We are about ready to put brick veneer on an existing home. Upon inspection we have encountered a 2″ differential in the grade of the foundation.
The house has been sitting for 3 years and there are two small stair stepping cracks on a 2 foot crawl space. The house is 30 x 40, 2 story. The stair step cracks are on the lower side of the house at 40 foot long.
Before attempting to veneer the house with brick I wanted other professionals opinions as to whether they thought 2″ would be anything to worry about and if after 3 years the house has settled to where it is going to go. The soil is expansive clay located in northeast Georgia. The foundations are adequate with 20″ x 12″ footers and 12″ block with applicable reinforcement. I am confident in the foundation, however I am uncertain of the added weight of brick veneer being a future problem. I am aware of the available foundation remedies, i.e. piers and mud-jacking, however, I wanted to hear the opinions of others if 2″ of settling is anything to worry about.
A brief history, this house is a spec house which has been dried in for over 2 years. As I am finally getting around to finishing the exterior this is the first time I have noticed settling cracks.
I would appreciate any opinions or advice.
Thank you,
Samantha
Replies
Samantha, if this is a fairly new house on expansive clay it may not be done moving -- that is to say, if the moisture conditions under the house change, the house will probably move again.
It would be wise to consult with locals who have specific experience with that type of soil.
I've seen houses that were over a hundred years old with substantial seasonal movement because of expansive soils drying and re-wetting.
> I've seen houses that were over a hundred years old with substantial seasonal movement because of expansive soils drying and re-wetting.
Yup. That happens with the adobe we have here in LA. It moved like that a thousand years ago, it'll still be moving a thousand years from now. With deep footings and good drainage, you can keep the seasonal movement from affecting the structure.
-- J.S.
On a humorous (?) note, I have heard of sellers running a sprinkler system around the foundation to close up cracks so potential buyers wouldn't see them, also heard scare stories about the expansive clays in North (stand up and take your hat off) Texas.Just this week pulled several hundred CY of expansive clay and rock out of a building site, overexed 2' to 4' below footings.Scary stuff, eh?I didn't know that there were adobes in LA. Isn't it amazing how long those things can last? Gotta love it. I guess the earthquakes don't bother them?
Not only do they have adobe structures, but the adobe he was refering to is the name used for the type of clay under the buildings in many places.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
There are a few historic adobe buildings on Olvera St., and a small one from the Civil War era in San Pedro. That one was a powder magazine. It survived because a wood frame structure was later built up around it. It was discovered and preserved when the surrounding structure was demoed.
Adobe as a building material isn't a good thing in earthquake country. The ones we have left are the few that were built short and thick enough. Heavy stuff up high is a bad idea around here.
-- J.S.
Sam,
Since I work on houses that are 100-200 years old, 2" is nothing to me, especially over 40'.
I do not work on the same clay you have and frost is a big issue up here, but let me throw out a few thoughts.
In 40-50' it is not uncommon for a foundation to end up 1" to 1.5" off level just because of sloppy work with the optical builder's level. one common error is to set up at the short end and shoot down the length of the building, so that if the setup is off a quarter inch at the end closest to the level, it can be off over an inch at the other end. If the setup is near center, the error is less or may be the same at each end. I always double check things, and now use a lasar level. If this is your problem, it is probably not going anyplace, but since you have cracks in that stemwall, you have settling...
Another common problem is overdigging for the footer. That foot should be poured on undisturbed soil but when a sloppy excavator overdigs and covers up his error, the footer ends up on slush, which then settles out. If this is the case for you, it is not finished settling yet - not until you get full load on it and wait a couple years.
I'm going to such detail here because if I hear you right, your company is responsible for the work done so far, so you need to identify the source of the problem within your company so you can avoid it in the future.
Finally, let me applaud you for trying to do the right thing. I have not head many complimentary things about the constructioon climate/culture in your state regarding quality work so by doing every thing you do a step better than your peers, you will soon stand head and shoulders above the crowd and reap the benefits of the reputation that goes with excellent work.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Thank you for your response it was full of a lot of good information, very helpful.
I had the same idea about sloppy work with some of our guys using the builder's level so I checked it myself with our lead man and verified the differential is actually 3/4". Upon further investigation I discovered that the soil is extremely dry and rechecked the elevations the day after a good rain and noticed a difference as much as a 1/4" so there is some expansion/contraction going on with the clay soil. I have decided to proceed with the brick veneer as the footers are more then substantial and the hairline crack showing in the corner of the block are not big enough to even stick a razor blade through.
I appreciate your compliment and your feedback. We build for clients, although this is our first spec home and we take a lot of pride in quality work. This is the reason I wanted input from other professionals.
Samantha