Insulate the soil under a heated house- an unnecessary waste of effort and money, since the cold mainly penetrates into the underground space through the base of the building. Therefore, for floor insulation wooden house First of all, it is necessary to arrange insulation of the basement part of the foundation. Then cold air will not penetrate under the floor and cool it. Please note that our ancestors in the villages did not insulate the floors, but walked around the house barefoot or in socks. This is because the houses had rubble, which were needed not only for sitting on them and husking seeds. In addition, to insulate the base, and therefore the floors, you can add soil or slag and inside foundation. This insulating bedding is made along the external walls under the floor to a width of up to one meter and a layer thickness of 250-300 mm.
During reconstruction floor insulation It must be borne in mind that the height of the underground must be at least 500 mm. Ventilation of the underground space in the summer is carried out through vents in the basement walls measuring 200-250 mm, which are located at a distance of 4000-5000 mm from each other on all sides. Wetting of the water supply pipe and the wall from it indicates that the ventilation of the underground is not at the proper height, which is why the temperature and humidity conditions in it are disturbed. And with high air humidity in the underground, moisture vapor settles in the form of condensation on cold pipe. In the cold autumn-spring period of the year, vents should be closed, or rather, plugged with a plug made of heat-insulating materials.
For wet soils, it is necessary to install a waterproofing layer in the underground, which can be made of crumpled clay, concrete, plastic film and other materials, and the surface level of this layer must not be lower than the ground level outside the building. In this case, the upper surface of the soil in the underground must be freed from the plant layer and cleared of debris.
To insulate floors, the internal space between the beams is filled with thermal insulation material, for which it is best to use non-flammable insulation based on mineral wool from glass or basalt fibers. Typically, for this purpose, products are used in the form of mats, which are laid on top of the rough flooring.
The use of polystyrene foam and similar materials on the inside of premises as insulation must be approached with caution. Almost all of them, if they do not burn, then support combustion, while emitting toxic substances, which is fraught with extreme situations death or loss of health.
Of course, you can choose something from local inexpensive materials: such as dry coarse sand, sawdust or slag. You just need to take into account that they must first be prepared: treated with an antiseptic, dried and mixed with fluff lime to protect the backfill from breeding rodents in it. In this case, it should be at least 10% of the volume of material for backfilling. The mixture is thoroughly mixed until the composition is completely homogeneous. For more even mixing organic materials with powdered lime, pour all components onto a wooden or metal board and turn over with shovels until completely mixed.
When insulating a floor structure with local materials, the subfloor is lubricated with clay lubricant with a layer thickness of 15-20 mm, onto which, after drying, dry coarse sand, sawdust or fine slag is poured to a height slightly higher than half the beams. Sand or slag is poured with a centimeter layer of liquid lime mortar, dry well and only after that the clean floor boards are laid.
When using local materials for backfill, you should pay attention to their toxicity. If these materials are not checked for toxicity, then it may turn out that you, without knowing it, are placing an environmental bomb in the structure of your home, which can subsequently affect the health of family members. To prevent this from happening, it is best to use proven insulation materials, the quality and safety of which are guaranteed by appropriate certificates.
A vapor barrier layer is laid on top of the insulation to protect it from moisture vapor. It should be noted that it is necessary to leave an air gap on top of the vapor barrier layer, and provide ventilation openings covered with grilles in the corners of the rooms. In small rooms, the holes should be in two corners diagonally, and in large rooms - in each corner. In addition, along the top of the beams, every 500-600 mm, you need to make several cuts with a depth of no more than 20 mm. This should be done to ensure free air circulation in the underground space. Instead of ventilation holes You can use special skirting boards with gratings, and leave a gap of 15-25 mm between the floorboards and the walls. In addition, this gap is necessary for soundproofing the flooring.
All wooden structures The floor is made of dry wood, the humidity of which should not exceed 18%. In addition, when installing plank floors, measures must be taken to prevent wood from becoming infected with wood-boring beetles, house fungus, rot and mold. Therefore, floorboards with back side, and the subfloor boards, lower crowns houses, beams and logs on all sides must be treated with antiseptic compounds. Available in the retail chain as ready-to-eat protective equipment, and “semi-finished products”, which should be prepared strictly according to the instructions included with the package.
