Three reasons to make a screw pile-foundation and arguments against cloud

In some cases it is necessary to build a foundation on screw piles, and when this type of foundation under the house - money thrown away

About a lot of myths and legends-screw pile foundation. Some believe that the screw piles - a cheap and versatile alternative to the concrete bases for a permanent home. Others believe that the metal piles with a blade on the end are suitable only for non-critical and light buildings. For example, frame lodges, arbors, terraces, fences, utility blocks. Is it really? The answers in this article.

Content:

• "Pitfalls" screw-pile foundation
• How to make high-quality screw-pile foundation
• Cheap piling helical foundation - a myth
• The real price of a screw-pile foundation
• In some cases, justified the use of screw-pile foundation

Problems pile-screw foundation

"Low" price for a screw-pile foundation, many developers beats common sense. The word "low", not just in quotes. Why screw piles - it is, in fact - not a cheap pleasure, we describe below. Now on the other - about the negative experience with the use of screw-pile foundation.

Omissa

Participant FORUMHOUSE

I frame houses in 2 floors in height. The dimensions of the structure 8500h9000 mm. Under the house a hard-boiled 26 screw piles with a diameter of 108 mm. Piles Screw the machine to a depth of 1500-2000 mm. Trunks concreted and headroom just put on the pile without welding. The plot with a slope. Piles are clipped to a height of 400 to 750 mm and tied beam 15x15 cm. So, when someone goes to the second floor, the feeling that the house reeling. How to fix it?

Portal users have given Omissa tips:

• Check whether the loosened soil around the pile.
• Weld headroom to the piles.
• To strengthen the structure by diagonal "struts" of angle steel with a shelf 5 cm.

The user's followed this advice.

Omissa

We scalded pile area and welded all headroom. Feels like, the house is much more stable, although, in the corners, felt some vibration.

So, the problem is almost solved. Go ahead.

Artriot

user FORUMHOUSE

I built a frame house on screw piles. Size "box" 7000h9000 mm. Diameter 89 mm piles. The length of only 2000 mm. The height of the piles above the ground is not more than 700 mm. It turns out that the pile is screwed to a depth of no more than 1300 mm. In the first year of the pile was the bulge. Not much, but it is unpleasant. Then, when the next year rang out cold, flooded the pile so that no longer opens the door to the vestibule. On the second floor from the walls he stepped ceiling. Crumpled metal. Raise the corners of the house can be seen with the naked eye. Piles most kicked in the corners and along the perimeter of the house. piles settled in the summer. I think cut pile and pour melkozaglublennuyu tape.

The photo below was obvious that the house raised a corner.

Oleg 52

user FORUMHOUSE

I have a two-storey karkasnik size 9h11 m pile-helical foundation. The house is habitable. The facade is decorated with stucco. Soils subsidence, distending. After a year of the piles subsided from 2 to 5 cm. The most interesting is that the foundation of the firm with the name twisted. Pre-made geotechnical survey and gave their svayschikam, but apparently to no avail. The foundation has already repaired under warranty. Piles built up. Additional spun pile diameter 133 mm. Summed up the I-beams, but guarantees that further drawdowns will not be there. Continue to "play" with screw-pile-foundation does not want. It is necessary to somehow strengthen the foundation of reinforced concrete strip shallow. How to do it? House to raise impossible, t. To. Wet road facade crack.

Notice in the photo below. Around the pile, due to the twisting piles dug pit, the soil is ruined. At this point, the water is constantly going and further, both the guide and runs down the barrel of the pile downwards into the ground where the soil was soaked.

Oleg 52

Svayschiki, just turn away, dig a deep pit. Almost everywhere I saw the pile-helical foundation, the ground around piles failed. If installers say, so why do they dismiss. Mol: "It's always build. To the dense soil is still far (all pile length of 2.5 m. Or more), and from the lateral loading jib help. "

Airstats

user FORUMHOUSE

Oleg 52 low load-bearing capacity of soil under the piles. In addition to the blades, they do not really hold anything loose soil, side friction is weak. It is generally believed that only 4 meters of penetration of the pile are held in the ground side by pressure and friction. It is better to pour warmed MZLF and make blind area.

Topos proposed Oleg 52 mount drainage and protect the perimeter of the house from the rain. Oleg 52 the participants decided to take the advice of the portal and fill in "tape" under the house. After characteristic slogan for the construction market in Russia: "If you want to make as it is necessary - do it yourself!".

How to make high-quality screw-pile foundation

You can say that all of the above problems with screw-pile foundation have arisen due to gross violations,committed in the course of construction. This is partly true. On the portal There are many topics where people pop the tape sags and slab foundations, in which vbuhali cubic meter of concrete. But, on the device of pile-foundation of the screw, is greatly influenced by t. N. "human factor". Too many hacks, in the season, wants to capitalize on stilts. At first glance - the work of ingenuous and simple, but it only seems.

