CA1073258A

CA1073258A - Roof ventilation

Info

Publication number: CA1073258A
Application number: CA268,716A
Authority: CA
Inventors: Evo Romagno
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-12-24
Filing date: 1976-12-24
Publication date: 1980-03-11

Abstract

ABSTRACT OF THE DISCLOSURE

In a building having a mansard roof the side wall is provided with an elongated opening extending along it just beneath the roof edge, and special ventilator means are provided in the opening to allow the entry of air, and to exclude precip-itation. Preferred ventilator means include an elongated per-forated plate, extending in one direction from one edge of the plate and diagonally across it, a shielding plate provided with a terminal connecting flange extending in the direction away from the perforated plate and perpendicular to it, and extending in the opposite direction from the other edge of said ventilator plate a support plate perpendicular to the ventilator plate.

Description

~73Z5~3 This invention relates to the ventilation of a "Mansard"
or "hip" type roof.
By dictionary definition, this is a form of curved roof, the lower slope of which approaches the vertical and usually contains dormer windows, while the upper slope is more nearly flat.
This type of roof usually covers the second floor and attic of a house and has no eaves. More specifically, the side of the house having this type of roof is coverecl with a false wall. The attic encloses an air space of triangular cross-section covered above by the roof and insulated below by insu]ation above the ceiling of the second floor.
With the mansard roof, in winter, heat loss through the insulation reaches the attic in the form of hot air whose heat is transmitted through the roof sheeting and shingles to heat the snow on the upper part of the roof. The melting causes a flow of water to the perimeter of the roof which freezes to cause ice build-up. Frost also builds up on the underside of the roof-ing boards all around the perimeter. This ice and frost cools the air inside the attic which meets with warmer air (heat loss) ~
20 coming through the insulation and this causes frost build-up on -the roofing nails that protrude and on the underside of the roof-ing, specially towards the roof periphery, where the air is deadest The frost on the underside of the roof melts and will drip off as water, as soon as thawing temperatures are encountered. This cycle repeats itself daily, when the nights are cool and the days warm. The greater the temperature change the greater the problemO
In the summertime the sun heats the air in the attic. This stored heat expands through the insulation and heats the room below making it uncomfortable or putting an extra burden on the air-conditioning equipment.
There have been a number of attempts to overcome the ; problem. These have involved re-roofing, i.e. by putting new .~ , . : :: ..
. . . . .
: . .

~7~ZS~

shingles over the old ones. Another attempt has been by putting a metal sheet around the perimeter of -the roof instead of shingles.
A protective built-up border of asphalt or plastic cement of 18 inches to 2 feet wide has been applied around the perimeter of the roof. Still another attempt has been to blow rnore insulation into the attic. This creates a further problem, since as the insulation builds up, and touches the roofing deck, more conden-sation occurs.
None of the solutions mentioned have been satisfactory.
So it is an aim of the present invention to provide an effective means of overcoming the problem. This is accomplished according to the invention by providing a ventilating space between the roof and the side wall and incorporating in this space special ventilating means, and providing an exhaust ventilator towards the top of the roof. With this arrangement, hot air rises from the bottom of the attic space to the top where it is removed by the exhaust ventilator to be replaced by fresh air coming in through the intake ventilator.

A preferred intake ventilator, according to the inven-tion, comprises a perforated ventilator plate which is to he placed horizontally. At one slde, the ventilator plate is connect-ed to a lower support plate which is juxtaposed to the side of the building over the shingles and nailed or screwed to the wall.
The other side of the ventilator plate is connected to a down-wardly extending narrow flange which serves as a water-drip which in turn is connected to a shielding plate which extends upwardly and diagonally inwardly towards the roof to join an upper connect-ing flange for juxtaposition to the side of the building at the junction of the roof. Above the lower end of the support plate extending in the direction of the ventilator plate is a flange extending outward to serve as a weather baffle against precipita-tion.
Having thus generally described the invention it will be referred to in more detail by reference to the accompanying drawings showing preferred arrangements and in which:-FIGURE 1 is a fragmentary perspective view partly in section of a house with a mansard roof which has been modified, after lts normal construc-tion, to include a ventilating arrangement according to the invention, . FIGURE 2 is a fragmentary cross-section -through the side of the house of Figure 1, FIGURE 3 is a fragmentary vertical cross-section through a part of a house with a mansard roof to which a ventilating arrangement according to the invention has been applied during its construc- .
tion, FIGURE 4 is a perspective view on a smaller scale show- ..
ing a house with a mansard roof equipped accord-ing to the invention, and FIGURE 5 is an enlarged perspective view showing a preferred type of ventilator according to the invention.
Referring more particularly to the drawings, there is - .
shown in Figure 2 a fragmentary perspective view of part of a house having a mansard or hip type roof which has been modified to include ventilating means according to the invention. Posts 15 support the insulated wall. Ceiling headers 17 are supported by the posts 15 and extend around the periphery. Joists 19, which appear along the front edge of the house and are spaced ..
apart in parallel relationship across the ceiling are carried by . .
the joists 17.
The roof is supported on rafters 27 which extend diagon- .