Added: 05/29/2012 20:38
Discussion of the issue on the forum:
Is it possible to put insulation and waterproofing directly on the ground, and then not put anything on the floors at all? The ventilation in the underground-basement seems to be normal, but the wall near the water pipe and the water pipe itself are always wet in the summer.IN general design The extension was such that everything was done on metal posts dug in and concreted with spots in the ground. The frame and the walls themselves were attached to these columns, but there was no foundation as such. The floor used to lie there on parole - somewhere there were pieces of iron, somewhere there were pebbles, bricks were placed under the joists. More precisely, there weren’t even logs there, but they were cobbled together from what was there - somewhere a healthy beam, somewhere a wide board, somewhere completely empty and everything fell through. In general, everything has rotted for a long time and is being dismantled quietly. As it was, I don’t want to do it anyway. I haven’t decided yet which one is correct.
In general, there were two long rails and a pipe as supports. The plan is not just to lay them on the ground, but to place them on brick pillars or small areas filled with concrete. And then these platforms are somehow adjusted in height to one level by laying bricks or pieces of wood of the required thickness.
Lay these rails parallel to them, and then lay the logs across them.
Only at first I found on one site that for the floor you need timber 150 by 100, preferably, and then boards for it. And I planned to lay these bars in 1 meter increments
On another site yesterday I read about laying a plywood floor. And they write there that optimal size log 40 by 100 mm. And they are placed in increments of 40-50 cm.
Well, 40 cm may be too thick, but now I’m thinking about this option, to take thinner bars like theirs, and place them more often, in increments of 50 cm.
But they install their floors on a concrete slab. And there is support over almost the entire surface of the floor, and I have only three points - the ends of the beams on the rails, and a 4-meter round pipe in the middle, as a third point, so that the logs do not sag too much. Will such a section be enough for me, given that the distance between the points will be a little more than 2 meters?
Or don’t bother with these rails and make more columns?
How did who do it?
And the second question, since there is bare ground there, and the wind is whistling, blowing everything through, we need to somehow waterproof it.
In general, now I decided to start by pouring a small strip of “foundation” under the existing walls. It’s not very deep there down to the sand - about 20-30 centimeters deep - it’s easy to remove the layer of earth down to the sand, and cast such a narrow strip - about only 10-15 cm wide - right under the wall, so that rainwater from the street, from the roof, does not flow under the house, under this floor. And then I’ll start to think something inside. Maybe the roofing felt should be laid on the ground? Or will it be dry anyway if the cracks from the street are closed on all sides with this tape?
I need the cheapest one economical option, but also so that you don’t have to redo it in 5-10 years, and don’t regret that everything is already screwed in, the partitions are there, and you need to dismantle the floor of the house in order to redo these floors.
it blows everything away
most cheap option- lay foundation blocks and make a floor on them
think about it, if there is air exchange under the floor, is it necessary to do anything there at all....
but if you cover the vents with tape, don’t forget to make ventilation holes
the cheapest option is to lay foundation blocks and build a floor on them
Therefore, I am inclined to the option of casting these platforms on site. It will be the same concrete. I'll somehow be able to handle it with a shovel. Before this I filled in small volumes.
Well, foundation blocks are both expensive and very heavy. Here you either need equipment, or 10 healthy men who will help move them. And with delivery too headache. And no one there will really help me. Either one person will do everything, or a brother will come up for a day at most to help drag something heavy.
Therefore, I am inclined to the option of casting these platforms on site. It will be the same concrete. I'll somehow be able to handle it with a shovel. Before this I filled in small volumes.
you're not thinking about that)))
a 20*20*40 block weighs about 30 kg.
you're not thinking about that)))
a 20*20*40 block weighs about 30 kg.
And I don’t know what thickness of reinforcement to use either. I'll probably take 8 mm.
Well, if they are like that... We need to see how much they cost on average. And then I still have to cover up the joints between them. Water will flow through these joints 100 percent, and then this design will be of little use. It won't save you from the frost, only from the wind?
And the earth also has this property - it moves when it freezes and unfreezes. I think that these blocks, without their reinforcement, will rise and fall on their own. The result will be trouble, not a foundation.
I want to take long reinforcement along the length of the entire wall of the house, and put two rods of them into this strip. This way, at least she will walk entirely, and not in parts. Although I really want two rods, how many are needed, I don’t know for sure. Maybe one is enough there.
And I don’t know what thickness of reinforcement to use either. I'll probably take 8 mm.
seal the base with a flat shiver
They probably cost 50-60 rubles per piece.
