Foundation for a bathhouse with a drain on screw piles: how to make it and what to consider

January 25, 2020 Stroyexpert Home page » Foundation » By construction project

Water drainage and bathhouse foundation

The main purpose of the foundation is the strength and reliability of the structure. Therefore, the foundation itself must meet similar requirements. However, during operation, drainage water can have a destructive effect on the structure. Therefore, the base of the bath and the drainage of water must be interconnected. Therefore, the foundation for a bathhouse with a drain must be carefully planned.

Do-it-yourself sewerage in the bathhouse

The construction of the bathhouse itself requires certain skills and knowledge. But you can still make a foundation for it and improve the structure yourself. Even if you purchased a plot of land where there is a bathhouse, but the water is drained in an unorganized way, you can make a bathhouse with a sewer yourself. A water drainage system can be arranged using modern materials that will collect and drain water from the building.

If you are just starting to build your own bathhouse, then this method will certainly allow you to save a lot of money. With a fairly simple process of installing a water drainage system. The whole process consists of installing a plastic base that will be mounted into the floor. If it is quite problematic to find a plastic sheet in stores, then you can use a regular membrane used for artificial reservoirs. It has a number of undeniable advantages:

quite thin and durable;
waterproof;
easy to solder or glue;
withstands large temperature differences;
easy to install;
is an environmentally friendly material.

Types of foundations for a bathhouse and their advantages

You can build any type of foundation for a bathhouse, each of them has its own positive aspects:

Various foundations for a bath

Strip foundation is the most common foundation. It is popular due to its ease of construction and durability. Can be built on almost any soil. The deficiencies of the soil are compensated by the depth of the foundation.
A monolithic slab base can be erected anywhere, as it is not subject to swelling.
A column foundation is a more economical option compared to a strip foundation. Can be used on sloped areas. Such a foundation makes it possible to organize the drainage of water from the bathhouse at later stages of foundation construction.
A pile-screw foundation is similar to a columnar foundation, but is more durable and reliable. In addition, a pile foundation is an excellent solution for areas with large differences in height.

Direct work

In addition to PVC film, a plastic ladder is also needed. The hole in the floor should be slightly larger than the diameter of the ladder, since a film 1 mm thick will be placed around it. The ladder should be installed in the corner of the room, at the lowest point of the floor slope.

Using a jigsaw or other tool, a through hole is cut in the floor. All ends of the boards obtained as a result of sawing must be treated with a special septic tank for wood, which protects them from rotting.

When installing the ladder, pay special attention to ensure that it does not protrude above the floor, since wooden gratings will be installed on top for people to walk on.

When the hole in the floor is cut, and after pre-installing the drain you have made sure that it does not protrude above the surface, you can begin laying the film or membrane.

The ladder is directly attached to the top. The places where it comes into contact with the film should be generously coated with sealant for plumbing work. In order for the sewer pipe to be securely fixed, under the floor it is securely attached to the base or joists of the floor itself.

Of course, the film will have to be changed. But this method is quite simple and economical to use, and it will only have to be changed after 2-3 years. The sewer pipe that runs under the floor must be insulated with special materials.

Be sure to take into account the length of the sewer pipe itself. It should pass under the bottom edge of the foundation and drain water into a drain or septic tank. Ideally, the distance from the bathhouse to the sewer should be about three meters.

Foundation for a bathhouse with a pouring floor

The contact of the base with water depends on the type of floor. A regular pouring floor allows water to pass underneath and contributes to the foundation getting wet. This option is more correct to use where the upper layers of the soil do not have a serious impact on the strength of the foundation - screw piles, strip stone or block .

To avoid exposure to water, it is better to equip a drain - seal the floor with water drainage into a special container. In this case, any foundation for a bathhouse with a pouring floor can be used; other factors will influence the choice. We recommend that you familiarize yourself with three factors that influence the choice of foundation.

When installing a pouring floor, waste water is removed through cracks in the floor.

Holes in the foundation for sewerage

Often, when installing a sewer system, the owner of a bathhouse is faced with one main problem - how to route the pipes through the foundation. There are few ways:

Drill holes in the foundation for the sewer pipes and run them through them.
Direct laying of sewerage under the foundation.

It seems that it is easiest to arrange holes for pipes at the initial stage of constructing the foundation, but as practice has shown, this option is not always feasible. This is often due to the fact that the planned size of the holes ultimately does not correspond to the specified parameters.

There may be several reasons for this:

the quality of materials used for the construction of the foundation;
loose soil or its shrinkage;
changes in the project during installation work;
errors in the design or construction of the foundation itself.

