There are several techniques that an underpinning contractor can use when looking to strengthen an existing foundation. Among these techniques, some are more commonly used than others for various reasons. Mass concrete underpinning and the use of helical screw piles for underpinning are among the most commonly used techniques.
In this article, a comparison between the use of mass concrete and the use of helical screw piles is made for the benefit of homeowners looking to have an underpinning exercise done.
In terms of transportation, helical screw piles are advantageous in the sense that they are much easier to transport. With mass concrete underpinning, there are a number of individual products that need to be transported to the site, all of which are used to make the concrete mix.
Screw piles are ready-made, and they are not a bulky product. Therefore, the use of helical screw piles could end up being much more affordable because the cost of material transportation for the underpinning exercise is relatively lower.
The Question of Labour
There is a lot of labour required for mass concrete underpinning. One of the reasons why mass concrete underpinning requires more labour is the fact that the concrete mixture has to be prepared on-site before the concrete is poured onto the part of the foundation that needs to be strengthened.
In the same breath, there is a lot of excavation that needs to be done before a mass layer of concrete is poured on the foundation. This is another reason why mass concrete underpinning is a more labour-intensive process.
Helical screw piles are made ready for installation right from the dealer. Also because of their size, the installation of helical screw piles requires a less excavation to be done on the foundation.
Lastly, there is the question of load-bearing capacity when it comes to different underpinning techniques. In terms of load-bearing capacity, a layer of concrete is likely to have a higher load-bearing capacity than helical screw piles.
However, helical screw piles are advantageous in the sense that they have the capacity to bear loads immediately after the installation of the pipes is complete. With mass concrete underpinning, the concrete layer needs to be left to cure first before it can bear loads safely. This could take a few days.
Talk to your underpinning contractor about helical screw piles if you need your foundation to be strengthened.