I meant to use these blocks as linings for the joists, and not to lay down tape from them...
under the blocks it is natural to pre-prepare the place - remove the soil, and make a sand and gravel cushion, roofing felt on the block, and logs on the roofing felt
seal the base with a flat shiver
And with what step are the logs themselves laid?
Understood. There will be crushed stone anyway, there is sand there. We need to see how much they cost. So you can stick it in like a column, put it on the end? Or are they placed horizontally?
Well, this is not the biggest problem - I can’t find these blocks - they can be cast on site. But at what distance should we place them? If, as I planned, at the beginning, at the end of the room and in the middle, then the distance between the supports will be 4.7 in half = 2.35 meters. This is fine? Or do we need to install more of them? What cross-section should the beam be at such a distance so that it doesn’t break, and I don’t need a large supply - I don’t plan to keep elephants there. At most there will be large, heavy cabinets with all sorts of junk, and a sofa. The internal partitions will also be hanging on supports, that is, they will not be tied to the floor.
And with what step are the logs themselves laid?
but this depends primarily on what the floor will be made of and what the load will be on it...
Well, you didn’t write the floor area))
I am a supporter of using lag 50*150 every 60-70 cm.
but this depends primarily on what the floor will be made of and what the load will be on it...
It’s just that, ideally, I would make two fulcrum points and that’s it. The middle columns, after all, can also rise and fall over time from winter to summer, and the floor will either sag or bulge into a hump. Or simply the log will not rest on all points.
50 to 150... And as I understand it, they are placed edge-on? Or flat? (with the narrow part standing or lying down?) I just watched one video - they did everything the other way around. After that I was completely confused.
How many supports do you have under these joists? How long were they?
It’s just that, ideally, I would make two fulcrum points and that’s it. The middle columns, after all, can also rise and fall over time from winter to summer, and the floor will either sag or bulge into a hump. Or simply the log will not rest on all points.
room dimensions?
under each block, as I already wrote, make a pillow to minimize heaving
room dimensions?
naturally the log is placed on its side, I try to have support points every 2 meters, sometimes 1.5
under each block, as I already wrote, make a pillow to minimize heaving
The total length of the room is 4.7 meters (the logs are planned to be this long) the width is different everywhere - it starts at 5.5 meters, then narrows to 3.5
I would put 4 blocks under the log
So that's probably what I'll do.
Flat slate is of course also an option - to close the base. But I don’t know how long it will last. I've never seen anyone seal the bottom with it. And then I looked at the dimensions - 1.5 meters is the maximum length. Again, the pieces need to be put together somehow. Or overlap it in two layers so that water does not leak.
What is the best way to insulate? I read that they pour expanded clay. But minimum thickness The layer should be 10-15 centimeters. If we take my area, it comes out, according to the most conservative calculations, 5.5 * 4.7 * 0.1 = 2.5 cubic meters. 1 cube of expanded clay seems to be 1800 rubles = 4650 rubles - just pour it on the ground anywhere. It will be painfully fatty. We need to come up with something more economical and effective. The premises are planned as heated residential premises. Gas is carried there. And no one will allow the street to be flooded. (this is why I again think that slate is not a very good option)
The main thing about the logs is the height. The span length (from support to support) for 150mm is no more than 2.5 meters. Well, 3, but they will already play a little. That is, for 4.7 - two spans, three pillars (stones, curbs).
Or you can knock down two 100x150 (to save on the vertical, you can take 50x150) with the letter T upside down. According to the loads, it should be enough for 5 meters (I don’t remember exactly, I need to raise the formula, see the indicated sites). Place two supports at a distance of 4-4.2 meters (the overhang near the wall, taking into account the thickness of the pillar, will not play a role). The lower beam can just be used as a shelf for the subfloor. Place such logs at a distance of 70-80 cm (between planes). Here you can use expanded clay between the subfloor and the finishing floor.
Again, as an option, put a normal concrete strip foundation on a sand cushion just below the frame (to compensate for random movements) with a protrusion inward. And put logs 250 mm high on it (the same prefabricated ones).
There are many descriptions of flooring options, joists, foundations, etc.
You can lay 50x150 logs on the edge. Or make packages. Or "channel". Depends on the span length, available materials, floor coverings.
You can use fragments of curbs as linings. A couple of years ago there was a lot along the edge of the ravine behind Stroydepo and to the right after the cafe. People from all over the city flocked there. Accordingly, enterprising people recruited for themselves. Maybe there will be one now.
