What You Need to Know About Building on a Slope
This Montana cabin takes advantage of its sloped lot with a walk-out basement on the backside. See more of this home here. Photo: Joseph Hilliard
Question: My wife and I own property with a gentle slope. I’ve heard it’ll cost a fortune to build up the ground for a slab foundation. Would I save more by building a house with a basement?
Slabs and slopes often don’t play well together. It isn’t just the cost; there are other problems as well. Bringing a slope up to level for a slab usually requires building a stem wall or retaining wall on the lower edge of the foundation and adding fill dirt to provide a level base. But be careful: Placing a slab on fill opens the door for cracks and settling. Make sure your builder or excavation team takes great care to compact the fill.
Another issue is drainage. Building codes require that non-masonry building materials be at least 8 inches above the soil surface. I recommend doubling this height to protect log walls from damaging rain and drifting snow. This means adding even more fill. If you’re trying to avoid a basement, consider using a crawlspace. This will require a footing and short wall. If you’re building where winters can be severe, normal footings must be several feet deep.
Also, ask your building about frost-protected shallow footing (FPSF) to reduce the amount of digging and concrete. This building technology has been used in Scandinavia for half a century and provides a more energy-efficient foundation system for less money. As an added bonus, your crawlspace will offer some storage and allow you to run electrical wiring and plumbing—a much easier route than running these through a slab.
Photo: Elk Ridge Builders
Question: What are some pros and cons of building on a slope?
Building on a slope offers the possibility of a walkout or lookout lower level. This means daylight instead of the dark mustiness of a subterranean basement. Being able to finish all or part of the lower level allows you to build more home for less money.
Sloping lots offer a lot of aesthetic advantages, too. In a forest, a home built on a slope may mean that windows on one side will take in views of a forest canopy and provide a sense of living in a tree house. In more open country, a slope can provide your home with a commanding view of mountains, lakes or meadows.
Slopes have two potential drawbacks that can cause some anguish to your builder and pocketbook: accessibility and drainage. Steep slopes are difficult to access with the heavy equipment needed to build your foundation. The time required to build your foundation is often increased, and it may be necessary to pump concrete to your foundation. This can mean increased costs.
Sloped home sites also present drainage challenges. If you build at the top of the slope, chances are you won’t face any issues. But if your site is on the side of a slope, you need to pay special attention to the amount of water that can flow toward your home and its foundation. Building codes require that the land immediately around your foundation slope away from it. This may mean your builder has to create a foundation that is partly exposed on the “upslope” side with fill dirt added for a slight counter slope against the house. This step has a positive side: less digging, and the so-called waste soil from excavation may be used as fill.
See also: How to Choose the Best Possible Site to Build
These Ohio homeowners took saw their sloped lot as an opportunity to take advantage of the view. See more of this home here. Photo: Richard Lee
Question: Our lot has a 15 percent slope. Does this type of grade require a special type of home design?
A 15 percent slope means that, for every 100 feet of horizontal distance, elevation changes 15 feet. This may not seem like a lot, but let’s consider how building on a slope like this affects your foundation.
Imagine that your home has overall dimensions of 28 by 60 feet. If you orient the house so that the 60-foot dimension is in the same direction as the slope, the lower corners will be 9 feet lower than the upper corners. If you orient the house so the 28-foot dimension is along the slope, the lower corners will be about 4 feet below the upper corners. As you can see, the latter case involves much less digging.
You can easily determine your home site’s slope with some string, a tape measure and an inexpensive “string level”—a small level vial that hangs from the string and is available from hardware stores. Simply stake one end of the string and measure off a distance down the slope with it. Hold the string taut and level and measure the distance from the string and the ground. Transfer this information to a sheet of graph paper and sketch in your foundation to see how the slope will affect your foundation.
See also: How to Pick the Perfect Piece of Land
Photo: Peter Amend, Courtesy of Real Log Homes (See more of this home here. )
Question: Is building on a slope more expensive? Will there be extra excavation costs?
Usually, building on a slope requires less excavation than building on a site on level ground. However, if the slope is steep, the excavator may have to do some grading around the side in order to gain access. Also, steep slopes may require the use of more specialized equipment designed to operate in rougher terrain. Steep slopes may require a lot of final grading to re-direct water flow and protect your foundation. This occasionally requires your builder to haul in and spread more fill dirt, which can increase the cost of your foundation significantly.
