House insulation with sawdust concrete. Cost and comparison

Some self-builders, for reasons known only to them, choose sawdust concrete as a wall material. The walls are cast on their own:

Sawdust concrete has low strength and building a house out of it is a dubious matter, it is not known how it will behave after years under load. But using this material as insulation is an interesting option.

An example of wall insulation of a wooden house. Bars are stuffed, formwork is screwed on them and the mixture is tamped into it in the proportion: sawdust + cement + gypsum 5: 1: 0.05 (glass) + PVA glue (200gr).

The mixture is kneaded in a concrete mixer to a semi-dry state. Lime is needed to preserve sawdust. But ideally, use calcium chloride (soak sawdust in this salt) - this is how chips are treated in the production of wood concrete. PVA glue must be chosen not for carpentry, so that it does not contain sugars (only pure PVA). Everything is rammed with a bar. In fact, in this example, the author doubled the thickness of the walls.

To make this "pie" more securely fastened to the wall, a wire is screwed to the wall. Then the insulation will definitely not fall off. Characteristics of the thermal conductivity of sawdust concrete, its thermal conductivity coefficient is from 0.08 to 0.12 W / meter / Kelvin.

The advantage of this technology is that the walls can be plastered and painted with facade paint. No siding curtain is needed. The insulation has good vapor permeability - the wood behind it will not rot. In contrast to those cases when a polystyrene foam insulation is mounted, which will also increase the fire hazard of the building.

What is the price of such a heater? If you brought the sawdust free (almost any sawmill gives it away), then we take into account only the cost of cement. We count. In 1 batch of a concrete mixer there are 5 buckets of sawdust and 1 bucket of cement. It turns out that in 1 m3 there are 20 concrete mixers or 5 bags of cement (4 buckets each). The cost of cement (including PVA and lime): 350 rubles / bag. Total: 1750 rubles / m3

The cost is not so low. For example, used foam can be purchased for 750 m / 3, EPS - 5400 rubles / m3. But sawdust concrete is a non-combustible material and ants and mice will not live in it.

The insulation process is shown in the video:

I believe that for remote villages, where the cost of delivery of building materials is high, this type of insulation of old buildings can be considered.

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Photos are taken from open sources, from Yandex. Pictures

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