Stones under the joists can be poured directly into the level into the formwork made of boards and/or plywood using a hose with water. Well, or just make the formwork level and pour it along the edges.
The main thing about the logs is the height. The span length (from support to support) for 150mm is no more than 2.5 meters. Well, 3, but they will already play a little.
The foundation can be made from piles of flat slate and sand. About half a meter will be good. The slate here is just a limiter. Insulation - sand. Products, for example, from sewer pipe. Through two sheets of slate and sand.
If everything around is flooded with water, then without normal drainage it is all useless. We need to start with him. Either divert horizontally or drill drainage wells.
I also think so - cast the columns straight into the formwork level, so as not to have to worry too much about fitting. There was a lot of stress with the boards - all the good ones went into action, but I don’t want to leave rot in the ground, and I don’t know if there will be the required number of boards for the formwork. But the old slate taken from the roof was piled up. I think it will be suitable for formwork, so that it can be left there without removing it? I’ve just never tried sawing. I want to try sawing it to size with a grinder. Well, if it hurts, you’ll have to give up this idea.
at 30.4.2014, 15:15
Answer
3-4 vertical rods 8-12 mm in diameter. Very desirable from defrosting.
You can drill holes and stick round ventilation ducts (150mm) into them as formwork. The columns will be just a sight for sore eyes. But more expensive, of course.
Read the rules for cutting slate on the Internet. There it is necessary to wet the saw line. And there are still nuances.
Oh... I remembered, I also have an asbestos pipe. (about 20 cm in diameter) True, small. It won't be enough for many columns. But that's an idea. I saw this. Pour it into it and that’s it. But again, it probably doesn’t cut well, just like slate. We must try.
Why is there essentially fittings inside the pipe? It seems to me that it will be strong. Well, if there are any scraps left, of course I’ll put them in. And for such a small diameter, 4 rods are probably too much. One or two is enough.
So, here's the problem: We are building a wooden house from timber. House on strip foundation. We already have a roof, windows, doors, a rough floor has been made (see) with insulation and we are starting to lay the finished floor. In the spring, after the snow has melted, I notice that the boards lined from below to subfloor became damp and even became covered with mold and mildew (despite the fact that they were treated with bioprotection).
What to do in this case, if there is dampness, humidity, or even mold under the floor in a wooden house?
After looking at a bunch of sites on the Internet, talking with experienced summer residents and individual developers, I collected for myself next complex relatively simple measures to get rid of dampness under the floor. Which is what I want to write about now.
Firstly, it should be noted that there are two reasons why the floor is damp:
Moisture penetration. Water passes through the ground outside, under the foundation strip, and rises inside to the surface, hence the dampness.
By the way, I already wrote how I did it. So, the inside walls of the foundation also need to be covered with mastic for waterproofing. So that moisture does not “rise” along them.
Poor ventilation. In our normal climate, there will always be moisture (in the air, in the ground). If you do not arrange proper ventilation, then this moisture will not be removed from under the floor, hence the feeling of dampness, mold, mildew, etc.
It is to eliminating these causes (or more precisely, minimizing their influence) that you need to direct your efforts.
I will note that I have the opportunity to crawl under the floor, because... it is raised above the ground, although not very high. This just allows me to do something. The second thing I have provided is hatches in the floor through which you can go down. But what I didn’t do (but could have been done) was not removing the layer of black soil from the ground under the house, not pouring expanded clay. They say this could improve the moisture situation in the crawl space.
So, what can you do if there is dampness, moisture and mold under the floor?
The activities are listed below, but they do not have to be done in the order listed here, and some things can be omitted at all if the effect is achieved without them.
1. Place polyethylene on the ground
It is better to take thick polyethylene with a thickness of 150 microns. In theory, it should protect against the evaporation of moisture from the surface of the earth and prevent plants (if the fertile layer is not removed) from germinating. Polyethylene can be replaced with roofing felt. But crawling under the floor on roofing felt is much less comfortable. Another option is steam and waterproofing (type C or D), especially since it, as a rule, remains during the construction process.
Take polyethylene in a roll and roll it out so that it overlaps, i.e. so that the pieces overlap each other by 15-20 centimeters.
