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dcalabro
Hydraulic Cement Falling Out

1920s home that probably has a stone foundation. The interior is parged with cement. A few months ago I removed all of the loose paint, used bleach to clean mineral deposits, rinsed with clean water, did a hydraulic cement patch, and applied drylok after a week of drying+curing. Now I have 2 issues:

1. The mineral deposits are back and have leeched through the drylok. No idea what I did wrong. I thought it would have held back the moisture and maybe peeled off a little. I think someone recommended bleach here or another forum so i don't know if that was the issue.

2. The hydraulic cement is peeling away from the hole. I understand you usually want to inset a patch like this but I have no way of doing this unless I remove a substantial chunk of the wall. The hole I am trying to patch is about 10 inches in diameter. Think of the shape of a crater on the moon.

Overall I know moisture comes from outside but it's all concrete so I don't really want to dig everything up to waterproof outside.

Clarence
Re: Hydraulic Cement Falling Out

Check on XYPEX Concentrate DS - 1
Use this than use your patch material.
www.xypex.com

JLMCDANIEL
Re: Hydraulic Cement Falling Out

Hydraulic cement expands as it dries, I would think you would want that property in a patch.

Jack

dcalabro
Re: Hydraulic Cement Falling Out

I understand it expands as it dries but as it expanded over months it pulled away from the hole. I'm just not sure if there is a better type of patch or if there is a better way to get it to stick.

JLMCDANIEL
Re: Hydraulic Cement Falling Out

Not a big concrete man, but have heard you sometimes need a bonding agent.

Jack

Clarence
Re: Hydraulic Cement Falling Out
dcalabro wrote:

1920s home that probably has a stone foundation. The interior is parged with cement. A few months ago I removed all of the loose paint, used bleach to clean mineral deposits, rinsed with clean water, did a hydraulic cement patch, and applied drylok after a week of drying+curing. Now I have 2 issues:

1. The mineral deposits are back and have leeched through the drylok. No idea what I did wrong. I thought it would have held back the moisture and maybe peeled off a little. I think someone recommended bleach here or another forum so i don't know if that was the issue.

2. The hydraulic cement is peeling away from the hole. I understand you usually want to inset a patch like this but I have no way of doing this unless I remove a substantial chunk of the wall. The hole I am trying to patch is about 10 inches in diameter. Think of the shape of a crater on the moon.

Overall I know moisture comes from outside but it's all concrete so I don't really want to dig everything up to waterproof outside.

The white deposits are effervescence / salts this will cause the new and old to push away from each other.
The Xypex product will stop this process.
For the patching material use a product like Quickrete Heavy Duty Masonary Coating.
Or use anyother repair type mortar.
Also there are Epoxy's available for concrete repairs.

JLMCDANIEL
Re: Hydraulic Cement Falling Out

Clarence is the Xypex product also a bonding agent or don't you think one is needed.

Jack

Clarence
Re: Hydraulic Cement Falling Out

Xypex is not a bonding agent.
Before using a bonding agent understand that most agents are Re emulsionable.
If a bonding agent is needed use a mixture of 1 part cement 1 part sand and water to make a brushable sulry and dash it on than use the Xypex.But if the existing concrete contains Salts than the bond maybe broken. Xypex would stop the migration of the moisture thru the affected area.

SouthernCanuck
Re: Hydraulic Cement Falling Out

Have had some extensive experience working with stone, block, clay basement foundation walls. After years of battling water infiltration from the inside out the only sure way is to dig from the outside, repair, lay new weeping system and forget about it.

If this is just not an option which is understandable, you can do a few things to limit the infiltration of moisture thru that foundation wall.

1) Ensure that all down spouts from the eaves divert water well away from the exterior walls.

2) Check the grade of the gardens, walkways, lawn, driveway and ensure there is a good slope away from the foundation wall.

3) If the downspouts drain directly into a storm sewer often debris including tree roots, severed clay tile as well as a dozen other reasons the water saturates the area as it does not make the run to the sewer system. In turn this water takes the route of least resistance and developed drain plains towards the foundation wall. A plumbers scope will determine if you have proper drainage.

Back to the repair. Best results for interior to exterior repairs are achieved by drilling through the foundation from the interior beyond the existing wall and injecting hydraulic slurries at low pressure hoping to seal the voids from the exterior.

That effervescence you are seeing is that moisture coming thru. Don't forget not all moisture is a liquid. But make no mistake there is moisture evident in your wall.

dcalabro
Re: Hydraulic Cement Falling Out

The property is in an urban setting with concrete directly in front of the wall for 8 feet to the asphalt street. Otherwise, I would have no problem hand digging by myself. I've seen shows where they put sheets of foam insulation directly against the wall. Is this possible or will it still cause issues? My thought being if its truly impossible to stop 100%, how do you deal with it without health/building concerns over the long term?

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