Introduction and foundation issue?

[Michael Girard]

Hi Folks,

I haven't posted in this forum before, but could sure use the benefit of your experience with a possible foundation issue, if you can spare a moment.

I've finally decided to buy house and it's a raised 1912 Victorian on level ground in California (mild climate). The perimeter concrete foundation shows signs of deterioration, but I don't know if it's unusual or normal, and whether it demands attention or can be left alone. I'm attaching some pictures, in lieu of thousands of words. Your opinions would be appreciated. :-)

If the pics appear in the order I insert them, the first shows a place where patching was done. The second shows a stretch of degraded concrete. Third shows where a section of the old foundation was capped. Thanks, in advance.

http://picasaweb.google.com/mikeyg/3838Crouchspace?authkey=Gv1sRgCNb85erL-Nv0GQ#5545797209908583394

http://picasaweb.google.com/mikeyg/3838Crouchspace?authkey=Gv1sRgCNb85erL-Nv0GQ#5545797193104720178

http://picasaweb.google.com/mikeyg/3838Crouchspace?authkey=Gv1sRgCNb85erL-Nv0GQ#5542579041076901666

[Randy Mayo]

Michael

Just based on your photos your concrete foundation appears to suffer from a condition called Alkali-silica reactivity or ASR. Alkali-silica reactivity is the process in which certain minerals (mostly glass type silica) in the presence of moisture are broken down by the highly alkaline environment of concrete producing a gel that expands creating tensile forces in the concrete matrix which cause cracking of the concrete. The cracking then allows more water to infiltrate into the concrete creating more gel, more expansion etc. Ultimately the concrete fails or disintegrates. This usually occurs over along period of time and based upon the age of this house and the level of deterioration ASR may be the cause. Find an engineering materials and/or testing laboratory in your area and ask if they test for Alkali-silica reactivity (ASR). Good luck....

[Gunnar Alquist]

Hi Folks,

I haven't posted in this forum before, but could sure use the benefit of your experience with a possible foundation issue, if you can spare a moment.

I've finally decided to buy house and it's a raised 1912 Victorian on level ground in California (mild climate). The perimeter concrete foundation shows signs of deterioration, but I don't know if it's unusual or normal, and whether it demands attention or can be left alone. I'm attaching some pictures, in lieu of thousands of words. Your opinions would be appreciated. :-)

If the pics appear in the order I insert them, the first shows a place where patching was done. The second shows a stretch of degraded concrete. Third shows where a section of the old foundation was capped. Thanks, in advance.

http://picasaweb.google.com/mikeyg/3838Crouchspace?authkey=Gv1sRgCNb85erL-Nv0GQ#5545797209908583394

http://picasaweb.google.com/mikeyg/3838Crouchspace?authkey=Gv1sRgCNb85erL-Nv0GQ#5545797193104720178

http://picasaweb.google.com/mikeyg/3838Crouchspace?authkey=Gv1sRgCNb85erL-Nv0GQ#5542579041076901666

Michael,

As a home inspector and not an engineer, I would have recommended an engineer. Fortunately, Randy provided you with some expert advice. I also noticed unbraced cripple walls. Pretty common on older homes in Oakland. Should have those braced as well since this area is seismically active.

[Tate Dog]

A lot of the buildings here apparently had site made cement or site mixed concrete that is now deteriorated. As a result, most foundations of this era are or have been replaced. One needs to fix any drainage issues while replacing the foundation to eliminate the moisture issues. They outlawed "capping" some years ago for fairly obvious reasons (it's hard to get enough concrete around the rebar to make it strong enough. There are a number of foundation contractors in the area, ask around or check the web for references. The water here is pretty kind to galvanized pipe but the nipples can rust through. Looks like you have pretty good access to do the work. The hearth looks normal for the era, could dump brick below in a big one. Fair amount of code clean up, hope the price reflects. Got heat and hot water for showers though.

[Michael Girard]

Thanks Guys,

This is really helpful information, and interesting as well. Your assessments reinforce what I was told by a contractor who came to take a look, and it's always helpful to have independent corroboration.

From the looks of it, with the general loss of integrity of the concrete, ASR seems to be the likely culprit. We're factoring in the possibility of needing a new foundation as we negotiate the price, and I'm sure the cost estimates will be quite entertaining.

When I talk to the foundation contractors, I'll ask them if they do anything to mitigate ASR in their mixes.

Again, thanks so much for the great info, guys.

Gunnar, do you have any recommendations for an inspector in/around Oakland?

Cheers,

Mike