See also: Your Step-by-Step Guide to Log Home Construction
Photo: James Ray Spahn (See more of this home here.)
Question: We have a 2-acre gently sloping lot in a gorgeous area that’s sometimes prone to mudslides. What major factors should we consider before we build?
If you’re in mudslide country, you don’t want to find yourself upon the ground that may slide or be in a mudslide’s path. Study your site carefully to determine where water and mud have gone in the past. If possible, visit your site during a heavy downpour and see what happens to the water. Gentle slopes don’t usually pose a great threat, but building your home on the lip of a steep slope raises the possibility that rushing water may scour under your foundation and send your home sliding. If your building site presents any risk of mudslides, it’s best to talk with a civil engineer or an experienced excavator.
This log home built along a slope takes in 270 degrees of scenic North Carolina wilderness. See more of this home here. Photo: Joseph Hilliard
Question: We want our sloped property to have gorgeous landscaping. What can I do with a sloped lot?
Landscaping on slopes requires some attention to detail. First, make sure that the landscaping you have in mind can handle the slope. If some of the plant species you’ve chosen have difficulty establishing their roots in sloped areas, you may want to create a series of retaining walls. The construction of retaining walls is both an art and a science. Not only does it require a feel for the aesthetics of the landscape, but you must understand the forces that affect the wall and the construction required to control them.
Short retaining walls (2 feet or less) are fairly simple, but as the walls exceed 2 feet in height, the weight bearing on the back of the wall makes construction more challenging. It’s important to build the walls to resist the forces of the soil they hold. This may mean extra reinforcement and the use of “dead men,” which are anchors for the wall.
Sloped lots usually offer a world of design and building possibilities. If you plan correctly and work with your builder to properly map out and excavate your home site, you’ll get the best of both worlds: an efficient home plan and some amazing views.
See also: Five Tips to Hardscaping Your Property
Photo: Southland Log Homes (See more of this home here.)
Seven Quick Tips for Success When Building on a Slope
- Create a daylight basement in the excavated wedge area under homes on the downside slope. You’ll create a great view with an additional room, instead of an underused crawl space, and without enlarging your home’s footprint.
- Reverse your layout. Sloping sites allow a more modest appearance from the front and a grander one from the rear, especially with dramatic windows, such as prows. When building on a slope, it is often best to put your “front” door behind the house.
- Have your driveway access the home from above, not below. You’ll avoid having to cut the driveway into the side of the hill and build retaining walls to keep dirt and stone from falling onto it. Placing your garage at the front of the top level opens up views at all levels in back of the home.
- Build tall. Taller homes with smaller footprints require less excavation and grading, both of which are major construction expenses. And a narrow, stacked house with an open floor plan can bring views to all or most rooms.
- Avoid building on the very top of a hill or mountain. A panoramic view is great, but it will also raise your heating costs by exposing the home to cold winds in winter. Use the slope to shelter the house and narrow the view’s focus.
- Properly site your home. Site your house to avoid winter shade and summer sun as much as possible.
- Make the house part of the view. Build to conform to the land’s contours, and blend rather than clash with the topography.
Learn more about building on a slope:
Sloped Sites Vs. Flat Lots: Which Is Right For You?
Is a One-Level Log Home Cheaper Than Two Stories?
Your Guide to Daylight Basements
4 Massing Strategies for Building on Sloped Sites
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There’s something exhilarating about building a house on the side of a mountain or hillside. It’s like you’re on the precipice of the world looking out at all the possibilities. But building on a sloped site is not easy. You have to figure out how the structure wants to relate to the terrain, how the foundation will be designed to support the house, and if the construction crew can operate machinery around the site. Feasibility studies help uncover a lot of these constraints and opportunities.
In our Lincoln Bluff project in Washington, we designed a home that was built into the hillside and cantilevered out above it. We also completed a comprehensive architectural feasibility study for an undeveloped property along a ravine in Columbus, OH. It was a small lot with an even smaller buildable area above a 30-foot shale cliff. As we learned about the constraints and opportunities of building on a sloped site, we studied the various massing ideas for the home. To us, good architecture should always take advantage of the site and give it a more significant role in the architecture rather than leveling off the grade and plopping the house down.
