Estimate of a house from foam blocks: examples of calculations

Saving time in this fast-paced age almost always goes hand in hand with saving money, which is why ready-made foam block house designs with estimates are always very popular and it looks like this demand will not weaken in the foreseeable future.

But it's one thing when you get a building according to someone else's taste, and it's completely different when you yourself participate in the development of the project and can independently determine all the costs that await you.

Material calculation

If you purchase ready-made estimates for the construction of a house from foam blocks, then in this case you will find yourself tied to a specific project, which is not always convenient, and sometimes even unacceptable due to the terrain, site or soil.

Therefore, we will now learn the simplest way to calculate materials for the foundation and the box, without taking into account floors and roofs. For example, we will use a 6x8m building with a terrace, a kitchen and three rooms (the plan is shown in the figure above).

Foundation

• Of course, foam concrete is a fairly light material and some use screw piles for such structures, which are excellently justified, but nevertheless, such zero cycles are more often used for lightweight structures, such as baths, summer kitchens and country houses. More often, a strip foundation is used, which can be deep or shallow, monolithic or prefabricated. Such a foundation is more time consuming, and the price for it will be higher, but such an arrangement allows you to equip a cellar or basement under a residential building.
• For calculations, we will choose a monolithic structure, as it is more difficult to manufacture, but more reliable in operation, and the estimate for building a house from a foam block will include these costs. First of all, it should be said that we will not calculate the amount of money, but the amount of building material that we need, and you can easily find out the amounts by multiplying this amount by the price of this material in your region at the moment.

• First, let's determine the dimensions of the tape and imagine that the pouring will be carried out on non-rocky soil, which means that we will make the foundation shallow, 60 cm from the ground, but we will dig a trench 80 cm, since we need a sand cushion. The width of the tape with a block of 200X300x600 mm will be optimal 0.5 m if the laying is done in half a stone (the remaining 20 cm will go to finishing work). The outer part of the foundation (basement) will be poured into the formwork and the total height of the tape will be 0.6 + 0.4 = 1.0 m with a width of 0.5 m.
• Now, in order to find out the volume of the tape, we need to find out its length, and for this we add up all the trenches that were dug according to the plan drawn above: 8 * 3 + 7.3 ++ 6 + 4.3 + 3 + 4 = 48.6 linear meters . This means that we need to pour 48.6 * 1.0 * 0.5 = 24.3 m 3 of concrete for a monolithic foundation. But we can order it to be brought in a mixer ready-made, or we can do it ourselves.
• The most commonly used brand of concrete is M 300, so we will make up the amount of ingredients according to it, as required by the instructions - it consumes per cube: 385 kg of cement M 400, 1080 kg of crushed stone or gravel, 705 kg of coarse sand and about 220 liters of water (everything depends on humidity fillers). Now it remains to calculate how much each material will be needed separately: cement - 385 * 24.3 = 9355.5 kg; sand - 705 * 24.3 = 17131.5 kg; crushed stone - 1080 * 24.3 \u003d 26244 kg; water - 5346l (approximately).
• We also need to fill a pillow under a monolithic tape 0.2 m thick, which means that we will additionally need 48.6 * 0.5 * 0.2 = 4.86 m 3 of sand, and this will be approximately 5000 kg (it all depends on humidity). Then, in total, we need 17131.5 + 5000 = 22131.5 kg of coarse sand.

Advice. When an approximate estimate is drawn up for the construction of a house from foam blocks or other building materials, then loose fillers (sand, crushed stone, cement) should always be purchased a little more. The fact is that they crumble and remain on the ground during unloading.

• For a monolithic base, you will need a frame made of reinforcement, and in our case a design with two longitudinal load-bearing rows of 2 reinforcement each (section 12 mm) and jumpers (section 10 mm) of smooth-walled or corrugated reinforcement is quite acceptable. Their step will be 0.5 m, and the frame in cross section will be 30X65 cm, then the pieces of the rod will be obtained: horizontal - 0.35 m, and vertical - 0.7 m, in total 0.35 * 2 + 0.7 * 2 = 2.1m one ring. In addition, for longitudinal carriers, based on the fact that one profile has 6m, we will need tires for joints, which means 3 * 4 = 12 pieces of 1m, total 12m or 2 rods.

