The question arose about attaching the Mauerlat board to the wall. Yesterday I got the idea to drill holes vertically in finished wall to a height of 3 blocks (750 mm), take reinforcement for 10, pour mortar into the holes and drown the reinforcement in them, and weld studs to the top of the reinforcement, and so on after a meter. The question is: will such a unique anchor hold it? It looks very tempting and technologically advanced...
Is an armored belt needed on the Mauerlat?
A reinforced concrete armored belt should be placed on top of the wall for seismic resistance. And studs are inserted into it to secure the Mauerlat.My house is also made of gas silicate blocks, the walls are 30 cm thick, I made an armored belt 20 by 20 cm, and another 10 cm of block so that there is no cold bridge.
The weight of the armored belt is quite sufficient. And it’s not just laid on top of the wall, but poured directly onto the wall, i.e. cemented to the top row of the wall. Those. As a result, the weight of the armored belt + the weight of the top row will be more than your three rows of blocks.
And the armored belt at the same time solves another problem - it distributes the weight of the ceiling beams. Beams cannot be rested directly on blocks.
***I plan to fasten the rafters and beams to the mauerlat using screws and metal corners - there are a lot of different ones on sale now. wire is somehow rude and unaesthetic.
That’s how I attached it, but I couldn’t find ready-made corners, I sawed it myself from a regular 50x50 corner, drilled holes, and used screws...
Dual use of materials
50 boards for straps and ceiling beams, and made forests out of them.
Yes, there is a board, but I’m too lazy to fence... There are 2 and a half rows left... They gave me rental sawhorses welded from rebar, so I use them... I’m just too lazy to move sometimes!
And what, there is no basement or attic in the house and there won’t be?
I have a base 1 m above the ground, + walls 3 m, and + in the attic around the entire perimeter 1.2 m. That is. full-fledged forests were needed.
And you still need to fill the armored belt around the entire perimeter...
So that the roof doesn't blow off
Regarding “so that the roof is not blown off by the wind,” there is another technique - the straps are tied with good wire to the crutches driven into the third row of walls from the top. Without such a wire connection, it is necessary to solve the problem of firmly attaching the straps to the Mauerlat.
Raise the walls another six blocks and create an attic
If yes, then it’s not too late for you to raise 6 more rows of blocks and very inexpensively double the area of the house using a full-size attic. This is exactly how I did it. Moreover, it is not necessary to finish the attic right away; you can leave it for later, as a spare floor, when you have the money and desire for it.
Construction Chronicle
seal
waterproofing
Mauerlat, impregnated with fire-bioprotection and tightened with studs - I will attach beams and rafters to it.
Opinion 1:
On my house the mauerlat is mounted, with the edge close to the outer wall... And will you let it out like a strap, placing the mauerlat against the inner wall?
And you will let it out like a strap-on, placing the Mauerlat to interior wall? The straps will be attached to the beams, the beams will stick out from the outside of the house.
Why weren’t the studs embedded in the concrete of the reinforced belt in the center and placed at the very edge of the concrete?
The studs are welded to the reinforcement at 12, and it sits on the glue in a hole 75 cm deep (3 blocks). I think there is no way to turn it out - I added additional cement to the glue.
Question:
why not put the beams on the belt?
Answer:
What to fasten it with? And the Mauerlat acts as a load distributor over the entire area of the wall... something like this.
Opinion:
Mauerlat close to external wall, and attach the straps to it.
Answer:
I don’t think this is good. We look at the loads from the rafters - the rafters tend to stretch the house, that’s why they rest on a beam, which takes the load down and to the side... If you lean it on the wall, you can break the wall in winter with snow - there were already precedents... .
But if you install a central purlin, the snow pressure will act differently:
Accordingly, the load inside will be held by the partitions.
Load distribution
Then the load will be on supporting surface, otherwise - as in the photo - the entire load is on the fastening and it will simply turn out if you add screws, but without screws it will just be loose. And the beam and rafters can simply split.
Truss placement
It would be better to connect the farms like this:
I intentionally left gaps so that it would be clear how to connect the elements of the truss. It is better to place the rafter leg on top, as shown in my drawing, and not on the side, as in your photo.
Opinion about straps
My straps are attached to the mauerlat and rest on it with a sawed-off piece, then going out - but approximately in the middle of the straps in height, there is a tightening, i.e. a horizontal board that connects opposite rafters to each other and prevents them from moving apart. And the Mauerlat lies on a full-fledged 20*20 armored belt with 4 reinforcement bars inside, you can’t squeeze it out with snow...
