tear off low slope roof and replace with pre fab trusses

[SaubleBeachrental]

I have 46' x 34' two storey cottage that has a ridiculous roof pitch (less than 1 in 12) sloping from the front to the back of the 34' span. As such the weight of many snowfalls has bowed the roof (where no supporting walls are) causing water damage along one back wall. I would like to consider tearing off old roof and replace with a proper pitched gable roof with scissor trusses to have a vaulted ceiling. Obviously weather timing is critical, but I have seen new construction truss roofs partly built in sections (say thirds) and then placed on the roof by a crane. This would allow for quick coverage relatively of the open floor below. Has anyone done something like this?

J

[marson]

Well, no I haven't done this. But there are some things to consider. First, it is going to take a honkin big crane to lift a 34 foot wide truss set, especially on a house that size (the crane's capacity goes down as the distance from the turret increases. This will be no truck mounted crane like you see lifting trusses at jobsites. Think Grove or something similar. Do you have a lot of room? You will have to have room to frame the roof, park the crane within it's lifting radius and swing the thing up there. What kind of surface do you have to work on this roof--you will need a flat place to build the roof. a slab would be ideal. Also, there is the whole problem of dimensions. Is your house square and are the bearing walls parallel? Pretty hard to figure out until you tear the old roof off.

I'm not saying it can't be done, but the logistic challenges are daunting. I once tore a second story off of a house--spent 500 bucks on a 30X40 rubberized tarp. Yeah it sucked to haul that thing out at the end of every day, but it worked.

good luck

[longshot]

you could also consider rafters instead of trusses, if the crane would be too expensive

[Noncompliant]

What your probably saw was a hip roof using trusses. The middle section is one continuous truss with one or more sisters nailed to it to create in essence, a beam. This was probably on the end of a continuous run of trusses. After the beam sections on each termination, trusses are run 90 degrees from the other run of trusses. They look like 1/2 trusses. Continued smaller 1/2 trusses continue down the hip.

Have also seen 1/2 trusses joined at wall section on a simple roof.

Go to a truss company and talk to the engineer with specs on your cottage. He can tell you what's possible.

[marson]

using rafters would increase the time he has his house open to the elements