There is one more observation - moisture can not only come from below, from the soil, but also condense from moist air. As a result, puddles will appear on the polyethylene (roofing felt) that cannot go into the ground. You can get rid of them only a) by poking a hole and releasing water into the ground, b) due to normal weathering, simply put, a draft.. So covering the surface of the earth without ensuring proper ventilation (see point 3) is not very good good idea, which may even make the situation worse.
2. Get rid of mold if it appears inside under the floor
As I said, I have mold.
Trying to cover wooden surfaces something like tar did not give anything. Then I bought anti-mold (I think it was Neomid), took a Zhuk sprayer (this is one in which you pump air, and then, as if from a spray bottle, you spray everything you need under pressure - boards, trees, bushes, etc.), climbed with it under the floor and sprayed all the boards underneath.
Yes, don’t forget the respirator and even with it, control your well-being without being under the floor!
If the mold does not disappear immediately, the operation will need to be repeated. Pay attention to choosing a sprayer that is not small, but not large either - with a large one it will be more difficult to crawl. And, of course, you need to provide yourself with protective equipment - glasses, a mask. And (important) - make sure that air flows under the floor, taking breaks in time (again, see point 3.) so as not to suffocate there.
3. Provide ventilation under the floor
Make additional holes - vents in the foundation. This is key to ensuring ventilation so that moisture and dampness are removed from under the floor.
It is clear that it is necessary to provide for ventilation when pouring the foundation, in my case this was done. But it turned out not enough.
There are standards and formulas for calculating the number and area of vents; information about this can be found on the Internet.
I will note that construction crews, as a rule, do everything without taking these standards into account and, in general, it seems that they do not care about such norms and rules.
In general, in my case, the foundation was a rectangle with a wall in the middle and a part attached to it for a porch-veranda. And there were only three vents with a diameter of 110 mm.
I solved the problem simply - I invited specialists with a diamond drilling installation, who in a couple of hours added several holes in the foundation with a diameter of about 120 mm (however, the cost of each hole was about a thousand rubles).
The diagrams show what happened and what happened to the vents in the foundation.
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It should be noted that after these additions, a breath of wind was already noticeably felt under the floor. Although, now I would make even more products - I could add through holes also across the long side of the house.
4. Make a blind area
Perhaps the main step after ventilation to get rid of dampness under the floor is a blind area along the entire perimeter of the foundation. The farther we divert the water in the ground from the foundation, the less of it will pass under the foundation into the house.
If there is a lot of water and the blind area does not help, you will have to make additional irrigation ditches in the ground. The general idea is this - water from the house, from the walls, from the roof, and simply from rain along the blind area, moves away from the foundation and ends up in a specially made groove or pipe along the blind area, which can be hidden underground. And then it flows along it somewhere further to the side. Do not forget to provide the required slope for such drainage.
By the way, a blind area can be made relatively simply without pouring concrete, using a profiled membrane, this video shows how:
The next photo shows a fragment of the foundation, on which two options for closing the vents are visible (they are different, because the vents were made in different times and turned out to be different diameters), plus not yet brought to finishing blind area from the same profiled membrane:
5. "Clay Castle"
Moisture and dampness can pass under the foundation not only along the surface of the earth, but also inside, along the ground. This is especially true in cases where the site has a slope, and even the ground under the floor is below the surface level of the site. Water from rain or melting snow in the spring naturally passes under the foundation strip and rises to the surface inside the house, under the floor. As a result, the floor is damp and damp. In this case, a conventional blind area will improve the situation, but may not eliminate water completely. Irrigation ditches may seem cumbersome and difficult to install. Try the following.
To eliminate this path of moisture penetration, a so-called " clay castle" - that is, they make a barrier to water in the ground from compacted clay. If this is not done immediately before the foundation tape, then it can be done after installing the blind area. We dig a narrow ditch along the area to be strengthened, deep to the clay layer (in our territories this is usually within 50 cm) and pour the clay there, compacting it.
Instead of clay, you can use the same membrane - just install it vertically and order it. Thus, forming a wall in the top layer of soil that does not allow water to pass through.
It is clear that these activities are carried out where the soil itself consists of such parts as the upper fertile (water-permeable “black soil”) and the lower, clayey and water-impervious.
6. Make gutters
Another important point, which can significantly reduce dampness around the house (even if there is already a blind area) are gutters. If you still don’t have gutters installed on your roof, then they definitely need to be done. Then the water from the roof (and its in rainy weather a lot) will go through the gutters away from the house.
7. Protect the floorboards below from moisture using a vapor barrier
Another additional option, which I have not tried yet, allows you to protect the boards below from dampness and moisture evaporation from the ground.
