Roofing requirements for ventilation
#1
01-06-21, 07:59 PM
Roofing requirements for ventilation
Hey all,
My in-laws live in Southern California (Los Angeles/San Fernando Valley area) and had the roof of their single story detached home replaced back in 2016. Recently they were looking into getting the attic insulation changed out which led to other findings. The insulation contractor noted multiple issues but one he pointed out was that there's no ventilation from the range hood in the kitchen (it's not against an exterior wall) going up to the roof and that there should be flashing installed and a T-Top so it can exit through the roof else it's a potential fire hazard.
That said, when the roofing company installed this roof is this something that they should have accounted for and were they required/supposed to install the flashing/T-Top for the ventilation?
My in-laws live in Southern California (Los Angeles/San Fernando Valley area) and had the roof of their single story detached home replaced back in 2016. Recently they were looking into getting the attic insulation changed out which led to other findings. The insulation contractor noted multiple issues but one he pointed out was that there's no ventilation from the range hood in the kitchen (it's not against an exterior wall) going up to the roof and that there should be flashing installed and a T-Top so it can exit through the roof else it's a potential fire hazard.
That said, when the roofing company installed this roof is this something that they should have accounted for and were they required/supposed to install the flashing/T-Top for the ventilation?
#3
01-07-21, 04:15 AM
If the roofer fulfilled the contract, there is no basis for finger pointing. If the range hood is discharging into the attic space, the vent should be changed to exit above the roof. Is this the reason for the attic insulation being changed? An experienced HVAC company can do this without any damage to a 4 year old roof.
#4
01-07-21, 09:03 AM
Ah ok. This is what the section of the ductwork looks like for the range - it seems like this may have previously been exiting through the gable vent? It's not clear to me. 
The attic insulation is more so my father-in-law wanting to take advantage of a local rebate from the power company that's offering it (up to $1 back per sq foot). He wants this to help keep the house warmer (during winter) and cooler (during the summer) but also thinks it's contributing to poor air quality, although has no real way to substantiate this claim. I think the purported reduced air quality might be due to holes/rips/disconnects in the HVAC ductwork more than the attic insulation:
The attic insulation is more so my father-in-law wanting to take advantage of a local rebate from the power company that's offering it (up to $1 back per sq foot). He wants this to help keep the house warmer (during winter) and cooler (during the summer) but also thinks it's contributing to poor air quality, although has no real way to substantiate this claim. I think the purported reduced air quality might be due to holes/rips/disconnects in the HVAC ductwork more than the attic insulation:
#5
01-07-21, 09:12 AM
Group Moderator
Its not uncommon to see ductwork from exhaust vents (kitchen and bath) that simply vent "toward" a fresh air source. Not saying its correct... just that its not surprising.
Some of those ducts don't even look like they are hooked up to anything. Its possible some were abandoned during a past remodel.
Some of those ducts don't even look like they are hooked up to anything. Its possible some were abandoned during a past remodel.
#6
01-07-21, 09:18 AM
Right... the second picture I posted the duct work is completely disconnected. And the third picture shows a big tear/hole in one of the ducts. All this (in addition to the exhaust vents) just need to be addressed and remediated first before the insulation IMHO.
That said, with that kitchen exhaust ductwork - can they have it exit at the gable vent? Or does it really need to go through the roof?
That said, with that kitchen exhaust ductwork - can they have it exit at the gable vent? Or does it really need to go through the roof?
#7
01-07-21, 09:29 AM
Group Moderator
Technically, by today's standards, ducts should be physically connected to an exhaust hood, either soffit mounted, wall mounted or roof mounted depending on the circumstances. Just pointing it at a gable vent is not correct. But you see all sorts of stuff in older houses that were built before codes and inspections.
#8
01-07-21, 09:44 AM
The insulation contractor said he can install venting at least for one of the bathrooms because it exits the siding rather than the roofing. He mentioned that he would avoid dealing with any roof venting because he wouldn't want to potentially invalidate any warranty from the roofing company that installed the roof. My father in-law has an HVAC contractor that he has used in the past and who he trusts so maybe it's better just to have his HVAC contractor take care of everything.