Therefore, most experts still recommend drilling holes in a ready-made foundation. But here too many difficulties arise. Strong concrete is not easy to drill. In addition, such work should be carried out with the utmost caution, since any crack that appears in the foundation during the work will render it unusable.

Holes in the foundation for sewerage are made using tools such as a hammer drill, an impact drill, a diamond-coated drill and a hammer. It should immediately be noted that this process is quite labor-intensive. When carrying out work, the tool may rest not only on stones, but also on reinforcement.

What foundation for building a bathhouse will be optimal?

There are several basic options for bases for baths, with which you can make a high-quality drainage of wastewater with your own hands without compromising the integrity of the structure as a whole.

It is important to know which effluents will dominate the drain. And if a sewer system is not provided, then a columnar or screw foundation on piles is perfect for such purposes.

Its production takes little time, it is relatively inexpensive and is durable. And the most important thing is that you can do it yourself without the use of special construction equipment in limited areas of the construction site.

Advice from professionals

Before starting work, especially when it will be carried out in a structure that has been in operation for several years, be sure to make sure that there are no hidden water pipes or wiring in the foundation structure.
While drilling, do not forget to cool the drill and tool. Check it for chips, dents or scratches.

Regarding the size of the holes, the following requirements must be met:

The diameter of the finished hole must be at least 50 mm larger than the diameter of the sewer pipe, or more.
To reduce the load resulting from pressure from water pressure. It is advisable to mount the transition unit at the junction of the vertical and horizontal pipes.
Considering that over time the bathhouse may shrink. It is advisable to place sewer pipes in metal sleeves provided in such cases. The space between the walls of the sleeve and the pipe is filled with heat-insulating materials.

Sewage through the foundation, installed correctly, will be the key to comfortable use of the bathhouse.

Technology for constructing a screw foundation for a bathhouse with a drain on metal piles

Calculation of permissible loads on the base of the bathhouse, selection of the type and size of screw piles;
Marking the construction site, choosing the location for installing piles;
Preparing the trench for reinforcement and pouring concrete;
Installation of screw piles in accordance with building codes;
Leveling the structure horizontally, further reinforcement;
Insulation of the main foundation along the outer perimeter;
Installation of sewer pipes, their insulation;
Creation of a second floor inclined towards a larger angle of wastewater discharge or under the formed entrance to the sewer pipe;
Pouring the main floor.

Bathhouse on screw piles.
For small compact baths, which are made on site from wood or logs, a screw foundation on piles is the optimal solution. Its production takes several days, you can do it yourself, and there will be no subsidence of the foundation due to the small loads on the supporting structures. But when installing a screw pile foundation, you must strictly adhere to the technology and prevent the piles from moving vertically in different directions.

Sewerage inside the foundation

To avoid problems and the labor-intensive process of draining sewerage through the foundation or under it, you can lay pipes directly into the foundation itself at the stage of its construction.

Laying the sewerage system in the foundation must be done at a depth below the freezing level of the soil. Sewer pipes are firmly fixed during the process of reinforcing the future base of the bathhouse and are securely attached to the fittings themselves. It is important to fix the position of the pipes as accurately as possible and ensure complete sealing of the joints, since once the concrete is poured into the formwork, nothing can be corrected.

The sewage system must be discharged from the foundation either into a central system, or if there is none, then into a septic tank. Of course, it is often irrational to remove wastewater from a bathhouse through the general sewer system of a house due to the long length of the route. Therefore, it is quite advisable to install a small septic tank.

Despite the fact that wastewater from a bathhouse does not cause any harm to nature and the environment, since it mainly contains flavorings. contained in shampoos or shower gels, the use of septic tanks or cesspools without a bottom is prohibited.

The easiest way is to purchase a plastic container and simply dig it into the ground, connecting it to a drain pipe. This method does not require the installation of additional treatment facilities, but it will have to be freed from wastewater that will accumulate during the operation of the bathhouse. To do this, specialized equipment is called in to pump out the waste. The cost of service will depend on the company's prices.

Positive and negative sides of the “barrel” foundation

One of the advantages of the technology of constructing a foundation from metal barrels filled with concrete is the needlessness of constructing formwork. Firstly, this significantly saves time, and secondly, it does not require special qualifications of workers. But, unfortunately, there are many more disadvantages to this type of work. In particular, they relate to the effectiveness of the method used.

Few households have the number of 200-liter or other metal barrels needed to construct a foundation, so they will have to be purchased. Such a purchase can be much more expensive than the cost of boards, fasteners and other materials necessary for installing the formwork. Also, in most cases, it is irrational to overuse concrete when filling the required volume of metal shells, especially in the case when it is necessary to deepen the foundation by more than a meter due to the low freezing horizon of the soil. In this case, you will have to install not one, but two barrels in height. Although, under small structures with deep groundwater, it is often practiced to install a sand cushion instead of additional deepening, and on rocky soils the barrels are left directly on the surface.

