Plane Of The Existing Roof Slope
And this is a project best saved for dry weather.
Plane of the existing roof slope. Most roof s have a pitch in the 4 12 to 9 12 range. Although some rooflights appear to be flush with the roof they are fixed to a weathered upstand of 150mm housed within a concealed free draining deck or with a secret gutter surrounding the rooflight. There are 2 sets of numbers that convey a roof s pitch. You re going to want the pitch of your new roof to be steeper than that of the old roof.
If you choose a simple trussed roof or addition with two angled planes that will be the easiest project. Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. The bottom of our blind valley was about 30 inches short of the bottom of the porch roof so we extended the line of the valley down to the edge of the new roof. The roof pitch is how much the roof slants.
A strict reading of these words would be that it is specifically the roof slope that must front the highway. By this we mean that it is not in line or flush with the roof covering. A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof. These relate to how high the roof is from the rest of the house rise and compare this to width or length of the house from corner to corner run or span along a single wall.
The up slope end of a simple shed roof that rests near the eaves of an existing roof can usually be supported by the rafters of the old roof. By building a dormer onto an existing roof a cramped attic can be transformed into usable space thanks to the creation of additional headroom and floor space all bathed in natural light provided by dormer windows. It s based on convention and math. In england and wales the gpdo states that permitted development rights do not apply where alterations to the roof of a dwellinghouse extend beyond the plane of any existing roof slope which fronts any highway.
To do this we had to extend the plane of the shed roof out over the porch roof creating a small triangular extension of the existing roof. The tricky part is determining pitch for any existing roof. A dormer loft conversion is a structural extension which projects vertically from the plane of a sloping roof. You ll need to remove the existing shingles and cut.
Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials.