Stone Wall Restoration-Repoint.
On this project we have an old limestone wall that has been around for many, many years. This wall makes up part of the foundation of a house that is located in Lancaster city. Stone foundations are common in older homes in Lancaster county. Limestone is a dense very hard stone making it a good material for foundation costruction, because it doesn’t break down very easily. Also it isn’t as porous as other stone and that helps to prevent water peneration. Another reason why stone is a common building material for foundations in older homes is because, back in the day they just used whatever they dug out of the ground close by. If you want to know what type of stone are found in a particular area all you have to do is look at the old stone farm houses. Farmers had to clear them out of their field’s anyway. So, it was a free building material.
As durable of a building material as stone is the same cannot be said about the mortar joint. Often the stone will outlast the home by hundreds of years however the mortar joints usually will be the point of failure because they have a life span. So, eventually they will need some type of maintenance. Before Portland based cements were widly availabe Clay and Lime was used as mortar. As someone who has had to chop that stuff out of walls, I can tell you that stuff got really hard. Eventually though it just turns back into dirt. How long that takes to happen depends on a few factors. The main one being moisture. If your walls are constantly saturated that will greatly accelerate that process.
If you have foundation walls that are wet after a heavy rain there are a few things you can check that might be an easy solution. The first one is your gutters, make sure they are not clogged so water can make it to your down spout. The second one is make sure your grade is sloped away from your foundation especially where your down spout drains too. After rain if you notice puddles anywhere outside of your house along the foundation you do not have proper drainage. Finally if you live in an area with a high water table than installing a sump pump can help.
The home owner on this project had a new door installed. Before they could do that I had to repoint the area where the door is attached to the stone walls. So, they had something solid to run their tap cons into. It was also repointed about 2 feet to the left of the door jam. I chose to take a photo at this point in the project because it shows how the wall looked originally next to how it looks after being cleaned off and repointed. On the left side of the photo the walls were built using clay and lime mortar and had stucco applied using the same material. After years of water penetration the stucco was just falling off and the mortar joints were ready to be repointed. This entire wall ended up looking like the section close to the door. This photo shows the transformation that is possible, that not only looks a lot better but also adds strength back into your walls. Also helping to keep water out