Difficult clay soils and high groundwater levels require laying the foundation below the freezing level, otherwise the swelling forces may be higher than the foundation pressure, which will lead to the lifting of the barrels and distortion of the structure.

It is also necessary to understand that moisture-saturated soils after thawing often cause changes in the location and subsidence of metal foundation pillars if the deepening, backfilling or sand cushion was carried out incorrectly.

Preliminary work

Before you start pouring the foundation, be sure to take into account the soil characteristics of the area chosen for the bathhouse. For this, the services of a surveyor, of course, will not be required, but the soil should be examined. This will help you quickly decide on the most acceptable type of foundation:

soil containing clay, gravel or coarse sand is suitable for building a strip/column frame;
light heaving soil will best “accept” a strip foundation (be sure to add a sand cushion to it);
Any foundation can be placed on quartz soil or soil with fine sand.

Advice. To ensure a strong and durable foundation, consider the likelihood of landslides and ground subsidence. It is important to correctly calculate the required foundation depth.

Make the area selected for the frame for the bathhouse slightly inclined to ensure sufficient drainage for natural waters. Level the surface of the area and remove the surface layer of soil. Make markings using pegs and cord. Keep in mind that the width of the wall of the future bathhouse building should be 10 cm greater than the width of the foundation.

There are several types of foundations with a drain. Most often, everything depends on the financial capabilities of the owner of the future bathhouse, on changes in height and type of soil (as mentioned earlier). Let's look at them in more detail.

Right choice

Depending on the soil, the foundation for a bathhouse with a drain can be selected based on several criteria.

Firstly, this will ensure the stability and durability of the building, and secondly, its functionality and level of comfortable stay in the steam room. Which foundation would be the right choice regarding the soil bedding:

Peat soils require a slab structure. They are expensive, but provide maximum stability of the bath.
Sandy and sandy loam surfaces. Columnar or prefabricated foundations can be used. Such soils have a high level of moisture drainage, so any type of foundation will be justified. Moisture will not stagnate at any level, so it will not cause damage to the base.
Heavy soils with lamellar clay require pile structures with a grillage that will protect them from the effects of low temperatures in winter.

Foundation for a bathhouse - a barrel for beginners

The barrel bath can be placed on various bases.

In practice we have found application:

"Sand Pillow" When installing it, a mixture consisting of sand and crushed stone is poured and thoroughly compacted;

Paving slabs. Suitable base for level ground. If the landscape cannot be called ideal, the area is first leveled, compacted, and then tiles are laid. The base is a layer of sand or concrete screed;

Monolithic foundation. Is an expensive option. Involves concreting or asphalting the site on which the barrel bath will be located;

Wooden shield. It is used primarily to level the site, and at the same time becomes the basis for the building;

Wooden beams or metal channels. They are laid along the building being installed;

Columnar foundation or concrete pedestals. A suitable option for doing DIY work. Not the best solution for loose soil or wetlands.

The choice of the appropriate option is made taking into account various factors.

Columnar foundation

This type of foundation is not inferior to the first in strength and quality, but will cost less. It is undesirable to use such a foundation only on heaving soil.

Advice. A columnar foundation is not intended for massive walls, so you should not build heavy foundations for a bathhouse on top of it.

There are many options for installing a columnar foundation; they have only one thing in common - markings for installing future supports.

Laying technology

Since it is quite difficult to talk about all the installation options for this foundation, we will focus on the simplest possible diagram:

Columnar foundation

we make marks in the corners of the bathhouse for the location of future pillars (the distance between them should not exceed 2 meters);
We drill in the marked places a well one and a half meters deep with a diameter of about 25 cm.
we insert asbestos cement pipes (diameter about 20 cm) into the wells, having previously wrapped them with roofing felt;
we fill the space around the pipe with tightly compacted earth;
pour 1/3 of the concrete solution into the pipes and raise them a little so that the mixture gets to the bottom;
add the solution, leaving about 150 mm to the top edge of the pipes;
insert the reinforcing bars and add the remaining solution to the top;
we lay a brick wall between the pipes, deepening it into the soil by 25 cm;
cover the entire surface with cement mortar. After it has dried slightly, we cover the foundation with a waterproofing layer.

Selection of drainage system

If the bathhouse will have a toilet (brown drain), a septic filter or VOC is required; if there is no bathroom, gravel filtration (gray drain) is sufficient.

To install a sewer system, it is best to use special pipes with a diameter of 11 cm for a septic tank and 5 cm for a gravel filter.

