Fifth generation successor to the family building materials business, Henry Frerk Sons, Matthew Wolf’s

Great Great Grandfather started the company as a general store in the early 1870’s.

Wolf says it looks like “his thing” is going to be restoration. “Every generation put their own mark on the

company. It’s very important to me to do the same.”

According to Wolf, ”Lime mortar has been used in America since the settlers. Portland cement (what we

use today) was first developed in England in the 1870’s, but wasn’t widely used in the U.S. until the

1930’s, because it was very expensive to produce and there were few manufacturers around making it.

When the price came down enough for contractors to use it laying brick, cement took the market over by

the 1940’s.”

One of the biggest differences between cement and lime mortar is that

cement gets very hard very fast, and lime mortar takes a very long time to

set. There are 7 different types of mortar differentiated by their hydraulic

properties – the degree to which lime works with water to grow crystals

and get hard. The more hydraulic mortar is, the harder and faster it gets

hard.

Lime putty has zero hydraulic properties, “…it’s like sour cream”. On the

opposite side of the spectrum is Portland cement; it’s made from the same

rocks, but with different additives.

In between the two are: NHL – Natural Hydraulic Lime 2.0, 3.5 and 5.0

rated from weakest to strongest, Pozzolain Lime – Developed by the Romans, and Natural Cement –

Developed in New York and used to build the Erie Canal, lighthouses, and other structures.

Wolf says the Romans were really

the first to develop lime. It was

tried and true for centuries, “…but

Portland cement did such a great

job of advertising we forgot about

lime mortar. Portland is for

resurfacing and isn’t necessarily

the way to go with restoration.”

Matt is committed to the belief if

a building was built with lime

mortar, it should be rebuilt with

lime mortar. “With restoration,

lime mortar breathes better – but

you don’t want it to go through

the brick. Pre-1930 commercial

buildings usually have this

problem. You can test for the

original mortar, but it’s very expensive.”

Glad to see lime mortar is being widely recognized in preservations now, Wolf says contractors, in general,

are reluctant to use it because “they grew up with cement.”

Fortune Restoration works closely with Matt’s company to master the art of lime mortar. “I’m excited

about working with them because their technical skills are so great. They are covering the walls with

burlap and hand chiseling to maintain ‘proper historic masonry renovation’.”

In an effort to defray the expense of maintaining historic building applications with integrity, Frerk was the

first building supplier to make a “bulk silo” for lime mortar to help bring down the cost. “We often see

more damage with bad re-pointing because the wrong stuff was used. It really should be a do-it-right-or-

don’t-do-it-at-all undertaking.”

Read the full article here.

Additional Reading:

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How to Choose Paint Color for Your Vintage Home

Historic Italian Victorian Restoration - Wilmette

Historic Landmark Home - Kenwood

Award-winning Preservation Project - Oak Park

Painting, Masonry & Carpentry 6619 N Lincoln Ave. Lincolnwood, Il 60712 847.674.2500

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