Home Repair

What to do with very old basement walls?

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We live in an older house- pre 1900, and we have a stone foundation
so the walls in the basement are stone. Not like nice fireplace stone, but
jagged large stones. Some of it is actually bedrock that goes right into
the ground in one corner - that area is actually dirt.

The material between the stones is very crumbly and dry, powdery, and
constantly falling out in small amounts. No matter how much I
would brush the walls, there will always be more. Sometimes it even
comes out in chunks. I have reached my limit, and have decided I have
to do something about this. HERE IS THE QUESTION! What in the world
can I use to fix this? I have given a great deal of thought to spraying on
some kind of paint- like drylock or some such. Plastering over is out of
the question. Apparently at some point many years ago someone tried
that and I still have small areas where sheets of it fall off onto the floor.
I am at a loss here, I HATE hate hate to admit that.
Anyone have any ideas? Please? OK, I'm begging...

I would try the drylok UGL waterproofing paint. Buy a gallon and try a small area to see how it works. I don't know about spraying it on though. It is very thick and on the can it says to work in with a brush. Maybe you could contact the manufacturer and ask about this particular application.

You could just build a wall in front of the stone wall, insulate, then sheetrock with greenboard moisture resistant drywall, paint and never worry about it again! But I would still use the waterproofer Drylok first to seal as best as possible.

Good Luck... TheGuru
Painting on is really not an option. The product tends to 'roll' along with the
brush, because of the amount of loose material. I know the
drylock is really thick, but the one I am familiar with can be thinned with
water. I thought maybe I could thin it and apply several coats.
I will try a small amount- maybe it won't be as bad as I think. I have
put up with these crumbly walls for long enough. It makes the entire
house dusty, it gets into the furnace, the cats drag it around, and my
basement has never ever felt clean because of it. However, it is
really not worth the time, effort and $$$ to build out walls. It really won't
add any value to the house either. The exposed beams still have bark on
them, and the duct work makes the ceiling down there too low to bother
with finishing it out.
Thanks though, I am gonna try a small area with several coats thinned-
I guess it really can't hurt anything!

That's true it can't hurt to try a small area.

What about using a shop vac first then try to brush on the drylok?

You could try the vacuum then a spray bottle with water to dampen the wall. Then try to brush it on. Maybe...

Try a bunch of different ways and see which one works best.
I actually did use the shop vac on the walls- a lot. There are many places
where I am too afraid I will suck out too much and the foundation will
be comprimised! I know that sounds like I am joking, but only a little. So
much crumbling going on, even small pieces of stone have fallen out.

I think I will dampen a section and put the dry lock on. Our new Lowes is about to open- about 3 miles away!
OMG!!! I am so excited I can hardly stand it. If you can't find me - I'll
be at Lowes! I'm a power tool and plywood kind of gal.

I posted a whole long response about this and how to do it before the server crash... of course that post didn't make it to the backup in time.

Basically you want to repoint the foundation, with a soft mortar.

I'll see if I can find it again.

REPOINTING YOUR FOUNDATION: The mortar chosen for repointing is one of the least understood yet most important details in repairing masonry. Through most of the 19th century, masons used lime mortar. This slow-drying, soft mortar was compatible with the stone used for most foundations. Near the turn of the century, masons added Portland cement to the lime to make a harder mortar for the cast concrete blocks that were popularly replacing stone. In each case, the mortar was always softer than the adjacent masonry units. Slow-drying, soft beds of lime or lime/Portland mortar allowed buildings to settle initially and adjust to the contraction/expansion rigors of this climate. Lime and lime/Portland mixes are still appropriate for repointing. Hard Portland mortar was not used historically and cannot successfully be used today. Mortar that is harder than adjacent stone, brick, or block will crack, allowing moisture penetration and increasing the chance of spalling. If the mortar fails, it cannot be removed safely from the masonry where it is firmly attached. Finally, beware of inexperienced contractors who urge you to cover your foundation with stucco. Stucco (sometimes called parging) is not a substitute for repointing and repairs; it often covers up the problem rather than actually remedying it. For more specific repointing instructions, refer to Chapter 4[http://www.landmarksociety.org/discover/rehab/chapter4.html].
I say move! I hear Linglestown is nice!
Nah! Repointing would be nearly impossible not to mention WAY too
expensive. I believe mine is the old soft lime type, but my major
problem is the constant dirt and grit. My foundation is well over 2 feet
thick and the beams are actually logs- bark and all. Anything major is
sort of out of the question. Gonna do the drylok today (I hope)
I'll let you know what happens

