Roofing question

[Surface Tension]

To allow air flow from eve to ridge.

What I've pictured when reading the thread is, vaulted ceiling with rafters.

Insulation with no air space. Moisture and ice dams are common with that.

So the fix for both is to create the space for venting with the furring strips.

Leaving the old deck on but cutting that 2" off along the eve allows the air to flow from the soffit and out the ridge vent.

[LwnmwnMan2]

You're dead on Surface.

We don't have any issues with ice dams on the house, only minimal from melt / refreeze from top down.

The garage is the opposite, but we have a furnace with no vents in there. The furnace isn't used much, just when I need to work on a piece of equipment.

We will be venting that area now.

We have soffit vents around the entire house, and about a 1/2" gap between the old decking and the insulation. There were no vents here before as I said, so the new ridge vent should work fine.

[K_Josh87]

no, its a air space that would allow air to travel bottom to top... I imagine this system would work well with a vented drip edge as well... it would leave an air space between the "insulated" area of the vault the shingles, which probably does not exist right now...

[CAMAN]

Interesting. So how do they deal with vaulted ceilings in new construction? Make a sandwich like described here or just keep the insulation away from the underside of the sheathing?

And I'm curious why the inspector recommended doing this. It seems as though the old system was working fine for I'd assume 20+ years with no major issues except the obvious sagging issue and I'd point a finger at undersized sheathing before anything else.

And if there truely was inadequate ventilation, after 20 years the damage has already been done with mold/mildew problems etc. I cant see how making a sandwich would fix the problem without first removing the old sheathing and repairing everything.

[chad austin]

Vaulted ceilings in new construction have scissor trusses which allow an air space above the insulation. For instance a 6/12 scissor truss would have a 3/12 vault on the inside of the house if you will.

[LwnmwnMan2]

Interesting. So how do they deal with vaulted ceilings in new construction? Make a sandwich like described here or just keep the insulation away from the underside of the sheathing?

And I'm curious why the inspector recommended doing this. It seems as though the old system was working fine for I'd assume 20+ years with no major issues except the obvious sagging issue and I'd point a finger at undersized sheathing before anything else.

And if there truely was inadequate ventilation, after 20 years the damage has already been done with mold/mildew problems etc. I cant see how making a sandwich would fix the problem without first removing the old sheathing and repairing everything.

The house was built in '78, so over 34 years old. The old shingles were 17 (+/-) years old.

[K_Josh87]

the system isn't "failing" but most likely your shingle life will suffer due to it being a "hot roof" but, IMO this is minor in this case if no problems have occurred with ice dams and leaks in the past, and good materials are used ont he new roof.

[dougger222]

Did a roof a couple weeks ago with the new durations and was not impressed at all. The fabric strip is a bad idea and the shingles were nothing like the durations we installed in the past couple years. A good friend of mine is a 3 state stormer and he only installs durations and also said the new shingle is nothing like the old shingle in terms of quality and ease of installations.

The only good thing about the new duration is the space in the tar.

[K_Josh87]

we've done a couple now with the new ones, really did not notice much of a diff. in the shingles from the previous year, other than the fabric nail strip, which is even tougher than the plastic strip... So I am just curious what you found wrong with them?

[LwnmwnMan2]

Did a roof a couple weeks ago with the new durations and was not impressed at all. The fabric strip is a bad idea and the shingles were nothing like the durations we installed in the past couple years. A good friend of mine is a 3 state stormer and he only installs durations and also said the new shingle is nothing like the old shingle in terms of quality and ease of installations.

The only good thing about the new duration is the space in the tar.

I too would like to know about the ease of installation. The only problem we had was trying to get something of a match between the upper and lower tab and to keep the color somewhat consistent from one shingle to the next so you didn't have straight / solid color changes anywhere in the roof.

It would have been nice that as you are into a pack of shingles, that those shingles would just lay out. We had to spread out 3-4-5 bundles of shingles at a time to get them to somewhat match up from one shingle to the next.

[K_Josh87]

i wonder sometimes if this has to do with where they come from and if lots match or not... I have not ran into this on a roof we have done YET, but have seen ones done that obviously had different lots mixed... and not spread out/mixed...

[K_Josh87]

also,

I have ran into where a bundle will have defects where the laminations do not line up correctly, this is a pain to deal with, but happens in the landmarks as well...

[LwnmwnMan2]

We tried opening the bundles upside down, right side up, working from the left, working from the right. Out of the 74 bundles of shingles, I would say 4 had shingles that laid down in a row.