Summarized below are 4 massing strategies and project examples for building a home on a sloped site. A good design concept should include one or more of these strategies:
- Sitting the house ON the ground
- Embedding the house INTO the ground
- Floating the house ABOVE the ground
- Sticking the house OUT OVER the slope
1. Sitting the house on the ground
Sitting the house on the ground is the traditional, straightforward approach. It utilizes one of the easiest construction methods and is economical because it minimizes excavation and foundation costs, provided you’re not doing a lot of site grading to level off the earth.
The Ravine House by Darcy Jones Architects. Photo by Ema Peter Photography.
Dalarna House by Dive Architects. Photo by Åke E:son Lindman.
2. Embedding the house into the ground
Embedding the house into the ground helps integrate it better with the land than simply sitting it down on top of it. The home feels grounded and is more responsive to the terrain. It can sit lower to the ground if you locate programmed space that traditionally is on the 2nd-story level to the lower level that is buried in the hillside. This low-slung appearance is a great way to minimize the massing of the home as seen from the road or from elevations above.
However, with this approach comes increased excavation and foundation costs. You’re digging out more earth and hauling it away, and you need thicker foundation walls to retain the earth of the sunken house form.
Below are two examples of embedding the house in the ground.
Wakatipu Heights House by Mason & Wales Architects. Photo by Marina Mathews Photography.
Detached House T by Kreiner Architects. Photo by Volker Wortmeyer.
You can also embed the house in the ground with a reverse floor plan. This works well if access is from above. In this case, you can organize the floor plan so that the main public spaces are on the upper level (where your front entry may be) and your private bedroom spaces are on the lower level. This gives your main living spaces the best view because they are higher up in the house. It may also help create a dramatic entry with a view.
House DB Klaus by Jürgen Hagspiel Architects. Photo by Norman Radon.
Bowen Island House by omb Architects + Designers. Photo by Ema Peter Photography.
Regardless of where access is, you could also do a terraced floor plan if space allows. In this strategy, you could stagger the floor levels, creating split levels or small changes in elevation. This works well if the goal is to create a meandering experience, to break up spaces without walling off rooms, or to better relate to the surrounding topography.
Terraced House by Hufft. Photo by Hufft.
E-type House by RTA Studio.
3. Floating the house above the ground
This approach raises the home on supports, whether on stilts, piers, or solid walls. The benefit of this approach is that you can minimize site disturbance with a smaller footprint. This can be especially important if you are trying to navigate large tree root structures, bedrock, or steep slopes.
With this strategy, you feel like you’re living in the trees since most of the programmed spaces are raised up on a higher floor level. You can also possibly see under the house clear through to the other side of the site depending on the floor plan. This is another way of connecting with the site visually.
X House by Snow Kreilich Architects. Photo by Corey Gaffer Photography.
Apus Rupanco by Aguilo Pedraza Architects. Photo by Marcos Zegers.
4. Sticking out over the slope
Lastly, one final approach is cantilevering the home. You can anchor part of the home to the site and extent the other half out over the terrain. This creates dramatic overlooks and views of the surroundings for an immersive and exhilarating experience. However, it does come at a cost since there will undoubtedly be structural implications to think about. This approach could also minimize site disturbance and help avoid significant foundation expenses.
Two Hulls House by MacKay-Lyons Sweetapple. Photo by Greg Richardson Photography.
Balancing Barn by MVRDV.
A Hybrid Approach
The above massing strategies are all viable options for building on sloped sites. The particulars of the site, design goals, and budget will all play a part in confirming which strategy or strategies are best.
Here’s one final thought on these strategies: It’s not uncommon to see two or more strategies for a custom home design on a sloped site. You could lift the home on piers and cantilever it out over site boulders. You could embed it in the earth on one side and stick it out on the other. You could terrace it across varying topographies where part of it is lifted above the ground and other parts are embedded.
Here are two projects we enjoy that combine two or more of the above strategies.
OZ Residence by Stanley Saitowitz | Natoma Architects. Photo by Bruce Damonte.
Schlotfeldt Residence by Omar Gandhi Architects. Photo by Ema Peter Photography.
At YR Architecture + Design, we strive to create modern custom homes that integrate with their surroundings no matter the landscape or design approach. In our opinion, how the structure speaks to the land and the responsive design that the home takes creates a more authentic solution that’s timeless and fitting of its place.
