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Q: Repairing a Sandstone Foundation ( Answered 5 out of 5 stars,   4 Comments )
Subject: Repairing a Sandstone Foundation
Category: Family and Home > Home
Asked by: jayson-ga
List Price: $25.00
Posted: 26 May 2002 06:57 PDT
Expires: 25 Jun 2002 06:57 PDT
Question ID: 18163
I own a home built in 1939 which was constructed with a sandstone
foundation and poured concrete basement floor.  The walls are
approximately 2 feet wide and 6 feet tall.  Due to age and neglect by
the previous owner, they are in need of repair.  On the outside edge
of the wall the mortar is chipping off in chunks (in some places I can
poke my finger all the way in), and during heavy rain there is water
dripping through parts of the wall in the basement.

I consider myself a bit of a "handyman" and was looking for *detailed*
information on how to go about repairing the wall from the inside and
out. Keep in mind this is for REPAIRING not replacing since the basic
foundation is in pretty good shape (it's not leaning nor or there any
large cracks).  Here are the details I am looking for:

* How to prep the wall for repair
* Best type/brand of materials to use
* Tools needed (rental tools if necessary)
* Step by step instruction / tips
* Any other pertinent info to get the job done right!

Please let me know if you need any additional information to help
answer this question.  Thanks in advance!
Subject: Re: Repairing a Sandstone Foundation
Answered By: missy-ga on 26 May 2002 11:31 PDT
Rated:5 out of 5 stars
Hi jayson!

I scrounged around all of my favorite DIY sites on the 'Net, and
virtually all of them, when presented with the question of "How do I
repair my foundation? I can stick my finger through in some spots!"
said "Replace the whole thing.  If it's that bad where you *can* see
it, it's probably that bad where you *can't* see it."

But you said you didn't want to replace it, so I made a few phone
calls to see who could explain things, then printed your question out
and took it in to see Jake in the Building Materials department at the
Home Depot in my neighborhood.  He explained everything, and gave
suggestions as to where to find more details on the 'Net.  (They won't
specifically talk about foundations, but the techniques do apply.)

Jake's first question, after recommending replacement and being told
"No, he wants to *repair* it." was "Has he had it professionally
inspected?"  You didn't mention that here, so we went on the
assumption that you haven't yet done so.  Jake highly recommends it,
however, to make sure you don't get started on the repair and discover
that you're in over your head.  Sandstone is apparently considered a
bad idea for foundations these days - they look nice, but they just
don't stand up to pressure very well, and tend to do nasty things like
leak, crumble and crack.  To repair them, you have to treat them like
concrete - not as pretty as sandstone, but the best way to repair

The first thing you'll need to do is make sure the foundation is clean
and dust free.  Wash the foundation with warm soapy water and a
moderately stiff brush.  DO NOT use a power washer.  Make sure to
remove all crumbly areas with a chisel or ball peen hammer.

Next, make sure the foundation is completely dry.  If you have a space
heater in the basement, turn it on for a day or two.

Jake recommends that your next step be to plug all holes and cracks,
inside and out, with Quikrete Water Stop Cement:

[ ]

You can do this with a small trowel, and use a wooden dowel rod to
push the plugging material into the deeper holes (you'll want to patch
the ones that go all the way through from both sides if possible}. 
Quikrete gives a brief tutorial in their projects section:

Repairing leaks in Concrete and Masonry
[ ]

To repair chips and corners, you can use Quikrete's Quick Setting
Cement Tutorial:

Repairing with Quick Setting Cement
[ ]

Once you've patched up all the holes and repaired all the chips and
corners and everything has dried, you're ready to resurface.  For
resurfacing, you'll need Quikrete Concrete resurfacer:

[ ]

Wet the foundation down, then mix the resurfacer according to the
package directions.  Jake says you'll want to mix it a little thick,
since it's going up on a wall, instead of being laid out on a
horizontal surface.  Apply with a trowel, smooth with a squeegee, and
let it all dry completely.  Seal the inside with Quikrete Acrylic Cure
& Seal:

[ ]

There's a tutorial here:

Sealing Concrete and Masonry
[ ]

Your very last step is waterproofing the outside of the foundation. 
Jake recommends DeWitt's Foundation and Liquid Roof.  I wasn't able to
find it online, but Jake assures me that any reputable building supply
carrier will have it - instructions are on the bucket (it's a big,
black, 5 gallon bucket).  Application of DeWitt's should keep your
foundation leak free for up to 20 years, says Jake.

It's a time consuming project, but considerably less expensive than
replacing the whole thing.  Even so, please take Jake's suggestion -
get it inspected first, to save yourself possible headaches later.

You can find everything you need for your project, including free
pamphlets, expert advice, and more in-depth project books to either
purchase or peruse in the store at your local Home Depot:

Home Depot Store Locator
[ ]

If there isn't a Home Depot in your area, try Lowe's.  I can't speak
personally for their selection and service, but they seem to be
comparable to Home Depot in layout and available help:

Lowe's Store Locator
[ ]

Lowe's also has a tutorial related to your problem here:

Repairing Leaky Cracks in Masonry Walls and Concrete Floors 
[ ]

Good luck!  I hope the project ahead of you is less daunting than my
sources have made it out to be!

jayson-ga rated this answer:5 out of 5 stars
Thank you for the excellent research!  I think I might have made the
problem out more serious then it sounded.  When I stated I can stick
my finger in a few spots I didn't mean all the way through... my
finger isn't quite two feet long.  :)

Looks like I got a fun project ahead of me next week.  I'll let you
know how it goes!  Thanks again!

Subject: Re: Repairing a Sandstone Foundation
From: morris-ga on 26 May 2002 08:09 PDT
      I was going to take a shot at answering your question, since I
enjoy restoration work myself, but I wasn't having much luck finding
the excact info you're looking for and didn't want to prevent another
researcher from giving it a shot. Your might find the following link

Even though the guy is not in favor of do-it-yourself, he has some
good tips. Sandstone seems to have been more common in barn than house
foundations, though it probably depends on what region you live in.
Good luck.

Subject: Re: Repairing a Sandstone Foundation
From: webadept-ga on 26 May 2002 11:54 PDT
I was going to take this one on as well, and even had it locked and
ready. Also, finding very little on the Internet to "repair" I
resorted to making a phone calls to experts. What I found was that
"replace" was the only real way to go and that "repair" was probably
going to cost you more than taking it out and redoing the whole thing.

I didn't find a single contractor willing to even think about "repair"
and I'm sure you have had the same experience. What I would suggest is
that you consider the reason for this may be because its not a good

Anyway, with everything I was finding, I decided to let another try to
find options for you, after all everyday someone is doing something
someone else said was impossible, so you might find you can "repair."

Subject: Re: Repairing a Sandstone Foundation
From: morris-ga on 26 May 2002 17:14 PDT
Glad I released it. missy-ga got game!

Subject: Re: Repairing a Sandstone Foundation
From: missy-ga on 26 May 2002 18:45 PDT
Nah, missy got Home Depot within sight of the front door!

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