The foundation is the foundation of the house





18.04.2011 09:40
Articles about real estate | The foundation is the foundation of the house Foundation - construction, which has not, in fact, nothing to do with aesthetics, design, style. And virtually invisible. Foundation - construction, which has not, in fact, nothing to do with aesthetics, design, style. And virtually invisible. That is why the future homeowners often pay so little attention to it. And in vain ...

Price erection of the foundation is 15-20% of the total project cost (if any cellar or basement - 30%), and the cost of violations of the zero cycle, even at first glance insignificant, could eventually exceed any conceivable interest. Worth, literally worth to the owner, though very far from the construction of subjects, given the time and effort to level the basics insight into several important aspects of the construction phase. Question - what are the basics?

Soil, water and frost ("national characteristics")


Importantly - the adaptation of the project to local conditions - namely, geology and climate. We were overwhelmed by the cold, difficult soils and high groundwater. The most reliable and durable - rocky - ground, low-penetration, is very rare. More places to detrital soil, which requires penetration of about 0.5 m. It is even easier to find the area of ??sandy soil with sufficient immersion in 0,4 - 0,7 m. This soil is strongly compacted and sags, but does not retain water and freeze slabo.Odnako resource "of sandy areas" under the current rapid construction dried up in her eyes.

Left without any sandy loam, clay loam, clay, not to mention the marshes, where without spending on drainage work is necessary. These soils are not only that it is easy to tighten and become blurred, but also rising, puchatsya sub-zero temperatures, pushing the foundation. From this and called heaving.

The most important parameters that need to know when developing the site: the depth of soil freezing and the groundwater level (GWL) in the locality. They determine how the project meets the area, and dictate what is appropriate to lay the foundation. The first option has its own "regional standards". For example, in Moscow, St.Petersburg, Voronezh and Novgorod regions high-mounted freezing depth is 1.4 m. However, there are always local features, so it is useful to extract information from the immediate, professional mastering stations.

GWL even approximate defies standardization. You can believe only the results of well-conducted geological surveys in the locality. But with the results of preliminary research on their hands to the customer is not a sin itself - and it's easy - to make general calculations. And if it turns out that GWT above freezing depth - not stinted on the conduct of appropriate protection for the foundation. Cost of most expensive "prevention" is incomparably lower than the loss to "cure".

Engineering and geological studies. These include studying the composition and properties of soil taken from drilled wells in the area, pits, and chemical analysis of water. In the construction of wooden houses depth of such wells shall be 5 m for brick and stone - 7-10 m. The wells requires at least four, at least in the corners of the future house.

When will purchase the finished cottage would be nice to see how "correct" his foundation, that is an effort to get results earlier examination and sampling most of the foundation laying for the purpose of comparison.

It makes sense to specify a few important aspects related to the depth of the foundation. Thus, the regulatory depth may be reduced under certain thermal conditions of the building, because heated rooms warm soil depends largely on the floor construction and materials.

Depth of laying the foundation depends on the specifics of the relief, and for buildings without basements - from the planned underground utilities, the nature and magnitude loadings.

Band, bar, pile ... Is there a choice?


In preparing a project type and design of the basement to the primary material at home - wood, brick, concrete blocks, frames, etc. - and his height. However, soil conditions and topography of the site can make a "forced" adjustments in the direction of amplification - hence more expensive - support at home or on the contrary, to allow a nice savings. It is necessary to allow time for discussions with professionals. And, above all, you can not resist a well-known bias, it is better to build the foundation of the most profound and massive.

Foundation of "combined" from the chosen design type (tape, solid, columnar, pile) and technology favorites (team, monolithic). Accordingly, if the bookmark is made to a depth of 5 meters, the foundation will be considered shallow-buried, and if further this mark, then - buried. Here we note that when operating the excavator trench under the foundation is best done initially by about 20 cm above the authorized depth for the subsequent accurate finishing (cleaning, alignment) manually.

This approach greatly improves the quality of the foundation base. These preparatory steps (callout axes, excavation and compaction) are usually from 5 to 25% of the total cost structure to the foundation.

Type of foundation is determined primarily by the weight of the house, presence or absence of the cap and the basement, the properties of the soil. Two - and more storey cottage with serious designs on a fairly firm and dry soil is usually put on strip foundations, precast or monolithic.

On heaving soils with active dynamics of groundwater optimal slab foundation. The latter, in fact, is a composite, because the concrete slabs (solid, precast-monolithic or monolithic-cross) on top, like a raft, laid the foundation of the same tape. This design is optimal for all soils for buildings of light frame structures.

Make sure shot if possible to avoid subsidence and rotting vegetation layer of soil before digging trenches or pits on the entire building area, including the blind area.

Formwork for the foundation. Advanced professionals put in the pit reusable metal, rather than "moribund" wooden formwork into which is placed fittings and is pouring concrete. This provides the foundation shuttering more smooth and even, and therefore more durable and resistant to cold weather surface. A true professional, in addition, makes concrete bar with date filling and gives it to the customer complete with a passport in the concrete, with a certificate and a check on the receipt voucher.