But in the first house, it was done like this: a mauerlat, ceiling beams on it, another board across the beams on them, and the straps rest on this top board. Those. almost like in your drawing, only one more board has been added across the top.
Corners and strips for fastening rafters
I bought a gentleman’s set and had to run around the market, but it cost about 3 thousand rubles in total for hardware for the entire roof; I saved a lot.
I laid out the rafters and the beam on the ground, sawed everything, twisted it, then untwisted it - now half the beams and rafters have become templates, according to which I sawed the blanks, with drilled holes - just screw them on the roof, no adjustments, everything should match. I started installing the beams, by the evening I screwed half of them ! I'll try to install the rafters tomorrow. Something quickly...
In the places where I indicated with arrows, fasten with self-tapping screws, otherwise the strap will slide!
The joint must be insulated and insulation must also be placed under the beams, otherwise the heat will escape, as in the photo:
The first rafter went up this evening!
And yet I would connect the rafters to the beam like this:
By slings
There will be vertical supports - so I think everything is fine...
Why spend money on wind and moisture insulation?
Yes for the future.
And don’t forget to nail the rear rails on top of the film!
I want to stretch the film over the bare rafters, then lathing and ondulin, so as not to hit the extra slats.
So I thought, maybe I could use long screws to tighten it up additionally after adjusting the straps?
may crack... I would better lane I cut it out of tin... it could be doubled for strength and I would tighten the sides with short screws... it would be much stronger
But the weight of the roof + the weight of wet snow will not withstand this method of joining.
I think it's easy! I have rafters 150 tons by 50 and a beam 180 by 50 - the margin is higher than the roof - with this section they make houses 10 by 10 and everything holds together, and it’s nailed down at random - I saw it myself
They make 10 by 10 houses with this cross-section and everything stays together, nailed together haphazardly - I saw it myself
And you didn’t look closely, the rafters on the mauerlat/beams are there on top, or stuck to the side like yours, i.e. Is there a risk of sliding down under load?
It is necessary that the rafter is at least a third of its thickness, standing firmly on the mauerlat/beam, so that it does not have the opportunity to slide even a centimeter.
Unfortunately, your method of fastening does not have the necessary rigidity...
Maybe you can change the attachment point of the rafters to the beams?
Or at least put vertical supports from the beam to the rafter, about 1 meter from the edge (these supports will also serve as the frame for the side wall of the attic), and make a groove in the rafter under this support - so that the rafter rests rigidly on it?
Saving on sheathing
Builder: I want to stretch the film over the bare rafters, then the sheathing and ondulin, so as not to hit the extra slats
And the sheathing will touch the film, but this is not permissible - the vent must remain. gap!
Strengthening the buckley-rafter assembly
I strengthened the connection beam-rafter with huge screws and self-tapping screws 200 mm long - it holds tightly. The frame is almost ready for film - I bought Ondutis A 100 membrane, tomorrow I will start covering the film. They promise to deliver Ondulin tomorrow evening - I bought 70 sheets according to the calculation using a special program http:// ondulineroof
Ondulin was purchased at a price of 375 rubles per sheet from Lera Merlin (nails are included, but I’m inclined to use self-tapping screws)
Rafters
I advise you to tighten the straps with a crossbar like the letter “A”, at least from an inch, approximately between the third sheathing boards from the top.
Don't forget wood - organic material. It changes throughout “life”. It will dry out in the heat and expand in high humidity. Any very strong fastening will become loose over time.
I think you are building a house for a long time?
Why not cover it with iron?
I don’t like iron - it rattles in the rain, snow falls, and it rusts quite badly, I won’t say anything about installation, I have to hire a team. I’ll install Ondulin myself... And it’s no worse, as practice shows. Regarding maintainability, Ondulin is easier replace it rather than fuss with metal. In general, this is my conscious choice, I made it even before the house was built.
Roof sheathing
Finally, I started installing the roof after all sorts of minor delays - installing gutter holders and so on. Today, in half a day, I covered half the roof with film and sheathing, tomorrow I will continue. I ordered a crown for the top of the roof from the roofing center, I’m waiting. Something with the windows is a bummer - today is the deadline according to the contract - I called back, they said they would call back and keep quiet - tomorrow I will start demanding them.
