I am planning to put on a new roof over my home this summer. I have been getting lots of quotes, unfortunately not consistent advice from roofing contractors. I have been recommended IB after tearing off the existing tar and gravel, IB over existing tar and gravel with a buffer layer, mirror seal (sounds interesting but is more expensive than IB), and modified bitumen torch down.
Can someone provide me with some information on whether I should learn towards IB over existing T&G or tear off the roof first and put IB over the bare boards? I do have some insulation up there right now that I would like to keep if possible. And perhaps someone with experience using mirror seal or modified bitumen can chime in too?
Nobody studies to be a roofer. Conflicting information results from conflicting opinion, conflicting experience and incomplete knowledge.
You would think that you would understand better after getting additional roofing bids. The opposite is true. The more roofers you talk to, the less consensus you find. There is no 'base of knowledge' for roofers.
I have not heard of Mirror Seal or IB Roofing, I wonder if anyone else has ? Perhaps you can find out what kind of roofing it is. More than 90% (maybe 98%+)of Eichler owners use foam roofing or tar and gravel roofing. It appears that you are not even considering either of these.
IB roofing is a vinyl membrane, similar to Duro-Last. your insulation is under your tar. to roof over your T&G roof, the gravel will need to be removed, though any gravel left behind (stuck in the tar) could puncture the membrane.
most likely, your insulation quite old and isn't too effective. consider a tear-off and replacing the old insulation with new rigid, adding no height, but R factor. plus while you're up there, electrical upgrades can happen too.
personally, I like the T&G roof. Inexpensive, long life, original look. I currently use a Duro-Last roof. when it comes time to reroof, I will return my house to it's original T&G (using white gravel), though my Duro-Last has performed well.
funny, I have never seen IB mentioned on this site. the factory is just down the street from me. they must be getting into out of state residential. more competition Randy!