Hi All,
Background:
I'm building an oak-framed lean-to on the side of our single garage, to cover a patio area that is currently covered in rain every single day... I have acquired 6 good used double-glazed units each of 2632*668mm from a conservatory roof and plan to use them as the roof of the new structure. The garage is single story, with the lowest slate of the pitched roof finishing 2550mm above patio floor level. The 6 glass panels will be attached using aluminium glazing bars supported by 7 oak rafters of 50*150mm section, with both ends of the rafters resting on oak beams of 150*150mm section. Each oak beam will be supported by oak posts, with the beams and posts adjacent to the garage being attached to the garage by stainless threaded bars set in epoxy. The posts and beam away from the garage will have two diagonal braces running parallel to the garage wall, with the rafters providing stability perpendicular to these. Pictures and very simplified outline below.
Problem:
The most challenging issue currently is maintaining maximum headroom below the lowest oak beam, which will be beneath the end of the rafters away from the garage, on the edge of the patio. For this reason, I would like to fit the glass at a very shallow pitch, and I'm currently working with 4 degrees from horizontal. This seems appropriate as we live on a hill in Cornwall, so snow-loading risk is minimal and there are no trees nearby to drop foliage on to the structure. The easiest method of joining the glass roof to the pitched slate roof, would be to start the glass beneath the existing guttering. However, this makes clearing the gutters in the middle very difficult. I would gain ~100mm in height if I remove the existing guttering from the garage, and position the high end of the glass roof exactly where the pitched roof ends. At a pitch of 4 degrees, the glass would fall 184mm across its span. Glass unit is 24mm thick, rafter (with birds mouth cutout) is ~100mm, beam is 150mm, so that leaves headroom of ~2092mm. That isn't bad headroom in my opinion, and I could probably go lower (1900mm?), either by increasing the pitch of the glass roof, or by starting at a lower point on the garage.
Questions:
1. If my plan above seems reasonable, what is the best method of flashing from the pitched garage roof, on to the low-pitched glass roof? I want this to be a good join as access will be difficult one the glass panels are in place.
2. If my plan seems unreasonable, what could be adjusted/changed to improve things given the space and materials available?
Background:
I'm building an oak-framed lean-to on the side of our single garage, to cover a patio area that is currently covered in rain every single day... I have acquired 6 good used double-glazed units each of 2632*668mm from a conservatory roof and plan to use them as the roof of the new structure. The garage is single story, with the lowest slate of the pitched roof finishing 2550mm above patio floor level. The 6 glass panels will be attached using aluminium glazing bars supported by 7 oak rafters of 50*150mm section, with both ends of the rafters resting on oak beams of 150*150mm section. Each oak beam will be supported by oak posts, with the beams and posts adjacent to the garage being attached to the garage by stainless threaded bars set in epoxy. The posts and beam away from the garage will have two diagonal braces running parallel to the garage wall, with the rafters providing stability perpendicular to these. Pictures and very simplified outline below.
Problem:
The most challenging issue currently is maintaining maximum headroom below the lowest oak beam, which will be beneath the end of the rafters away from the garage, on the edge of the patio. For this reason, I would like to fit the glass at a very shallow pitch, and I'm currently working with 4 degrees from horizontal. This seems appropriate as we live on a hill in Cornwall, so snow-loading risk is minimal and there are no trees nearby to drop foliage on to the structure. The easiest method of joining the glass roof to the pitched slate roof, would be to start the glass beneath the existing guttering. However, this makes clearing the gutters in the middle very difficult. I would gain ~100mm in height if I remove the existing guttering from the garage, and position the high end of the glass roof exactly where the pitched roof ends. At a pitch of 4 degrees, the glass would fall 184mm across its span. Glass unit is 24mm thick, rafter (with birds mouth cutout) is ~100mm, beam is 150mm, so that leaves headroom of ~2092mm. That isn't bad headroom in my opinion, and I could probably go lower (1900mm?), either by increasing the pitch of the glass roof, or by starting at a lower point on the garage.
Questions:
1. If my plan above seems reasonable, what is the best method of flashing from the pitched garage roof, on to the low-pitched glass roof? I want this to be a good join as access will be difficult one the glass panels are in place.
2. If my plan seems unreasonable, what could be adjusted/changed to improve things given the space and materials available?