Ondulin - is it worth it?
They said there was a super hailstorm, all the metal was twisted, at least something happened to the ondulin...
I covered the roof with foil... I'm waiting for the ridge on the roof when they do it, I intend to start covering it from above, but practice will tell... However, it's scary to climb on top! I've had enough fears...
Ventilation
Sergey! Don’t forget to cut the film along the ridge for ventilation, you understand!
Answer:
Understood nothing! This is not in the instructions for my membrane! I don’t have a film, but a vapor-permeable membrane - I tried it, you can even breathe through it, but as the night rain showed, it doesn’t allow water to pass through! In my opinion, there is no point in cutting - it already “breathes”
Attic floor
Well, this kind of floor would be in the attic - almost perfect... I'll cover it with a glossy yacht varnish - you'll fall in love... It's still modern batten this is a thing! It’s a pity you can’t lay beds in the house - heated floors won’t work
Today I wanted to take some photos of the views of the house - I finally finished lining the roof! But the battery in the phone ran out, so I only got the first photo... I'll continue tomorrow.
Well, today I managed to take a photo... .
Tell me, what is the pitch of the studs for maluart?
I don’t remember, I drilled about a meter later... Then be sure to use a vacuum cleaner with a plastic tube to remove the dust. Then he took glue and cement for strength, diluted it thinner and poured it into the holes, into the reinforcement with 15-inch studs welded at the ends. That's how it all was
Do-it-yourself aerated block house
Foundation
Material for building a house
The roof of a house refers to the building envelope, which is designed to protect interior spaces from external influences. The roof of any building consists of several layers: a load-bearing base (rafter system) and a multi-layer waterproofing coating. The base of the roof of the house must withstand the load from the weight of the covering, as well as wind and snow loads. All this is transferred, in turn, to the walls of the house. The multilayer coating protects the interior from external precipitation, winds and cold, and also prevents heat loss.
Scheme of reinforcement of a house made of aerated concrete.
The roof for a house made of aerated concrete, depending on the angle of inclination, can be flat or pitched.
A flat roof can have a slope of 1.5-2.5% (that is, 1.5-2.5 cm per 1 m of length). The slope depends on the material and the number of layers.
Pitched roofs of aerated concrete houses can have different angles of inclination, which also depend on the type of material. For soft roofs the slope is less, it should be no more than 50%. For sheet materials that are more hard, the maximum tilt angle can reach 90 degrees.
Diagram of the roof of a house made of aerated blocks.
Various roofing materials, differing in their characteristics, can be used as a top covering.
The choice depends on various criteria (type of roof, operating conditions, climate, etc.). The load-bearing base of the roof on aerated concrete can be made in from several types of materials. For flat roof it could be concrete or reinforced concrete slab floors or screeds, as well as prefabricated screeds made from sheet materials. For pitched roofs a rafter system made of metal or wooden elements is used.
Flat roofing materials
Scheme of a power reinforced concrete belt.
Flat roofs in aerated concrete houses are usually installed combined, that is, without an attic. Most often used as a supporting base sheet materials— OSB, plywood, flat slate, fiber cement boards. The sheets are stacked on wooden sheathing along load-bearing beams. The insulation is fixed between the load-bearing beams.
Bitumen-polymer roll materials and polymer membranes are used as a waterproofing coating.
Flat roofs of aerated concrete houses can be made from polymer mastic, which forms a multilayer continuous film. The coating must be reinforced with a material that has a base that is not subject to rotting (fiberglass mesh, polyester fibers, etc.). Before applying mastic, it is necessary to carefully prepare the base, remove all dirt and dust. Then the composition is applied to the base, after drying, forming a monolithic waterproofing film. The main disadvantage of such a coating is the uneven coating, a complex structure, since it is difficult to maintain the same thickness over the entire area. Therefore, it is not recommended to make the roof of a house from gas silicate blocks from mastics.
Bitumen-polymer roll options
Attic layout sloping roof with your own hands.
Bitumen-polymer materials are usually laid in two layers. They are fixed by fire using gas-flame equipment or using mastic. For better adhesion, it is recommended to treat the base surface with a bitumen primer.
The rolls are glued to the base from bottom to top parallel to the cornice. Each subsequent piece of roll is glued onto the previous one with an overlap of approximately 100 mm. The second layer is laid on top of the first. In this case, the seams should shift relative to the bottom ones by half a roll or at least 200 mm.