Igor3

user FORUMHOUSE

I have been repairing and shifting foundations of houses. I often hear about the piles that rock, or sink their sticks. Technology-helical pile foundation has nothing to do with it. The causes of accidents - illiterate calculation and incorrect installation of screw piles, aggravated by soil characteristics.

Unlike machine screw-piles, with manual installation, the builders can get tired or just to fake that adversely affect the quality of the screw-pile foundation.

according to Igor3 House on stilts swinging if:

• Piles insufficiently buried.
• The builders dug a very deep pit.
• Piles clipped too high above the ground and there is diagonal "struts."
• Selected small diameter piles.
• Insufficient number of piles.
• Soft soil.

Piles sunk if:

• Under piles of soft soil.
• Not made the calculation of bearing capacity of the pile, and, importantly, the soil under the blade of the pile.

So, the basis of a reliable screw-pile foundation - Design and calculation of data on the geology of the siteRather than determining the length and diameter of piles on the phone or on the principle of "so did a neighbor." At first glance, it seems that all issues are solved simply - ordered geological engineering survey. Then gather the load on the future structure of the ground, and makes a calculation chosen piles. At this stage, the developers expect "gotcha" that can completely nullify the idea of ​​making high-quality screw-pile foundation.

al185

Super Moderator FORUMHOUSE

Lovers simplified "calculating" weight loads through the house for an unpleasant surprise - the risk of non-uniform sediment along the axes. In fact, a competent collection of axial loads shows - they are very different axes. At karkasnikov 1-2 floors, the load on the perimeter in the range of 10-25 kN / m = 1-2,5t / m and internal to 40-50 kN / m = 4-5m / m.

The interior walls in the building are always more loaded than the external.

Now find the designer, who will be able to make educated calculation of the screw-pile foundation, with the collection of axial loads, and structural analysis of SP 50-102-2003 "Design and installation of pile foundations." There is such?

If the belt and slab foundations can partly compensate for the differential settlement, and redistribute the load without the occurrence of an emergency, the pile face down, each by itself.

One more 'Myth', that the pile foundation can be calculated by the probe screwing the pile and thus explore the soil in the area.

al185

In my opinion and any designer - this method - a lottery from the field of psychic and ufology.

The reason is that the effort at trial piles tightening effect of the year. For example, data in the early spring when the soil is in a state of moisture saturation, ie. E. within the maximum base degradation properties will differ from those obtained during the trial pile screwing summer - at the end of August, when water is scarce or winter.

Soil conditions during test screwing only valid at the time of screwing. This method does not account for seasonal, long-term (Karst, flooding) and technogenic deterioration of the base.

yra88888

In normal geotechnical studies revealed virtually all features overlying layers, including the capacity, and the ability to detect prosadochnyh lenses. Taped seams more stable and suitable for the perception of stress. As determined and the initial subsidence pressure filtration coefficient and other properties of the soil, which trial twisting not determined.

Design of pile foundations without appropriate sufficient data engineering and geological surveys are not allowed.

Mandatory types of work, regardless of the level of responsibility of construction projects and types of pile foundations are well drilling, laboratory tests, and static or dynamic sensing ground.

Remember!On helical pile foundation even stone house you can putFor example, aerated concrete. The only question is, if we ignore the cost of the foundation, whether the ground will stand under the load of the blade, a small area of ​​unlocking all the piles, compared with a tape or slab foundation.

For comparison:

• Area bearing screw "108" of the pile, with the blade diameter of 300 mm - 0.07 m²
• Area bearing screw "133" of the pile, with the blade diameter of 350 mm - 0.09 m²
• Area MZLF bearing only a portion, of width 600 mm and length of 1 m - 0.6 m²

T. e. bearing area only 1 meter of the strip foundation, with the width of the sole of 0.6 m, screw piles = 6-8! And when constructing a foundation pile-screw not taken into calculation of the frictional force on the pile in the ground that the barrel length of about 1.5-2 m, which is stored in the freezing zone.

Cheap pile-screw foundation - a myth

If you go online and put in a search engine query "cost-helical pile foundation turnkey", then, depending on the region and the greed of sellers come the following figures:

• The foundation of 6x6 m - 26 - 30 thousand. rub.;
• The foundation of 9x9 m - 45 - 55 thousand. rub.;
• The foundation of 10x10 m - 70 - 90 thousand. rub.

Note: The cost of the average.

Sounds great, does not it? Who are the developers do not want to save on the foundation. Especially if we add the standard advantages "screws" which voiced svayschiki:

• The term of service of the foundation - more than 100 years.
• Installation for 1 day and at any time of the year.
• Pile Foundation cheaper monolithic 2-3.

And now come down from heaven to earth. What is included in this price? Most likely you will be offered a standard size piles, with the amount calculated by eye and spans of 3 m. T. e. "Base" pile under the light house:

• stem diameter - 108 mm;
• pile length - 2500 mm;
• blade diameter - 300 mm,
• pipe wall thickness - 4 mm;
• plus headroom 20x20 cm, plus installation.

