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I have unusual details, could you explain or can I tell you what I know about the subject?

*Using the modern grapevine jointer in brickwork is a form of what is also called “bastard pointing” whereby the genuine article

Saving money on your historic restoration project

How to Save Money with your Historic Restoration Project was commissioned by Zion Evangelical Lutheran Church of Tamaqua, Pa., to diagnose and address the failure of a church tower which utilized man-made cast stone for trim details.

Regional Heritage Charleston, South Carolina

For the record, Doug Scott a local mason to Charleston for over 25 years, had a hand in all this!

Regional Heritage Lancaster, Pennsylvania

For the record, Randy Ruth a graduate of the Thaddeus Stevens College of Technology had a hand in all this!

Trinidad and Tobago

They seem to love me in de Islands. Got invited to Barbados and others to run more workshops. I guess

Misc Training Work

The following are examples of training work we have done. Wehave provided training for volunteers of non-profit run historic sitesand

2012 APT/PTN Convergence Workshop at American College of the Building Arts (ACBA)

Charleston, SC – September 30 to October 4, 2012 Cap is missing bricks on both ends of entrance arch to

Building a Lime Test Wall

Please watch our 3 part video series on our Lime Test Wall in Cameroon Africa  

Restore Wesley United

Click here to read a PDF with the details of this workshop!

Mentoring Young Masons at the Speakers House

Trappe, Pennsylvania, USA - May 2009 AiP’s project at The Speaker’s House had a different format than usual, but all

“Mind the Gap” – Traditional Chinking and Daubing

12th annual International Preservation Trades Workshop , IPTW 2008 “A Place for the Trades” Barre, Vermont. July 18-20, 2008 Andy

Galleting in the Garden

The Bronx, New York, USA – August 2008, August 2009, August 2012 On a sunny morning in August, 2008, more

Re-Plastering the Jean [Jacob] Hasbrouck House

New Paltz, New York USA – August 2007 Restoration work at the Jean [Jacob] Hasbrouck House has been a multi-year

PastForward San Francisco 2018: Preservation for the People In SPECS!

During the summer, Melissa Luo interned at and assisted our laboratory staff with mortar color simulation projects including determining

Lime Paints User Recomendations – Guide

Vibrant and beautiful, the St Astier lime paint range is the perfect compliment to lime plaster, render and harling, suitable

Israel Nature and Parks Authority The Conservation of the Archeological Parks The use of St. Astier Natural Hydraulic Limes

Israel Nature and Parks Authority The Conservation of the Archeological Parks The use of St. Astier Natural Hydraulic Limes First

Render on Wooden Lath – Guide

External rendering on wooden lath using St. Astier products. Timber framed buildings, historic or new construction have a tendency to greater

Render on Metal Lath – Guide

External Plastering (Rendering on Metal Lath Using St. Astier Products) The main difficulty in working on lath is ensuring the

Sands for NHL Mortars – Guide

Choosing the correct sand when making a mortar is of extreme importance. Sands should be clean and uncontaminated by clay/silt.

NHL Limes: Injection and Grouting – Guide

INJECTION – PURE LIME PUMP NHL5 1bag + 10.5gal of water Capacity: 35 cu. ft./hr NHL 3.5 1bag + 10.5gal

Lime Concrete – Guide

Lime Concrete for Floors, exposed aggregate / tamped finish Ingredients. 10 x 66 lb bags (660 lbs) NHL 5 per

NHL Renders – Guide

NHL Renders General information Sands for renders Background preparation Two coat work Three coat work Protection Good working practices Render

Pointing with NHL – Guide

Pointing with NHL Understanding mortars Choosing mortars Resistance to salts Protection and working practices Repointing: preparation, application, finishing Repointing dense

NHL Render – Guide

Background Prepare background Re-point and dub out as necessary with compatible mortar. Stipple Coat Cast or sprayed on only Must

Plaster on Blocks – Guide

External Plastering (Rendering) On Concrete Masonry Units To obtain the highest vapor permeability a block construction should be built with

Render on Cob – Guide

Cob is a very simple (and efficient) form of construction that has probably been around forever in some form or

Plastering with a Spraygun – Guide

This method is particularly suitable to ensure optimum bonding even on smooth surfaces. Spraying is recognized as the best method

Plastering with NHL – Guide

Using St. Astier NHL plastering mortars instead of non hydraulic putty mortars reduces the working time by about 50%.  NHL