There is a known problem of choosing between the teams strip foundations and tape monolithic foundations. Proponents of the first overlap on many years of experience in construction projects, the reliability, durability and cost structures of reinforced concrete blocks, that these foundations have shown its effectiveness in the northern areas, in places with high GWL and silnopuchinistymi soils.

However, precast foundation, although it is cheaper to cast (approximately 20%), requires more skill and professionalism (the specific location of the blocks, fitting them in the corners, fill joints and gaps, the device is more reliable waterproofing), and - of special equipment and a platform for its installation.

Monolith is almost universally used in the West, requires less engineering and technological costs and hassle with waterproofing. Practice also shows that the monolith is optimal if the draft of heavy load-bearing walls, and in addition, it is suitable only in conditions of excessive swelling soils.

Important moments, which is not a sin to track the customer himself: beetle bags of sand and gravel at the bottom of the pit (for sandy and sandy loam soils quite a gravel pad) should be conducted using vibroelektroplity rather than manually, and - of each layer separately; waterproofing before placing reinforcement should be protected atsentom or slate; pauses in the process, especially before pouring the concrete, should not avoid loosening the soil and falling under the influence of rain and humidity fluctuations.

There is a known problem of choosing between the conveyor belt teams and monolithic foundations. Proponents of the first overlap on many years of experience in construction projects, the reliability, durability and cost structures of reinforced concrete blocks, that these foundations have shown its effectiveness in the northern areas, in places with high GWL and silnopuchinistymi soils.

However, precast foundation, although it is cheaper to cast (approximately 20%), requires more skill and professionalism (the specific location of the blocks, fitting them in the corners, fill joints and gaps, the device is more reliable waterproofing), and - of special equipment and a platform for its installation.

Monolith is almost universally used in the West, requires less engineering and technological costs and hassle with waterproofing. Practice also shows that the monolith is optimal if the draft of heavy load-bearing walls, and in addition, it is suitable only in conditions of excessive swelling soils. Important moments, which is not a sin to track the customer himself: beetle bags of sand and gravel at the bottom of the pit (for sandy and sandy loam soils quite a gravel pad) should be conducted using vibroelektroplity rather than manually, and - of each layer separately; waterproofing before placing reinforcement should be protected atsentom or slate; pauses in the process, especially before pouring the concrete, should not avoid loosening the soil and falling under the influence of rain and humidity fluctuations.

In any case, on heaving soils strip foundation must be solid frame, which creates a rigid system of overlapping bands. For laying the foundations malozaglublennyh addition to concrete, use, and others, quite economical materials that are acceptable for small single-storey houses. On dry soils nepuchinistyh often apply additional layers of sand with gravel, rubble and broken bricks, as well - a brick.

The latter requires additional measures for protection from moisture. Rubble foundations, record strong and durable, fit large size of the boulders and rock fragments, collared with cement mortar. Rubble concrete foundation, built in the mold or trench with vertical walls consist of a solution filled with small stone rubble and gravel.

Pier foundation (range of materials for them is very wide) are optimal for the construction of wooden and frame houses without basements and cellars on heaving soils in deep freeze as well as in cases where the employee base soil lies at a depth of 3-5 m. The principal limitation for these foundations - the site with a height difference, which lay their contraindicated.

The foundations of this kind is very economical: on consumption of materials and wages are almost double, while deep-and sometimes five times cheaper than tape. But there is one significant problem: the need for the device so-called zabirki, connecting wall between the pillars of brick, concrete or rubble for insulation and protection of underground space. Find artists who know how to do it correctly - is unfortunately sometimes not an easy task.

Variety of columnar - pile foundations. They are becoming more common in projects of single-storey houses, as very effective in soft soils and high GWL. Piles or use ready-made or make them directly in the drilled wells. Apply a pile-stand, reaching base to firm ground, or hanging piles, to create a support at the expense of soil compaction and friction. Pile foundations are considered the most environmentally friendly by their impact on the soil landscape. Moreover, they are increasingly seen as the most progressive. However, there remains the same problem - lack of professional staff. Therefore, for inclusion in the draft pile foundation is important to enlist the support of specialists.

Filizoly, acrylics, styrenes ... The more isolated?

Waterproofing is akin to the human immune system. And it is important not only for "health" of the building itself, but also to a large extent - of its owners. In the cost structure on the foundation it takes 5-10%.

With a serious approach waterproofing "build" in three lines of defense at home. First - internal. As a rule, it is necessary only in homes with basements. Second, external, directly on the wall surface. The third - also outside, with special treatment of the soil.

Basic types of waterproofing used in the construction of a separation of the soil around the perimeter of the building - obmazochnaya, painting, cast, okleechnaya, surfaced, injection, penetrating. What should be applied in a particular case may suggest a specialist.