When using bitumen-polymer rolls, it is prohibited to connect the material at 90 degrees to vertical elements. It is necessary to provide special “flanges” with an abutment angle of 45 degrees. The height of the junction can be different and it depends on the climatic area, but must be at least 350 mm.
The top layer of the bitumen-polymer coating must have a protective layer in the form of a sprinkle of mineral chips. This helps protect the roof of a house made of aerated concrete from the negative effects of ultraviolet rays and mechanical damage.
When choosing a bitumen-polymer material, you need to pay attention to the type of reinforcing layer and the flexibility of the beam. The reinforcing layer directly affects the tensile strength and durability of the material. The cheapest, but also the most fragile is fiberglass. Polyester has the best strength, the cost of which is much higher. Intermediate position takes up fiberglass.
Scheme of fastening the Mauerlat to the wall using an armored belt with studs.
Flexibility on the beam characterizes fragility bitumen coating at low temperatures. The elasticity of the rolls is ensured by additives in the form of special modifiers. Economy class bitumen-polymer materials have beam flexibility up to -5 degrees, middle class - up to -15 degrees and premium class - up to -25 degrees.
When using bitumen-polymer roll materials it should be remembered that in winter time The movement of people on a flat roof is strictly prohibited. In addition, you cannot remove snow from unused roofs.
Polymer membranes
Roofing membranes are divided into three main groups:
- EPDM (TEPK);
Scheme of insulation and soundproofing of the attic.
EPDM membranes are roofing rubber (or synthetic rubber). A feature of the material is increased elasticity and high relative elongation, reaching 600%. Such membranes are produced without a reinforcing or armoring layer. The thickness of the material is 1.2-3 mm.
The membrane is glued to the base in a similar way to a bitumen-polymer coating. The only difference is that rubber glue is used for gluing, which is applied as a continuous or spot coating to the canvas. The membrane is then rolled with a rubber roller.
The EPDM membrane can be fixed using the ballast method, when the fabric is not glued to the base. In this case, fastening is carried out by loading it with gravel or tiles from above.
PVC membranes consist of plasticized polyvinyl chloride and a reinforcing layer of fiberglass mesh. Such membranes are classified as low-flammable materials. The special corrugated surface provides protection from ultraviolet rays. The thickness of the membrane is 1.2-1.8 mm. At the same time, manufacturers guarantee a service life of up to 35 years and flexibility on the timber down to -25 degrees.
Membrane sheets are glued together using hot air, for which special roofing welders or an industrial hair dryer. In changeable weather and strong winds It is more difficult to make high-quality seams, this must be taken into account.
DIY roof diagram.
PVC membranes are secured to the load-bearing base using mechanical fastening or a ballast-roofing system.
TPO membranes are made from thermoplastic polyolefins. The membrane does not contain plasticizers, which ensures a longer service life than PVC membranes. In addition, TPO material has high chemical resistance. However, a high coefficient of linear expansion leads to the formation of waves on a mechanically fastened roof. Therefore, TPO membranes are most often used in ballast-roofing systems.
Materials for pitched roofing
In the construction of houses made of aerated concrete, they have become widespread pitched roofs. This is due to more simple device roofing, a wide selection of roofing materials, the best technical properties.
The most common roofing materials used in low-rise buildings are:
- profiled sheet;
- soft tiles:
- metal tiles;
- composite tiles;
- ondulin;
- smooth galvanized sheet.
Corrugated sheet roofing
Scheme of the structure of a gable roof.
Profiled sheets are produced by rolling a smooth galvanized sheet using rollers. Sheets are available in lengths up to 12 m and widths up to 1.05 m. The wave height can be different. The most suitable profile is 21 mm high.
Profiled sheets are attached to a rafter system consisting of beams and sheathing. The sheets are fixed to the sheathing using self-tapping screws or nails installed in the wave. The installation of the roof begins with the installation of valleys and eaves strips. After this, the installation of profiled sheets is carried out, which are laid from bottom to top with an overlap in the longitudinal and transverse directions. The final stage— installation of end strips, ridges, junction strips, ventilation and passage elements.
The material is cut using a hacksaw for metal, hand power saw or scissors. The sections must be treated with special paint, which will protect the sheets from corrosion. You cannot use a grinder, as excessive overheating will cause the paint and varnish protective layer of the corrugated sheet to burn out.