Shelter Coat/Consolidation – Guide

The purpose of a shelter coat is to provide protection to surfaces that suffer unduly from the effects of erosion

NHL Renders – Guide

Defect Causes Remedies Shrinkage & Cracking greater than 3/16″Less than 3/16″ Hairline cracks General or partial movement of the background

Working with Mix & Go – Guide

Mix & Go is a premixed product designed to provide all the benefits of traditional lime mortars for wider general

Making NHL Mortar – Guide

NHL Mortar preparation: can be mixed in normal Mortar mixers. Put approx two-thirds the amount of water, one third the

Cladding – Guide

St. Astier NHL products for use with masonry cladding. For the purpose of this document Masonry Cladding means thin sections

Ashlar Joints – Guide

Traditional ashlar jointing and bedding mortars were made with lime and crushed chalk, usually with a small amount of crushed

NHL Mortars: Consumption Chart – Guide

NHL products are bought by weight but mixed by volume. Their low density in comparison with other binders means that


If you have a “chink” in the armor of a building it is usually due to different or moving materials

Our American Institution

The United States of America and its Heritage The central theme in the inheritance we receive as citizens of the

Biography of Andrew L deGruchy

A Quotable Quote: Why you should send your kids to Trade School… “My mother has always been unhappy with what

Minimalist Japanese-inspired furniture

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New home decor from John Doerson

Ullamcorper condimentum erat pretium velit at ut a nunc id a adeu vestibulum nibh urna nam consequat erat molestie lacinia

The big design: Wall likes pictures

Parturient in potenti id rutrum duis torquent parturient sceler isque sit vestibulum a posuere scelerisque viverra urna. Egestas tristique vestibulum vestibulum

Sweet seat: functional seat for IT folks

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Reinterprets the classic bookshelf

Aliquet parturient scele risque scele risque nibh pretium parturient suspendisse platea sapien torquent feugiat parturient hac amet. Volutpat nullam montes mollis

Minimalist design furniture 2016

A taciti cras scelerisque scelerisque gravida natoque nulla vestibulum turpis primis adipiscing faucibus scelerisque adipiscing aliquet pretium. Et iaculis mi velit

Green interior design inspiration

Vivamus enim sagittis aptent hac mi dui a per aptent suspendisse cras odio bibendum augue rhoncus laoreet dui praesent sodales

Non vestibulum lacus sociosqu

Ac haca ullamcorper donec ante habi tasse donec imperdiet eturpis varius per a augue magna hac. Nec hac et vestibulum

Old Stone Basement Foundation FAQ

This is part of a series of blog entries that will feature mason, Randy Ruth. Randy was the former lab

Let’s Talk Sand

Our Ecologic™ Mortar uses a sharp well graded proprietary blend, so it’s not just ANY sand! The dictionary definition of

Restoring Mt. Vernon’s Upper Garden Wall

by Debra Grube and Samantha Horvath is providing a custom blend of our Ecologic™ Mortar for the restoration of

Lime as a Green Build Material

Here’s How St. Astier Natural Hydraulic Lime (NHL) Plays An Important Role In Construction As A Green Build Material. St.

Restoring St. Patrick’s Cathedral

An Undertaking of Passion and Love is a big part of helping to restore a prominent landmark in New

Another Successful Straw Bale Building with Natural Hydraulic Lime Plaster – Little Rock Arkansas

Straw bale construction is the best of both worlds, it is a green and sustainable way of building and can

Limelight on the Restoration of the Rotunda at the University of Virginia

The University of Virginia is the only US university with a World Heritage designation, it’s conservation is of the utmost

Chemistry of Lime Mortar – Neighborhood Preservation in Philadelphia

The Chemical Heritage Foundation released an episode of their award winning podcast Distillations.  In this episode, Randy Ruth, formerly of

Repointing the First Congregational Church Hudson, OH – A Restoration Success

Here’s a brief summary of the project at the First Congregational Church of Hudson (OH) project by John Burnell, Principal,

UVA Rotunda

Repair Campaign at the Rotunda, University of Virginia Restores with Lime

We’re so proud to be part of an incredible restoration campaign currently taking place at the University of Virginia. The

Preserving America’s Historic Barns – A Conversation With Historian Jeff Marshall

Watch our Limelight on America’s historic barns. Historian Jeff Marshall discusses his appreciation and understanding of barns, barn builders and

Historic Lime Stucco and Plaster Repair in New Jersey

The Technical Install Team of was called in to reverse some of the inappropriate finish that had occurred over

Colorwash Stain, For Brick Walls With Mismatched Brick

Q: There are some bricks in wall that are mismatched in color. Is there a way to have them match

Featured in this Old House Magazine

FAQ Friday: What are Silicate Paints?

