View Full Version : Molasses in cement in old construction- looking for historical info

Malcolm Schweizer
10-27-2014, 10:15 AM
Good day all:

I am restoring a home built in 1836. The home is stone and mortar, skinned with brick. Back in the sailing days this area was a Mecca for sugar cane which was mostly used to make rum. They also boiled it down to make molasses. The molasses was added to mortar as a binding agent, giving the mortar a caramel hue. I need to repoint some of the mortar, and I want to make it the way they made it back then, partly so it matches, and partly because the stuff has held up 178 years, so it must be good.

An an internet search turned up numerous articles about adding sugar to cement to make it cure faster. I am looking more for a historic recipe for mortar made with molasses. With as many folks here interested in historic woodworking, I thought perhaps someone may have run across a historical recipe.


Larry Edgerton
10-27-2014, 1:50 PM
Don't have an answer but that is very interesting...........


Bruce Pratt
10-27-2014, 2:18 PM
There has likely been some change in surface color of mortar over the last 178 years. Even if you can find an original formula, the color match may not be what you are looking for. Perhaps consider using a custom mix of some of the modern cement dyes to match the present color of the mortar.

Malcolm Schweizer
10-27-2014, 3:02 PM
Yes, the plan if all else fails is to just play around with dyes. I am also interested for historical reasons in finding the original formula.

The the house next door is even more interesting, and I hope to be able to acquire it as a workshop. It is made from blue granite that we call "bluebitch," although I think "blue bit" is the original name. The trim is gold brick that was used in ballast in ships. You can see where someone did a horrible job repointing some of the stone. Roughly 25x30 and a freestanding open structure, it would be easy to make into a workshop, and would be pretty cool. It is a perfect example of old Danish Caribbean construction.

Tom M King
10-27-2014, 4:04 PM
It wouldn't have been Portland cement. Most likely lime mortar. Send a sample to Virginia Lime Works, and they will be able to provide a very close match. If anyone knows anything about mixing molasses into it, they will. We use their lime mortar all the time working on old chimneys and foundations. http://www.graymont.com/sites/default/files/pdf/vl_20111_catalog.pdf

updated to add: Unfortunately, it looks like Va. Lime Works went out of business last June. It's a real shame. They were a pleasure to deal with, and really knew their stuff.

I'll look for another supplier, and post here. I'll be needing one too pretty soon. We have a whole stone basement foundation to do for a 1784 house.

Malcolm Schweizer
10-27-2014, 4:18 PM
Yes, it would be lime mortar. They also used a lime wash over the stucco as a finish. I was amazed that in my house I was able to find some of the original lime wash still intact under years of paint. It was salmon color. Perhaps not THE original, but certainly very, very old.

Tom, check out Bioshield clay-based paints for that basement, IF you are stucco and painting it. They let water breathe out of the walls. I posted a thread here about it. http://www.bioshieldpaint.com/index.php?main_page=index&cPath=93

Tom M King
10-27-2014, 4:26 PM
Thanks. The original was just laid with dirt out of the yard. It has all tumbled down because it was poorly laid, and the basement was dug out after the house was built on a stone foundation. Long story short, we're probably going to use modern mortar, but it will be colored the dirt color, and tucked way back into the gaps between the stones. We have some original stonework that did survive intact on that site, so we will match it as closely as possible. It will all be left with the natural stone exposed. You can see some of our stonework on my website: www.historichousepreservation.com (http://www.historichousepreservation.com/) We used my waterproofing system on the basement, and it will be drier than any new one from now on.

I like to use lime mortar on old brickwork-like the chimneys we rebuilt the tops of that you can see in my website, but depending on how hard the stone is, and how far back out of the weather the mortar is, I'm not completely against modern mortar. On the stone foundation repairs you see on my website for the 1828 house, all the replacement mortar, and retucking the chimneys, was lime mortar made to match the original by Virginia Lime Works.

I found this place, but know absolutely nothing about it: http://www.limeworks.us/index.php I'm pretty bummed that Va. Lime Works didn't make it after such a noble effort for so long.

Steve Peterson
10-27-2014, 7:16 PM
Another variable will be the sand mixed with the lime/cement. Years ago we started building a small pump house using locally collected river sand for the bottom half. We ran out of sand and had to purchase some to finish the top half. There is a definite line marking the switch, even with the same ratios of cement.


Tom M King
10-27-2014, 7:46 PM
Mixing various sands was how Va. Lime Works matched existing old mortar. On one old house that had a lime mortar, stone foundation, the decision was made to put a ground gutter down to prevent dirt splashing back up on the foundation. The house had very little overhang, and no gutters. The ground gutter was made from stone that was a pretty close match to the foundation stone. Lime mortar would not have held up long enough to set up to withstand the 26' water fall off the roof. We used white Portland mix mortar, and white sand, with a little bit of modern mortar colorant to bring the color up to match the very light lime mortar in the foundation.

Even sand coming out of the same quarry can vary in color from one day to the next, or if it comes out of different places in the pile. When doing a building with a lot of mortar joint square footage, it's good to get enough truckloads of sand to have some left over to throw away after the job is finished. If there are obvious color variations after the trucks have dumped it in a pile, it's good to stir it all up with a frontend loader to start with.

Larry Edgerton
11-01-2014, 8:25 AM
I just restored an 1876 Italianate farmhouse with a cut field stone basement. Stones were 2'x1'x1' thick, all joints were 1" and extremely uniform, and when I checked it for height it was no more than 1/16 off. Amazing. Joints were done in the beaded style and are still in good shape.

There are quite a few of this style in the area and I am trying to buy an abandoned 100'x40 barn foundation made of these stones. I want just the stone.

I have seen no work that compares in my lifetime of working on homes. Story goes that these stones were cut in Europe and used in ships as ballast when they came to pick up iron from the Great Lakes, but I can not confirm that.