If you’d like help creating a thoughtful, well-designed custom home on a sloping site and would like our help, get in touch with us today. We’d love to hear more about your project and discuss how we can help you.
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Building a house on a sloping lot – features
Building a house on a sloping lot is quite a challenge for builders. Difficult terrain causes difficulties and forces to increase the budget. Preference is usually given to more comfortable flat areas.
However, some, on the contrary, prefer just such difficult construction options. The reasons for this are simple:
- More options for unusual architectural solutions;
- Most often, a beautiful view will open from the windows of the future building.
However, the development of projects for houses on a slope requires careful study, taking into account all the nuances. If you follow all the technical points at the time of the design and construction of buildings in such areas, then the result will be stylish and spectacular cottages.
We will talk about the features that you need to pay attention to in this article.
Advantages and disadvantages of building on a slope
Before making a decision, we recommend that you familiarize yourself with the pros and cons of building a residential building on a hilly area. The positives include:
- Originality – the cottage on the hill looks out of the box. In such cases, it is possible to realize the most unusual design idea, using atypical layout and landscape solutions;
- Savings on sewer systems – future owners of the house will not need to use a pump to pump out sewage. For the outflow of waste, it will be enough just to lay the required number of pipes, and the waste water itself will be removed by gravity;
- Possibility to make an original garden or kitchen garden – it is convenient to divide the slope into terraces, in which the plants will not interfere with each other and receive enough light. Terraces can be used as decorative elements of the site. Climbing plants can beautifully decorate a balcony, walls, roof. The project of a house on a plot with a slope reveals wide horizons in this direction.
Disadvantages of such a layout should also be noted:
- The need to strengthen the soil – in the process, it will be necessary to strengthen the soil so that a landslide does not occur. This can be done by installing retaining walls or special terracing along the slope;
- Significant ground preparation and excavation costs – sloping terrain is usually characterized by difficult terrain, and this complicates the digging of a pit for a house and further laying of the foundation. As a result, this increases the budget spent;
- Mandatory, high-quality waterproofing – the foundations of ordinary buildings are laid horizontally, while some of them are deep in the ground. For the normal strength of such a house, competent waterproofing is required.
Consider all this, ideally at the stage before the acquisition of the site.
Construction of foundations in hilly areas
Geodetic measurements are a must before starting construction: they will help to accurately determine the slope angle. Then, the level of groundwater is identified, as well as the composition of the entire soil on the site.
One should be wary not only of ravines, but also of artificial slopes. Make sure before building that your hill is not the result of dumping waste or soil.
Then the issue of site orientation is decided. Some experts believe that the southeast and south slopes are ideal, while the southwest and west will be too hot. However, on the territory of the Russian Federation, summer is mostly short-lived, therefore, preference is often given to the western and southern slopes. If the site is located in the southern region with a hot climate, then the house is best located in the northern part of the site.
Pay attention when choosing a site: you need to take into account not only the beautiful view, but also the convenience of the entrance. It is important to build a building in such a way that it is easy to drive up to it. The project of a house on a plot with a slope must necessarily include planning in this matter.
Foundation types for uneven areas
The foundation is the subject of maximum attention, the final strength of the whole house depends on it. To date, on hilly areas, such types of foundations are used as:
Let’s take a closer look at each of these types.
Used in areas with a slight slope. If the slope angle is higher than 20%, this type of arrangement becomes economically viable only if the basement is erected.
Be sure to use reinforcement, it gives the base the desired strength. Pay attention to the level of the upper plane: it must be perfectly horizontal. For pouring, choose soils that are not prone to waterlogging and seasonal freezing. If necessary, a small level of slope can be leveled by pouring and then tamping the surface to the level you need.
It is a type of strip foundation. Such a foundation on a site with a slope is used in the presence of large height differences.
Before pouring concrete, builders equip terraces that are equal in area to parts of the house. At the same time, a trench is dug at each individual site, formwork is mounted, and reinforcement is carried out.
Parts of the base will be connected to each other by retaining walls or lintels. It is necessary that in the end the total slope angles coincide directly with the slope angle of the bearing part of the soil.
For construction on hilly areas, the pile type is most often used. Retaining columns are installed as foundations.
The most common solution is to drive screw piles, which are then bridged.
Strong reinforced concrete piles in combination with a wooden strapping made of durable timber are a reliable and durable structure for a future home.