Silicate Dispersion Paint is also known as Inorganic Mineral Paints and is unique in regard to its ability to breathe

Preserving Historic Brick at the Shirley Plantation

The historic Shirley Plantation is situated along the James River right outside Richmond Virginia. It was constructed in the early

Repointing A Historic New Jersey Home

Historic masonry restoration completed by the Technical Install Team of in Moorestown, New Jersey. This circa 1790 historic brick

Restoration Well Underway at the University of Virginia

The prestigious Lawn at the University of Virginia is currently in the middle of an enormous restoration campaign. This past

FAQ Friday

Two weeks ago I attended The 12th International Congress on the Deterioration and Conservation of Stone in New York City.

Limelight on Historic Brownstone Restoration – Alfred’s Victorian

Alfred’s Victorian Restoration Story –  with Andy deGruchy This beautiful late 19th century Hummelstown brownstone was recently restored by deGruchy Masonry Restoration, the

Replica Lithomex Brick for Charleston Old City Jail

The 2012 APT/ IPTW Joint Preservation Conference is almost here. We’ve been busy preparing for the workshop we’ll be participating

Mineral Paints and Stains Make a Breathable and Durable Mural on a Historic Building

1 man 560 hours 28 days 1 Beautiful/ Durable/ Breathable Mural Jim Gloria of the Totts Gap Art Institute completed

Conserving A Pennsylvania Treasure, New Hope’s Historic Parry Mansion

The Parry Mansion located in downtown New Hope Pennsylvania is one the finest relics of the river town’s historic past.

Historic Brownstone Restoration With Breathable Natural Hydraulic Lime

This beautiful late 19th century brownstone was recently restored by deGruchy Masonry Restoration, the Technical Install/Training Team of Using

Favorite Books on America’s Building Heritage and Masonry, FAQ Friday

While it may not be directly in front of you, information about our building heritage in the United States and

Restoring the Historic French Quarter with Breathable Lime Mortar

Founded in 1718, the French Quarter or Vieux Carré is the oldest neighborhood of New Orleans. Much of the quarter’s

How To Stay Cool While Working with Lime in Extreme Heat

With temperatures across the U.S. exceeding well beyond the 90° F during the day and relentless scorching sun I have

Discussion on Masonry Preservation and Sustainable uses for Lime

Join us June 27th in Lancaster PA at the Central Pennsylvania Preservation Society. Lab Tech Randy Ruth will be presenting

How do Natural Hydraulic Lime Mortars Compare to Common Type-O Mortars Containing Portland Cement?

For well over 30 years it has been common practice to prescribe the use of a Type-O masonry mortar for

Yes, We Can Save The Frank Furness 19th Street Baptist Church

This beautiful church was designed by Frank Furness and is located at the corner of 19th and Titan in South

Tadelakt Plaster Finish is FINISHED at the Bucks County Designer House

The walls are complete in the powder room at the Bucks County Designer House in Doylestown, PA. Here is a

Tadelakt Plaster Application At the Bucks County Designer House & Garden was commissioned to complete a Tadelakt plaster application at the Bucks County Designer House in Doylestown PA. Tadelakt is a

Understanding Mineral Paints and Stains for Masonry Applications

Ecologic™ Silicate mineral paints are mineral paints made using potassium silicate, also known as waterglass. They are combined with inorganic, alkaline-resistant

Sand for Natural Hydraulic Lime

What Sand Should I Use With Natural Hydraulic Lime For Repointing My Building? FAQ Friday

How to choose sand for Natural Hydraulic Lime Quick and short of it…. when choosing sand for Natural Hydraulic Lime,

“Soft Reds and Hard Tans” Exploring Historic Masonry Architecture in the French Quarter

New Orleans. It’s quite the town especially during the weeks leading up to Mardi Gras, known as Carnival. Technically beginning

The Bill of Rights for Masonry Structures

                    Photo Credits: Bryan Papciak Sean K Maxwell Kate Milford Steven

Repairing Broken and Damaged Stone and Brick using Lithomex – FAQ

Of course following the Lithomex technical data sheet is important to ensure a quality application, but what about the little things

The Mysterious Newport Tower, Restored Using Natural Hydraulic Lime

The Newport Tower is a peculiarly placed piece of stonework.  It currently resides in Touro Park surrounded by one of the

A Green Portland Cement Alternative, FAQ Friday

You might ask yourself… How is Natural Hydraulic Lime (NHL) a green building material? The simple answer would be that

Lime Paint Brush (Natural Bristle) vs other paint brushes? FAQ

Often when applying Lime Paint the surface texture may be rough, such as that of a brick, stone or stucco.