When working with profiled sheets, even when complex roof houses made of aerated concrete, a minimum amount of waste is generated. The advantages of corrugated sheets also include low cost material, a wide range of colors, ease of installation, durability, resistance to various external influences.
Metal roof
Diagram of a house made of aerated concrete.
Metal tiles are metal sheets 2.5-4 m long and 1.15-1.185 m wide. Distinctive feature is the presence of waves in both longitudinal and transverse directions. Such a device makes roofing material similar to traditional tiles.
The metal tiles are attached to the sheathing. For the lathing, bars measuring 40x90 mm, 32x100 mm, boards 180x25 mm with a pitch of 300-350 mm are used. Along the valleys and cornices, the sheathing is installed as a continuous flooring. Sheets of metal tiles are attached to a groove under the transverse edge of the sheet. Fastening is carried out using self-tapping screws, average consumption— 6-8 pieces per 1 sq.m. Otherwise, the installation of the material is similar to the installation of corrugated sheets. The skates are additionally sealed using ridge seals.
Metal tiles have a different coating, which makes the material resistant to weathering, corrosion, and gives the coating color fastness and shine.
When installing a roof made of metal tiles, a large percentage of material waste occurs, which increases as the shape of the roof of a house made of aerated concrete becomes more complex. In some cases, waste can reach 50%.
Soft tiles
Soft tiles are individual shingles 1 m long and 250-350 mm wide. The material has a multilayer structure: the bottom layer is made of modified bitumen with glue applied to it, the central layer is fiberglass, upper layer— modified bitumen with a decorative coating of mineral chips. Soft tiles are distinguished by a wide variety of colors and attractive appearance.
Installation flexible tiles carried out on a continuous sheathing made of plywood, boards, OSB. First they are attached to the roof cornice strips, then valley carpets are installed. The laying of shingles must begin from the ridge-eaves part. The covering is first glued to the base and then further secured with roofing nails. The joints between the shingles are treated with mastic. The final stage of installation of flexible tiles is the installation of ridges, passages and ventilation passages, and end strips.
Life time soft tiles- 25-50 years. Roofing material is ideal for roofing complex shape. Trimming after work is 3-5%. When installing the coating, it is worth considering that you cannot work with it at temperatures below -5 degrees.
Ondulin coating
Ondulin is a corrugated sheet with a bitumen base. The material has a reinforcing layer of roofing cardboard or cellulose fibers. The surface of ondulin is coated with resin and mineral pigment. Standard sizes sheet of material - length 2 m, width 0.96 m, thickness 3 mm. There are 10 waves per one such sheet.
Ondulin belongs to economy class roofing materials. The coating is inexpensive, has a fairly simple appearance, and its service life does not exceed 15 years. The reinforcing layer of ondulin is susceptible to rotting, and bitumen has low flexibility on the timber.
Installation of ondulin is similar to installation of profiled sheets. The material is also attached to the sheathing using roofing screws with a painted head or roofing nails.
It is inappropriate to use ondulin when constructing the roof of a house made of aerated concrete. It is better to use this roofing material for constructing roofs country houses, various outbuildings.
Foam concrete blocks are an excellent choice for construction work. They combine structural functions and thermal insulation capabilities. But the presence of pores in the material makes the blocks different from dense bricks or durable concrete. Because of this, many people have a question - how to attach a roof to foam block walls. Let's try to understand the existing methods of performing this construction unit.
Roof types
To build roofs on foam blocks, all known options are used. Perhaps we can divide them into two types – flat and pitched.
There are no problems with the first option. Floor slabs are laid on the walls and a roofing pie is arranged. The load is distributed evenly across all walls.
The blocks on which the roof rests will be in the same conditions if the masonry walls were erected further, and the upper floors would put pressure on them.
There are more options for pitched roofs:
- single slope;
- gable;
- attic;
- hip or hipped;
- pull-hip.
There are more complex unclassified forms. But it's not that important because they mean the device truss structure, supporting the overlap.
The load effects from the rafter legs, if they are fastened directly to the walls, will be point-like, for this reason problems are created in arranging the fastening units of the roof to the foam block material. But first you need to understand the features of rafter systems.
