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When we talk about roofs it is important to identify the type of roof correctly. Here are the six basic types it is important to grasp that these are architectural styles, so not all steep roofs are Mansard. Many homes have slight variations on these themes and some have several shapes on separate out buildings. Levco has dealt with everything except a Gambrel to date, but we are only a phone call away from that. Recently we were faced with a faulty shed roof that seemed to fail in the middle as a result of folks setting asphalt shingles on too shallow of a slope. The fix was to add metal roofing. I have a situation where asphalt shingles were placed in a mansard type roof edge and they failed to stick and hold down too.
The slope or pitch of a roof is described in ( a number : 12) so a 7:12 means for every 12″ in run it rises 7″ in elevation.
The International Residential Code IRC for Idaho a low slope roof is anything under 4:12 and shingles should definitely ever be used when the pitch is 2:12 or less. With 4:12 special double underlayment is recommended. What happens is that water starts headed down the roof with gravity helping and it wicks under a poorly sealed shingle or it puddles as the snow load bends the roof down and finds all kinds of ways in. Metal roof is a solution but a “Torch On” membrane would have worked well also. Keep in mind the snow loads when considering low slope roofs from a structural perspective an overbuild of a better slope is often a viable solution.
Other common places for problems occur when a gable roof terminates into a side of a wall. The siding is rarely flashed property ( the subject of a future blog) and the siding is too close to the roofing so water wicks up into the siding and in some cases into the home through a ceiling or recently through the head casing of a sling glass door. The good news is that when there is a problem the solution is usually obvious to the trained eye. This is where experience plays a huge role. Be sure to contact a knowledgeable contractor to find and fix your roofing problems.
Although we have focused much attention on low slope roofs, high slope roofs have their issues as well. In addition the weight of roofing materials plays a roll in the structure, I have seen many a sway back terracotta tiled roof in my day. With the new craze of DIY shows more than one bearing wall has been removed without proper supports being replaced. A vivid memory is of a garage that had been converted into a living space that I was inspecting for a potential buyer. The ceiling joists had been removed and the walls were bowing out. Another one in my neighborhood that is still for sale where the front room was vaulted by removing ceiling joists again causing a sway back roof and bowing front wall. Are there solutions to these problems? Yup, it starts with a plan and permits, often the advice given during plan review will prevent a structural failure.
Remember we now have a 2 roof maximum before you must rip off and replace here in Boise Idaho. Contact us at Levco builders for all of your remodeling needs.