This option was suggested in the store - buy a vapor barrier film (type B), for example, isospan B, and attach it to the boards from below. Thus, the boards will be protected from evaporation from the surface of the earth, will not get wet and will not become moldy.
In order to ensure ventilation, the vapor barrier must be attached with sagging, this will ensure air movement between the film and the boards.
Which side to make the film down - smooth or rough? I will say unequivocally that it does not let steam through either way. The roughness is designed to allow tiny drops of moisture to accumulate on uneven surface, collected into large drops and eventually fell back down. Thus, it is better to make the rough side down, and the smooth side towards the boards.
However, you won’t have to protect the boards from moisture if moisture doesn’t collect at all. But if all the measures have been taken, but it was not possible to completely get rid of moisture, then this point can become the last line of defense.
Note after a while: if doing a vapor barrier on the bottom of the boards is difficult and labor-intensive, don’t bother with it - it doesn’t seem to be of much use.
By the way, are the boards impregnated with bioprotection?
In theory, all your subfloor boards should have been treated with bioprotection before installation. Note that this does not prevent mold from forming on top of the boards. But if biosecurity has not been done at all, treatment must be carried out. Be sure to use a respirator and be extremely careful under the floor, staying as little as possible in the underground space.
That's probably all. It should work. If you can offer your ideas, materials and actions to get rid of dampness under the floor, send them to stroim@site for publication here.
P.S. What if nothing helps?- Try it forced ventilation. In stores that sell all kinds of fans and ventilation pipes, you can buy a fan - from the simplest one, which is placed in the bathtub at home, to more powerful ones. You can try the simplest one, but it will be of little use (although for small areas the effect will also be noticeable after a day or two of work). Insert the fan into the hole in the foundation from the inside so that it draws air out, make an extension cord and run it for a long time. Can also be placed underground heat gun and try to dry it with it. It is clear that you will not turn it on all the time, only temporarily and not forgetting about electrical safety in a damp room.
P.P.S Once again I would like to draw your attention to the fact that it is worth installing hatches in the house when building the floor. And in such quantities that you can climb through them into the desired part of the room. However, remember that in winter these hatches will require insulation, so do not overdo it.
Initially, due to its physical properties, the soil under the floor of any building is a constant source of moisture. With slight deepening it is dry appearance the underground soil “opens up” moisture and bad smell rotten. Everyone negative impacts damage caused to structures and people from a damp underground will not be described in this article. Let's look at how you can deal with moisture under the floors of buildings.
What are the sources of excess dampness and moisture?
The first way
In the absence of a good blind area ( cement-sand mixture, asphalt concrete mixture on hot bitumen), water from the roof of the structure will certainly begin to accumulate under the floor through foundation cracks.
The height of water rise through capillaries (cracks in foundations) is from 300 mm to 500 mm, which forces vertical insulation (a layer of roofing material is glued with hot mastic to the wall of the house and to cement screed before laying the outer part of the blind area, at an angle of 90 degrees). Later you will finish the plinth decorative materials, and the roofing material will remain inside, as your insurance against external water.
The second way
Groundwater is located high. Especially in the autumn and spring periods. The movement of water will be along the path of least resistance, namely towards your floor. The solution is additional drainage (see below).
Properly carried out drainage work, along with joint landscaping storm system, are guaranteed to ensure the absence of moisture not only in the underground and in the house, but also in the adjacent area, which in turn has a beneficial effect on the lawn, shrubs and trees.
The third way
Warm and humid air penetrates through the vents into the underground. On cold walls it condenses and settles in the form of dew.
In a dysfunctional underground, humidity can reach 80 percent. However, humidity up to 50 percent is considered normal, and 30-50 percent is ideal.
The problem of damp underground is solved as follows
First way
Sealing foundation walls from the inside. Additional high-quality concreting followed by gluing the walls and floor of the underground with polyethylene reinforced film. The main difficulty in performing such work is sealing the film joints until they are airtight, especially in the corners. It is necessary to use special sealants and mastics. The film is secured to the top of the wall using plastic dowels.
To protect against mechanical damage An additional layer of concrete is placed on top of the film. Of course, doing this on the floor is easy, but you will have to tinker when placing the film on the walls. It is possible that concrete will not hold up over a large area of walls, in which case they are covered with bricks in one row or protected with plastic sheets.
