How to fill an exterior crack

Hi,

I live in a house built in the 1850's. It has a stone foundation (shale?). Sometimes there is mortar in the gaps. There is a sidewalk (3' wide) poured right up to it. Due to differential settlement, uneven rates of expansion and contraction and maybe a host of environmental reasons, there is a large crack between the sidewalk and the foundation, which recently began to let water into the basement. There is evidence that this crack has opened up before, and the fix (evidence of at least 2 prior fixes) has been to fill in the gap with some sort of cement-itous material, which cracks and disentigrates after a few years. I am looking suggestions for a better way to repair - I immediatally think silicone would be a good material because it should maintain a good seal and allow for different rates of expansion and contraction/differntial settlement, but I am concerned about silicone's ability to withstand the elements - we are good for about 10-15 inches of snow/ice every year. Any other suggestions, recommendations or orders?
Thanks,
Mark

 

Can you give us the dimemsions of the "large crack"? I would probably cut out at least 3 inches if it isn't the wide already, going down to the soil, mix some portland with sand & fill it with that.

 

Well, it is the length of the house. It ranges in nominal width from 1/8" to 3/4" - 1" being the extreme. Depth is usually less than an inch.

 

What you have is really a two fold problem. There are cracks in the foundation too. If there weren't, the water wouldn't enter the basement, even though the walk is damaged. I understand that you don't want to do all that digging if you can avoid it & the previous owners thought the same way.

Since the crack is jaggered, it's not guaranteed that any of the sealers will reach every spot. That's why they only buy so much time. If you saw cut a straight line about 3 inches from the house, the thickness of the cement, you could fill it with new cement. It's more work but I don't think you'll have to bother with it again.

 

Yes, the foundation is stone laid about 160 years ago and there are without doubt ways for the water to move through. But the water never came through like this until recently. I decided to use a masonry grade caulk (said something about concrete cracks on the front of it) to fill it. If that doesn't work, I will re-do it your way. I still think I will need something between the sidewalk and the stone though, otherwise this is just going to happen again?

Thanks for your help.

 

Good luck with it.
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Make sure you use backer rod or your caulk job will fail sooner, rather than later. Use quality brand of caulk like 3m, Dap, Sika.