Posted by Jonathan Maguire on Tue, Aug 17, 2010
The following article 4 Steps to an “Economic Foundation Repair” is taken from myfoundationrepairs.com. The article is useful when you have a complex foundation problem. Generally, we refer you to a professional 3rd party engineer if an agreement cannot be made on what repairs are needed. A typical engineer will cost between $350 and $500, but is almost always worth the expense.
In these trying times of a recession, one doesn’t like to spend money on non-essential items. Buying a new 47” Vizio Flat Screen TV on sale is a non-essential item, having your foundation repaired is an essential item,. Foundation problems do not fix themselves. The signs of foundation problems might temporarily leave as the seasons change, but will return with greater possibilities of more damage. How can a homeowner receive an “Economic Foundation Repair”? This can be accomplished by following four easy steps:
1. Hire a Professional Engineer:
Why do you need a professional engineer? You want a professional engineer first to look and assess your foundation problems. This will explain why it has happened and how to fix the problem. Therefore, when it is time to solicit bids for your project all contractors need to bid what is required by the professional engineer. How do you find a professional engineer? Search yellowpages.com or yellowpages for heading Engineers, from here look under subheadings for Structural.
2. Follow recommendations of the professional engineer:
Engineers are not doing work for the sake of doing work. They have been trained in school as well as in the field of what is right or what is wrong. How much experience do you have? The recommendations should be carried out, but that doesn’t mean you shouldn’t question the reason why. A good professional engineer will explain the reasons for the recommendations. He or she is only looking out for the safety of you the customer and your home.
3. Hire a professional contractor:
When hiring a professional contractor ask your professional engineer for referrals to call. Get at least 3 to 4 quotes on the exact work the engineer has requested to be done. Make sure your contractor is licensed and insured with referrals of similar work. Review and have the contractor explain all work he is quote.
4. Proper Drainage:
After all work is completed, make sure you have the correct drainage completed. This might involve new gutters, down spots, French drains, or foot drain and sump pumps. The major contributing factor to foundation problems is water. Make sure you get water away from you foundation as quickly as it appears. If you take the steps in proper drainage you could save money down the road from having to get other parts of your foundation repaired.
As a homeowner, to get an economic foundation repair one must get professionals involved. This will save you time and money in the long run by insuring your foundation is correctly repaired the first time. The contractor you have chosen should complete the work as directed by the engineer. It is then your obligation, as a homeowner, to make sure your house has the correct drainage. If you have questions on the correct drainage, be sure to ask your structural engineer. If you follow the 4 steps mentioned your success rate of economic foundation repair can be achieved, as well as, preventing future foundation problems elsewhere in your home.
Posted by Jonathan Maguire on Sat, Jul 31, 2010
Failing foundations can happen for a variety of reasons. We have discussed several issues in previous posts and will continue to do so in future posts. But when you have a failure, what should you do? One historically bad idea is to bring in bags or trucks of concrete to pour under the existing home. The thought behind this is – Concrete is a solid base, it is used for footings, it spreads the load out, and it will fill all the voids. And while these are all true of concrete, the one aspect you do not see listed is the weight of concrete. Concrete weighs around 145 lbs./cubic ft, although depending on the mix it could be more or less. If you multiply by 27 you will get the weight by cubic yard (which is a standard for concrete trucks) = 3915 lbs/cubic yard. (as a side note: soil can weigh between 60-120 lbs/cubic foot).
We will use an example of a corner of a home that is showing settlement on a 10×10 corner of the house. If a contractor decided to pour concrete under this corner, he may want to pour it one foot thick and may go 2-3 feet into the existing home. If that’s the case then he would have poured 40-60 cubic ft of concrete (or 2-3 yards). This equates to adding between 7,830 and 11,745 lbs to the corner of your home. Stay with me – because an average single story brick house on a slab weighs around 1,141 lbs per foot (or for this 10×10 area – 21,679 lbs). Basically, the contractor just increased the weight of your home by 50% – and this is using conservative numbers of what the contractor poured, and a very modest home (a 2 story brick house on a basement would have a weight of 3,656 lbs per foot). We have heard stories and seen jobs where the amount of concrete poured under a corner of house is 6-7 yards or around 25,000 lbs.