When using only gray drains (no brown ones), you can use a standard flat drain. Thus, from a washing compartment with a sloping sealed subfloor, water will be removed directly into the gravel drain.

Previously, the “gray” drain was carried out immediately behind the bathhouse, but according to the latest Sanitary Regulations, such water requires gravel purification or passing through alkaline filtration.

Barrel foundation

Question:

How to install tackles on a foundation made of “barrels”?

Vitaly, Perm.

Answer:

Hello, Vitaly from Perm!

Your question is formulated incorrectly. And I can only guess about its essence.

Some smart head realized that instead of making normal types of foundations, you can use ordinary metal barrels of standard sizes (about 0.6 meters in diameter and about 0.85 meters in height). The capacity of the barrels is 200 liters, the thickness of the walls is made of steel up to 1 millimeter thick. /This is the most common type, although others are occasionally used/.

The lid of such a barrel is removed if it is removable, or it is cut off if it is welded. Sometimes the bottom is also removed. The result is a shell, which is installed in the place of support of a house, bathhouse, or other buildings. Depending on the size of the structure, there are from 4 to two dozen or more such support points. Then concrete is poured into the shells (essentially formwork). Sometimes it is butted and reinforced. Waterproofing (usually roofing material) is laid in two layers on the upper plane. To separate the foundation material from the wall material and prevent further penetration of moisture from the soil.

As a result, point supports are obtained for the lower rim or reinforced grillage belt for the construction of frame walls. Let me make a reservation right away that there may be many options different from what has been said.

The shells of the barrels can be buried to the extent that the soil freezes, or they can be installed directly on the surface of the earth, with a compensation cushion made from a layer of sand more than 10 centimeters thick underneath.

What are the pros and cons of these barrel foundations?

One undoubted advantage is that you do not have to bother with the construction of formwork for point supports of the foundation. Because formwork often requires boards, other materials, fasteners, tools and a lot of time to construct it. And so - I brought the barrels, installed them, poured concrete and everything was ready.

But there are a lot of disadvantages, and the main one is that a lot of concrete is wasted. Judge for yourself, what is the cubic capacity of the required material to fill a 200 liter barrel? Extremely ineffective. What if you are worthy of building where the depth of soil freezing is more than a meter? And do you want to comply with the deepening of the foundation recommended by the designers and still leave half a meter of the base above the ground? Then you will have to use two barrels stacked on top of each other. Material consumption doubles.

But be that as it may, examples of such construction are practiced and most often the barrels are not buried, but simply a layer of sand is poured under their shells and filled with rubble concrete without reinforcement. Basically, this is used for the construction of the same baths and other not very large structures with an area of less than 40 square meters.

Depending on the moisture saturation of the soil in the spring, all sorts of nuances are possible in the form of changes in the position of the “barrels”.

And now to the essence of the question, because I only voiced the topic of the foundation from “barrels”, and not what you are asking.

So, tackles on the foundation made of barrels. When you say tackles, you probably meant one of two things.

First. A device for dragging logs or wall beams onto foundation “barrels”. Since they can have a length of 6 meters and a large cross-section. To haul such large items, log assemblers use a device in the form of two long logs laid at an angle on supports (your barrels). Two ropes with hooks are thrown onto the log (beam) being dragged in and it is pulled up along the inclined logs. Nothing more is required except strength and agility. And so that the worker who hooks the hooks below does not “open his mitten” and can jump to the side if the log flies down from the height of the thirteenth crown.

Second. If, more than expected, by the concept of tackles you mean a trivial blind area around the perimeter around your bathhouse, then it is usually constructed. That is, you outline the external and internal contours of the blind area (edged boards are usually used to limit it so that the material of the blind area does not extend beyond its dimensions).

The inner line usually runs along the centers of the barrels, and the outer line at a distance of about 0.6 meters from their outer surface. Then you dig the soil on the bayonet of a shovel, remove it, pour a layer of sand about 0.1 meters thick, then you can pour a layer of crushed stone in a layer of two to three centimeters, lay down a welded mesh for reinforcement. Every couple of meters there are wooden slats (temperature compensation gap, which in the future should not allow the screed to burst).

Then a layer of concrete screed about 4 - 5 centimeters thick is laid. Everything is leveled and ironed.

It is mandatory to maintain a slope away from the building (approximately 1/10, that is, for one linear meter of the width of the blind area, the difference in its height should be 0.1 meters).

Sometimes waterproofing made of roofing felt or its analogues is laid under a layer of sand, also sloping away from the building. But I don’t think that this technique is used by clients who build foundations from barrels; it turns out to be quite expensive.

And lastly, if you did mean something else by the word tackles, then formulate the question more clearly and in detail. Otherwise the answer cannot be guaranteed.

Good luck!