There are three primary foundation repair options for your slab-on-grade home.
There are multiple types of foundation piers and piering systems for repairing slabs. Most companies will tell you theirs is best. The truth is, most systems and foundation repair methods installed correctly have a very successful track record. Most engineers understand that some systems work better in certain areas than others, but will agree that pressed concrete cylinders work great as foundation piers, so do steel piers and drilled piers for your Austin foundation repair.
BEST foundation repair option – HELICAL PIER SYSTEMS
A helical pier is a steel pier that is screwed into the ground, similar to an auger bit. However, these piers do not displace the soil. They burrow down into the ground. We think Helicals are the best choice in piers to replace invasive and expensive drilled-bell bottom concrete piers. The advantages of helical pier systems over drilled pier systems are many. For instance, time of installation is much faster, cost is much lower, geotech soil samples are not typically required and the client property is not disturbed the way drill piers create a mess. Douglas Foundation Repair can install a helical pier system on the perimeter and interior of buildings making these foundation piers our top of your choices for foundation repair solutions. Cost is similar to pressed steel piles which we love, but Helicals have the advantage of not needing the building itself to “press” or push the foundation piers into the ground. Another advantage of a helical pier system over a steel push pier system is a helical pier system can be installed where there is little chance of hitting a rock or solid strata bottom, like many areas east of hwy 35. We can also use helical piers to support new construction foundations to prevent any future foundation repair needs and we can use helical piers to build pier and beam, or crawl space foundations. Douglas Foundation Repair’s helical pier systems can solve foundation problems when other foundation piers just cant.
BETTER foundation repair option – PRESSED STEEL PIERS
This type of pier works well in areas where bedrock can be reached. It is more expensive than pressed concrete cylinders, so many firms sell fewer pressed steel foundation piers than your home might need, spreading them too far apart so the bid can be accepted. If you ever see a home with a scalloped look to the fascia, that home probably has pressed steel piers.
Installers use the house’s weight as resistance to press interlocking steel segments into the ground on the outside edge of the foundation. Steel foundation piers can reach much deeper depths than other systems. This makes sense because they are less than ½ the width of concrete cylinders and have smooth surfaces. They need to hit bedrock to be successful. Once the pier is driven to refusal, the top segment of the pier is attached to the foundation with a bracket.
The advantages of steel foundation piers are that they are less invasive to the property to install. They go deeper than other systems and they are installed in a minimal amount of time.
The disadvantages of steel piers is that they are expensive. So often they are spaced too far apart. They need to hit bedrock so they are not appropriate for all areas. They are not installed under the foundation, but on the side of it and they are corrosive.
GOOD Foundation Repair option -Pressed Concrete Piers
We like concrete foundation piers made of pressed segments of concrete cylinders. This type of repair system is the most widely installed in Texas. The concrete cylinders can be solid or have 5/8” holes in the middle. Some firms that use the hole style cylinders say that they use the hole to install a cable or a piece of steel to keep the cylinder aligned as they press them in. This is mostly a marketing idea to differentiate themselves from other firms as most engineers will explain that the hole in the cylinder actually weakens the cylinder and the tensile strength that these firms say their piers have is not required and not proven. The hole can actually provide a highway for surface water to penetrate to the bottom of the pressed cylinder causing failure. We only use solid concrete piles and install these very accurately with great success.
Concrete foundation piers are pressed into the soil using the weight of the structure as resistance. As they are pressed down, another cylinder is placed on top of the first. These piers are pressed to absolute refusal, by either hitting bedrock or when the weight of the structure cannot push them any further. This type of pier does not require being on contact with bedrock, they work by surface friction on the soil that they have penetrated. Concrete cylinders are placed under the foundation beams and can be installed under the interior portion of the structure as well. Because these foundation piers are less expensive to install, more piers per job can be afforded. Remember, your home is a slab-on-grade foundation. When it is raised by foundation repair, it is now an elevated slab. The more point loads you provide, the less the span deflection, which is a good thing. Each pier is pressed bearing many times the weight it will actually carry as multiple piers will share the load simultaneously when all the piers used are in place and supporting the load. This is why this system is applicable to so many different situations.
Pressed pier advantages include: Being very reliable, the most cost effective system, are installed relatively quickly, they are installed beneath the foundation, not next to it and can be installed under the interior of structures to create “as-built” level condition to the slab. Pressed cylinders install with minimal damage to the landscape.
Some of the disadvantages of pressed concrete piles include: They do not provide up lift resistance similar to bell bottom piers and they can be a slightly more invasive installation than steel piers.
At Douglas Foundation Repair, we want you to be empowered in knowing your options and our foundation repair methods. Have questions? Please ask us!