street Synagogue began in the late 70s when volunteers and the Friends of the Eldridge Street Synagogue initiated efforts that led to an $18.5 million dollar repair campaign. This campaign included repointing work of the facade using historically accurate Natural Hydraulic Lime Mortar from LimeWorks.us Additional repairs to the ceiling, wallpaper, paint and almost every aspect of the central room was restored returning it to its original glory. The final element was set during the fall of 2010, the stained-glass window commissioned by Kiki Smith and Deborah Gans is the only 21st century element inside the historic space.

More details of the Eldridge Street Synagogue restoration can be found in the latest issue ofTraditional Building Magazine

We also visited the Cathedral of Saint John the Divine and the Ephesus Seventh Day Adventist Church in Harlem. Both have used in-kind repair materials from LimeWorks.us. By using breathable masonry repair materials, all of these historic structures will surely stand as testaments to the rich history of the Big Apple for generations to come.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

All Photos Copyright: Sean K Maxwell

Imported Lime Paint Brush

Generic Paint Brush

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

The rescue effort of the Eldridge Street Synagogue began in the late 70s when volunteers and the Friends of the Eldridge Street Synagogue initiated efforts that led to an $18.5 million dollar repair campaign. This campaign included repointing work of the facade using Ecologic® Mortar from LimeWorks.us Additional repairs to the ceiling, wallpaper, paint and almost every aspect of the central room was restored returning it to its original glory. The final element was set during the fall of 2010, the stained-glass window commissioned by Kiki Smith and Deborah Gans is the only 21st century element inside the historic space.

More details of the Eldridge Street Synagogue restoration can be found in the latest issue of Traditional Building Magazine

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

All Photos Copyright Sean K Maxwell

A: When used as a finish over any sort of acceptable masonry Lime Paint can create a beautiful durable finish, when applied appropriately. Chalking of a Lime Paint can be reduced when it is applied in numerous very this coats as always recommended. Although it will not be eliminated, it will certainly help for the longevity of the coating. Now if chalking is of the upmost concern there is a simple solution. By applying one thin coat of PrimaSil, (potassium based “water glass”) almost all chalking is eliminated. The color of the finish may change slightly depending on the absorbency of the background and Lime Paint. Typically, this is so slight that it is inconsequential.

Q: What is the correct method for total repointing?

A: Correct total repointing requires removing the joint to a depth of approximately 2-1/2 times its width and then using a compatible mortar in relation to the final p.s.i. and both the liquid and vapor transmission rate as that of the remaining joint and brick. High lime content pointing mortar is compatible with
the soft and absorptive nature of historic brick which rely on their “fired skin” to protect themselves and the building from rain intrusion. If high concentrations of Portland cement were in the repointing mortar instead of lime, when moisture in the brick were to expand and contract during freeze/thaw cycles, often the unyielding mortar forces the softer face of the brick to exfoliate thus leaving a vulnerable unburned “salmon” center of the brick exposed to the elements.

A team from LimeWorks.us recently visited the site and put together a collection of images seen below. The names carved in the stones represent the counties of Ireland. St. Astier Natural Hydraulic Lime was used throughout the memorial walls and cottage, supplied by LimeWorks.us. The structure has been holding up very well and we are very proud to have been part of this important piece of built heritage.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

All photos Copyright Sean K Maxwell

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Bricks can hollow back quite profusely in some cases. What are some of the causes?

Don’t forget vermin. Accelerated wetting and drying cycles near the bottom of the brick building cause an increase in the decay of the soft bricks. However, where there is water and calcium rich lime mortar there can be ants and bugs nesting in and behind the wythe. Masonry Bees are found in some parts of the country and will burrow. Sparrows and Starlings will take the calcium bits from lime mortar and like a cuttle bone use the grains for digestion. Some very deep holes in the brickwork are from wood peckers who sense the presence of the bugs and they hone in on certain areas in an attempt to get to them. Here’s one example that may have been caused by a combination of water and animals.