It is already clear that the main part is the rafters, connected by lathing and holding the roof. They are divided into two groups:
- inclined - supported at both ends on a wall, racks or mauerlats;
- hanging - supported only by the lower ends, and the upper ones hang freely. In combination with other elements they can form a farm.
Installation
Let's figure out the sequence of work.
If there is an armored belt
With its presence, the design is reliable.
The monolithic belt is represented by a strip of reinforced concrete material located along the upper perimeter of the walls. It can be arranged using blocks and other piece materials.
The main purpose is to bind the masonry and distribute the load evenly across all existing walls. Arranged according to cellular concrete, it creates additional protection of the surface from punching.
Monolithic reinforcement can be done in a formwork structure, but most often block rows are laid on both sides of the wall to create a tray. Reinforcement is installed inside, which is then poured concrete mixture.
Filling the belt makes it a little more difficult general design object, but gives it reliability and makes it more durable. The cost of work increases, but only slightly, because steel material and a lot of concrete mortar is not required.
If a large object is being built, or a heavy roof is expected, then the device reinforced belt is considered mandatory.
There is no need to install the Mauerlat on the foam block; the rafters will be secured to the reinforced belt without it. But it will be better if this element is present, since wood fastener easier to insert.
How to attach the Mauerlat to the foam block? Installation of the element is carried out in two ways:
- At the moment of pouring the concrete mixture, anchors are laid. For them, holes are drilled in the Mauerlat in order to tighten them to the concrete with nuts. The method is reliable, but requires precise marking of the centers of the holes.
- The Mauerlat is drilled for the studs after it has been laid on the concrete. The drill must go through wood and concrete. The studs are additionally fixed adhesive composition, or you will have to use expansion type anchors.
It should be noted that a waterproofing layer must be installed between the wall and the Mauerlat.
Now in the rafter legs you need to select the angle at which they will rest against the Mauerlat; as an addition, you can set corners along the edges. Some craftsmen choose a groove in the Mauerlat to create a more reliable fastening and eliminate the possibility that they will move along the wall when the corner is destroyed.
Those who wish can tie the mauerlat and rafter leg with wire, which is also permitted.
A support block is secured to the rafters with steel plates, with which it rests against the mauerlat beam. Additionally, a metal square is strengthened along the entire surface, for which transverse grooves are selected in the rafters. You can secure such a stop not with a metal plate, but with two more bars, which will create an additional stop.
At the end section of each rafter leg, you can make a recess in the form of the letter “V”, with which it will rest against the mauerlat. But in this case, the rafter will not go further than the wall.
It should be remembered that foam concrete easily absorbs water. For this reason, it is recommended to make decent roof overhangs, which means extending the rafter legs.
As an addition, you can use clamps made of wire, metal tape and other material. They cover the rafters and are pulled to the bottom. The clamp is fixed with dowels to the inner surface of the wall. This measure is good when it is necessary to create an additional margin of safety for the connection between the roof and the wall.
Without armored belt
How to attach the roof to the foam block in this case?
It should be noted here that this method easier - roofing parts are laid on the surface of the walls. This option is good for outbuildings erected on their own.
When installing the roof, you should Special attention devote to the Mauerlat. Without it, fastening rafters to foam block walls is not recommended. The element will evenly distribute the load forces on the walls; its width should be equal to the size of the wall.
The mauerlat is fixed to the block masonry with dowels or pins. It is best to plant them on a mortar mass or glue them in. The diameter of the fastening elements must be at least three centimeters to prevent loosening.
When the racks or the upper ends of the inclined rafter legs rest on a partition made of foam block material, then it is necessary to lay a purlin on top that distributes the load over the entire available area.
If hanging rafters will not have puffs, then they will “move apart” in different directions, and the only obstacle to this will be the wall. If it is made of foam block, then the mounting pins will begin to loosen under the load. Therefore, puffs are considered mandatory, and the non-raised type is better.
The same reason does not allow the installation of a mansard type of roof, the side rafters of which transmit the load horizontally. But such restrictions can be circumvented if additional rafter fastenings are installed, extended beyond the dimensions of the walls to the floor beams, which act as tie-downs.
Conclusion
It probably became clear how to make a pitched roof on a foam block or another, more complex one roof structure. Remember that over the entire surface of the block masonry you should place wooden beam- a Mauerlat that will take on all the loads from the ceiling and distribute them in equal shares to the walls. With the help of such an element, you can install the roof of any commercial facility and even a residential building with your own hands, if you feel confident.