What are the advantages worth noting:
- Such a foundation on a sloping site can be installed on any type of soil, unlike other foundation options, because the piles will be driven well below the freezing level;
- Cheaper than any other option if significant piling is not required;
- After installation, builders do not have to wait weeks, months for shrinkage. Due to the strapping with a bar, stress in the base of the building is completely eliminated. It does not shrink, cracks do not appear on the floor and in the walls, that is, immediately after the installation is completed, you can live in the house;
- Suitable for a site with different angles of inclination;
- Work can be carried out at any time of the year and day;
- Much less damage to the site, leaving the opportunity to preserve nature;
- If necessary, can be combined with other types of foundation.
Installation of reinforced concrete piles allows builders to adjust the angle of inclination, that is, the future house will stand even with a significant difference in height on the site.
The binding, or otherwise the grillage, is made of timber, and it:
- Helps to fasten piles driven into the ground;
- Evenly distribute the load from the weight of the house on all piles at the same time;
- Protects the building from the negative effects of weather conditions – rain moisture, snow, melt water, etc.
Specially treated wood is used, which is characterized by a particularly long service life, high strength and resistance to moisture. In the construction of modular-frame houses, coniferous timber is widely used.
Natural conditions due to the height of the supports above ground level (approximately 0.7 m) do not affect the finished building at all. This completely solves the problems of high humidity on the site and / or unstable soil, and makes it comfortable to build on sites with a slope.
After careful surveying, the pile field is marked out. Specialists with reinforcing bars mark exactly where the piles will be located. At the same moment, the geometry of the foundation of the future house is checked. Special equipment delivers reinforced concrete piles to the site and carries out driving. Due to the operation of a special impact mechanism, one part is driven into the ground in just a few minutes. The work is monitored by operators and engineers who control the process using a level. Additionally, metal plates are then mounted to accommodate the strapping from the timber. It takes a maximum of several days to install such a base.
It is worth noting another significant plus of this type of foundation in relation to all other types – versatility. It is suitable for the construction of a private house, and a cottage, and a summer residence. It can be installed on any terrain and on any type of soil, you do not even need to level the ground before starting construction. It is only required to choose piles of the desired length and shape. The length can also be any.
The company Modul2 uses pile foundations in the construction of prefabricated houses. This ultimately makes them available everywhere.
Other things to consider
Building on sloping sites requires more careful planning of building placement. It is important to correctly calculate the depth of the foundation, as well as take into account all the nuances of distributing the load at home.
In addition, experts strongly do not recommend erecting a residential building in the lowest part of the site, and there are a number of reasons for this: A so-called “pocket of cold” will form around the house, and this is uncomfortable;
Strengthen the ground with:
- Fences as retaining walls – they can be made of limestone, brick and concrete slabs;
- Stones of various sizes – looks aesthetically pleasing, while being highly functional;
- Geotextile for strengthening slopes – does not rot, does not tear, frost-resistant;
- Geomats for slopes and slopes – polymeric materials that are intertwined with plant roots, significantly enhancing reinforcement;
- Geogrids for special soil reinforcement – suitable for steep slopes;
- Geogrids for soil stabilization – they are non-toxic, do not interfere with the germination of plants through them, let water pass through them;
- Slope gabion structures are complex ecological modular systems that can be combined with other reinforcement options.
It is also important to take care of the soil on the site, growing shrubs and trees on it. They absorb excess water, plus at the same time strengthen the slope with their root system. Be sure to think over the landscape of the site before the arrival of special equipment, try to keep the vegetation to the maximum, especially the turf.
Junipers, pines, cedars, hawthorns, lilacs, wild roses, quince, blackberries, sea buckthorn, tree peony, deutsia, vinegar tree, snowberry, chaenomeles are considered leaders among plants in strengthening the earth.
Properly erected foundation will guarantee a long service life for your house. If all the nuances are taken into account, then neither precipitation nor ground pressure will adversely affect the foundation. That is why it is important at the stage of laying the foundation in no case to save on materials and listen to the opinion of specialists. Unnecessary thrift here will lead to a decrease in the strength of the building and, as a result, to other troubles for future residents.
Features of building houses on a slope
Important to know | Features of building houses on a slope
Features of building houses on a slope
You can build on any terrain. Although costs will vary, the right technology
construction will minimize them. You can fit the structure of the house into the relief of the site at the stage of developing a house project from SIP panels, or you can
go for a large amount of earthworks and fit the terrain to your chosen project. The second option is usually more expensive.
and it is better to contact him with a minimum bias.