Maxmm- I wish we could move! I hate living on the main drag. But I
do love Annville! We're staying here. It took me years to get used to
this town, and now I don't want to leave. The tax increase is gonna
stink, but there will be lots of vacant houses!

How did the drylok work out? Did it seem to seal the smaller spaces?
Every weekend I prepare to do the job- I certainly intend to get it done.
But every weekend something else comes up and I find myself doing
something else. My mother has been cleaning house and I have ended
up bringing lots of things home from her house and these things are
mostly what has taken up so much of my basement time! (I do have a
rather nice - and very old- chest to show for it tho. Embarassed )
I am going to get something done this weekend - I promise. Who knows
what it will be - we have so many things started. I could spend the next
few months just finishing things. Actually, now that we have quit
smoking and are often looking for things to do, finishing all these
things sounds like a great idea!
Will let you know when I get around to it, how it went.

OK! Take your time... The stones aren't going anywhere!!!!
Have you tried Drylock yet? I'm suffering with the same problem and eaglerly awaiting your answer!
I think she decided to move instead! LOL

I will PM her about it.
I posted the other day, but it never made it through -sorry.

I did try the drylock - I am not happy with the result.
The dryness of the stone and remaining chinking kept
me from getting a good bond.

For what it's worth, I have learned a few helpful things since
my attempt at drylocking.
If there is a moisture problem, resolve it first. If there is
moisture coming through the block (if you have block) it
can actually destroy the block on the other side of the drylock
and you may not know it right away. It will eventually remove
the drylock from the surface. This is not the problem I was
having but, it might be good to know.

I am learning and asking more questions with local pros before
I put any on the basement walls in the new house. I do have
a bit of moisture there, but I think it will be resolved with
new gutters and downspouts and some build up around the

Good luck- and thanks Ron for the heads up!

i own a 100+ year old house and i may just throw out there that your house has been standing for 100+ years as is. The old dirt mortered stone was done that way for a reason, it drains and breaths, letting water through. Dry lock may change this and cause unexpected results. Houses like this need good drainage and landscaping to keep water away.
Well actually the original post wasn't about water or drainage
at all. That house sat at a very high point and the basement
was very dry. We never had dampness in that basement. I was
unhappy with the stuff coming off the walls and onto the floor,
and thought maybe I could stop that from happening with
the drylok. At some point years ago someone tried to plaster
over the rock and that too fell off - in fact is still falling off.
For sure, they don't build them like that anymore. The
landscaping and drainage are just fine and it's a rock solid house.
Just dirty in the basement. Wink

My reply is 3 years after the original question so is posted for anyone in the present/future seeking the same answers.

my 1913 stone foundation basement also had mortar that had turned to sand and was falling out. Previous owners parged over the stone which helped for a short while but eventually water seeped through the useless mortar and cracks in the two layers of concrete parging.

I removed all of the concrete parging and much of the loose mortar (several stones also came out.... kinda scary). I sprayed the remaining mortar with a clear liquid called "Radon Seal...www.radonseal.com" This gave the mortar back it's strength. I repacked the rest of the wall with standard premixed mortar. Apparently this stronger mortar is okay to use on the INSIDE of stone foundations where give isn't as critical. I then used a sacking/parging mix to skim coat the wall for extra water resistance (mortar, even treated with Radon Seal is still pretty water permeable). It has been a couple of months and well into the Spring thaw and things seem to be holding up quite well.