'' ' - - . : - . , ', . ~ , . . . . ..

~L~73Z58 ally upward from a bearing connection with the ends of the joists 19. A roofing deck 31 of plywood or boarding is applied on top of the rafters 27. Shingles 32 cover the roofing deck 31. Between the ceilin~ rafters 27 and between the respective joists 19 are end blocks 33 which normally block the space between the joists 19, the roofing deck 31 and the header 17.
A main wall 40 of plywood or wallboard is applied over the posts 15 and finished on the inside. A false wall is con-structed as follows. Supporting beams 41 are connected at their top end to the rafters 27 and extend downward and slightly outward to a supporting structur'e 43 which connects the beams 41 to the side wall 40. Plywood or wallboard 34 is applied over the beams 41 extending from the supporting structure 43 to the roof.
The construction described provides a roof indicated generally by A which meets the wall of the house indicated gener-ally by B at the edge of the roof and a superimposed false side C which meets the side B and the roof A at the edge of the roof.
A ceiling-floor C extends from the top of the side and end walls to provide with the roof A an enclosure of triangular cross-section which constitutes the attic space. The space is closedat the ends of the building by a wall (not shown) which can be the same as that of the side or may be a conventional vertical wall. Insulation 30 covers the ceiling-floor.
The wall and roof construction is modified to ventilate the attic as follows. A piece 33 of each end block is removed to leave a space between the top of the end block and the roof.
A strip usually about two inches wide is cut out of the wall sheeting 34 to provide an air passage 28.
A special intake ventilator D is applied to the house to cover the opening 28. The ventilator D is an elongated structure of galvanized sheet metal having a narrow connector plate 39 which is juxtaposed to the wall board 34 and nailed to _ 4 _ "' , .. . .. ~ . - . . - . . .

~73~5B

it. Extending outwardly at a ~5 angle from the connector plate 39 is a spacer plate 37 which, in turn, is connected by a ridge lock 37a to a perforated ventilator plate ~1 which extends hori-zontally inward. The ridge lock 37a provides a downwardl~r ex-tend-ing flange constituting a water-drip structure. On the other side of the plate 41 is a ridge lock 41a connecting it to a downwardly extending support plate 43 which i5 jux-taposed to the wall board 3~ and nailed to it. The plate is bent upwards and then outwards in a flange 45 constituting a weather baffle 45~ The ventilator device D can be made all in one piece. A preferred material is 30 gauge galvanized sheet metal.
Ventilators E are provided in the roof to allow air to leave the attic space while preventing ingress of precipitation.
Figure 3 is a fragmentary cross-section through part of a house which has been designed to ins-tall the applicant's ventilator system when first constructed. The same numbers are used, as ln Figure 2, in connection with similar parts except that th~y are raised by 100.
In this case, about 2 inches of the siding 123 is omitted 0 1 inch below the roofing deck to provide a ventilating opening p 136. Then, the ventilator ~ of the invention is mounted in place as shown to cover the opening 136. A metal flashing G is then a~plied over part of the device ~, and over part of the side wall ~of the house and part of the roof A, as shown, at the corner underneath the roofing shingles.
Operation In operation, hot air in the attic space rises under the roof A and leaves the ventilators E causing air to enter the at~ic through the ventilator D. So, circulation is induced to keep the attic ventilated at all times. In winter this prevents overheating the roof to melt the snow as described above. In summer, the circulation removes hot air from the attic space so ;' . : ':

~73Z58 as to reduce heating the room below.

Claims

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. In a building construction having a mansard roof and side wall defining an attic space therebeneath, said roof and side wall meeting at a bare peripheral edge, an elongated opening immediately below said bare edge, said elongated open-ing communicating with said attic space, and ventilation means disposed in protective relation over said opening and including a portion permitting the flow of air therethrough and prevent-ing the entry of precipitation and moisture therethrough, said ventilation means comprising an upper plate portion secured at said bare peripheral edge, a shielding plate diverging down-wardly and angularly relative to the outer surface of said side wall and integral with said upper plate portion, a perforated plate integral with said shielding plate and projecting inward-ly in protected relation beneath said shielding plate, said perforated plate being connected to said side wall substantially immediately beneath said elongated opening whereby air may readily pass therethrough and temperatures in the attic space will be modulated, and a precipitation deflector projecting outwardly from said side wall in spaced relation beneath said perforated plate, said shielding plate including an integral water-drip structure depending at the lower edge of said shielding plate and below the plane of said perforated plate and at the outermost edge of said perforated plate, said ventilation means being located at the uppermost portion of said side wall at the edge of said roof.