Deciding on the site
The choice of solution depends on the slope of the site. So, the angle of inclination up to 3% is called the minimum, it is suitable here
option with the movement of earth masses, you can choose any standard project.
If the slope is 7% (small slope), then for private houses it is enough to fill the soil (with
For a slope of more than 8%, a basement is usually designed. To reduce the volume of excavation, do not align
building site, and cut off the lower part of the slope, where they plan the basement.
At 15-20% or more (steep), it is necessary to develop an individual project. Usually this is a multi-storey house with
utility rooms or a garage on the first tier. Such projects
country houses are clearly not budget, but visually very spectacular.
Given the above, we choose the design of the house and technology. It can be any, but in areas with
slopes, lighter options are more economical: wood, frame structure or SIP technology. Let’s stop our
choice on the latter, as more rational. On inclined sections, slab and strip foundations are very
labor-intensive and expensive, but when building a house from SIP panels, they can not even be considered. Of the remaining
columnar or screw piles, we choose the latter as more technologically advanced.
To calculate the number and length of piles, it is necessary to determine what soils and at what depths lie, whether there are
lenses and quicksand, often found on the slopes, the level of groundwater and the depth of freezing. Calculation
pile field on a slope is very difficult, this work should be entrusted to professionals. small organizations,
who twist piles on flat or slightly sloped areas, based on standard solutions, will, of course,
cheaper, but even a small mistake in the construction of the foundation jeopardizes the bearing capacity of everything
A bit of history
English engineer A. Mitchell decided to make the work of pile drivers easier and suggested not to hammer piles like nails, but
twist like screws. To do this, he provided the pile with a sharp threaded tip. Screw piles in Russia
began to be used since 1880 with the light hand of engineer Karlovich. Over time, the piles improved,
new materials were used, finally, a tip with blades was invented. At first they were used by the military
builders for the construction of temporary buildings, then they began to be used during restoration and where the dynamics
driven piles was dangerous for objects located in the immediate vicinity of piling. But only
Recently, screw piles have been used in individual construction.
Types of screw piles
There are four types of screw piles:
Welded tip – more often used for technical buildings, baths, fences, gates.
Some are used for housing. However, this method is only suitable for the construction of temporary
buildings, but not for the construction of a permanent home.
Cast tip – for low-rise residential construction and light industrial
Two-bladed propeller – for large objects and on light soils in an individual
Piles with increased bearing capacity – used everywhere, except for rocks.
For the construction of SIP panels 3 and 4 view
obviously unreasonably expensive, so consider the first two.
Weld End Piles
drilling blade. The quality of these cheap piles is quite low, which is why such piles are usually used under
fences, bathhouses and makeshift houses. The weak point is the welded joint (too high probability of marriage) –
this is an inaccuracy of cutting, and a change in the properties of the metal when heated,
and small thickness of the blades.
But all this is not a disadvantage of technology, but the result of its violation. The use of special steel grades will not change
metal properties when heated, laser cutting will avoid cutting deviations, and human
The factor is present in all variants and can only be reduced by automating the process. Exactly
therefore, you should contact only trusted companies with a modern technical base.
Of course, from a reliable supplier, piles will be more expensive, but you will be sure that you are paying for a high
quality of equipment and materials.
Piles with cast screw head . The tip is made by precision casting in
vacuum environment from steel ST-25 and ST-35. The thickness of the blade at the base is 13 mm with a diameter of 300 mm (for welded
usually 4–5 mm). The barrel is made of a steel pipe (it is better to choose a seamless material), at the end
a cast tip is inserted and scalded. For pipe with a diameter of 108 mm, the wall must be at least
mm. Depending on the characteristics of the soil, such a pile can carry up to 6 tons.
As you can see, there are welded joints in this version as well. The use of seamless pipes will reduce the risk of corrosion and
will increase the service life of the pile, but special attention should also be paid to the connection of the head. Passports
and test certificates of welded joints, although not a 100%, but still a guarantee.
There are also piles of thick-walled tubing – tubing. The quality is not inferior to piles with cast
tip. Wall thickness 6.5–7.5 mm. Steel is designed to work without anti-corrosion protection in
Compared with the water and gas pipe (4 mm), the strength of the tubing is five times higher,
and corrosion resistance – in seven. The blade in this case is made of structural steel, which is
35% stronger than the standard version. The use of tubing significantly improves corrosion resistance – the main
screw pile problem.