Second way
Creating effective ventilation. If supply and exhaust ventilation does not cope with its functions, a forced one is installed.
However, it is still desirable for natural supply and exhaust ventilation to work.
An influx will flow through the vents fresh air, and exit through a pipe of quite impressive diameter (up to 0.5 m). Moreover, the bottom of the pipe, which acts as an exhaust hood, should start almost from the bottom of the underground, thus, the cold air located below will tend to rise.
Under bottom part exhaust pipe, you can install a lit candle under the exhaust pipe for some time. The heat created by the candles will be enough to speed up air exchange by creating additional draft. Thus, the underground can be dried relatively quickly.
Third way
Performing drainage groundwater. To perform such foundation drainage, grooves are made along the perimeter of the underground foundation at a slope towards one of the corners of the building. Water through a pipe from this corner enters a sealed drainage well located outside the house. From time to time, water from the well will have to be pumped out.
Fourth method
Option at your discretion. During the cold season, close the vents with foam plastic plugs.
The point is that the outside warm air can contain much more moisture than cold.
As a result, it creates additional dampness due to condensation on the underground walls.
Disadvantages of this method: what to do in case of sudden temperature changes?
In the underground, as a result of the lack of ventilation, the processes of mold formation and rotting can be significantly activated. However, this method is worth a try because it is very easy to implement.
Fifth method
The easiest, but quite effective way eliminating dampness in places where it is impossible to reach - cover the ground under the floor of the building with one of the waterproofing materials: plastic film, roofing felt, etc. However, it is better to do this during the construction period, before starting the subfloor. Or tear up and re-lay the floors. Moisture will not be able to rise up from the ground, which means it will not penetrate through the waterproofing material. Press down the film in several places. So that the film cannot move for any reason (omnipresent moles, drafts through vents, etc.).
It should be noted that there are other methods of dealing with dampness in the underground. We hope that the options described will give you some ideas and help you solve the problems of combating high humidity under the floor of your home!
Waterproofing is necessary for any structure. Moisture entering the room can render the wooden parts of the house unusable, promote the appearance of fungi and the proliferation of microorganisms and insects. All this can lead to health problems, destruction of parts of the house and cause the need for unscheduled repairs and even partial reconstruction of the entire house. Waterproofing is especially important, including waterproofing the floor on the ground in houses built in areas where there is a significant amount of groundwater.
Purpose
Groundwater is found in almost all regions of our country and in all climatic zones. Even in the driest areas, the soil contains moisture. The only difference is at what depth it is located. The depth of its occurrence is called the groundwater level (GWL). Based on the height of their occurrence, the following levels are distinguished:
- high – depth up to two meters from the surface of the earth;
- low - more than two meters.
At any water level, moisture will gradually rise from the soil to the surface through the capillaries present in any soil. According to the laws of physics, the height of water rising in capillaries can reach 12 m. This is enough not only to moisten the walls, but also to completely flood some rooms. It should also be taken into account that the construction of a house will necessarily raise the groundwater level in the construction zone, again, according to the laws of physics. There are often cases when residents of private houses, who have lived in dryness and comfort for many decades, suddenly find their basements flooded immediately after the construction of a multi-story building nearby.
Physics also explains a paradoxical, at first glance, phenomenon - the denser the soil, the better the water rises. This is explained by the fact that the pores in such soil are thin and narrow, and this causes greater liquid pressure in them and, consequently, a higher rate of moisture rise.
The higher the GWL, the greater the likelihood of moisture getting from the ground into the room, the more serious the waterproofing should be. From capillaries in the soil, water enters the capillaries of the foundation concrete or the pores of other building materials with all the ensuing (literally) consequences. Moisture getting into the pores of the walls is fraught with another problem - when freezing, the water expands, which leads to cracks and destruction of the walls or foundation.
Device
For proper waterproofing, it will not be enough to simply lay a sheet of roofing felt under the covering. Waterproofing on the ground under the house is a complex multi-layer structure.
The main layers of waterproofing are:
- The soil is as compacted and compacted as possible. This must be done to level the surface for the next layers;
- Crushed stone about ten centimeters thick;
- Sand is a layer of the same thickness.
It is better to compact the last two layers thoroughly. They are the first serious obstacle to moisture.
The remaining layers must be made depending on the groundwater level:
- Waterproofing - you can use rolled bitumen materials, bitumen mastic;
- Concrete screed – a layer of reinforced concrete 4-5 cm thick;
- Vapor barrier - you can also use bitumen roll material based on fiberglass;
- Thermal insulation - polystyrene or foam.