Fantastic! I am going to check this out. Sounds like
a perfect solution.
Do you think I have to actually take out the old stuff
or can I brush out all that is loose?
I hate to say it, but I am looking at solving a problem
for 'right now' and not 5 yrs from now, if you get my

I had crumbling limestone walls in my basement built in 1919 I took some xopex think i spelled it right but mixed that with a tad bit of cement bond and it solidified everything up before i could run my hands down the walls and pick up the crumbling pieces now its all solid again. did take a wire brush to it first to wipe off the really bad stuff
OMG I have the same problem that no one has been able to resolve for years.

1. Which is better Radon Seal or Xopex?

2. Where did you get Xopex?

3. I'm a little concerned with using the Radon Seal as you must remove all prior coatings. Most of it is off but there are a few spots where it is hard to remove what looks to be Tar. Must I gouge out all coatings first?

4. What Mortar did you use? In the past I had some had some success with a topping cement you buy at home depot. I'm not sure if you should use a cement weld topping first, for better adhesion?

To sum up I have the same problem with my 1915 house. The walls look like they will fall apart but are over a foot thick, so I'm not concerned about the structural strength. So it sounds like I: should scrape the walls 2. apply either Radon Seal (brush or spray on?) or Xopex 3. coat with some sought of mortar (maybe a topping cement)?

Thanks for your advice

I have a similar situation and I was told by a cement contractor that he refinishes basement with galvanized steel anchored to the wall and then gives the walls two coats of cement. The second coat according to him can be applied with decorative swirls as you would do plaster. I have not had it done because of finances and thought about doing it myself, one wall at a time.
Well I have no more worries!Th house is sold, we closed on
10/1/08!! Yippy skippy for me!
Anyway - the buyer had someone come in and give an
estimate for fixing up the basement walls. I do not know
exactly what that consisted of, but I know they plowed a
bunch of holes into the walls when they came to inspect it.
The estimate was several thousand - so I'm glad I didn't
get into that job.

Still, I'm curious if they will do it and how it will look after!
I liked the reply indicated that the mortar contained lime and was allot softer that what is used today --researching things is a good first step.
That being said, logic ----if water is penetrating an interior wall, itís coming from the outside.
And although we would all like to do repairs the easiest way, a quick fix isn't the best solution.
So you really need to dig out at the foundation and seal it properly.
We all watch the Reno shows and now have come familiar with the new membrane and fibre products. Plus the dimpled sheeting and laying B-O and draining gravel.
This is not an easy job for most people. But it is doable by the home owner.
If you do decide to do this, decide how much you "do " want to do -because if you can't complete it in time the weather could cause more damage .
So maybe you would just like to save some money by doing the digging out yourself and let the contractor do the sealing --it's up to you but the labour is big $$.
Then after all is done you can use great sealing products for the inside and not have to worry that water will penetrate through the wall..
hope my info way useful.
I am also dealing with a very old (113 year old) foundation built of very solid rocks and very crumbling mortar. I pulled scraps of newspaper out from between the stones which were dated July, 1942, but were most likely shoved there a little later as the winter winds crept in.

Much of the information here in this thread has been informative, but I wish it had been more current.

My game plan involves stuffing some scrap metal (wire and screen) into the larger holes, then filling what's left with a "non-shrinking mortar repair" mix I found, which is hopefully also non-expansive. The huge gaps between the foundation stones have me concerned, but I don't want to disturb their delicate balance.

Will try to remember to update of my sucessful results or horrid failure =/
same problem here, I will check back for new updates.
the answers have really helped me..we have the crumbling walls inside too...someone did stucco...but alone it is best...the water problem is from the outside so we are going to cement the outside perimeter and make the grade slant away from the house. We have some dirt and mud there now till it dries around here...raining like mad..and the neighbour fixes his leaky eves troughs...
crumbling walls:

2 options: 1)cover with expanded wire plater mesh held in place with galvanized nails. trowel on mixed cement that comes in bags. Did this with an old chimney years age and almost had to dynamite it when we took it off later on! It does work

2) again cover with wire mesh and have foam sparayed on (30 to 20 cents a square foot) solves crumbling and insulates.

