how to build a new roof over the existing

[browfish]

I plan on extending my bungalow by changing the two hipped ends into gable ends. To do this the ridge beam obviously needs to be extened quite considerably. I had planned to build the gable end up (block work) and then install a new steel the full lenght of the house, nearly 15metres.
I had hoped to install this new steel just above the existing ridge and then install teh new roof over the old one before removing it from the inside. THis way i can do most of the works myself at my own pace without losing too much heat and weather tightness. Has anyone got any advise on how to do this eg, how to i keep teh water out where i have to penetrate the existing room eg where the gable ends are built up and where supports will obviously need to be put in to the existing wall plate.
Any help appreciated. Is this possible?

 

[RedHerring2]

Two options, as I see it:
1: a temporary roof over the top of everything, of timber/scaffold and tarpaulins, or
2: Sheeting it each time after work and uncovering it each time before work.

Obviously the first one is more expensive, and the second is more inconvenient, especially in the wind if you try it on your own.

At some point I'm going to have to do the same and will go option 2.
I'll try to to time it for better weather and bring in some additional labour to reduce the time.

Remember the Project Management Triangle, with Cost, Scope and Time for each side. Increase one to decrease another. E.g. increase resources to decrease time

 

[^woody^]

Doing a major roof alteration and "at my own pace" do not really go together

The two options are as above, but constantly removing and re-sheeting can take up a lot of time so as you may not get much work done in the day, and is very stressful - particularly when gale force winds are forecast

 

[browfish]

I know it obviously best to replace the roof as quickly as possible. I put a complete new roof on my last place and it probably took a couple of months to get it finished in the mean time the first floor was completley open to the elements bar some tarps that just got shredded in the winds. We had water running down the inside walls as some stages that turned to ice! Wont be repeating that as we didnt have kids back then about 5 years ago. I have however design the extension/roof alterations in a way that i can do it in phases so that the whole house isnt out of commission at the same time.

My neighbour has done exactly what a plan with the new roof floating about 8 inches above the old one. He has only removed the old roof now that the new one is waterproof. I just feel a little cheeky poking him for info as i dont really know him and he is a roofer and may expect the work.