Filling holes in stone foundation

[Jeffrey J. Kosowsky]

There are several round "holes" in our stone masonry foundation presumably from old pipes that have been subsequently removed. The holes are about 2 inches in diameter and extend through the foundation just below the level of the sill.

I would like to fill in these holes but was wondering what is best/easiest?

Do I mix my own concrete? (if so, what type?) Is there a good patching premix? Any other suggestions?

[Joseph Meehan]

I would not suggest concrete. The mortar and many of the stones used in those old foundations is much softer than concrete and many of the products used today. Mixing the hard setting concrete could damage what you already have.

I don't have any suggestions for specific materials. Maybe someone else will have some good suggestions.

[Brikp]

Just some "Mortar Mix" will do fine. Concrete uses stone aggregate for strength, like in a sidewalk. Mortar is used for pointing between stone and bricks and for bricklaying. Cement is the binder used in both Concrete and Mortar Mix.

For everyone who doesn't know (Not a dig to the OP or anyone else specifically)

Concrete is not cement, cement is not concrete, mortar is not concrete, concrete is not mortar, mortar is not cement, cement is not mortar

[Jeffrey J. Kosowsky]

Perhaps some silly questions but I am new to this stuff...

1. Will any "Mortar Mix" work or are there different types?
2. Is there a pre-mix or is it better to mix up a dry batch?
3. Can I fill the whole hole (maybe 6 inch deep by 2 inches wide round cylinder) at once or do you need to apply in layers?
4. Does it shrink or expand when it dries? (and if it does, how do you keep it relatively level with the surrounding area?)

[William Deans]

Greetings

For an "easy" and "quick" fix just spray a can of expanding foam into the holes. Use the rest of the can to seal any other air leaks you may have. This is not the "best" fix. The foam will always look like foam (even if you paint it). Foam is not as durable as mortar. On the other hand it will take you less than five minutes, doesn't involve heavy bags of mortar, mixing, dust, etc. Plus the expanding foam is just a "way cool" product to use. You will be sure to impress the kids.

Hope this helps,

William

[Brikp]

1) Any old. Sacrete is one brand, Quickrete is another. For such a small hole you will still end up buying a 40lb bag. Should cost under $4.00 IIRC. 2) I'm not sure I have seen pre-mix. Quickrete may have small tubs of the stuff. They also have a "Hydraulic Cement" that can expand and help plug water if you have water problems. 3) You can fill the hole completely as long as your mix is not too thin causing it to slump out. You can use a whisk broom or something similar to smooth down any irregularities once it starts to set up but before it dries. 4) No, it doesn't shrink or expand, unless its the hydraulic stuff I mentioned in #2 above. (Hydraulic cement sets up in seconds and is a pain to work with IMO)

You will need some type of trowel to goop it in there. An old tablespoon would do. If you use your fingers it will seriously dry out your skin. Some will advise wearing gloves. Be a man, don't.

If I were you, I would just go ahead and get the smallest bag you can get at the blue or orange store. Probably 40lbs. Mix up about 1/3 of a bucket full and see how far you get. you will be surprised by how much you will need if you fill the holes completely.

See

for the hydraulic stuff

[William Deans]

Greetings,

1a. Yes, just about any mortar mix will work (for your purpose). 1b. Yes, there are different types-- but your applicatoin is not very demanding.

If I were in your shoes I would purchase this product:

60 Lb. Mortar Mix Item #: 10391 Model: 14115

$2.93

[Jeffrey J. Kosowsky]

Thanks SOOOO much for the help...

[Jeffrey J. Kosowsky]

In general, is there any disadvantage to "stiff" mixture? i.e. is it less strong? does it bond less well to the surrounding masonry? etc.

Very helpful!!!

[William Deans]

Question:

Answer: In general, the less water the stronger the mortar. The properly cured bond is equally strong.

So what are the disadvantages? If the mortar dries out too so> > 1a. Yes, just about any mortar mix will work (for your purpose).

[m Ransley]

For you Mortar Mix, be sure to wash out the hole with a hose. You will not affect the wall with a hole repair, be sure hole is clean.

[Jeffrey J. Kosowsky]

Just went to the Home Despot tonight and the guy in building materials (who seemed to be somewhat knowledgeable) discouraged me from buying a straight Mortar Mix and instead recommended some Acrylic cement patch stuff (I forget the full name). He claimed that Mortar Mix is made for joining bricks and that it would not stick properly to a hole in the cement wall. The Acrylic product apparantly includes cement, sand, plus some additives to help binding.

His advice sounds logical, but on the other hand the product he recommended is about 10 times as expensive on a pound-for-pound basis, so maybe he just was ripping me off :)

Any thoughts?

[David Modine]

Typical box store employee. If he knew what he was talking about, he'd be out in the field making far more money than standing around in an orange apron giving bad (overpriced) advice. Acrylic or latex addatives, or premixed morters which include them, are great for aplications where the mud is thin, and/or needs to strongly grip adjoining surfaces. Overkill for your situation. Follow the good advice you received from others here. Mix cheap mortar mix with just enough water to make it like brown sugar consistancy. Pack it in firmly. Moisten the surrounding area a few times over a few days. I'd fix that hole with a 3-1 mix of coarse sand-Type II Portland, if it were me, but I have these two componants of mortar on hand all the time. I think the premix stuff is a bit lean on it's cement content, but for your situation it should be fine.

[Jeffrey J. Kosowsky]

Thanks for the straightforward advice!