Roof Ventilation 4180 sw 99th
Work in progress, incomplete, will be improved after cogitation.
We do not want to use Lomanco vents. I will install rafter vents instead.
Questions
(1) Which rafter vents should I use? Lowes Hillsboro (2022 August 30) has many in stock, and the customer reviews are informative. Home Depot is ship-to-store only, I can't shop and examine materials.
From Lowe's "Rafter Vent" search results:
Durovent 22x48-in Raft(?) Vent - foamed polystyrene. (probably no)
ADO Products Rafter Vent with Baffle 24?x46-in. White emits/absorbs less infrared, better insulation. Baffle protects soffit vents.
polystyrene - one reviewer calls them "egg crate material", too fragile? (maybe no)
- I would prefer a vent shaped and white like this but a more durable plastic.
proVent 22x48-in Rafter Vent. Black, may be more durable plastic, but emits more infrared. Won't bend, won't keep old insulation out of soffit vents. (maybe yes)
(2) Are there commercial suppliers near Portland with more choices and better materials for rafter vents?
(3) Do bugs/bees/wasps build nests in the air channels? I can inspect the long/skinny channels with my borescope.
- Cleanout: If the plastic vents are stapled, removal will damage them. If I use lath-screws, I can remove and replace the vents. I will probably use staples as you recommend. I have a hammer stapler, but I will use a hand/lever stapler if that works better.
- I have adhesive plastic patches that I can put over the spots where I staple or screw. That will reduce strain and tears.
Notes
When we bought the house, the attic insulation was a few inches of black rock wool. I shoved that towards the edges and put in two layers of Owens-Corning Roll insulation (lower course parallel to the ceiling beams, second course across the beams.
At first, the rock wool blocked some of the soffit vents (which were partly painted over by PriorOccupant). I cleaned and replaced those soffit vents and cleared gaps in the rock wool to them. I will clear more gaps in the rock wool when I add the rafter vents.
I also attached some 8 inch wide ADFORS 8 inch Charcoal Fiberglass Vent Mesh inside the soffit vents that I cleared, to screen out the bugs. I still have a big roll of this material, and will attach it to new soffit vents before you install them.
I did not redo the soffit vents on the two-story-high south and east sides of the house. My extension ladder is not stable enough to do that safely, nor are my balance and reflexes good enough (vestibular damage, sigh). I'll leave that to careful professionals. I can work on the removed vents in my garage shop while the pros do other tasks.
I built a two foot wide particle-board and 2x4 "slide" the length of the attic, running from the old ceiling hatch in the hallway to a new hinged 2x4 foot steel hatch on the garage side, with a fold-down ladder. . . That hatch is wide enough to fit a sheet of plywood through, if necessary. . . Kludgy-looking, but it works well. Probably needs more fireproofing at the edges of the hatch.