Updated over 7 years ago on . Most recent reply
100 year old stone foundation repair
I have acquired my 3rd Buy and Hold property which will require more work then needed in my previous two. I'm going to leave this post just to the foundation. A little about the home. It was built in 1910 and is a semi detached (I guess you would call it, one side of the house shares a wall with neighbor) 3 bed room 2 bath city home in Little Italy Wilmington, DE. I love the place as there's a ton of upside, I just have to get there. Starting with the stone foundation I noticed the mortar is missing/crumbling in some areas. I can see a tan/brown sand underneath where the mortar was. When you touch it the sand material falls right out. I know that you need to remove all the old mortar but how far into the joints do you go to remove that sandish material? Do I put backer rod in there? I have the ability to do this and just want to make sure I'm doing it right. I have attached pictures of an example area and greatly appreciate any info what so ever. Also interested in hearing opinions on what mortar type to use. I've read anything from type S, custom lime mortar mixes, to getting your mortar tested.
-Josh
General view of my foundation/brick wall. There is a sidewalk that meets the stone foundation.
The brownish area in the center of the photo is a small problem area.
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Josh, with the flaki-ness of the mortar. I'd say you're right that it is a limestone base but you can just stuff the hole full and you'll be fine. That is a common repair we do. When we do new siding and windows on a house, we offer to fix the foundation and it only takes a few minutes. The whiteness on the brick is called efflorescence and but it isn't necessarily a bad thing, mostly just a cosmetic annoyance. It's essentially just salt, but it is indicative of water penetrating your brick. When that house was build, they intentionally did not use the red brick all the way down, typically because when water splashes the ground it causes wearing of the mortar just like what you're seeing. So they typically use a stone that is less prone to wear.
I can see what looks like a gutter running down and stopping at the lower foundation. This gutter is sending water to the concrete below which is splashing back onto your mortar and causing premature wear on both the foundation and the concrete.