SU953143A1 - Roof cornice - Google Patents

Description

(54) EARNTS ROOFS

one

The invention relates to the construction, specifically to the construction of the eaves of a roof in residential and industrial buildings, excluding the fall of the icicles formed on it.

Known cornice on the attic and combined (attic) roofs with a coating of sheet steel, fiber-reinforced cement sheets, etc. 1.

The disadvantages of the known constructions are that due to the imperfection of the heat insulation between the interior of the building and the roof, as well as due to heat generation from the ventilation ducts, heating pipes, chimneys, etc., the temperature of the roof in winter is 8-10 ° C above the ambient temperature, while the ambient temperature from 0 to -10 ° C, the snow on the roof surface starts to melt and the water forming the tala flows down the slope into the gutter that is in the colder zone above the eaves part of the wall . In the gutter, the water freezes, forming a flat layer of ice in it - ice. In addition, tala water freezes in the funnels of the open drainage system, plugging them and preventing it from flowing down the drain pipes from the roof. Upon further ingress of melt water, it is poured through a layer of ice filling the chute and flows down from the eaves overhang. It should be noted that the passage zone 5 of the icy gutter, tala water is cooled to a temperature close to 0 ° C. The iron eaves overhang, which practically does not have heat exchange with the roof and is as a result of this at a negative ambient temperature, ices and ice and icicles form on its edge. Upon the occurrence of a repeated thaw, the eaves with an overhang, made of relatively thin dark-colored iron sheets with a high absorption capacity, are rather quickly heated by solar radiation to a temperature above 0 ° C. An icicle, having a bright, shiny surface, well reflecting external thermal radiation, is less heated than the cornice on which it was formed. At some point, the force of adhesion of the icicle to the cornice overhang is so weakened that, under the influence of its own weight, the icicle breaks away from the eaves and falls.

Closest to the present invention is the execution of a cornice, aimed at preventing icicles from forming by covering the cornice overhang with appropriate materials, by giving the edge of the cornice a special trough-like shape with facing the edge of the metal trough with rubber or special hydrophobic materials 2.

Giving the ledge overhang a trough-shaped or any other form, as well as the use of hydrophobic coatings, although they can bring a limited effect, but it will require a radical reworking of all the eaves, which is associated with large material and labor costs. In addition, such a cornice is structurally folded and cannot be applied on already existing buildings.

The aim of the invention is to improve the performance of the eaves of the roof.

This goal is achieved by the fact that the roof eaves with external drainage, including a cantilever roof overhang and a gutter with a water collection funnel, the cantilever overhang is equipped with water freezing elements made of a hydrophilic material with low thermal conductivity attached to the lower and upper sides of the cantilever overhang of the roof to the whole curtain rod length;

As mentioned above, the icicles are caused by the temperature regime of the roof — and its design features (angle of inclination, etc.). Since both of these reasons are practically impossible to change and rationally, there is still no economic way to remove icicles, a solution to the problem can be found in finding ways to hold the icicle on the roof until it is complete.

The drawing shows the eaves of the roof, cut.

On the roof 1, having a eaves overhang 2, which is 120-150 mm wide for buildings below ten floors, an element for freezing water from a hydrophilic material with low thermal conductivity, for example a board 4 of m soft woods. Board thickness must be at least 20 mm. Board 4 is attached to the eaves overhang in such a way that its edge protrudes 50-70 m. On the eaves with the most abundant icicle formation, two boards 4 and 5 can be used, one of which is attached below, and the other on top of the eaves, below the gutter 6.

The device works as follows.

Tala water forming on the roof during the thaw flows to the eaves overhang

and before it freezes, it abundantly permeates the board attached to it. At the next freeze, the water that has soaked the board freezes and the icicles formed on it become firmly attached to the board. In this case, the icicles stick to the board much more strongly than to the surface of the roofing iron of the cornice. When re-thawing, the icicles remain hanging on the frozen board until it is fully grown. This happens for the following reasons.

The specific heat capacity of wood (or another material used for the element) is 3 times higher than the specific heat capacity of steel (0.3 cal / g hail vs. 0.1 cal / g, hail).

If we go from the specific values of heat capacity to real, then for one running meter of the cornice overhang made of steel 0.8 mm thick and 100 mm wide, the heat capacity will be equal to 8 cal / hail. At the same time, the heat capacity of a meter of pine

boards 100 mm wide and 25 mm thick will be equal to 250 cal / ha, i.e., 30 times more. This means that with the same external heat load the wood board will heat up to 30 times slower,

5 than the steel roof, and thus the time required to thaw the ice that had frozen the board is as long.

The second circumstance, causing long-lasting retention of the icicle on the wood plank, is related to thermal conductivity.

0 steel roof and wood. The thermal conductivity of wood impregnated with 30% water is approximately 0.88 W / m hail, compared to the thermal conductivity of steel, equal to 5.04 W / m hail, i.e., almost 7 times less. Thus, under the influence of external heating, the frozen board is heated to ambient temperature 210 times slower than steel eaves. From this it follows that the icicle formed on a wooden base remains frozen to the board for almost the entire day. At the same time, under the influence of positive ambient air temperature and direct solar radiation intensively absorbed by ice, the icicle does not fall to the ground, but completely melts.

Due to the low thermal conductivity of ice in a narrow temperature range, the character of the change in the shape of an icicle during melting corresponds to the shape of its formation.

On iron-clad roofs with an organized or unorganized drainage system, the formation of icicles on the eaves overhangs occurs at ambient temperatures of up to -5 ° C. For years of data only for Moscow, the number of days with temperatures ranging from 0 ° C to

 -5 ° C is 52 per year. This means that icicles on the eaves of buildings are possible within 52 days. On the other hand, maintenance costs for cleaning

Claims (2)

from icicles and snow of the attic roofs with organized drainage and iron coating in Moscow conditions is 0.25 rubles. for 1 m roof. In Leningrad alone, the cleaning of the eaves of the roofs from the icicles formed on them consumes about 150 thousand rubles a year. Claim V A roof eaves with an external drain, including a cantilever overhang of a roof and a gutter with a drainage funnel, characterized in that, in order to improve performance, the cantilever overhang is equipped with water freezing elements made of a hydrophilic material with low thermal conductivity attached with the lower and upper sides of the cantilever overhang of the roof for the entire length of the eaves. Sources of information taken into account in the examination Osipov l. city and others. Civil and industrial buildings. M “Higher School, 1964, p. 231, rice 129 2. Patent of Germany No. 2643348 cl. E 04 D 13/06, published in 1978 //////////// 7 ///