The attic is a hot dirty nasty place.
Flex ductwork in attic.
Flex ducts on the other hand are smaller and tube shaped like giant shiny worms.
It was new when the ac was put in 7 years ago.
The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports.
Hold the loose end of a roll of duct support webbing against the side of a roof joist sitting directly above the flex.
Flex ducts themselves do not sweat however if the connection points are not sealed correctly and duct leakage is occurring then you can get sweating at those points.
Blown in insulation is cheap.
The higher in the attic the hotter it is.
The right choice in ductwork for you likely depends on the specifics of the attic above your in law suite.
Ducts are to be part of what is inside the house not part of.
Not part of what is in the attic.
This type of duct means a smoother interior with better air flow insulation applied on the outside to cut down on fibers getting into the system and a durable shell not easily punctured by rodents or uv light.
The lower the cooler it is.
How to hang flex duct in an attic 1.
Secure the webbing to the joist by hammering a 2 inch roofing nail through the webbing and into the side of the joist.
Ducts up high get tore up.
The attic ductwork is flex duct work.
The really bad news is that with old metal duct systems the only option is replacement of the ducts to stop the rain in the attic.
They just tear through them smash them climb on.
The supports need to be at the manufacturer s recommended spacing but no longer than 4 maximum.
They both have advantages and disadvantages.
Recently i had another hvac company come out and put in a new bathroom vent and they told me they believed the duct work was full of water.
Here are some advantages for each.
Just blow the attic to r 38 and over the top of ducts if needed.
Flexible duct is a plastic tube that is reinforced with wire and then insulated on the outside.