Hydraulic Cement
Summary: Hydraulic cement expands as it dries to fill cracks in concrete foundations. This expanding cement helps waterproof a cracked foundation. The following manufacturers make hydraulic cement.
Hydraulic Cement
Many homeowners don't realize that ordinary Portland cement shrinks when it dries. The shrinkage is very little, however it does shrink. This means that if you patch a crack or a hole, a very tiny leak may form after the cement dries.
Hydraulic cements do the opposite. They expand as they dry. In new construction I use them to fill the void areas in foundations around water pipes, electric wire sleeves, foundation form holes, etc. The stuff works! Often it has a short 'pot' life. This means that you should only mix up enough material that you can comfortably use in 10 to 15 minutes.
There are numerous manufacturers of hydraulic cements. I have listed just a few. If you purchase a brand not listed, be sure the label says that it expands as it dries.
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Author's Note: The following email comment was received from Art, a Cement Manufacturer's Representative in Southern California ...
Hi Tim, Being a hydraulic cement in itself has nothing to do with expansion, although some hydraulic cements will shrink less than others, but this is due to them being a sulfoaluminate based cement, not a Portland cement and has nothing to do with them being a hydraulic cement. Being a sulfoaluminate cement is also the reason you have the shortened working times.
Thanks,
I hope you take this in the spirit in which it is intended and that is to just help your site be better. Your definition of a hydraulic cement is misleading. According to ASTM (American Society for Testing & Materials), a hydraulic cement is a cement that creates a chemical reaction when it comes in contact with water (hydration) and will cure under water.
Art / Cement Mfg. Rep.
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Comments:
Marty 17 Dec 2007, 14:21
Hydraulic cement manufacturers suggest that a dovetailed opening be made
along the crack prior to loading the cement. What is the suggested way of
achieving this dovetail in the case of a basement wall? Therefore the
constraints are an interior space and a vertical surface. The best
suggestion I have so far is to use a circular saw with a diamond blade.
AsktheBuilder 17 Dec 2007, 17:16
Marty,
Why not explore the use of epoxy injection for dealing with those cracks? Read my column about this method.
Marty 18 Dec 2007, 11:49
Tim,
Are there gotchas with epoxy if the crack is not fresh and the surfaces not clean and dry?
AsktheBuilder 18 Dec 2007, 16:35
Marty,
Ask the epoxy people that you choose to use.
Donna Guerrieri 07 Jan 2008, 11:24
You were helpful last time, one more question please. Water is coming in
around the water main line in my basement. Not the pipe. I went to buy
hydrualic cement, and the handyman I use suggested we wait until the
spring. Afraid the pipe may crack while the product expands. My basement
is about 55 degrees and while it is not significant water, there is still
water. I know once the ground freezes water will stop flowing. I live near
New York City, NY. I need your advice Please.
AsktheBuilder 07 Jan 2008, 11:48
Donna,
The cement will not hurt the pipe...... Install it now.
VINCENT DIPIETRO 11 Jan 2008, 09:39
I HAVE A CRACK IN THE FOUNDATION AND HAD IT INJECTED WITH EPOXY. THIS
METHOD FAILED BECAUSE THE EPOXY SHOULD OF BEEN INSTALLED WHEN THE SURFACE
WAS DRY. I LIVE IN NEW YORK AND I CAN'T SAY WHEN THE SURFACE WILL BE
COMPLETELY DRY. SHOULD I USE HYDRAULIC CEMENT INSTEAD. OR WAIT. YOUR HELP
WILL BE APPRECIATED.
AsktheBuilder 11 Jan 2008, 10:52
Vincent,
I would use epoxy. Follow the written instructions. Use fans or heaters or a torch to accelerate drying.
Jim 14 Jan 2008, 14:36
I have a block wall foundation installed in the 50's. I am consdering
adding a second floor to my 1 story home. Would hydraulic fill in the block
be a viable method to increase the stuctural strenght of the existing
block?
AsktheBuilder 14 Jan 2008, 14:44
Jim,
That term must be a regional one. If it is a sand/cement slurry or pea-gravel concrete, that is excellent. View all comments |