The final layer is another reinforced concrete screed, on which the coating can be laid. However, as already mentioned, the presence of these layers depends on the groundwater level under the house.
Low groundwater level
If the groundwater level is low, this may be enough to prevent moisture from entering the lower areas of the house. In this case, they do this: a layer of dry clay is placed on the bedding, which is also carefully compacted. Recently, instead of clay, a coating has appeared on sale in the form of two thin layers of mineral fiber and a layer of dry clay between them. However, this material was not received widespread due to some problems during its installation.
The next layer is concrete screed. The screed is reinforced using a special mesh. After the screed has dried, a layer of bitumen mastic is applied to it, which serves not only as an independent waterproofing material, but also as an adhesive base for laying roofing felt sheets.
High groundwater level
Depending on the height of the groundwater level, it is used various ways waterproofing:
- At a level of twenty centimeters or less, the foundation walls are covered bitumen mastic. A layer of clay 10 cm thick is laid under the concrete screed;
- If the ground level is from twenty centimeters to half a meter, two layers of rolled bitumen material are laid on the concrete screed. On top is another concrete screed;
- At a level of more than fifty centimeters, waterproofing must be made of three layers of rolled material. A concrete slab must be laid on top. The joints between the slab and the walls are insulated with polymer tape coated with bitumen.
Polystyrene foam or extruded polystyrene foam is used as insulation. Considering the fragility of these materials, as well as the fact that a concrete screed will be laid on top of them, the insulation layer is covered with plastic film. This must be done to avoid damage to the material during installation and during operation.
Some craftsmen prefer to use fiberglass mats as insulation. However, laying concrete can cause the fiberglass layers to shrink, causing the wadding to lose its properties. thermal insulation properties, and its moisture resistance will decrease.
Foundation waterproofing
To ensure the most effective insulation of the entire structure from moisture, it is better to waterproof the foundation at the stage of its construction.
Distinguish the following types foundation waterproofing:
- vertical – treatment of foundation walls with waterproofing materials;
- horizontal - includes the creation of a drainage system, as well as the laying of waterproofing materials between the tape and the foundation walls.
Drainage system
Drainage system must be done if the groundwater level is at the foundation level or higher. It is also needed when groundwater accumulates due to poor permeability of the soil under the house.
The drainage system takes the form of a trench about thirty centimeters wide and deep, dug along the perimeter of the foundation at a distance of about a meter from its walls.
The bottom of this ditch is covered with a layer of geotextile, the width of which is equal to the perimeter of the trench walls. A five-centimeter layer of gravel is laid on top of the fabric. Then a special asbestos pipe is placed there to drain groundwater. It is covered with gravel on top and everything is wrapped in the edges of geotextile. Last stage– the trench is covered with earth.
Vertical insulation
Treating the foundation walls is necessary to prevent moisture from penetrating into the room through the foundation walls. For this, the following materials are used:
- bitumen mastic - applied to walls, can be used either independently or as an intermediate layer;
- roll roofing materials– roofing felt or roofing felt;
- dry construction mixtures - plaster.
Bitumen mastic is made from petroleum bitumen with the addition of plasticizers and fillers. It fills the pores of the material from which the foundation walls are built and prevents moisture from penetrating through them into the room. For the best effect, the mastic is applied in two to four layers. The advantages of this method include:
- ease of application– applied using simple painting tools;
- efficiency - the method reliably protects the room from moisture;
- versatility– can be used as independent waterproofing, or before laying other materials, for example, roofing felt;
- cost – one of the cheapest insulating materials.
Flaws:
- quick drying– requires high speed of work, hot applied mastic must be applied immediately before work;
- fragility– every few years it is necessary to make a new layer.
Rolled materials are used for laying between walls and the foundation strip, as well as for application to walls.
The advantages of the method include:
- accessibility - a wide range of such materials includes many various types waterproofing in various price categories;
- durability - service life reaches fifty years.
As disadvantages, it is worth noting installation problems roll materials on vertical surfaces. This requires treating the walls with other materials, for example, the same mastic, as well as the availability of special tools and skills for carrying out such work.
Dry mixes
Dry mixtures are one of the most common types of waterproofing. It not only promotes waterproofing, but also levels the walls before applying other coatings.
It has the following advantages.