"Frank words of wisdom"
Here is the only solution I found that works 100%! Put up a Block wall infront of the existing lime wall, then backfill. Make sure to tie the Block into the floor, and into one another in the corners. You will lose just a few feet of space, but it's so worth it!

manzullo2@verizon.net wrote:
crumbling walls:

2 options: 1)cover with expanded wire plater mesh held in place with galvanized nails. trowel on mixed cement that comes in bags. Did this with an old chimney years age and almost had to dynamite it when we took it off later on! It does work

2) again cover with wire mesh and have foam sparayed on (30 to 20 cents a square foot) solves crumbling and insulates.

"Frank words of wisdom"

WHOAH! NEVER NEVER NEVER insulate the inside of a rubble wall in a cold climate. This would increase the impact of the freeze/thaw cycle and lead to even further damage to the structure.
I must preferace by saying that I am not a woaterproofing expert and I not do I know if this will hold back the 100 year storm but it worked here for me in Boston and did not cost too much.
I have a 100 plus year old Victorian house with a rubble foundation. When I purchased it 12 years ago the interior basement walls wept an puddled on the floor.
I did much research and also recalled questioning a waterproofing expert that a client of mine had hired. I picked his brain while he quoted her job for my future projects.
What I did was what most of you already have described with the exception of one major thing.
The primary reason basements often leak is because there is standing water around the perimeter of the foundation due to faulty gutters or improper grading. In most cases, once the rain water problem is solves the basement leak. even through old walls.
So here is my list.
1.) Divert the rain water away from the perimeter foundation by repairing gutters, downspouts or adding leaders. Add more downspouts if necessary. Regrade any areas that slope towards the foundation. If regrading is not possible then the installation of a perimeter drain or "French Drain" may be necessary.
2.) Wire brush and vacuum the interior walls to be sealed. If the basement is empty you may even lightly power wash the walls to remove all of the loose old mortar but be very careful with the pressure or you will remove too much.
3.) Fill all cracks and holes larger that 1/8" with Hydraulic Cement. "WaterPlug" is a typical brand I used.
4.) Here is where one might tuckpoint all of the joints but I did not. It is probably best to do so with a proper portland cement mortar.
5.)Once the walls are dry and clean, apply a coat of cement bonding adhesive. I used "Weld-O-Bond.
6.) Once the bonding agent is tacky you can parge the walls with a lime mortar mix. http://en.wikipedia.org/wiki/Lime_mortar
7.) After the parging has cured, this could take 2 to 7 days depending on thickness, apply 2 coats of masonry waterproofing paint. I used "Dryloc."
8.) After everything cured I painted the walls.
I am not saying that this is the best way to waterproof a basement but it has been 10 years and we have has some unseasonable torrential down pours and I am dry as a bone down in my mancave full of musical equipment and tools. I actually installed a sump pump at a low point that has never turned on.
Good Luck
No humidity is another thing.
I noticed some tools starting to rust.
I think I need a better dehumidifier.
I'm hoping someone can give a little more advice on how to repair interior and exterior perimeter of the (102 yrs) old stone basement walls. They are about a foot thick but, I have a similar problem of sandy areas, crumbling, chunks of wall coming out and big gaping holes. I would like to secure, fix, seal, and repair these old basement walls. I would also like to follow up with interior finished walls to gain good square footage in the home. There is a cement floor that also needs repair. Our laundry room, furnace area, water tank are in the basement. The ceilings are high. Has potential. My wife and I live in an area considered desert and more arid than rainy. This has not prevented the decay of the foundational walls.
Someone posted about steel studs drilled into the old walls and then backfill. Is this a good interior method? What are the step-by-step methods. We plan on doing the work ourselves one wall at a time. I'm handy with tools, but need the know how on foundations. Especially old ones.
Someone even mentioned wire over the old stone, then a spray on cement sealer. What do you think? I'd like to finish the interior walls with sheetrock for a nice finished basement.



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