All of this to say that if your home is settling due to poorly compacted soils, loose soils, organic debris, builder debris, water issues, etc then the soil does not have the adequate bearing capacity to support your home. If the soil was not good enough to support the existing structure, why would anyone add a 10-30,000 lb anchor to an already sinking foundation? Once more, what do you think this will do when you have to repair the house after the concrete is poured? This repair – which would have cost a few thousand dollars to begin with, will ultimately cost several thousand dollars – not to mention you may not be able to lift a structure once you have added all the additional weight of concrete.
Before you decide to go with a contractor that wants to pour concrete under a corner of your home, or if you are thinking of pouring concrete under your home, do some research about helical piers and resistance piers. If you are a homeowner, then your largest investment depends on how you decide to repair a sinking foundation.
Background: Helical and Resistance Piers are considered deep foundations, which mean they both penetrate areas of poor soils to reach soils of adequate bearing capacity. They do not add weight to your structure, and require little disturbance around your home to install. They last for years and years and typically come with long warranties to protect against any future issues. Atlas Piers provides services in repairing foundations. We lift and stabilize houses all across Atlanta and the State of Georgia. We have been in business for over 20 years and have seen other companies come and go. If we can’t lift a house – it can’t be lifted. Visit our home page or call us @ 770.740.0400 for more information.
Posted by Jonathan Maguire on Wed, Jul 21, 2010
Garage Column failure is a very common issue around the Atlanta metro area. In fact, Garage Column settlement is one of the top 3 issues we see in foundation failures. So what is it and how do you fix it?
Garage Columns are the center columns between two or more garage doors into a garage. The Column is generally a structural element that carries either a brick load, beam load or header load. What this means is that the column generally carries a concentrated load where other parts of the home carry a line load across a continuous footing (think of the house over the garage door openings, instead of sitting on the ground they area passed to either side of the opening).
When many houses were built, the soils for the garage were moved into the area (especially when there is a basement) and then compacted. In many cases, the builder or grader failed to compact the soils enough to carry a concentrated load. These poorly compacted soils can cause the garage column to settle over time – if you have a brick house then you will have a crack above the garage column as this happens. As a result of the failure, you may also notice sheet rock cracks in any rooms above the garage. You may see a crack on either side of the garage floor where the floor slopes towards the middle.
The fix for this failure is typically to install 1-2 helical piers. In years past, when helical piers were not used as much, we would install resistance or push piers. It was a dangerous process, that put unnecessary stress on the column and resulted in many companies having warranty issues. Overall, it’s not a good idea to install a push pier under a garage column.
The typical installation for garage columns is to remove the driveway slab around the column, install 1 helical pier on either side of the column and then lift the column back in to place. Many of the cracks in the brick veneer will close, but you may still need to repoint (fill in) the mortar for a better look.
Some of the unknowns in repairing garage columns are 1) footing or grade beam under the garage slab, 2) depth of the helical piers, 3) lift results. Give us a call to determine what solution is best for you.
Posted by Jonathan Maguire on Fri, Jun 18, 2010
Here is a link/video to a job we are working on in NW Atlanta, GA. The current homeowner bought the house after helical piers were installed to fix a foundation problem over a debris pit (buried wood debris under the foundation). The helical piers were installed but did not penetrate the debris. Atlas Piers of Atlanta installed 3 resistance piers (or push piers) a few years later on another area of the house. Since the original helical piers failed due to poor installation (the company has since gone out of business, but started another piering company), Atlas Piers is now repairing the area above the debris pit with resistance piers. We will be updating a longer post about trash and debris pits, but wanted to share the video.
WSB News about trash pit found under a house
Posted by Jonathan Maguire on Tue, May 11, 2010
In part one of this discussion, we talked about what a helical flight is. This post will hopefully add some insight into how torque equates to loading in helical piers. We will also discuss one of the HUGE blunders of a local manufacturer.
Helical piers are screwed in by a hydraulic gear motor. This motor generates a hydraulic pressure on the gear that equates to a torque (force) on the pier being installed. This torque is then multiplied by a soil factor (when soil testing is done there is an actual number defined for the soil and for the product, when soil testing is not performed a generic ‘average’ is used). For the purposes of this post lets use the following equation (used from a technical manual written by Don Clayton, PE) -
Ultimate Capacity = Torque x “k”
where “k” is equal to the soil multiplication factor.
This is a simple equation, and to give an example for a light duty pier – we generally install our helical piers to 4,500 ft/lbs and use a standard average soil factor of 8.
Capacity = 4,500 x 8 = 36,000lbs ultimate capacity
since the ultimate capacity on a single flight is between 40,000-50,000 lbs (steel and weld capacity) – a contractor could use a single flight configuration for this loading.