• Now you can calculate the total amount of reinforcement, which will include an estimate for the construction of a house from foam blocks with a tape monolithic foundation. For reinforcement with a cross section of 12 mm, we need 48.6 * 4 + 12 = 206.4m or 206.4 / 6 = 34.4 or 35 profiles. In total, we will have 48.6 / 0.5 + 1 = 98.2 or 98 sets of jumper rings, which means that in total we need 98 * 2.1 = 205.8 m or 205.8 / 6 = 34.3 or 35 profiles by 6m.
• For each connection, a soft steel wire of 0.5 m is needed (folded in half), and in total the connections will turn out on the jumpers - 98 * 4 = 392 pieces and on the tires - 12 * 4 = 48 pieces, in total - 440 knittings of 0.5 m each. This means that the wire will need 440 * 0.5 = 220m, but since it is sold in coils, you will have to look for the optimal length.

Advice. To calculate the screed when pouring the floor, you can use the same calculation method as for concrete. Only the ratio of cement M 400 to sand here will be ¼.

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Counting blocks for walls

• Now let's see how an estimate is made for building a house from foam blocks on the stone itself. For such a project, for which we calculated the foundation, it is necessary to divide the load-bearing walls, where the masonry will be half a stone and partitions that can be raised to a quarter of a stone. Means. We will need the area of ​​the spoon (the side of the stone) - 200 * 300 = 60000 mm = 0.06m and the area of ​​\u200b\u200bthe bed - 300 * 600 = 180000 mm = 0.18m (remember these numbers).

• If our walls are 2.8 m high, then 14 half-stone blocks plus 14 0.5 cm seams will go into this, and then the total will be 2.87 m, but indoors, taking into account the screed and ceilings, it will be no more than 2.7 -2.6m (if the floors are not lowered below the plinth). In total, the load-bearing walls will be (8 + 8 + 7.3 + 6 + 4 + 1.3) * 2.8 = 96.88m 2, then half-stone blocks will need 96.888 / 0.06 = 1614.6 or 1615 pieces.
• The partitions are only (8 + 3 + 3) * 2.8 = 39.2m 2, then blocks in a quarter of a stone will go 39.2 / 0.18 = 217.7 or 218 pieces. In total, the estimate for a house made of foam blocks by the amount of stone will consist of 1615 + 218 = 1833 pieces.

• Now you can calculate the amount of glue that is spent on the butt joints (see photo above). The total length of the bearing walls is 8 + 8 + 7.3 + 6 + 4 + 1.3 = 34.6 m, then they will have 14 horizontal (2.8 / 0.2 = 14) and 58 vertical (34.6 /0.6=57.6) seams 0.005 m thick. This means that 34.6 * 14 = 484.4 m of the seam will go to the load-bearing walls, then only 484.4 * 0.3 * 0.005 = 0.7266 m 3 of glue. There are only 58 * 2.87 \u003d 166.46m vertical seams, which means that the glue will go 166.46 * 0.3 * 0.005 \u003d 0.249.69m 3, and only 0.249.69 + 0.7266 \u003d 0.97629m 3, which will approximately be is equal to 1000 kg.
• We have only 14m partitions and there we get 2.8 / 0.3 = 9.3 or 10 horizontal seams (total 14 * 10 = 140m) and 14 / 0.6 = 23.3 or 24 vertical seams (total 24 * 2 ,8=67.2m). If the total footage of the seams on the partitions is 140 + 67.2 = 207.2 m, then the amount of glue will be 207.2 * 0.2 * 0.005 = 0.20.72 or approximately 270 kg of glue. Then in total we need 1000+270=1270kg or 1270/25=50.8 or 51 bags of 25kg.
• The estimate for the roof will already be somewhat different, because there will probably need the help of specialists who will have to pay not only for the material, but also for the work. Yes, and much will depend on the complexity of the roof itself, because it can be single-pitched, double-pitched, four-pitched, tent, hip, half-hip, attic and multi-gable.
• A separate item of expenditure will be for heating and plumbing, not to mention insulation and finishing with facing materials.

Conclusion

Of course, the principle is clear to you and in the same way an estimate is made for the construction of a garage from foam blocks or the same summer kitchen. If you want to build a prefabricated strip foundation from the material of the same name, then the stone count will be exactly the same as for the walls.