Screw pile protection
black metal. All other piles must be protected. But remember that more dangerous corrosion
is a chemical that occurs at the interface of metal contact with water or oxygen. Destruction rate
metal depends on the level of acidity of the environment. For a year, the depth of penetration of rust in the absence of
metal protection, is: in clay – 0. 0032 mm, in sand – 0.00292 mm, at the border with water / soil – 0.0814
mm. The conclusion is simple: metal isolation from water and oxygen can protect the pile from corrosion.
There is also electrochemical corrosion. Stray currents contribute to the formation of electrolytic
dissociations that destroy the structure of the metal. Single cases can be discarded. Here is the closeness
tramways, railways and high-voltage lines will have to be taken into account.
There are many ways to insulate, traditionally the most reliable and modern technologies are also expensive. But from
of all options, we will choose the most reliable in the middle price category – processing with a polymer composition,
shrink film and combinations thereof.
We cover our piles with a polymer composition in the factory, and the most dangerous areas are the piles coming out of the ground
(15 cm down and 15 cm up) and welds when building piles, isolate with heat shrink film in the field
conditions. To do this, the film is heated and wrapped around the pile. As it cools, the film shrinks in diameter and
After the piles are installed in the design position, they are concreted. They do this not only to increase strength,
and to avoid the ingress of atmospheric oxygen and water. To determine the diameter, length and
number of piles, it is better to carry out control drilling; on a slope, this procedure is mandatory. Based
the obtained data, the bearing capacity of the structure is calculated. In order not to delve into mathematical
calculations, let’s say that for frame houses and houses from SIP panels, screw piles with a diameter of
108 mm and length
2.5 meters, if necessary, the pile is increased by welding. The main requirement is that the span is not
3 meters, installation of piles in the corners and at the intersection of axes is mandatory.
Installation of screw piles is carried out manually or mechanized. On level ground or with a slight slope
more rational manual option. In our case, on a slope, it is better to use a mechanical method.
The first pile is screwed in the upper corner of the field to the mark of the top of the base or cut with a grinder to this mark.
Then they screw in the remaining corners and dig small recesses (30 – 50 cm) under the rest of the piles. Twirl
ordinary piles, constantly checking the verticality. Permissible deviation from the vertical 10 mm. Pile
to the bearing layer, but not less than 1.5 m. Sometimes according to the project (and this happens on slopes
often) twist and inclined piles, as if creating a bush. The next stage is cutting piles
to the level of the first
corner and concreting of internal cavities of piles. If we are designing a house from SIP panels, then the heads are fixed
under a bar, but on a slope, even for houses made of SIP panels, on top of piles
a channel is mounted that connects all the piles into a horizontal stiffening disk. If the piles come out of the ground more
than one meter,
then for vertical rigidity and uniform load distribution, slopes are mounted.
Usually it is
a versatile corner with kerchiefs. Places for installation of cuts (ties) must be indicated in the plan
At the final stage of piling, welding seams are painted (polymer), as well as reinforcement
insulation in the ground-air zones and reinforcement of the seams of building piles with heat-shrinkable tape. Holes at piles
are filled up
Thus, when choosing screw piles, do not forget:
Piles at corners and at intersections of axes are required;
The span must not exceed three meters;
Immersion depth not less than 1.5 meters;
“Twisted – do not twist!” – this is a 100% drawdown, it is better to finish it;
The ground-to-air zone needs reinforced insulation, even if there is no seam;
It is better to take seamless pipes for the pile shaft;
It is forbidden to use screw piles as grounding;
The pile must extend into the bearing layer by at least 50 cm;
On slopes, a horizontal stiffening disk is mandatory, vertical stiffening is performed
Pile shafts are concreted.
And one more thing – do not be too lazy to check passports and certificates for the materials used and test certificates for welded
seams. The head and shaft of the pile have a different steel structure, such seams are very capricious. After graduation
piling works bring communications and mount a box of SIP panels.
The box has already been erected, but how to close the protruding piles? This is not only a matter of aesthetics, but also protection from rain,
wind and snow. Usually two options are used:
Hanging plinth. Attached to piles and bottom timber