Now for the HUGE blunder by a local manufacturer. Let’s review some details of helical piers:
- Torque is one of the main factors of the ultimate capacity of piers
- Helical pier types can handle different torques (thicker pipe = stronger, etc)
- Flights have an ultimate capacity of 40,000 lbs for the flights – but the pier torque is what generates the ultimate capacity.
I have run across the situation where a standard residential pier (.203 wall) is sold as a high capacity pier (60,000-70,000 lb ultimate capacity) by the salesman telling the contractor that he’ll just add another flight to the pier. If you double the flights you do add additional capacity, but the problem is – You simply cannot install a standard residential pier to the torque required to generate 60,000-70,000 lbs. The pier will fail during installation – remember the equation
Capacity = Torque x “k” where “k” is the soil factor.
60,000 = Torque x 8
60,000/8 = Torque = 7,500 ft/lbs
Typical residential piers can be installed to around 5,500 ft/lbs – max. You cannot get there from here no matter how many flights you add to the pier shaft (in fact you will notice the equation doesn’t even factor in the number of flights). But I’ve seen this, and I’ve seen general contractors buy this lie from the local company “engineer”.
Posted by Jonathan Maguire on Thu, Apr 08, 2010
This post will help describe how a helical pier works. Helical piers are used for foundation repair projects as well as new construction projects in poor soils. A helical pier is a round or square metal shaft with flights or helixes. What is a flight? It’s a steel plate welded onto the main shaft of a helical anchor (see picture). These plates are generally 3/8-1/2″ in thickness and have a pitch of 3″. This pitch allows the helical anchor to advance into the soil 3″ per revolution or 4 revolutions per foot.
How many flights or helixes are needed? Great question and there is no definitive answer for all applications. On a standard residential project where the loading is 10-30,000 lbs, one-two plates will work (each plate can handle between 20-25,000 lbs/ea depending on the manufacturer). Adding flights can increase the surface area that is made with soil and multiple flights decrease the loading required on each flight. We have found that adding flights can also help us install the product better as you have two or more flights pulling a helical into a the ground instead of just one single.
In part two of this blog, I’ll give some insight into how adding flights helps, and what are the limiting factors of helical pier capacities.
Posted by Jonathan Maguire on Fri, Mar 19, 2010
In 2003 there were 20 helical or resistance pier manufacturers, 4 of them were considered “Major”. The top two companies were AB Chance and Atlas Systems (where we received our name). In 2009 there were over 50 manufactures of piers, with AB Chance topping the list followed by Earth Contact Products then Dixie, RamJack, DriveRite, etc.
As you can see, there has been a LOT of manufacturers enter into the business in the last few years. Many of these manufacturers are making helical and resistance piers from their own shop or “basement”. The top companies – and ones with the longest history have licensed engineers behind all their designs, a full fledged manufacturing facility, and quality control. The smaller guys are making a few piers - and while some of these 2nd tier or 3rd tier manufacturers may have engineers that help design, there is no way to compete with the larger companies in quality control, manufacturing and oversight. When you are supplying multiple thousands of piers (sometimes tens of thousands of piers), your quality has to be top notch. You cannot afford product failures, you cannot afford for a 3rd party engineer or inspector to question your products. There is just too much riding on them.
Why does this matter? Atlas Piers of Atlanta only purchases from platinum manufacturers. We have too much at stake to trust a lesser manufacturer. So when you have someone look at making foundation repairs to your structure ask which helical pier or resistance pier manufacturer they install. Piers may seem like a commodity, but there are vast differences.
Posted by Jonathan Maguire on Wed, Mar 10, 2010
This video shows the basic helical pier installation sequence for residential applications. Helical piers are used for foundation repair or for new construction in poor soils.
Atlas Piers of Atlanta installs new construction helical piers in Atlanta; we install residential and commercial helical piers for foundation repair in Atlanta, Georgia, and across the southeast. See our main page for more information (www.atlaspiers.com)
Posted by Jonathan Maguire on Wed, Mar 10, 2010
Click the video below or check out the link to the youtube video at the bottom of the post. These show the process of installing a Resistance Pier for foundation repair. We have been installing resistance piers in Atlanta and across the Southeast for over 20 years. These are the strongest underpinning piers for residential foundation repair. Unfortunately, you cannot use them for every application. More to come on that later.
Atlas Resistance Pier Installation Video from AB Chance