How to attach the Mauerlat to aerated concrete without an armored belt?
On manufacturers' websites there are conflicting statements regarding the need for building a building from aerated concrete blocks. Some argue that they are quite capable of withstanding the expected load. Others, on the contrary, suggest playing it safe. However, all manufacturers and builders are confident that porous materials react negatively to point loads.
Therefore, it is necessary to distribute it evenly. If for any reason the installation of an armored belt is not possible, it is necessary to use. This will extend the life of the building.
The Mauerlat is most often made from the same material as the rafters - metal (channel, I-beam) or wood (timber)
What is a Mauerlat
This is a special design that is used to distribute the weight of the roof evenly across the walls. As a rule, it is made of wooden beams. It is to the Mauerlat that the rafters are attached to make the roof stable. The durability and reliability of the entire structure depends on the quality of installation.
The Mauerlat can be metal, but only if steel rafters are used. However, such structures are rare, since the cost of the structure increases significantly. In addition, fastening steel parts is much more difficult than wooden ones.
- Mauerlat functions:
- uniform distribution of the weight of the roof over the walls;
- reliable fixation of the rafter system;
protection and prevention of point loads on aerated concrete blocks. The minimum size of timber used as a mauerlat should be 10*10 cm. However, to ensure best quality
For clutches, it is advisable to use a material with a larger cross-section. It is permissible to use a log, but it is necessary to cut off the side that will be adjacent to the aerated concrete.
Hardwood timber performs these functions best. In order for it to last longer, it must be treated with antiseptics and impregnations that prevent rotting and insect damage. The beams must completely and evenly cover the walls. They are fastened together with nails or a straight lock. Due to the fact that the cross-section of the wooden material is smaller than the width of the gas block, the Mauerlat is placed on the inside of the walls. The distance to the outer edge must be at least 5 cm. Laying bricks with outside
building. Between aerated concrete wall
and the wooden mauerlat should be a waterproofing layer.
Methods for attaching the Mauerlat The Mauerlat can be attached directly to aerated concrete or using an armored belt. There are such connection methods wooden beam
- with wall:
- using steel wire;
- using anchors;
stiletto heels.
When using any of the above methods, you must ensure that the fastening is of high quality and reliable. Also, during installation, structural shifts should be avoided.
In private housing construction, wooden beams are the main material used to work on the mauerlat
Difficulties arise when connecting aerated concrete blocks to other structural elements. Conventional fasteners cannot hold in porous material. This is especially important when installing massive parts. There are several installation options that allow you to attach the Mauerlat to aerated concrete without an armored belt.
Purpose of the Mauerlat
One of the main load-bearing elements of the structure of the building is the Mauerlat. It is responsible for distributing the load from all roof elements: insulation, rafter system, cladding inside slopes, roof coverings. Its importance is commensurate with the importance of the foundation for the building.
Loads can be very large. Roof slopes have a bursting effect in a direction perpendicular to the walls. Wind and a layer of snow increase the pressure. Point loads are especially destructive for walls made of piece materials- brick and aerated concrete. Therefore, it is necessary to distribute the impact along the entire length of the structure. A wooden beam copes well with this task, resting against the end of the wall and fitting tightly to it.
The presence of a Mauerlat also simplifies the process of installing the rafter system. Connect with each other wooden elements easier than attaching them to monolithic wall. This makes it possible to do different variants connections: movable or blind using fasteners.
For the Mauerlat, a wooden beam with dimensions from 100x100 to 150x200 mm is selected. This element should be twice as thick as the rafter leg. The width is selected according to the thickness of the wall. It is better to leave up to 50 mm between the edge of the beam and the edge of the wall on both sides. This arrangement will protect the Mauerlat from weather conditions and insulate it efficiently.
If you make this element from logs, then installing the rafter legs and attaching them to the base may become more complicated. Some carpentry skills will be required for the job. Must be selected quality wood premium, without protruding knots, curvatures, signs of rotting and cracks.
The best choice is hardwood material, but it is not always possible to find it. As an alternative, carefully selected pine is used. Rafter system may consist of metal elements. In this case, the Mauerlat is made of steel (I-beam or channel).
Frame structures, houses made of logs and beams can do without a Mauerlat; its role will be played by the top row of the wall structure. Concrete buildings are less susceptible to point loads, so they can also do without a supporting superstructure for the roof if the ceiling is attached to protruding beams.