Restoration of the Eldridge Street Synagogue in New York City with Ecologic™ Mortar

In the heart of what is now Chinatown on the Lower East Side in Manhattan lives the Eldridge Street Synagogue.

Chalky Finish With Lime Paint, FAQ Friday

Q: I want to use Lime Paint as a finish of my basement walls but am worried about it chalking.

Checking up on the Lithomex Repairs at the Metropolitan Museum of Art

A team from recently ventured up to NYC. While there, they took some time to visit the Metropolitan Museum

Total Repointing/ FAQ

Total Repointing, FAQ Friday

Q: What is the correct method for total repointing? A: Correct total repointing requires removing the joint to a depth

Historic Fabric melded with Traditional Mortar at the Irish Hunger Memorial in New York City

Blocks from the World Trade Center Memorial and the construction site of the new World Trade Center sits a half

Damaged Bricks, The Quick Moving Culprit? FAQ

Bricks can hollow back quite profusely in some cases. What are some of the causes? Don’t forget vermin. Accelerated wetting

Green Construction in Today’s Built Environment – FAQ

Q: When people talk about “green” construction, I often wonder what the environmental benefit of the construction is. Is it

Lime Paint and Plastering System for Interior Application, FAQ Friday

Building on last week’s FAQ Friday, the use of lime paints doesn’t have to stop with use on the exterior

All About Lime Paint, FAQ Friday

Although they date back thousands of years, some of the best examples today of lime paint are those pictured in

Lime Mortar and Hardscaping, FAQ Friday

When it comes to hardscaping with masonry, I am all for mortarless construction. The beauty of a well built dry

Reconstruction of Historic Lime Mortar and Renders FAQ Friday

Q: I want to restore my old stone house and have heard there are ways to reuse the mortar already

Stucco Over Historic Stone Buildings, FAQ Friday

Q: Why are beautiful stone farmhouses and other historic stone buildings covered with stucco? Is it for insulation? If the

How Lime Mortar Traditionally Got it’s Color and How We Can Replicate this Today – FAQ

Seven factors that can affect the color of lime mortar in no particular order of significance, Lime, aggregate, pigment, water

Sandblasting Historic Buildings FAQ Friday

Q: Someone wants to sandblast my house. Should I let him sandblast? A: Invasive cleaning methods such as sandblasting or

Using Natural Hydraulic Lime in cold weather, FAQ Friday

Q: As fall encroaches upon us with its cold weather, a question that is going to be popping up with

Wet Basements and Masonry… FAQ Friday

Basements are notorious for moisture problems. Mold can spread quickly and cause serious health problems throughout a home. Here is

Burning Lime, The Traditional Way

This is an incredible video that really shows the difficulties of burning limestone the old way. Stacking wood, limestone and

Deteriorating Brownstones – FAQ

Q: I have an old brownstone house and some of the stone have been falling off, what can I do to prevent

One quick question on Natural Hydraulic Lime, FAQ Friday

Fall has arrived, this morning it was in the 40s! Randy has quick answer today in his FAQ entry… Q:

Techniques for Plastering a Wall, FAQ Friday

Q: I have painted drywall in my home and would like a lime plaster finish. How can I achieve this?

A Message from Ian Cramb, a younger man…

We got an email back in 2011 with some amazing photos of Ian Cramb. These photos are from 1958 in

repointing with natural hydraulic lime vs cement based mortars

Differences Between Repointing with Natural Hydraulic Lime (NHL) Mortars vs. Cement Based Mortars FAQ

Q: Is pointing with lime different from pointing with cement? I’ve done work with cement but I want to know what

FAQ Friday

Hooray, Today is Friday! Another rainy weekend will be upon us here in Pennsylvania, but now it’s time for another

Lime Mortars vs. Cement FAQ

Shall I use Lime or Cement? Q: Could I perhaps use cement and sand? What is the advantage of using