The most advanced species are obmazochno-piercing and injection types of insulation. Among the first very high performance show postmark on the basis of chlorosulfonated polyethylene and polyurea, applied to the surface of the basement under pressure. These materials are developed in Russia is extremely resistant to aggressive environmental factors do not decompose and, consequently, extremely durable. Other advantages: the quality of this isolation is easy to control, it can be applied to fresh concrete, and work with it in winter at temperatures down to-15C.

Deserves special attention is another very promising Russian design - Nutley, loose material on the basis of activated bentonite clay. In contact with water it forms a kind of gel barrier to retain it. It is shown that at a pressure of 40 atmospheres of water penetrates into the interior of Nutley no more than 2-3 cm Thus, the 4-cm layer of Nutley (in the mold or not) is quite sufficient for reliable protection of the foundation.

Actively developing technologies penetrating the insulation. Special formulations are applied to the wet surface of the basement and, thanks to moisture absorbed into the cracks and pores, clogging them, and then dries, turn into a solid crystalline phase. In the formation of new cracks and natural access to their soil moisture process is resumed, spreading to new areas: the insulating material "lives", revived the surface of the basement.

In a sense, akin to the technology method injection adjacent to the foundation (and basement walls, if any) of the soil. In this case, from the ground surface or directly from the basement through the body of the basement drilled wells on a standard depth and is pumped into them under high pressure reinforcing waterproofing materials. Thus, around the underground part of the building created a kind of protective "sarcophagus".

The composition of injectable solutions is determined by the geological and soil infiltration parameters, as well as the type and condition of the foundation. Most of those used against flooding today recognized materials based on epoxy, polyurethane and acrylic resins. Also developed technologies for protection against the rising capillary moisture by injecting a low pressure.

In its broadest application still remain, and roll materials - gidrostekloizol, filizol and others. They have their advantages, the technology of their styling has long worked, but with the available choice of materials of their flaws begin to speak to the fore. They are relatively fast decay. Control joints rather difficult. Means too much for their installation "human factor" - are often allowed to break the technology.

Keep in mind, and the importance of the original layout of the site with a mandatory unit slope to drain surface water from home. And also - on the enduring role of the blind area of ??waterproofing, which ends with zero-cycle construction.

"Theme" Groundwater is supplemented by a problem that can occur already in the process of pouring the foundation. Saturation of soil water to avoid siltation of pillows to handle it on a path binders, or by covering it with polymer film.

Blind area. It should have a width of 1,5 m and is made of three layers: the first - a soft, well-rammed clay, then - broken bricks or rubble, and the outside - cement or asphalt. The last layer is better to place one year after the laying of the first two. By the way, blind area - the only "designer" part of the zero cycle.

Thermal insulation


This area of ??protective technology live their own traditions and priorities. This area of ??protective technology live their own traditions and priorities. Technology in its booming, bringing to market new brands. However, in most cases, the foundation hosted directly on the plane touch the ground and construction of the house remains have long used concrete block, placed on the sand. Layer of expanded clay must always be protected by the so-called laitance. Arranged on top of a concrete screed.

On it, if there is no basement and ground facilities - concrete floors. In the presence of a basement concrete block used to often.

On it, if there is no basement and ground facilities - concrete floors. In the presence of a basement concrete block used to often. In this case, the most common technology remains at the taping of bitumen mastic interior walls of the basement foam (20 mm), then trowel on a grid-netting.

Among the major advanced materials - basalt wool (grade ROCKWOOL, ISOROC, PAROC, etc), staple fiber (URSA, ISOVER), extruded polystyrene (including URSA XPS, Penopleks). Basalt wool is durable, does not shrink, does not burn (used as fire insulation!), Eco-friendly. Recommend using this heater with a water-repellent impregnation composition, as well - to protect it from the inside vapor barrier material.

Very effectively and staple fiber, chemical resistance and possessing antimicrobial properties. It is recognized as the best zvukolizolyatorom. However, as basalt wool, it should be protected from steam and water (plus a special solution in foil).

Extruded polystyrene is durable, can withstand sudden changes in temperature, humidity resistant and therefore particularly suitable for insulating foundations and ground-basements. It is usually a layer of glue on the sealing areas to avoid conducting the cold in the room - a "cold bridges". At the same time it protects the waterproofing from freezing and physical damage. The only important thing to protect him from using a direct "hit" sunlight, otherwise the material can crumble.

According to various estimates, the cost of insulation for different types of foundations ranging from 5 to 15% of the cost of its construction.

In conclusion, we draw attention to a number of important details of construction, subject to the control of the customer. Better to work in the summer, under favorable weather conditions. Unacceptable fill shallow-buried basement in the frostbitten ground. You can not resist the old fallacy that the foundation must be defended before the erection of walls.

You must include a box of a cottage before the land is chilled and begins to actively push unloaded foundation. It is also important at the beginning of the construction itself, together with an expert to look into the pit and make sure that all elements of the mortgages - under a sewer, putting cold water and earth - are not forgotten, have introduced and implemented correctly. Finally, when choosing a contractor is to bet on the company, already having experience of construction in the area.

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