Now add to the cost of the screw pile-foundation "dopa":

• Plot with a slope? The soil is weak? We'll have to tighten the piles of greater length. Pay.
• The house has a fireplace is planned? Then it takes more piles. Pay.
• Piles too high will shorten the height from the ground and the need to strengthen the diagonal "struts"? Pay.

The list could go on, but, most importantly, that in the the end the customer will receive, the real foundation, or unfinished constructionWhich then will have to bring to mind? What do we mean? Added to the cost of:

• You will need to tie piles and do overlap, for example, timber and wood logs.

• Insulate the ceiling insulation, for example, rock wool. Wherein the thicker layer will take, ie. K. Below all purged. If you save, the winter is ice floor.
• Mount the vapor barrier.
• Lay subfloor, for example, SIR.
• Leave the house on stilts, as the "legs" ugly. Zabirko Hello! T. e. piles further have something to sheathe the outside, for example, flat sheets of slate, and then, are pasted on the tile.

Foundations should be compared to complex, completely ready for the "0" cycle. T. e., each of the bases must be brought up to an equal degree of readiness. Have a ready base of the first floor, which will be mounted on the wall. Face socle part foundations prepared under facing stone, tile or stucco, etc. D.

The cheapness of the screw-pile foundation -. An illusion, since in the cost price does not take into account the overlap and Zabirko..

Alfamayonez

user FORUMHOUSE

I have a house on a pile-helical foundation. "Feet" is no sewed. Insulated floor - 20 cm ecowool blew out, but still cold, the wind still blows. I will be warmed on the perimeter.

As a result, party portal averted from the house water, closed base and ground foam thickness of 10 cm. According to him, the difference in the comfort of the "before" and "after" striking. Then he will do warmed blind area.

The real price of a screw-pile foundation

And now the real price of a screw-pile foundation.

ibragimova

user FORUMHOUSE

We have built a customer frame house area of ​​280 square meters. m-screw pile foundation for 450 thousand. rub. Price - excluding trim the tree, but with the metal reinforcement. Total 60 spun piles, diameter 108 mm, length from 3000 to 4500 mm. Customer first wanted to build a house of aerated concrete on the belt foundation, but for the tape he counted 2 million. rub.

Sorry, no data on the form factor of mega tape for 2 million rubles! Interestingly, and how much it would cost UWB under the house?

landshark

user FORUMHOUSE

I made a pile-helical foundation under the house. As a result, the cost came out, like a good concrete. Total twisted:

• Under house - 70 piles, diameter 133 mm, length 7 m, the thickness of the barrel wall - 5 mm. Inside is filled with concrete M350.
• Under terrace - piles 30, diameter 108 mm, length 7 m, the thickness of the barrel wall - 4 mm. Inside is filled with concrete M350.
• At harness took 800 meters of profile pipes.

Oleg 52 its history, we have described earlier in this article, I spent on an emergency foundation 350 thousand. rub.

Alfamayonez

I figured. I strip foundation would cost the same amount, how much and screw piles.

conclusions

The purpose of this article is not to discourage you from screw-pile foundation or say that it is - a bad type of foundation. No, but to the choice of the foundation should be approached intelligently. So, there are three areas where the efficient use of screw-pile-foundation. It:

• Zatorfovannyh areas with high deposition thickness of the layer of peat. Areas with poor soil, where a set of measures for the full sample subsidence base vytorfovke, with the replacement of imported soil, such as sand, to exceed all reasonable limits.
• Areas with steep slopes. Uneven portions landslide danger where uneconomic alignment or building basement, partially dug into the slope.
• Areas where there is no opportunity to drive a heavy construction equipment. fast is required and, on the already developed area without a large amount of earthwork, foundation make a gazebo terrace. Build a foundation under the bath, giving carcass. Mount pier, bridge, put a fence made of profiled sheet on heaving soils.

In all other cases, think 10 timesAnd whether you need a screw-pile foundation? Or get ready mentally and financially, that you get the foundation, which will have to invest additional funds.

Advice from FORUMHOUSE: alternative screw-pile foundation, if there are indications of the designer to the use of piles, can become reliable precast reinforced concrete piles.

Before you decide to twist pile, study topics: 20 myths about the screw piles and Dipped in the house Ground Screws. How to fix? May fill a tape?

Recommended article:

• 3 arguments against conducting geotechnical surveys. Learn from an article, whether it is necessary to building a house on a plot of ground to explore and pursue hydrogeology?
• 5 reasons not to buy land on the slope or the main difficulties of building a country house on a plot with a steep slope.
• Warmed Finnish foundation - experience in manufacturing of the budget options warmed Finnish foundation.

And you on what foundation is built?

In the video - Insulated Finnish foundation: Mounting nuances constructional features different from similar types of plate foundations.

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