To attach the Mauerlat to expanded clay blocks without an armored belt, a closed scheme is used, which involves the construction of a frame that goes around the perimeter of the building. This design is the most reliable. If the gables are also made from aerated concrete, then it will not be possible to complete the frame laying scheme. In this case, you need to ensure the strongest possible adhesion between the wall and the timber.
Mounting options
Each of the Mauerlat installation options has its own advantages and disadvantages. There are several situations in which you can do without an armored belt and use alternative types fastenings:
Pressure reduction is ensured by the use of rafters hanging type, securely fixed with horizontal ties. Sloping rafters with a support point at the ridge, having a hinged connection, can also reduce the load.
Using wire
The simplest option, mainly used in the construction of brick walls. Between the top 4-5 rows, steel wire bundles are laid out, each containing 3-4 wires with a diameter of 3 mm. Their ends should peek out from both sides of the wall. The release of wire should be enough to cover the mauerlat beam, tighten and twist the loop. Wire bundles and subsequent connections must be located between pairs of rafters.
After preparing the wall, you need to lay out the waterproofing on its end. Timber is laid and leveled on top of the structure. Next, a wire loop is created and tightened using a pry bar. It is necessary to ensure a tight fit of the timber to the wall surface.
The placement of beams for aerated concrete blocks is carried out before the last two rows. This material is bulkier and heavier than brick, so the use of wire to attach the roof to aerated concrete walls is not always justified in practice.
For anchors and dowels
Aerated concrete is a rather fragile material, so screwed-in anchors and dowels can create a crack or chip on the surface. For high-quality fixation, you will need the longest anchors - 300−500 mm. Such mounts are quite expensive. Installing a Mauerlat using anchors includes several stages:
You can build up short sections of timber using lock connections such as “half a tree” and “in the paw”. They will need to be secured with a pin or anchor. The corners are combined in the same way; for better fixation, they can be reinforced with steel brackets.
It is better to use bars of the same length for joining on the wall.
Using chemical anchors
Chemical anchors are a new way of attaching a mauerlat to a wall made of aerated concrete. There are many on sale various types, so you can often stumble upon a fake. To purchase reliable material, it is better to give preference to proven brands: Sormat, Tox, Hilti, Tecfix, Nobex, KEW, Fischer, Tecseal, Technox.
Chemical anchors differ in the method of application. Ampoule type - a capsule containing a composition of 1-2 components is placed in the hole under the anchor. When exposed to air, the substance quickly hardens. The destruction of the ampoule occurs when a pin or anchor is driven into the hole; the composition covers everything free space, including thread. Hardening occurs after 25-45 minutes, depending on the air temperature. This fastening firmly fixes the material and can withstand heavy loads.
An alternative type is a polymer mixture in tubes or cartridges, distributed by a dispensing gun (in some cases, conventional models for sealants and “ liquid nails»). Installation of fastenings in aerated concrete goes through the following stages:
Chemical anchors for installing the Mauerlat on aerated concrete have a number of advantages:
The material also has some disadvantages:
- High price. Porous aerated concrete will require deep channels, which means a large number of composite.
- Chemical anchors don't hold up high temperatures. But heating over 100 degrees is rare for a Mauerlat, so the minus is not significant.
Application of embedded studs
You can fasten the Mauerlat to aerated concrete without an armored belt using studs that protrude from the wall and are spaced at the required distance from each other. The location of the embedded fasteners should be marked on the timber. To do this, the Mauerlat is placed on top and pressed lightly. The ends of the fasteners will leave marks on the material.
Then a waterproofing strip is strung onto the pins, and a beam with prepared holes is placed. The ends of the studs are sealed with washers and tightened with nuts. Mauerlat finds himself pressed tightly against the wall.
To embed studs during wall construction, you need to drill a hole in aerated concrete with a depth of up to 500 mm and a diameter that exceeds the size of the pin by 3-4 mm. Masonry adhesive is used to fill the channel. A pin is inserted into the composite mass until it stops and left until completely dry.
Another option for installing studs is to weld them to metal plates in a perpendicular position. The strips are laid in the seam before the final row of gas silicate blocks. They provide stud fixation and protection against pulling out. In the upper blocks you first need to drill holes for the pins. The edges of expanded clay blocks are straightened to avoid distortions due to the thickness of the metal plates.