There are several opinions about pile-screw foundations. Some consider this option to be ideal for relatively light frame houses and log cabins, others criticize it, citing their arguments. Let’s deal together with the myths that exist about foundations on screw piles.
The first myth: a pile-screw foundation is unreliable
In fact, there are reviews from homeowners that a house built on screw piles wobbles, sways, and the piles themselves begin to bulge. So, unreliability is not a myth at all, but pure truth? Not really. If there are problems with a house built on a pile-screw foundation, then the construction technology has been violated! We wrote about what the optimal size of screw piles should be. In addition, the reasons for house instability can be:
- Insufficient deepening of piles;
- Insufficiently large pile diameter;
- Excessively deep pit;
- A small number of piles;
- Weak bearing, too soft soil;
- Errors in pile load calculations.
If all the technologies were followed, the calculations were made accurately, and the installation was carried out by professionals, there will be no problems with the pile-screw foundation! In this case, it will be possible to say for sure that the unreliability of such a foundation is a myth..
Myth two: a pile foundation can be erected in just a day
Of course, the installation of screw piles is much faster than pouring a concrete foundation. However, it cannot be said that you can do it in just a day! This is not always the case. Firstly, the professionals always carry out test drilling and test screwing. This is necessary to find out the characteristics of the soil. It may be weak, too hard or rocky. The presence of stones in the soil will seriously complicate the screwing in of screw piles, and in some areas the soil can be so strong that even metal will not withstand. In addition, sometimes it is not possible to use the autobore and other special equipment on the site. In this case, the construction time of the foundation is also delayed..
Myth three: screw piles will rust in 10 years, the house will not last long
Experts say that a properly selected screw pile will last at least 50 years. The terms of operation depend on the following parameters:
- steel grades;
- metal thickness;
- quality of metal protection – painting, galvanizing, anodizing;
- soil aggressiveness.
In salt marshes and acidic soils, metal rusts faster. In addition, you should use a special paint to protect it, provide an anti-corrosion coating. Don’t use cheap formulations.
The fourth myth: during installation, the blades of the pile can break off, because of which it will sag
This can happen only in two cases – initially poor-quality screw piles were selected and the installation technology was violated. If the soil is solid, rocky, and the installation was carried out rigidly, then, of course, the blades can be broken. However, if you choose high-quality piles and do everything according to the rules, there will be no problems.
The fifth myth: it is possible to mount a pile-screw foundation only in the warm season.
Not true! In winter, the soil, of course, freezes, but a small top layer can be removed with a bumper and calmly engaged in the installation of piles. Experts say that in winter it is often even easier to work, and no beds with potatoes interfere on the site. As for pouring concrete at subzero temperatures, we devoted a separate article to this topic..
Myth six: screw piles are a new technology, not yet proven by time
In fact, pile foundation construction has been known since ancient times. True, then the piles were driven into the ground. In 1833, the Irish civil engineer Alexander Mitchell patented a device called the “screw pile”. Unlike conventional piles, screw piles are screwed into the soil. Initially, such piles were used for the construction of piers and lighthouses, then the field of application expanded significantly.
In Russia, screw piles have been known since the beginning of the last century, in particular, they were widely used in the field of military construction, in permafrost conditions. That is, we are not talking about any new product! Research in the application of screw piles has been carried out more than once, including in the USSR, the advantages of this technology have been proven by experts. True, in Russian low-rise residential construction, screw piles began to be used later, earlier they were considered the prerogative of the construction of industrial and military facilities.
The seventh myth: all screw piles are the same, differ only in price
Absolutely wrong. Piles differ not only in quality, size, metal thickness, corrosion protection, but also in scope. For example, there are piles created specifically for heaving, watered or permafrost soils. In addition, they can be cast and welded. So you should choose based on your needs, preferably in consultation with experts..
Myth eight: screw piles can be screwed in without a pit
Professionals consider this to be a violation of the installation technology, recommending that a small pit be made necessarily. This is due to the fact that the top layer of the soil is usually the most loose, and the blades of the pile in the first stage loosen the soil until they reach denser layers. Often, without a pit, it is completely impossible to screw in a blade pile. In addition, concrete can be poured into the pit to strengthen the structure..
Myth nine: screw piles are ideal for building a house on a slope
Yes, this option is quite common. However, a house on a slope can stand on other types of foundations; it is important to conduct geological surveys before choosing a base. The pile foundation may turn out to be the simplest choice in this case, but by no means ideal..
Myth ten: the floor in a house on a pile-screw foundation will be cold
This myth is connected with the fact that cold air will walk under the house, standing on stilts. However, if the floor is insulated reliably, then the problem is easily solved. And ventilation, by the way, will prevent the floors from starting to rot..
10 myths about foundations on screw piles
This WordPress post sets out to debunk 10 common myths about screwpile foundations, including that they can't be used for buildings, don't work in various soil types, are difficult to use, and more. In reality, screwpiles offer reliable robust foundations, can be used for various applications, are compatible with many soil types, and are simple to use. The article explains the advantages of screwpiles over other types of foundations, such as quick installation times, efficient removal and reinstallation, no heavy machinery required, and cost savings, as well as how their varying sizes and designs make screwpiles the ideal base for many projects.
House and cottage, suburban construction 
What evidence-based information can you provide regarding these claimed myths about foundations on screw piles? Are there any case studies or research studies that disprove or validate these myths?